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Antioxidants lower stroke risk

Eating a diet high in antioxidants may protect against ischemic stroke, an Italian cohort study showed.

People who had a diet high in total antioxidant capacity — an index that takes into account several different antioxidants and their interactions — had a 59% reduced relative risk of ischemic stroke (HR 0.41, 95% CI 0.23 to 0.74), according to Nicoletta Pellegrini, PhD, of the University of Parma in Italy, and colleagues. But there was no such relationship with hemorrhagic stroke, they reported in the January issue of the Journal of Nutrition. In fact, the highest intake of the antioxidant vitamin E was associated with a greater risk of hemorrhagic stroke (HR 2.94, 95% CI 1.13 to 7.62).
Considering evidence suggesting that oxidative stress and systemic inflammation are involved in the pathogenesis of ischemic stroke, the researchers noted that “a high-total antioxidant capacity diet could be protective as a consequence of its ability to deliver compounds with antioxidant activity and with a demonstrated anti-inflammatory effect.” But, they acknowledged that the mechanism for such activity was unclear may “go beyond the antioxidant activity of the numerous total antioxidant capacity contributors present in foods and beverages.”

Pellegrini and her colleagues set out to explore the relationship between dietary total antioxidant capacity and the risk of stroke among 41,620 people participating in EPICOR, the Italian segment of the European Prospective Investigation into Cancer and Nutrition (EPIC). None had a history of stroke or MI at baseline. Dietary intake was assessed with a food frequency questionnaire. In the study population, more than half of the total antioxidants consumed came from coffee, wine, and fruit. Through a mean follow-up of 7.9 years, there were 112 ischemic strokes, 48 hemorrhagic strokes, and 34 other types of strokes. After adjustment for energy intake, hypertension, smoking status, education, nonalcoholic energy intake at recruitment, alcohol intake, waist circumference, body mass index, and total physical activity, individuals eating a diet in the highest tertile of total antioxidant capacity had a reduced risk of ischemic — but not hemorrhagic — stroke.

Looking at individual antioxidants, the researchers found that participants consuming the highest amounts of vitamin C had a reduced risk of ischemic stroke (HR 0.58, 95% CI 0.34 to 0.99). Controlling for vitamin C intake did not negate the overall association between antioxidants and ischemic stroke, which ruled out the nutrient as the sole driver of the relationship. High intake of vitamin E, on the other hand, was associated with nearly triple the relative risk of hemorrhagic stroke. However, “it must be stressed that the small number of cases observed in this population strongly limits the validity of statistical observations on hemorrhagic stroke,” noted the researchers, who called for further studies.

Aside from anti-inflammatory effects, it is possible that the association between antioxidants and ischemic stroke risk can be explained by the interaction between polyphenols — the major contributors to total antioxidant capacity — and the generation of nitric oxide from the vascular endothelium. That interaction leads to the vasodilation and expression of genes that may be protective for the vascular system, according to the researchers. In addition, coffee — the main source of antioxidants in the study population — reduces blood pressure, which is a recognized risk factor for ischemic stroke, the researchers wrote.

They noted some limitations of the study, including the low numbers of cases when different types of stroke were analyzed, the measurement of total antioxidant capacity at baseline only, and the inability to rule out confounding effects of other dietary components, like sodium and potassium.

Source: Del Rio D, et al “Total antioxidant capacity of the diet is associated with lower risk of ischemic stroke in a large Italian cohort” J Nutr 2011; 141: 118-123.

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Tomatoes may reduce prostate cancer

Choosing to eat tomatoes not only reduces a man’s risk of developing prostate cancer, but also shrinks the existing tumors, claims a new Italian study. Researchers theorize that the secret may lie in lycopene, the powerful anti-oxidant that makes tomatoes red. Lycopene helps neutralize harmful free radicals that are implicated in various kinds of cancer, cardiovascular problems, macular degeneration and other age-related illnesses. However, the benefit was strongest for prostate cancer.

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In a bid to assess the prostate cancer-fighting properties of tomatoes, the researchers at the University of Naples conducted an experiment on rodents. For the purpose of the study, the researchers fed laboratory rats implanted with prostate cancer cells, with either a normal diet or that containing 10 percent tomato powder. The tomato powders were made from whole foods so the effects of eating the entire vegetable could be assessed as a nutritional supplement. The investigators noted that the animals fed on tomato powder exhibited slow progression of the disease and also had lower rates of prostate cancer. In contrast, those fed on a normal diet displayed no such benefits.

Joanna Owens, from Cancer Research Britain disagrees stated, “This study doesn’t provide enough evidence that tomatoes can reduce the risk of prostate cancer or prevent progression of the disease in humans. “Other risks such as age, family history and ethnicity are likely to play a much greater role than diet alone.” The study has been published in the journal ‘Cancer Prevention Research.’

