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22 October 2009

Green tea may ease mental distress: Study

Drinking five cups of green tea per day may reduce the incidence of psychological distress by 20 per cent, says a new study from Japan.

In a study with 42,093 Japanese individuals 2,774 people, or 6.6 per cent of the study population, suffered from psychological stress, and green tea consumption was said to improve psychological well-being.

According to WHO estimates, more than 450 million people suffer from stress worldwide, with 17 per cent of Europeans stating that stress is the most important risk factor to health. The related costs of stress estimated at €20bn in Europe (WHO) and $200bn in the US (International Labor Office).

Researchers led by Atsushi Hozawa from the Tohoku University Graduate School of Medicine report their findings online in the American Journal of Clinical Nutrition.

Green tea and its extracts already have a positive reputation, with studies reporting they may offer protective effects against Alzheimer's and certain cancers, improve cardiovascular and oral health, and play a positive role in weight management.

Despite reports already stating that green tea or its constituents might reduce psychological stress, no large-scale study has evaluated the relationship between green tea consumption and psychological distress, said the researchers.

After adjusting their results for potential confounding factors, including age, sex, history of disease, BMI, alcohol consumption, cigarette smoking, diet, and other factors, a significant inverse association between green tea consumption and psychological distress was observed for people who drank at least five cups of green tea per day, compared to those who drank less than one cup per day.

Being an epidemiological study, the authors could not offer any evidence as to what the active constituents behind the apparent benefits could be. Further study is needed to elucidate the bioactives and mechanism of action.

The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC).

Omega-3 may protect healthy men from chest pains

Increased intakes of omega-3 fatty acids EPA, DPA, and DHA may protect men against acute coronary syndrome (ACS), says a new study.

The heart health benefits of omega-3 fatty acids are well-documented, being first reported in the early 1970s by Jorn Dyerberg and his co-workers in The Lancet and The American Journal of Clinical Nutrition. To date, the polyunsaturated fatty acids (PUFAs) have been linked to improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements, and improved vascular function.

The new study, published in the British Journal of Nutrition, reported that increased intakes of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) may reduce the risk of acute coronary syndrome (ACS), an umbrella term for a range of symptoms including unstable angina and chest pains.

The Danish Diet, Cancer and Health cohort study involved 57,053 men and women. During an average follow-up time of almost eight years, 1,150 people developed ACS. Men who consumed more than 0.39 grams of PUFAs per day had an associated risk of ACS 27 per cent lower than men who consumed less than 0.39 grams per day.

When the researchers looked at individual omega-3 fatty acids, they did note negative association for EPA, DPA and DHA, but these were considered “less consistent”.

No benefits were observed for women, noted the researchers.

“We found borderline significant negative associations between the intake of marine omega-3 PUFA and ACS among healthy men,” they concluded.

Half a gram needed for heart benefits?

Earlier this year, a ‘state-of-the-art’ review concluded that the science behind the cardiovascular health benefits of omega-3 fatty acids supports recommended daily levels of 500 mg.

Parents can help their children grow to love vegetables

Mitchell Collins is only 4, but he's a burgeoning gourmet.

At an age when many toddlers subsist on macaroni and pizza, Mitchell loves hummus, peas and cottage cheese. He snacks on tomato and cucumber salads. And he begs for his dad's zucchini bread, made from vegetables Mitchell helped grow.

He hasn't always had such a good appetite, says his dad, Chuck Collins.

At 2, Mitchell ate no vegetables and got most of his calories from milk, formula and grits, Collins says. That changed when Mitchell began attending an Omaha child-care center, where children learn about nutrition along with the ABCs.

Toddlers there help tend a 60-foot table garden — watering, weeding and picking vegetables that they serve and eat together. Teachers don't force kids to clean their plates. But they do require children to taste everything, by asking for a "No-thank-you bite" when they don't want a full portion, Collins says.

"They eat stewed green tomatoes because they grew them," says pediatrician Laura Jana, owner of the Primrose School of Legacy and co-author of the American Academy of Pediatrics' Food Fights. "I didn't do that well with my own kids."

With one in three children overweight or obese, experts say it's never too early to help kids learn healthy eating habits.

Emerging research now suggests that parents can begin to shape a child's palate even in the womb, says Stanford University pediatrician Alan Greene, author of Feeding Baby Green, published this month.

A healthful 'imprint'

Babies actually have more taste buds before birth than at any other time of life. They can detect subtle flavors from their mothers' diet through their amniotic fluid, Greene says. These early exposures create a lasting "imprint" on children's tastes, Greene says. One study showed that babies of women who drank carrot juice while pregnant were more likely than others to enjoy carrots when they were 6 months old.

