Eat Your Green Vegetables: How to Keep Your Intestinal Tract Healthy

Researchers were surprised when they found that mice fed a diet without vegetables for just two weeks were missing important blood cells

If you want to boost your chances of keeping your intestinal tract healthy, consider eating more green vegetables.
Scientists at The Babraham Institute in Cambridge found that green vegetables are the source of a chemical signal that is important to the functioning of the immune system. Green vegetables ensure that intra-epithelial lymphocytes (IELs), a specialized type of white blood cell located in the gut and in the skin, function properly.
Researchers fed healthy mice a purified diet with almost completely no vegetables for two to three weeks. During that time 70 percent of the IELs lining the intestinal tract disappeared. Consequently, the mice were more susceptible to infection and had a more fragile intestinal lining which increased their risk of inflammation -- a surprise to researchers.
"This was surprising, since the new diet contained all other known essential ingredients such as minerals and vitamins," said Marc Veldhoen, senior author of the paper. "I would have expected cells at the surface would play some role in the interaction with the outside world, but such a clear cut interaction with the diet was unexpected. "
IELs comprise a defensive network under the layer of epithelial cells covering both inner and outer body surfaces. They are important for protecting against infection, maintaining a healthy gut, and healing wounds. IELs also help to maintain a healthy balance of "good" and "bad" bacteria and destroy infected cells that may be harmful.
According to Veldhoen and his team of researchers, the number of IELs depend on levels of aryl hydrocarbon receptor (AhR), a cell-surface protein which is regulated by a chemical component in cruciferous vegetables -- those from the mustard or cabbage families -- such as cabbage, broccoli, and Brussels sprouts. In the case of the mice, the loss of the AhR receptor caused a loss of microbes that live on the intestinal surface as well as a change in the composition of the microbes causing the mice to become susceptible to an artificially-induced form of an inflammatory bowel condition.
Dr. Brigitta Stockinger, head of the division of molecular immunology at the National Institute for Medical Research stated: "The food we eat plays a crucial role in influencing our immune system and we have been looking at the intricate biology that determines how cells in our intestines maintain an intrinsic protection against microbes. This study in mice is an important step toward increasing our understanding of how environmental signals shape immune responses at barrier sites such as the intestine."
Some of the characteristics observed in the mice are consistent with certain clinical observations observed in patients with inflammatory bowel disease; however, it is important to note that the results of this study cannot be extrapolated to humans because there may be other factors at work that have not yet been discovered.
Nevertheless, nutrition experts agree that most adults need to eat at least three cups of vegetables a day. The 2010 Dietary Guidelines for Americans recommend eating a variety of vegetables with an emphasis on dark-green vegetables, as well as red and orange vegetables.

Foods that boost your immune system

If you don't have good nutrition, you're missing a key weapon against colds and flu. Basics include the famously nutrient-dense leafy greens, berries and nuts. You may be surprised by these six other top immune boosters suggested by Tonia Reinhard, registered dietitian and author of Superfoods, and Joel Fuhrman, M.D., author of Super Immunity. Note: Don't expect immediate results. Fuhrman says you'll need superior nutrition for a few months to see a real effect on your body's defenses.
• Fatty fish: Oily fish such as salmon, tuna and trout are rich in selenium and omega-3 fatty acids (that's the good type of fat that reduces inflammation, increases airflow and protects lungs by increasing the activity of white blood cells that eat up bacteria). "Fatty fish has powerful immune effects and is so important for making the structures and antibodies for the immune system," says Reinhard. Prescription: Eat two servings of fish per week.
• Onions: Onions, leeks, garlic, shallots and scallions contain , not to mention health-promoting flavonoid antioxidants such as quercetin, allicin and anthocyanins, which have anti-inflammatory effects that fight infection and bacteria, says Fuhrman. Prescription: Eat a half-cup daily.
• Mushrooms: Consuming mushrooms regularly stimulates the immune system by increasing the production and activity of white blood cells, which help you fight off infection. Prescription: Eat cooked or lightly steamed, not raw, says Fuhrman.
• Yogurt: "Yogurt, especially Greek yogurt, has active cultures (known as probiotics) which are a friendly bacteria that keeps down the population of pathogens in the GI tract," says Reinhard. Prescription: Eat 8 ounces daily.
• Eggs: "The highest-quality protein of any food, eggs contain the compound choline, which keeps invaders from getting into the body," says Reinhard. "When we keep things from crossing the cell membrane, which causes inflammation, especially in the GI tract, we prevent autoimmune diseases like Crohn's and colitis." Prescription: Eat one egg for breakfast several times a week.
• Beans: A nutritional powerhouse, beans and other legumes are the most nutrient-dense carbohydrate source, says Fuhrman. Rich in zinc, beans increase the production and aggressiveness of white blood cells fighting infection. Prescription: Eat a half-cup twice a week.
• Greens: The most nutrient-dense foods, raw leafy greens contain less than 100 calories per pound, and are packed with nutrients that protect blood vessels, reduce inflammation and neutralize oxidative stress, says Fuhrman. Prescription: Eat a salad every day.
• Berries: Berries are low in sugar and high in nutrients and antioxidants, which reduces inflammation, prevents DNA damage, inhibits tumor angiogenesis and stimulates the body's own antioxidant enzymes, says Fuhrman. Prescription: Eat three fresh fruits daily.
• Nuts: With high levels of healthy fats, nuts are rich in a spectrum of micronutrients including phytosterols, minerals and antioxidants, which provide cardiovascular benefits, weight maintenance and diabetes prevention, says Fuhrman. Nuts are also high in protein and minerals like zinc, selenium and magnesium, which help fight off infection. Prescription: Eat 1 ounce per day.

5 New Ways to Beat Bloat

Many are high in one of five hard-to-digest sugars: lactose, fructose, fructans, sugar alcohols, and galactans. To help relieve your stomach symptoms, study your diet and follow these tips.
1. Stop Milking It.
If dairy makes you bloated, you may have developed lactose intolerance. Try lower-lactose foods (like hard cheese or yogurt) or lactose-free dairy products, or take a lactase enzyme.
2. Pick Fruit Carefully.
Berries, grapes, and citrus contain a near-equal ratio of the sugars fructose and glucose, making them easier to digest than fruits with more fructose, such as honeydew, apples, and pears.
3. Switch Your Starch.
If fructan-rich wheat, rye, or barley is behind your bloat, choose stomach-friendly rice, corn, oats, or potatoes.
4. Skip (Some) Fake Sugars.
Sorbitol, xylitol, and mannitol are sugar alcohols found in diet sodas and sugar-free gum. Avoid these if they bother you, or opt for products made with stevia or aspartame instead.
5. Be Smart About Beans.
Limit galactan-rich legumes (soy nuts, chickpeas, lentils, and all beans), cabbage, and brussels sprouts if they're causing you trouble. Soaking dried beans overnight or taking the OTC enzyme Beano may help.