 

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Caffeine consumption common in kids

Even young children appear to be consuming more caffeine, so much so that caffeine could be contributing to sleep problems in primary school children, researchers found. Three-quarters of children ages 5 to 12 consumed caffeine on an average day in a survey of parents at routine clinic visits by William J. Warzak, PhD, of the University of Nebraska Medical Center in Omaha, and colleagues. The more caffeine children consumed, the fewer hours they slept on average (P=0.02), the researchers reported online in the Journal of Pediatrics, although not drawing a causal link. The average intake was two or three times higher than the 22- to 23-mg daily average reported nearly a decade ago, they noted.

Eight- to 12-year-olds in Warzak's study averaged 109 mg of caffeine — the equivalent of nearly three 12-oz cans of soda each day. But even the 52 mg of caffeine consumed by 5- to 7-year-olds on an typical day was well above the level known to have a physiologic effect on adults, the researchers noted. “There's really no role for caffeine in kids,” Marcie Schneider, MD, of the Albert Einstein College of Medicine in New York City, emphasized in commenting on the study. “We know that caffeine raises your blood pressure, raises your heart rate, and can be addictive.” Unlike older teens who are likely drinking coffee to wake up in the mornings for school, the assumption is that younger kids are getting most of their caffeine from soda, noted Schneider, who serves as a member of the American Academy of Pediatrics Committee on Nutrition.

She urged pediatricians to raise parents' awareness of the issue, perhaps as part of the yearly checkup. “We routinely ask kids what they're eating and drinking,” “It may be something that is worth pediatricians pointing out to parents that this kid does not need caffeine in their life partially because it does some things that are negative.”

Warzak's group surveyed parents of 228 children seen at an urban outpatient pediatric clinic during routine visits about the children's average daily consumption of drinks and snacks with an emphasis on caffeine-containing items. None of the children had a known sleep disorder or medical condition that might cause bedwetting. Illustrated depictions were provided to help parents accurately estimate serving sizes.

Nearly all of the caffeine intake was consumed through beverages. Few children got a meaningful amount of caffeine from food. “Caffeine's diuretic properties have encouraged behavioral health practitioners to eliminate caffeine from the diet of children with enuresis,” the researchers noted. However, they found that intake didn't correlate with the number of nights a child wet the bed (P=0.49). Overall, enuresis was actually less likely in children who consumed caffeine.

The researchers cautioned that interpretation of these results may be complicated by cultural differences in reporting children's behavioral health concerns and that their study could not draw any causal conclusions. Schneider also noted the use of parental reports and the relatively small sample as limitations. Although the findings offered no support for removing caffeine from children's diets on the basis of bedwetting, Warzak's group concluded in the paper that “given the potential effects of caffeine on childhood behavior, a screen of caffeine consumption might be beneficial when evaluating childhood behavioral health concerns.”

Source: Warzak WJ, et al “Caffeine consumption in young children” J Pediatr 2011; DOI: 10.1016/j.jpeds.2010.11.022.

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Obesity may interfere with Vitamin D absorption

The more obese a person is, the poorer his or her vitamin D status, a new study by a team of Norwegian researchers suggests. The study found an inverse relationship between excess pounds and an insufficient amount of vitamin D, which is critical to cell health, calcium absorption and proper immune function. Vitamin D deficiency can raise the risk for bone deterioration and certain types of cancer. The researchers also suggest that overweight and obese people may have problems processing the vitamin properly.

The team noted that after the so-called “sunshine vitamin” is initially absorbed (through either sun exposure or the consumption of such foods as oily fish and fortified milk), the body must then convert it into a usable form, called 1,25-dihydroxyvitamin D. This conversion process, however, seems to be short-circuited among obese people, complicating efforts to gauge their true vitamin D health.

The findings are published in the January issue of the Journal of Nutrition.

To investigate the impact of obesity on vitamin D absorption, the team spent six years tracking 1,464 women and 315 men, with an average age of 49. Based on the participants' body mass index (BMI), an indicator of body fatness calculated from a persons weight and height, the average participant was deemed to be obese. About 11 percent were categorized as “morbidly obese.”

From the outset, overall vitamin D levels were found to be below the healthy range, the authors noted. By the end of the study, overall levels of vitamin D were found to have dropped off “significantly” while BMI readings rose by 5 percent. The research team concluded that having a higher-than-normal weight, body fat and BMI was linked to a poorer vitamin D profile. For example, people with the lowest BMI readings had 14 percent higher vitamin D levels than those with the highest BMI readings. Because vitamin D levels did not correlate properly with 1,25-dihydroxyvitamin D levels (and in fact appeared to have an abnormal inverse relationship), the authors suggested that future efforts to explore vitamin D status among obese people should test for both measures of vitamin D health.