Infants are surprisingly adventurous from the age of 6 months to 13 months, a critical time for the formation of their future preferences. They can learn to like almost anything, although it may take six to 10 tastings, Greene says.

Yet few parents make the most of this crucial window. Research shows that 94% of parents give up offering new foods after only five tries, Greene says. While children's diets have improved modestly in recent years, a new study of kids under age 4 shows that nearly a third eat no vegetables a day.

Introducing new flavors and textures gets harder as kids grow. After age 2 or 2½, when food preferences solidify, it could take 90 attempts to get a child to like something new — at least until puberty, when some kids rediscover their love for new things, Greene says.

Picky eaters often develop bad habits, filling up on familiar fast foods instead of eating more wholesome family meals, Greene says. That helps explain a worrisome trend: Nearly 25% of our meals today come from fast food, compared with 10% of meals two decades ago, Jana says.

Many parents don't realize the problem with letting babies have sweets. "If you start potato chips and sweets early, then everything else will taste bland," says Atlanta pediatrician Jennifer Shu, co-author of Food Fights. "It trains their taste buds."

Everyone wins

With so many temptations, parents who want to raise healthy eaters need to expose their children to the sights, smells and feel of vegetables early and often, Greene says. He encourages parents to take children to farmers markets, letting them hold lumpy sweet potatoes and smell ripe peaches.

Preparing homemade baby food with a food grinder is far cheaper than buying jarred foods, says Greene, who carries a small food mill to show parents how to do it.

Because these purees taste more like the "real" food eaten by adults, they help babies make the transition eating a family meal, says Annabel Karmel, author of Top 100 Baby Purees.

"We're conditioning our children to like something that doesn't taste like real food," she says. "Parents think they're saving time, but they're really causing themselves trouble down the line."

Like the kids in Jana's child-care center, children are more willing to try something if they've had a hand in preparing it, Karmel says.

Training toddlers to enjoy the family meal also saves parents time in the long run, because it keeps them from becoming short-order cooks, Greene says.

"Every bite of food is either an investment in your child's body, or a debt that we'll have to repay somehow," Greene says. Teaching children to love healthy food, he says, "is such a wonderful gift for the rest of their lives."

20 October 2009

Chinese herbs show promise for diabetes prevention

NEW YORK (Reuters Health) - A number of traditional Chinese herbs may help control blood sugar levels in people at high risk of diabetes, a new research review suggests.

The review, which examined 16 clinical trials of 15 different herbal formulations, found that the herbs generally helped lower blood sugar levels in people with "pre-diabetes" -- those with impaired blood-sugar control that can progress to full-blown type 2 diabetes.

When the researchers pooled data from eight of the studies, they found that adding an herbal remedy to lifestyle changes doubled the likelihood of participants' blood sugar levels returning to normal.

What's more, people using the remedies were two-thirds less likely to progress to diabetes during the studies, which ran for an average of nine months.

The findings appear in the Cochrane Library, which is published by the Cochrane Collaboration, an international organization that evaluates medical research.

The results, say the researchers, are "quite promising." However, they also stress that the studies had shortcomings in their methods that make it hard to draw firm conclusions.

"There are a lot of herbal medicine products on the shelves, but few have been subjected to a rigorous trial," lead researcher Suzanne J. Grant, of the Center for Complementary Medicine Research at the University of Western Sydney, in Australia, told Reuters Health in an email.

Many of the trials her team examined, she explained, had a "high risk of bias" that can overestimate the effects of the treatments.

The gold standard for proving a treatment's efficacy is a clinical trial where participants are randomly assigned to receive either the real treatment or a placebo, with both the researchers and participants unaware of who is taking the real drug.

Grant's team found that those processes were often absent or not clearly detailed in the trials they reviewed.

So, she said, there is still a need for more rigorous trials before any herbal product can be recommended for diabetes prevention.

The studies included a total of 1,391 men and women with either impaired glucose tolerance or impaired fasting glucose -- problems in blood-sugar control that lead to sugar levels that are elevated, but not high enough to diagnose diabetes.

The studies tested various Chinese herbal mixes traditionally used for blood-sugar control -- products like Jiangtang Bushen, Xiaoke huaya and Tang Kang yin.

In most trials, the products were added to lifestyle changes and tested against the effects of lifestyle changes alone -- though the specific changes were not detailed in most reports.

Grant suggested that if people with pre-diabetes do want to try an herbal product, they first consult their doctor and, ideally, take any herbs under a guidance of a health provider qualified in herbal medicine.