Vegetarians 'avoid more cancers'

Vegetarians are generally less likely than meat eaters to develop cancer but this does not apply to all forms of the disease, a major study has found.
The study involving 60,000 people found those who followed a vegetarian diet developed notably fewer cancers of the blood, bladder and stomach.
But the apparently protective effect of vegetarian did not seem to stretch to bowel cancer, a major killer.
The study is published in the British Journal of Cancer.
Researchers from universities in the UK and New Zealand followed 61,566 British men and women. They included meat-eaters, those who ate fish but not meat, and those who ate neither meat nor fish.

VEGETARIANS GOT NOTABLY FEWER OF THESE CANCERS: Stomach Bladder Non-Hodgkin's lymphoma Multiple myeloma

Overall, their results suggested that while in the general population about 33 people in 100 will develop cancer during their lifetime, for those who do not eat meat that risk is reduced to about 29 in 100.
Special protection?
The researchers said they found marked differences between meat-eaters and vegetarians in the propensity to cancers of the lymph and the blood, with vegetarians just over half as likely to develop these forms of the disease.
In the case of multiple myeloma, a relatively rare cancer of the bone marrow, vegetarians were 75% less likely to develop the disease than meat-eaters.
The reduction was less notable for fish-eaters with these cancers. The reasons, researchers said, were unclear, but potential mechanisms could include viruses and mutation-causing compounds in meat - or alternatively that vegetables confer special protection.
There were also striking differences in rates of stomach cancer. Although the numbers of cases were small, fish-eaters and vegetarians were about a third as likely to develop the disease as meat-eaters.
Previous research has already implicated processed meats in stomach cancer, so these findings were not entirely surprising. It is thought N-nitroso compounds found in these meats may damage DNA, while the high temperatures they are cooked at may also produce carcinogens.
But the same reduction for vegetarians was not found with cancers of the bowel, one of the most common forms of the disease. The vegetarians in the group in fact had a slightly higher rate of cancers of the colon and the rectum, although not significantly so.
But the relative risk for fish-eaters and vegetarians of cervical cancer was twice that of meat-eaters. The number of cases was small, and could be down to chance but the researchers said it was possible that dietary factors influenced the virus behind cervical cancer.
Professor Tim Key, the lead author, said it was impossible to draw strong conclusions from this one single study.
"At the moment these findings are not strong enough to ask for particularly large changes in the diets of people following an average balanced diet."
Vegetarian diets tend be lower in fat and higher in fibre, but they can require careful planning to ensure necessary protein and vitamins - notably B12, which is mainly derived from animal products - are taken in sufficient amounts.
'Complex process'
A spokesperson for Cancer Research UK, which funded the research, said: "These interesting results add to the evidence that what we eat affects our chances of developing cancer. We know that eating a lot of red and processed meat increases the risk of stomach cancer.
"But the links between diet and cancer risk are complex and more research is needed to see how big a part diet plays and which specific dietary factors are most important.
Myeloma UK said this was the first data of its kind for the bone marrow cancer "and for that reason we are treating it with caution.
"Dietary advice to myeloma patients remains aligned with national guidance - that they should eat a healthy, balanced diet high in fibre, fruit and vegetables and low in saturated fat, salt and red and processed meat."
Dr Panagiota Mitrou, Science and Research Programme Manager for the World Cancer Research Fund, said: "The suggestion that vegetarians might be at reduced risk of blood cancers is particularly interesting.
"However, this finding should be treated with caution since not much is known about the link between diet and these types of cancer. Further studies of vegetarians are needed before we can be confident this is actually the case."

Self-control in childhood predicts future success

FOR DECADES, our national conversation about education has been guided by a single, seemingly irrefutable assumption: It’s all about what kids know. Either children are learning to read, write, and do math, or they are not.
But what about character?
There is a personal virtue that plays a large role in determining whether a child will lead a rewarding, prosperous life, contributing to neighborhood and nation, or stumble into a series of disappointments and even crime. The Greek philosophers lauded it, and it informs the teachings of many world religions. And now a new wave of research suggests that inculcating this basic good, from the earliest ages, could transform our schools and renew our society.

The ancients referred to this virtue as temperance, but, in the argot of modern social science, it is often referred to as self-control — the ability to check one’s impulses, focus on what is important, and better oneself.
The modern investigation of self-control begins with marshmallows. In a famous 1972 experiment at a Stanford University day care, psychologist Walter Mischel gave a group of 4-year-olds a marshmallow test. The children were placed alone in a room with a marshmallow and told that they could either eat the marshmallow, or wait and be given two marshmallows later. Two treats are better than one, but kids varied wildly in their ability to delay the sweet thrill. The successful ones used all sorts of strategies — some hilarious, some heartbreaking — to resist temptation.
The big surprise came almost two decades later, when it was discovered that how well the children handled the preschool marshmallow challenge predicted how well they performed, for example, on the SAT. Self-control matters.
Just how much, though, only became clear a few months ago, with a study that tracked 1,000 people from birth to age 32. Scientist Terrie Moffitt and her colleagues found that self-control has a pervasive and powerful effect on the arc of a life.
Even adjusting for IQ and economic background, children who were more adept at self-control went on to lead better lives. They were healthier, less likely to abuse drugs, more likely to save, less likely to be convicted of a crime, and the list goes on. These “good choices’’ not only benefit the individuals who make them, but their friends, family — even taxpayers.
What makes Moffitt’s discovery of such great public consequence is another surprise. Self-control is like a muscle. It is not just something that one is born with, but something that can be strengthened through regular exercise. Equally important, everyone can benefit. Moffitt found that, no matter the starting point, any improvement in self-control meant brighter prospects, and steps down portended trouble.

Stubborn Food Myths That Just Won’t Die, Debunked by Science

Every other week, new research claims one food is better than another, or that some ingredient yields incredible new health benefits. Couple that with a few old wives' tales passed down from your parents, and each time you fire up your stove or sit down to eat a healthy meal, it can be difficult separating food fact from fiction. We talked to a group of nutritionists and asked them to share the food myths they find most irritating and explain why people cling to them. Here's what they said

Myth: Adding Salt to Water Changes the Boiling Point, Cooks Food Faster

This is one of those food myths that doesn't want to die. You'll hear it repeated by home cooks and professional chefs, but any first year Chemistry student (or in my case, a Physics student taking Applied Thermodynamics) will be able to show you how little the amount of salt you would add to a pot of boiling water in your kitchen actually alters the boiling point.
Yes, strictly speaking, adding salt to water will alter the boiling point, but the concentration of salt dissolved in the water is directly related to the increase in the boiling point. In order to change water's boiling point appreciably, you would have to add so much table salt (and dissolve it completely) that the resulting salt water would be nearly inedible. In fact, the amount of salt you're likely to add to a pot of water will only alter the boiling point of water by a few tenths of a degree Celsius at most.
So this is one of those food myths that rings of chemical truth, but only on scales that wouldn't be applicable for cooking. One thing is for sure though, adding salt to your pasta water definitely makes the resulting pasta tasty.