They also suggested that people who are overweight and obese might benefit from vitamin D supplementation and more exposure to sunlight.

SOURCE: Journal of Nutrition, news release, Dec. 14, 2010

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Obesity may interfere with Vitamin D absorption

The more obese a person is, the poorer his or her vitamin D status, a new study by a team of Norwegian researchers suggests. The study found an inverse relationship between excess pounds and an insufficient amount of vitamin D, which is critical to cell health, calcium absorption and proper immune function. Vitamin D deficiency can raise the risk for bone deterioration and certain types of cancer.

The researchers also suggest that overweight and obese people may have problems processing the vitamin properly.

The team noted that after the so-called “sunshine vitamin” is initially absorbed (through either sun exposure or the consumption of such foods as oily fish and fortified milk), the body must then convert it into a usable form, called 1,25-dihydroxyvitamin D. This conversion process, however, seems to be short-circuited among obese people, complicating efforts to gauge their true vitamin D health.

The findings are published in the January issue of the Journal of Nutrition.

To investigate the impact of obesity on vitamin D absorption, the team spent six years tracking 1,464 women and 315 men, with an average age of 49. Based on the participants' body mass index (BMI), an indicator of body fatness calculated from a persons weight and height, the average participant was deemed to be obese. About 11 percent were categorized as “morbidly obese.”

From the outset, overall vitamin D levels were found to be below the healthy range, the authors noted. By the end of the study, overall levels of vitamin D were found to have dropped off “significantly” while BMI readings rose by 5 percent.

The research team concluded that having a higher-than-normal weight, body fat and BMI was linked to a poorer vitamin D profile. For example, people with the lowest BMI readings had 14 percent higher vitamin D levels than those with the highest BMI readings. Because vitamin D levels did not correlate properly with 1,25-dihydroxyvitamin D levels (and in fact appeared to have an abnormal inverse relationship), the authors suggested that future efforts to explore vitamin D status among obese people should test for both measures of vitamin D health.

They also suggested that people who are overweight and obese might benefit from vitamin D supplementation and more exposure to sunlight.

SOURCE: Journal of Nutrition, news release, Dec. 14, 2010

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Mediterranean Diet Increases Fertility

Before treatment, the couple completed detailed questionnaires on their eating habits over the past month. When the researchers analysed the data, they identified two common diet patterns among the women. 1). The Mediterranean diet – defined as high in vegetables, vegetable bits, fish and beans, but low in snack foods and 2). The health conscious diet – which is high in fruits, vegetables, whole grains, beans and fish, and low in meat and snack foods.

The researchers found there was no link between the health-conscious diet and rates of pregnancy. But, the group that most closely adhered to the Mediterranean diet was more likely to become pregnant. The researchers did not assess pregnancy outcome, so the diet's relationship to the ultimate success of fertility treatment is not clear.

The Mediterranean and health-conscious diets had many similarities, but there are a few potential reasons why the former may affect fertility treatment success said the researchers.

One is the high intake of vegetable oils in the Mediterranean diet. Researchers noted that the Omega-6 fatty acids in these oils are the precursors to hormone-like substances in the body called prostaglandins. Prostaglandins, in turn, are involved in the menstrual cycle, ovulation and pregnancy maintenance.

In addition, the study found that women who most closely followed the diet Mediterranean way had higher levels of vitamin B6. One previous study found giving vitamin B to women who were having difficulty getting pregnant increased their chances of conception.

Still, diet is part of a person's overall lifestyle and the study could not account for all of the factors that could clarify the connection between the natural ways to Increase fertility Mediterranean diet and pregnancy rates

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Vitamin E May Decrease Pulmonary Disease

Ms. Agler and colleagues reviewed data compiled by the Women's Health Study, a multi-year, long-term effort ending in 2004 that focused on the effects of aspirin and vitamin E in the prevention of cardiovascular disease and cancer in nearly 40,000 women aged 45 years and older. Study participants were randomized to receive either 600 mg of vitamin E or a placebo every other day during the course of the research.

Although fewer women taking vitamin E developed COPD, Ms. Agler noted the supplements appeared to have no effect on asthma, and women taking vitamin E supplements were diagnosed with asthma at about the same rate as women taking placebo pills. Importantly, Ms. Agler noted the decreased risk of COPD in women who were given vitamin E was the same for smokers as for non-smokers.

Ms. Agler said further research will explore the way vitamin E affects the lung tissue and function, and will assess the effects of vitamin E supplements on lung diseases in men. “If results of this study are borne out by further research, clinicians may recommend that women take vitamin E supplements to prevent COPD,” Ms. Agler noted. “Remember that vitamin E supplements are known to have detrimental effects in some people; for example vitamin E supplementation increased risk of congestive heart failure in cardiovascular disease patients. Broader recommendations would need to balance both benefits and risks. “

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