Myth: Low Fat Foods Are Always Better For You

Alannah DiBona, a Boston based nutritionist and wellness counselor made this her number one food myth. She said:

"Without fat, the human body is unable to absorb a large percentage of the nutrients needed to survive. Additionally, fat deprivation prevents messages from being passed between neurotransmitters, resulting in all kinds of neural misfiring in the body! While good fats and bad fats do exist, the right fats in the proper amounts can actually aid in weight loss and cholesterol management."

The high-fat/low-fat food myth is one that's been around for a long, long time. Ultimately, it's more important to flip over the food you're about to buy and read the label, see what kinds of fats are in it, and then make an educated decision instead of immediately reaching for the low-fat version of whatever it is you're planning to buy, thinking it'll be healthier. In fact, many products that are "low-fat" are low in good fats as opposed to the bad ones, or substitute in other ingredients like sugars and sodium that you don't want more of in your diet.
Seattle-based Registered Dietitian Andy Bellatti also called out this particular myth. He said, "A good intake of healthful fats is beneficial for cardiovascular health. Prioritize monounsaturated fats (avocados, olives, pecans, almonds, peanuts) and omega-3 fatty acids (hemp seeds, chia seeds, sea vegetables, wild salmon). Virgin coconut oil and dark chocolate (80% cocoa or higher) also offer healthful fatty acids. Many low-fat diets are high in sugar and refined carbohydrates (i.e.: white flour), which are increasingly becoming linked to increased rates of heart disease."

Myth: Dairy Is The Best Thing For Healthy Bones

When I asked Andy Bellatti about the most stubborn food myths he's encountered, he noted that too many people confuse "dairy" with "calcium," assume they're the same thing, and think that dairy is the best thing for healthy and strong bones. He explained, "Dairy contains calcium, but so do dark-leafy greens. Milk is fortified with vitamin D, just like all milk alternatives. Additionally, bone health goes beyond calcium and vitamin D. Vitamin K is important for bone health (dark leafy greens have it, dairy doesn't). Magnesium (present in foods like almonds, cashews, oatmeal, and potatoes, but missing in dairy products) also plays an important role in bone health." Photo by Quinn Dombrowski.
Ultimately, if you're concerned about bone health, you should make sure to get enough calcium in your diet, and while milk and cheese are good sources of it, they're by no means the only sources. It's important-and can be just as healthy-to branch out and make sure you're eating dark leafy greens instead of just chugging down milk. Even the Harvard School of Public Health points out that milk isn't the only, or even the best, source of calcium, as does the University of Missouri's Nutrition "mythbusters." If you're looking for good sources of calcium and Vitamin D, consider collard greens, mustard greens, kale, and bok choy instead of milk.

Myth: Everyone Should Drink 64-Ounces or 8 Glasses of Water Every Day

This myth is a holdover from a poor attempt by a number of doctors who wanted to wage an ill-researched campaign against sodas and sugary drinks. Their hearts were in the right place, but the fact of the matter is that there's no uniform rule for how much water a person should drink in a given day. Alannah DiBona explains, "Water's been touted as the cure for all sins, and in some ways, it's true—proper hydration is necessary for just about anything body and mind-related. However, sixty-four ounces per day isn't going to always be the right number for you."  
My old nutritionist explained to me that I should try to drink my body weight in ounces of water, divided in half. She noted that's a good guideline for most people, but also noted that it's a goal—not a rule. When I asked her whether there would be real health benefits from it, she explained that it's not going to make my body work better or somehow stave off disease magically, but it will give me energy, prevent dehydration, get me up away from my desk and walking to the water fountain, and she pointed out that often our bodies interpret thirst signals as hunger. It's anecdotal, but I have to admit that drinking more water made me feel better by leaps and bounds.
While it's important to hydrate, it's not important to stick to an arbitrary rule defining how you hydrate, or how much you drink, or even where you get it, although water is obviously the best source of, well, water. "Nutrition is an individual science, and there will be days when your body and mind require less than the average recommendation," DiBona explains. "Remember that water is available to you through all liquids, fruits, and vegetables, and that the mark of proper hydration is very light yellow-colored urine."

Myth: High-Sodium Foods Taste Salty, So Avoid Salty Snacks

Andy Belatti pointed this one out when we spoke, and it's especially important for people who are managing their salt and sodium intake because they're at risk for hypertension or diabetes. While new research indicates that low-sodium diets may not be better for your heart, they definitely reduce your chances of high blood pressure or type II diabetes. The trouble with managing sodium though, is that not all high-sodium foods taste salty when you eat them.
"While surface salt (the type on pretzels and salted nuts) is noticeable, stealth sodium (that which is added during processing) is harder to taste. This is why many people don't realize that a Dunkin' Donuts corn muffin contains as much sodium as 9 McDonald's Chicken McNuggets," Belatti explains.
This fact is a testament to the importance of reading nutrition labels when you grocery shop, and why it's important to look up nutrition information for your favorite foods at restaurants or fast-food eateries either on the web or in-store when you're out for lunch or dinner. Sodium can lurk in strange and surprising places. Check out the National Heart, Lung, and Blood Institute (at the NIH) for more tips on reducing your sodium intake, and what to watch out for.

Myth: Eating Eggs Will Jack Up Your Cholesterol

A number of you took me to task on this one the last time I insinuated that eggs may not be healthy, and rightfully so. Alannah Dibona cleared this one up once and for all, and notes: "More often than not, a person diagnosed with high cholesterol will go out of his or her way to avoid eggs, which is really unnecessary. The body's cholesterol levels are influenced by certain saturated and trans fats; eggs contain very little saturated fat (1.5 grams of fat per large egg) and absolutely no trans fat. Depriving yourself of an egg means foregoing 13 naturally occurring vitamins and minerals (and a really delicious breakfast option)."  
Ultimately, eliminating eggs from your diet because you're concerned about cholesterol will do absolutely nothing for you, and instead may actually be harmful because you're missing out on the health benefits they have. The Harvard Medical School agrees, as does the Mayo Clinic, although they take a more metered approach to the issue, and suggest that if you love eggs, eat the whites and not the yolks. Both agree that even though the yolks have a lot of cholesterol, very little of it actually makes it into your bloodstream, where it matters.

Myth: Aluminum Foil and Cookware Is Linked to Alzheimer's Disease

If you haven't heard this one in a while, good-it was repeated often in the late 80s and through the 90s, and even though it's fallen out of fashion (largely because it's just not true) there are still a lot of people who believe it. This myth has its roots in research from the 1960s and 1970s that showed elevated levels of aluminum in the brains of Alzheimer's patients. The hyperbole alarm was subsequently sounded, and for years people were warned off of aluminum pots and pans, and even aluminum foil to store food.
Since those studies however, a great deal of research has been done into what possible connections aluminum may have with Alzheimer's Disease, and at best has failed to show any substantive link or connection between aluminum and risk for Alzheimer's Disease. At worst there have been conflicting results. Most experts at this stage believe any aluminum absorbed by the body is processed by the kidneys and urinated out, and it does not pose a threat for Alzheimer's Disease.

Myth: Don't Eat After 6/7/8PM

Both Andy Belatti and Alannah DiBona called this myth out in different ways. Andy went right for its throat, noting that it is "A silly weight-loss gimmick. What matters is what you're eating throughout the day. Food eaten after 7 does not magically turn to fat. This is also a ridiculous 'tip' for someone who goes to bed at midnight or 1 AM. This tip often 'works' because people end up reducing their total caloric intake." 
He's right: this myth comes from a half-scientific understanding of how digestion works. The idea is that if you eat too late and go to bed on a full stomach, your body's metabolism will slow down and instead of burning the food you just ate, you'll turn it all into fat and gain weight. That statement is only partially true, and isn't universal for all people. While it's true your metabolism slows down when you go to sleep, it doesn't stop, and you still churn through the food in your stomach, albeit slower. If your diet, exercise, and activity habits mean that a meal is more likely to metabolize into fat because you sit at a desk all day, eating it at 5pm versus 7pm isn't going to change that.
In reality, what really happens for the people who swear by this trick is that they don't wind up eating breakfast the following morning on top of a stomach full of food, and that they've blocked off areas of their night when they're not consuming food-as opposed to someone who would be tempted to have a late-night snack. In essence, they're just eating less overall. This myth is so popular that the ADA has a page dedicated to debunking it.
Belatti also makes the point that if you're the type of person who's up very late, setting an arbitrary time to stop eating at night isn't going to help you lose weight, it's just going to make you skip a meal. DiBona had something specific to say about meal skipping, and how dangerous it can be: "Just several years ago, I remember reading in Cosmopolitan magazine that skipping breakfast or lunch following a "night of indulgence" could aid in one's efforts to lose weight. The editors couldn't have been more wrong. If a meal is skipped, the body begins a process of metabolic slowing commonly referred to as ‘starvation mode.'" She continued, "Additionally, surges of hormones then encourage overeating at the next meal, resulting in a higher caloric intake at the day's end. Keeping one's blood sugar balanced with small meals and snacks throughout the day is a much more successful approach for weight maintenance and mental alertness."

Sports and child development

Does all work and no play make Jack a dumb boy as well as a dull one? This column presents one of the first empirical studies on the effects of sporting activity on the cognitive ability of children in Germany.

Physical inactivity is a growing problem. It contributes to the obesity epidemic and is particularly worrisome among the youngest in society. As a result, many countries have programmes aimed at increasing the physical activity of children – the "Let's Move!" campaign led by the US first lady, Michelle Obama, is a prominent example.
Folklore around the world tells us that physical activities are good for a child's development. Moreover, many scientific studies have shown a positive association between the level of physical activity and measures of children's health, skills, and wellbeing (Strong et al 2005). Yet, empirical evidence, at least about the causal effect of physical activities on the non-health outcomes, is scarce.
Our study (Felfe et al 2011) aims to fill this gap and to shed some light on the effect of sport activities on smaller children's human-capital formation. Our results reveal that active sport club participation leads to improvements in children's cognitive and non-cognitive skills, which are of similar size to the ones found for largescale educational programmes.
So far, the economic literature has mainly focused on sport activities among adolescents. A positive relationship between participation in high school sport and educational attainment, on the one hand, and professional success, on the other, is well established (Barron et al 2000, Eide and Ronan 2001, Pfeiffer and Cornelissen 2010, Stevenson 2010). Yet, the underlying mechanism is not yet well understood. In particular, the question of when and through which mechanism sport exerts its influence on people's educational and professional success remains open.
When addressing this question it is crucial to bear in mind that cognitive and non-cognitive abilities already acquired early in life are key determinants of success later in life (Heckman 2006). Thus, the focus of our study lies on sport participation during childhood. To be more precise, we focus on participation in sport clubs among children aged three to ten years in Germany. In Germany sport clubs are the key institutions organising sport activities of children. According to the German Olympic Association (DOSB, Deutscher Olympischer Sportbund 2009), 76% of boys and 59% of girls aged seven to fourteen are playing sports in a club. This is in stark contrast with the US, for example, where youth sport is much more organised by schools. In Germany most child and youth sport , both for leisure and competition, is organised in clubs. Schools play only a minor role.

Measuring the effect of sport during childhood

Our empirical analysis draws upon a cross-sectional (medical) survey for Germany, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). This dataset provides us not only with a wide array of children's cognitive and non-cognitive skill measures, but also with detailed information on children's health, sport participation, and their family background (5,632 children). Our main empirical approach is based on a matching estimation strategy. The basic idea is that we compare the outcomes of children who participate in sport with children who do not participate but are almost identical in other aspects, such as sex and age, their parents’ education and income, their brothers and sisters, their parents’ parenting style, or the characteristics of the neighbourhood they live in. As the KiGGS dataset contains a very rich set of characteristics, especially regarding parenting style of parents, we can match children on all-important observable characteristics.

Results

Our findings indicate strong positive effects of participation in sport on children's cognitive and non-cognitive skills (see Table 1). We normalise our measures of children's skills to be zero on average and have a standard deviation of one. In so doing we can interpret the size of the effects in relationship to the general variation in children's skills (measured by one standard deviation (henceforth, sd). Both cognitive skills, measured by overall school grades, and overall non-cognitive skills improve by 0.13 sd. The latter effect is mainly driven by a reduction in emotional problems (0.10 sd) and in peer problems (0.22 sd). The fact that children who engage in sport also fare better in terms of health (0.12 sd) and general wellbeing (0.11 sd) support these findings.
The size of the effects is in a similar range to the effects other studies find for largescale educational programmes. Head Start for instance, one of the most studied educational programmes in the US, has been shown to lead to improvements in children’s non-cognitive skills of around 0.2 sd and in children’s cognitive skills of around 0.06 sd (Currie and Almond 2011).

Empirical challenges: Is the effect driven by better parents or better children?

It is easy to cast into doubt whether our findings are driven by the fact that children, who are more likely to engage in sport, are endowed with a priori better skills or stem from a more advantaged family background. To the extent that these differences are unobserved, our suggested empirical approach may fail to estimate the causal effect of sport participation on children's development. In order to address these issues we pursue the following two alternative strategies.

• First, we take advantage of the panel dimension of a further dataset, the German Child Panel. The longitudinal nature of this dataset allows us to match children on their initial level of sport activity, skill endowment, and health conditions.
• Second, we exploit differences in the local availability of sport facilities. A better local supply of sport facilities should lead to higher sport participation among children, but should not be directly linked to an improvement in children's development (except via increased sport participation). Thus, it acts as an exogenous shifter of children's sport participation.

Discussion

Our results highlight the importance of physical activities for children's development. Encouraging children to participate in sport and providing the necessary infrastructure should therefore be, and in many countries already is, an important policy objective, although this statement has to be qualified by a cost-benefit analysis. Moreover, our results provide evidence that the positive effects of playing sports in a club are partially explained by an increase in physical activity as sport club participation does not crowd out other sport activities. The effects are strongest in cities, where children have fewer opportunities to be physically active outside of sport clubs. One further explanation for our findings is a reduction in passive activities such as watching TV. Nevertheless, ‘playing sports in a club’ has still many more dimensions, which, given the data at hand, we are not able to explore. Participating in a sport club exposes children to cooperation with other children in a team, which may also make them better team players in other situations in life. Playing sports in a club comes often along with participation in competitions. Victory in competition may raise children's self-esteem while defeat, despite eventual negative effects on children’s self-esteem, may teach them how to deal with such a situation. Future research should therefore try to dig deeper into the mechanisms through which sport activities may influence skill formation and disentangle the various channels through which the effect may work.

Table 1. Matching estimates for the impact of sport on children's development

Barron, J, B Ewing, and G Waddell (2000), “The Effects of High School Athletic Particpiation on Education and Labor Market outcomes”, Review of Economics and Statistics, 82(3):409-421.
Currie, J, and D Almond (2011), “Human Capital Development before Age Five”, in O Ashenfelter and D Card, Handbook of Labor Economics, 4(2):1315-1486.
DOSB, Deutscher Olympischer Sportbund (2009), Bestandsaufnahme 2009. Frankfurt/Main.
Eide, E and N Ronan (2001), “Is participation in high school athletics an investment or a consumption good? Evidence from high school and beyond”, Economics of Education Review, 20(5):431-442.
Felfe, C, M Lechner and A Steinmayr (2011), “Sports and child development”, CEPR Discussion Papers 8523.
Heckman, J (2006), “Skill Formation and the Economics of Investing in Disadvantaged Children”, Science, 312(5782):1900-1902.
Pfeiffer, C and T Cornelissen (2010), “The impact of participation in sports on educational attainment - New evidence from Germany”, Economics of Education Review, 29(1):94-103.
Rees, D, and Sabia, J (2010). Sports participation and academic performance: Evidence from the National Longitudinal Study of Adolescent Health. Economics of Education Review , 29 (5), pp. 751-759.
Stevenson, B (2010). Beyond the Classroom: Using Title IX to Measure the Return to High School Sports. Review of Economics and Statistics , 92 (2), pp. 284-301.
Strong, WB, RM Malina, CJR Blimkie, SR Daniels, RK Dishman, B Gutin, AC Hergenroeder, A Must, PA Nixon, JM Pivarnik, T Rowland, S Trost, F Trudeau (2005), “Evidence Based Physical Activity for School-Age Youth”, The Journal of Pediatrics, 146(6):732-737.

Sugar, and candy, do not make kids hyper

Let’s cut to the chase: sugar doesn’t make kids hyper. There have been at least twelve trials of various diets investigating different levels of sugar in children’s diets.  That’s more studies than are often done on drugs. None of them detected any differences in behavior between children who had eaten sugar and those who hadn’t.  These studies included sugar from candy, chocolate, and natural sources.  Some of them were short-term, and some of them were long term. Some of them focused on children with ADHD. Some of them even included only children who were considered “sensitive” to sugar. In all of them, children did not behave differently after eating something full of sugar or something sugar-free.
Personally, I think there are so many studies on this issue because after each was completed, the results were met with such skepticism that researchers felt the need to do another. This myth, perhaps more than any other, is met with disbelief when we discuss it, especially among parents.
In my favorite of these studies, children were divided into two groups.  All of them were given a sugar-free beverage to drink. But half the parents were told that their child had just had a drink with sugar.  Then, all of the parents were told to grade their children’s behavior.  Not surprisingly, the parents of children who thought their children had drunk a ton of sugar rated their children as significantly more hyperactive. This myth is entirely in parents’ heads. We see it because we believe it.
Even when science shows time and again that it’s not so,  we continue to persist in believing that sugar causes our kids to be hyperactive. That’s likely because there’s an association. Times when kids get a lot of sugar are often times when they are predisposed to be a little excited. Halloween. Birthday parties. Holidays. We may even be causing the problem ourselves. Some parents are so restrictive about sugar and candy that when their kids finally get it they’re quite excited. Even hyper.
This does not mean that there aren’t a ton of great reasons why our kid should not ingest large quantities of sugar.  As almost any parent knows, sugar has been linked to cavities and the obesity epidemic. Just don’t blame it for your child’s bad behavior.
References:

1. Hoover DW, Milich R. Effects of sugar ingestion expectancies on mother-child interactions. J Abnorm Child Psychol 1994;22:501-15.
2. Kinsbourne M. Sugar and the hyperactive child. N Engl J Med 1994;330:355-6.
3. Krummel DA, Seligson FH, Guthrie HA. Hyperactivity: is candy causal? Crit Rev Food Sci Nutr 1996;36:31-47.
4. Wolraich ML, Lindgren SD, Stumbo PJ, Stegink LD, Appelbaum MI, Kiritsy MC. Effects of diets high in sucrose or aspartame on the behavior and cognitive performance of children. N Engl J Med 1994;330:301-7.

The case for dietary supplements is collapsing

A succession of large-scale human studies, including two published earlier this month in leading medical journals, suggests that multivitamins and many other dietary supplements often don't have health benefits—and in some cases may even cause harm.

After decades of research on the possible benefits of nutritional supplements, the handwriting is on the wall: Vitamins look to be a bust for the majority of people, many leading scientists are concluding. Shirley Wang has details on Lunch Break.
The data have prompted some nutrition researchers to say taking vitamins is a waste of money for those without a specific nutrient deficiency or chronic illness. Such findings have also fueled a debate about whether the field should continue conducting expensive human trials to figure out whether the less benefit [supplements] showed," says Marion Nestle, professor of nutrition, food studies, and public health at New York University. "It's fair to say from the research that supplements don't make healthy people healthier."
For instance, vitamins B-6 and B-12 are often touted as being good for the heart, but several studies have failed to find that they lower risk of cardiovascular disease, according the Office of Dietary Supplements, part of the National Institutes of Health. Vitamin C hasn't been shown in many studies to lower a person's risk of getting a cold. Calcium, while important to bone health, doesn't lower risk of heart disease or cancer and may increase risk of kidney stones.
"We have an enormous body of data telling us that plant-rich diets are very healthy," says Josephine Briggs, head of the National Center for Complementary and Alternative Medicine, another NIH center. "As soon as we take these various antioxidants[and other nutrients] out and put them in a pill, we're not consistently getting a benefit."
Researchers and nutritionists are still recommending dietary supplements for the malnourished or people with certain nutrient deficiencies or medical conditions. For instance folic acid—the supplement form of folate——reduces the likelihood of a common birth defect if taken by pregnant women.
Studying the effects of vitamins and supplements in the real world is difficult, since people eat foods with multiple nutrients that can interact with supplements and skew results. And observational trials can only show an association, not cause and effect.
That is one reason the Council on Responsible Nutrition, which represents the supplement industry, says it is too early to say supplements don't have health benefits. Duffy MacKay, the group's vice president of regulatory and scientific affairs, says lengthier studies may be required to show the benefits of some supplements.
Micronutrients, which include antioxidants like vitamin C, hormones like vitamin D and metals like iron, are essential to the body in small amounts because they help facilitate important reactions in and between cells. Too much of them, however, can cause problems.
The effectiveness of many dietary supplements remains untested and makers aren't required to do tests before selling a product. Still, about half of Americans reported taking at least one supplement a month in 2006, in the National Health and Nutrition Examination Survey published in April of this year. The supplement industry brought in $28 billion in sales in 2010, up 4.4% from 2009, according to Nutrition Business Journal, an industry trade publication.
Vitamin users may derive a benefit from the placebo effect, experts say. And they often are convinced the supplements make them feel better, regardless of what studies show.
"The thing you do with [reports of studies] is just ride them out, and literally we see no impact on our business," said Joseph Fortunato, chief executive of supplement retailer GNC Corp., according to a transcript of the company's third-quarter conference call with analysts last week.
"Consumers believe in our products," a spokesman for GNC said. GNC's revenue grew 15.5% in the third quarter of this year compared to a year ago and the stock, which closed at $25.08, is up 0.5% year-to-date.
Of growing concern to many scientists are the increasing hints of harm from vitamins.
The first red flags started emerging nearly 20 years ago. Researchers thought from early work that extra beta-carotene could help prevent lung cancer, but two randomized trials published in 1994 and 1996 showed an increased rate of lung cancer among smokers who took beta-carotene supplements.
Oncologist Mark Heaney of Memorial Sloan-Kettering Cancer Center in New York showed in laboratory work in 2008 that vitamin C appeared to inhibit the effect of chemotherapy drugs for cancer treatment. Subsequent research has shown vitamin C may inadvertently protect cancer cells more than normal cells.
A study published this month in the Journal of the American Medical Association, known as the SELECT trial, found that vitamin E—previously thought to lower risk of prostate cancer—actually increased the chance slightly. The risk could be mitigated by the simultaneous consumption of another micronutrient, selenium, the study says.
Multivitamins aren't faring much better. Results from the Iowa Women's Health Study, published earlier this month in the Archives of Internal Medicine, found in a sample of over 38,000 older women, multivitamin use over time was linked with a slight but statistically significant increased risk of earlier mortality.
A studyof 1,900 men and women in 15 cities across Europe published in 2008 in the European Journal of Nutrition followed healthy elderly individuals for 10 years. Among smokers in the study, those who took multivitamins were more likely to die younger than smokers who didn't.
Another large trial examining postmenopausal women in the NIH's Women's Health Initiative found no discernible impact from taking a multivitamin on preventing breast, lung or colorectal cancer, cardiovascular disease or premature death, according to the 2009 study published in the Archives of Internal Medicine.
Some experts warn against overemphasizing the potential harm of multivitamins because it isn't clear how that statistical uptick in risk of death would translate into actual increased risk in real life.
The consistent failure to show benefits has led researchers at the National Center for Complementary and Alternative Medicine and elsewhere to call for more lab experiments and small-scale studies of how the nutrients work, after over a decade of pursuing large, clinical trials of particular supplements' effectiveness.
"We've missed a step," says Alan Kristal, a professor of epidemiology at the University of Washington who studies the links between diet and cancer. "We need to understand the mechanism by which these things are acting."
Roberta Anding, a nutritionist at Texas Children's Hospital in Houston, says some people need multivitamins and other supplements, but she is cautious about the risk from high doses of micronutrients. "It's no longer nutrition when the doses become high, it's pharmacology," she says.
The best way to get micronutrients is through a balanced diet, she says.
"If you're looking at this as, 'At least I'm [taking a multivitamin],' but you're not exercising or eating well, then it is a waste of money," says Ms. Anding, a spokeswoman for the American Dietetic Association, a research and advocacy group.

How the Potato Changed the World

Brought to Europe from the New World by Spanish explorers, the lowly potato gave rise to modern industrial agriculture

• By Charles C. Mann

When potato plants bloom, they send up five-lobed flowers that spangle fields like fat purple stars. By some accounts, Marie Antoinette liked the blossoms so much that she put them in her hair. Her husband, Louis XVI, put one in his buttonhole, inspiring a brief vogue in which the French aristocracy swanned around with potato plants on their clothes. The flowers were part of an attempt to persuade French farmers to plant and French diners to eat this strange new species.
Today the potato is the fifth most important crop worldwide, after wheat, corn, rice and sugar cane. But in the 18th century the tuber was a startling novelty, frightening to some, bewildering to others—part of a global ecological convulsion set off by Christopher Columbus.
About 250 million years ago, the world consisted of a single giant landmass now known as Pangaea. Geological forces broke Pangaea apart, creating the continents and hemispheres familiar today. Over the eons, the separate corners of the earth developed wildly different suites of plants and animals. Columbus’ voyages reknit the seams of Pangaea, to borrow a phrase from Alfred W. Crosby, the historian who first described this process. In what Crosby called the Columbian Exchange, the world’s long-separate ecosystems abruptly collided and mixed in a biological bedlam that underlies much of the history we learn in school. The potato flower in Louis XVI’s buttonhole, a species that had crossed the Atlantic from Peru, was both an emblem of the Columbian Exchange and one of its most important aspects.

Read more: http://www.smithsonianmag.com/history-archaeology/How-the-Potato-Changed-the-World.html#ixzz1cSWsrLxz

Read more: http://www.smithsonianmag.com/history-archaeology/How-the-Potato-Changed-the-World.html#ixzz1cSWcob8K

All Work and No Play: Why Your Kids Are More Anxious, Depressed

Esther Entin - Esther Entin, M.D., is a pediatrician and clinical associate professor of Family Medicine at Brown University's Warren Alpert School of Medicine.  

For more than fifty years, children's free play time has been continually declining, and it's keeping them from turning into confident adults

What are your memories of playing as a child? Some of us will remember hide and seek, house, tag, and red rover red rover. Others may recall arguing about rules in kickball or stick ball or taking turns at jump rope, or creating imaginary worlds with our dolls, building forts, putting on plays, or dressing-up. From long summer days to a few precious after-school hours, kid-organized play may have filled much of your free time. But what about your children? Are their opportunities for play the same as yours were? Most likely not.
Play time is in short supply for children these days and the lifelong consequences for developing children can be more serious than many people realize.
THE DECLINE OF PLAY
An article in the most recent issue of the American Journal of Play details not only how much children's play time has declined, but how this lack of play affects emotional development, leading to the rise of anxiety, depression, and problems of attention and self control.
"Since about 1955 ... children's free play has been continually declining, at least partly because adults have exerted ever-increasing control over children's activities," says the author Peter Gray, Ph.D., Professor of Psychology (emeritus) at Boston College. Gray defines "free play" as play a child undertakes him- or her-self and which is self-directed and an end in itself, rather than part of some organized activity.
Gray describes this kind of unstructured, freely-chosen play as a testing ground for life. It provides critical life experiences without which young children cannot develop into confident and competent adults. Gray's article is meant to serve as a wake-up call regarding the effects of lost play, and he believes that lack of childhood free play time is a huge loss that must be addressed for the sake of our children and society.
WHO AND WHAT IS INTERFERING WITH CHILDREN'S PLAY?
Parents who hover over and intrude on their children's play are a big part of the problem, according to Gray. "It is hard to find groups of children outdoors at all, and, if you do find them, they are likely to be wearing uniforms and following the directions of coaches while their parents dutifully watch and cheer." He cites a study which assessed the way 6- to 8-year-olds spent their time in 1981 and again in 1997.
The researchers found that compared to 1981, children in 1997 spent less time in play and had less free time. They spent 18 percent more time at school, 145 percent more time doing school work, and 168 percent more time shopping with parents. The researchers found that, including computer play, children in 1997 spent only about eleven hours per week at play.
In another study, mothers were asked to compare their own memories of their playtime, to their children's current schedules. Eighty-five percent noted that their children played outdoors less frequently and for shorter periods of time than they had. The mothers noted that they restricted their own children's outdoor play because of safety concerns, a fact echoed in other surveys where parents mentioned child predators, road traffic, and bullies as reasons for restricting their children's outdoor play.
Adding to the problem, Gray notes, is our increasing emphasis on schooling and on adult-directed activities. Preschools and kindergartens have become more academically-oriented and many schools have even eliminated recess. It is not that anyone set out to do away with free play time. But its value has not been recognized. As a result, kids' free play time has not been protected.
FIVE WAYS PLAY BENEFITS KIDS
When children are in charge of their own play, it provides a foundation for their future mental health as older children and adults. Gray mentions five main benefits:
1. Play gives children a chance to find and develop a connection to their own self-identified and self-guided interests.
As they choose the activities that make up free play, kids learn to direct themselves and pursue and elaborate on their interests in a way that can sustain them throughout life. Gray notes that: "...in school, children work for grades and praise and in adult-directed sports, they work for praise and trophies.... In free play, children do what they want to do, and the learning and psychological growth that results are byproducts, not conscious goals of the activity."
2. It is through play that children first learn how to make decisions, solve problems, exert self control, and follow rules.
As children direct their own free play and solve the problems that come up, they must exert control over themselves and must, at times, accept restrictions on their own behavior and follow the rules if they want to be accepted and successful in the game.
As children negotiate both their physical and social environments through play, they can gain a sense of mastery over their world, Gray contends. It is this aspect of play that offers enormous psychological benefits, helping to protect children from anxiety and depression.
"Children who do not have the opportunity to control their own actions, to make and follow through on their own decisions, to solve their own problems, and to learn how to follow rules in the course of play grow up feeling that they are not in control of their own lives and fate. They grow up feeling that they are dependent on luck and on the goodwill and whims of others...."
Anxiety and depression often occur when an individual feels a lack of control over his or her own life. "Those who believe that they master their own fate are much less likely to become anxious or depressed than those who believe that they are victims of circumstances beyond their control." Gray believes that the loss of playtime lessons about one's ability to exert control over some life circumstances set the scene for anxiety and depression.
3. Children learn to handle their emotions, including anger and fear, during play.
In free play, children put themselves into both physically and socially challenging situations and learn to control the emotions that arise from these stressors. They role play, swing, slide, and climb trees ... and "such activities are fun to the degree that they are moderately frightening ... nobody but the child himself or herself knows the right dose."
Gray suggests that the reduced ability to regulate emotions may be a key factor in the development of some anxiety disorders. "Individuals suffering from anxiety disorders describe losing emotional control as one of their greatest fears. They are afraid of their own fear, and therefore small degrees of fear generated by mildly threatening situations lead to high degrees of fear generated by the person's fear of losing control." Adults who did not have the opportunity to experience and cope with moderately challenging emotional situations during play are more at risk for feeling anxious and overwhelmed by emotion-provoking situations in adult life.
4. Play helps children make friends and learn to get along with each other as equals.
Social play is a natural means of making friends and learning to treat one another fairly. Since play is voluntary and playmates may abandon the game at any time if they feel uncomfortable, children learn to be aware of their playmates' needs and attempt to meet them in order to maintain the play.
Gray believes that "learning to get along and cooperate with others as equals may be the most crucial evolutionary function of human social play ... and that social play is nature's means of teaching young humans that they are not special. Even those who are more skilled at the game's actions ... must consider the needs and wishes of the others as equal to their own, or else the others will exclude them." Gray cites increasing social isolation as a potential precursor to psychopathology and notes that the decline in play may be "both a consequence and a cause of the increased social isolation and loneliness in the culture."
5. Most importantly, play is a source of happiness.
When children are asked about the activities that bring them happiness, they say they are happier when playing with friends than in any other situation. Perhaps you felt this way when remembering your own childhood play experiences at the beginning of this article.
Gray sees the loss of play time as a double whammy: we have not only taken away the joys of free play, we have replaced them with emotionally stressful activities. "[A]s a society, we have come to the conclusion that to protect children from danger and to educate them, we must deprive them of the very activity that makes them happiest and place them for ever more hours in settings where they are more or less continually directed and evaluated by adults, setting almost designed to produce anxiety and depression."
THE LOSS OF PLAY AND RISE OF ANXIETY AND DEPRESSION
There has been a significant increase in anxiety and depression from 1950 to present day in teens and young adults and Gray cites several studies documenting this rise. One showed that five to eight times as many children and college students reported clinically significant depression or anxiety than 50 years ago and another documented a similar trend in the fourteen- to sixteen-year-old age group between 1948 and 1989.
Suicide rates quadrupled from 1950 to 2005 for children less than fifteen years and for teens and young adults ages 15-25, they doubled. Gray believes that the loss of unstructured, free play for play's sake is at the core of this alarming observation and that as a society, we should reassess the role of free play and the factors that seem to have all but eliminated it from our children's lives.
When parents realize the major role that free play can take in the development of emotionally healthy children and adults, they may wish to reassess the priorities ruling their children's lives. The competing needs for childcare, academic and athletic success, and children's safety are compelling. But perhaps parents can begin to identify small changes -- such as openings in the schedule, backing off from quite so many supervised activities, and possibly slightly less hovering on the playground that would start the pendulum returning to the direction of free, imaginative, kid-directed play.

Recipe: Soy veg curry

Soy veg curry is an easy to make nutritious recipe.

Ingredients:

Soy beans- ½ cup
vegetables (of your choice)- 100 gms each
Jeera
Mustard
Red chillies
Garam masala- a pinch
Grated coconout-1/2 cup
Salt to taste
Oil

Procedure:

Soak Soya beans over night and pressure cook.

Finely cut the vegetables of your choice.

Take little oil in a pan and put jeera, mustard, red chillies and let them splutter.

To this add the vegetables and cook for five minutes with the lid.

Now add Soya beans, garam masala, coconut, and salt to taste.

Cook for five more minutes.

When did potatoes become unpopular?

By Kate Dailey BBC News Magazine

Potatoes have gone from nation-building superfoods to national pariahs. Why?

This week, the US Congress foiled plans to limit the amount of potatoes served in school lunches. Rules proposed by the United States Department of Agriculture (USDA) stated that potatoes, along with other starchy vegetables like corn, peas, and lima beans, could be served in school cafeterias only twice a week.

A Senate amendment passed on Tuesday, however, forbade the USDA from imposing such restrictions.
It was a small victory in an era when the potato is often under attack.
"Carbohydrate-rich foods in general have been vilified unfairly, and potatoes are the latest target," says dietician Elisa Zied, author of Nutrition at Your Fingertips.
In 2007, Americans ate 20% fewer potatoes than they did in 1997, according to a report from the United States Potato Board. In the UK, potato consumption decreased by 7.8% between 2005 and 2008.
It was not always this way. The potato used to be considered something of a wonder food. Grown originally in South America, its introduction to Europe literally transformed agriculture.
Fertile food Before the introduction of the potato, those in Ireland, England and continental Europe lived mostly off grain, which grew inconsistently in regions with a wet, cold climate or rocky soil. Potatoes grew in some conditions where grain could not, and the effect on the population was overwhelming.
"In Switzerland, for instance, the potato arrived in the early 18th Century and you can see over and over again as people started growing potatoes, the population grew," says John Reader, author of The Potato: A History of the Propitious Esculent.
"Birth rates rose, infant mortality improved, women became more fecund and all of that can be absolutely attributed to the potato."
For decades, potatoes were one of the most reliable sources of energy. They grew when other grains and vegetables could not, they required little processing once grown, and they packed a healthy dose of nutrients.
"For a 5.3-ounce, medium baked potato, you're looking at over 100 calories, very little fat, and one of the richest sources of potassium of any single food in the entire food chain," says nutritionist David Grotto, author of 101 Optimal Life foods. It is also a good source of vitamin C and fibre.
Defamed by diets Recently, potatoes have suffered from poor PR. Diets like Atkins and South Beach forbid potatoes because of their carbohydrate content. Starchy, carb-heavy food became synonymous with empty calories and low nutritional value, and the battle against potatoes became another front in America's relentless war on fat.

The facts do not bear that out, says Mr Grotto. "Our potato consumption has been on a decline, and I'd love to say that our obesity rate has declined as well, but that's not the case," he says.

One of the latest trends in nutrition, the Glycemic Index, has not been kind to the potato, either.
The index measures how foods affect blood sugar (glucose) levels, and is used to help people with diabetes control their blood sugar levels. Recent diet books have also proposed the GI as a good way to prevent weight gain and monitor health.
Carbs rank high on GI, and potatoes are a main source of carbs. But fears about their effect on health and weight are unfounded, says Mr Grotto, because potatoes are not eaten in isolation.
"We don't eat carbs, we eat food," he says. "The effect of protein and fibre with potatoes, how the potatoes are cooked, whether they are served as a reheated leftover can all have an effect on the glycemic index."
Deep-fried dilemma When it comes to its maligned reputation, a bigger problem is that the potato has started spending too much time with the wrong crowd.
"It's been demonised for its association with the deep fat fryer," says Grotto.
Not without reason. According to the Institute of Medicine (IOM) children eat less than half the vegetables they should - and of the vegetables they do eat, over 20% come in the form of potato chips, or crisps as they are known in the UK.
The regulations supported by the USDA - based of recommendations from the IOM - were in part to help promote different types of vegetables instead of the starchy standbys so often served with added fat and salt.
For Ms Zied, there needs to be a better approach. "The message to consumers should not be avoidance of foods that are naturally nutrient-rich, low in fat and relatively low in calories," she says. "The message should include finding ways to have potatoes and other healthful foods," prepared without an excess of sugar, solid fats, or calories.
But the truth of the matter is that school children love their chips. That is why Meredith Hughes, managing director of the Potato Museum, is not worried about pockets of anti-potato sentiment. "I don't agree that the potato is vilified," she says. "I think the potato is just taking off."
Ms Hughes and her family have built up the largest private collection of potato artefacts, currently located in New Mexico, but in search a permanent home. Both she and the museum are unaffiliated with the potato industry.
"The potato is an incredibly influential food," she says. "It has changed the course of history, it has influenced popular culture. It has saved people from starvation."
And at least for now, potatoes will continue to be plentiful in school lunches.

The amazing potato

 

• Potatoes were the first food to be grown in space
• There are more than 10,000 different kinds of potatoes, 5,000 of which are regularly grown and eaten
• Potato crystals were used to develop the first colour photography
• Biodegradable plastics can be created from potato starch
• Like humans, potatoes are 80% water