|
There is no difference in energy expenditure among modern hunter-gatherers and Westerners, according to new U.S. research that suggests eating too much, not exercising too little, might be the big problem. Scientists studied the Hadza of the savannah regions of northern Tanzania, who spend their days hunting and foraging for wild plants. Taking precise measurements and accounting for effects of body weight, etc., they found that the Hadza burned no more calories in a day than the average adult in the U.S. and Europe. The findings seem to indicate that the rise in obesity is due to increased food consumption, not decreased energy expenditure.
"Hunter-Gatherer Energetics and Human Obesity", PLoS ONE, July 26, 2012
Scientists have known for some time that frailty and vitamin D deficiency separately had harmful health effects on the elderly. But new U.S. research among 4,300 over-60 adults finds that low vitamin D levels increased the risk of death, especially among those already in delicate health. The researchers recommend that older adults be screened for vitamin D, and should maintain healthy levels of vitamin D by consuming fish and milk, and by getting more exercise in the sunshine.
"The effect of vitamin D and frailty on mortality among non-institutionalized US older adults", European Journal of Clinical Nutrition, July 26, 2012
Expectant mothers who take more than the recommended daily dose of iodine put their unborn children at risk of developing congenital hypothyroidism, according to a U.S. study. If left untreated, congenital hypothyroidism – or thyroid hormone deficiency – can cause neuro-cognitive impairments in infants and children. The recommended daily intake of iodine for expectant mothers is 200 – 300 micrograms (µg). But in three cases of infant hypothyroidism the researchers examined, the mothers had ingested 12.5 mg of iodine daily, or 11 times more than the safe upper limit of 1,100 µg. Sources of iodine include nutritional supplements, prenatal vitamins and seaweed.
"Congenital Hypothyroidism Caused by Excess Prenatal Maternal Iodine Ingestion", The Journal of Pediatrics, July 26, 2012
U.S. researchers report that the offspring of pregnant women who eat a low-protein diet are more prone to high blood pressure in adulthood because of the failure of an enzyme that moderates the hormone testosterone. In a study in rats, the researchers found that high maternal testosterone levels – associated with a low-protein diet – are caused by the activity of an enzyme that normally deactivates testosterone. When that enzyme, known as Hsd17b2, isn’t working properly, more testosterone reaches the fetus, boosting susceptibility to adult hypertension. The enzyme ordinarily converts testosterone to the less potent androgen, androstenedione.
"estational Protein Restriction Reduces Expression of Hsd17b2 in Rat Placental Labyrinth", Biology of Reproduction, July 25, 2012
Israeli researchers have discovered a link between adolescent obesity and bladder, urinary tract and colorectal cancers in adulthood. This threat can now be added to the growing list of dangers associated with adolescent obesity, including diabetes, heart disease and joint and muscle pain. Obese children – above the 84th percentile in body mass index – have a 1.42 percent greater chance – a 50 percent higher risk – of adult cancers. The study analyzed data from a longitudinal study of 1.1 million men in the Israeli Defense Forces.
"Measured Body Mass Index in Adolescence and the Incidence of Colorectal Cancer in a Cohort of 1.1 Million Males", Cancer Epidemiology Biomarkers & Prevention, July 24, 2012
Researchers at Cornell University have found that placing edible serving-size markers in tubes of potato chips can help curb overeating. The researchers conducted an experiment in which 96 students divided into two groups were served potato chips in tubes while watching videos in class. Some of the tubes contained chips dyed red. The students who were served tubes with chips dyed red ate 50 percent less than their peers. The researchers concluded that the red chips acted as unconscious “stop signs” that cut the number of chips consumed.
"Red potato chips: Segmentation cues can substantially decrease food intake", Health Psychology, July 24, 2012
A study based on data provided by Dutch pediatricians over three years finds that 67 percent of children with a body mass index associated with obesity had at least one symptom of cardiovascular disease. Fifty-six percent had high blood pressure; 54 percent had high levels of low density “bad” cholesterol; 14 percent had high fasting blood glucose; and one percent already had type 2 diabetes. The authors concluded that there is an urgent need for internationally accepted criteria for defining severe obesity as well as “guidelines for early detection and treatment of severe obesity and [underlying ill health].”
"High cardiovascular risk in severely obese young children and adolescents", Archives of Disease in Childhood, July 24, 2012
Some vegetables and other foods normally considered or marketed as “healthy” – compared to junk foods high in fat, sugar or salt – may actually be detrimental if excessive amounts are eaten, according to a U.S. university dietitian. Worrisome foods include those claimed to be healthy – e.g., “low fat” or “fat free” foods – that may be high in sugar or calories. Vegetables that should be eaten in moderation because they are high in starch include peas, corn and potatoes.
"Is There Such a Thing as Eating Too Many Fruits and Vegetables?", News release, Loyola University Health System, July 24, 2012
A long-term British study involving 23,500 middle-aged and elderly people finds that the risk of pancreatic cancer may be reduced significantly by increasing consumption of antioxidant vitamins C and E and the chemical element selenium. Pancreatic cancer kills about 250,000 people around the world each year. Only three percent of those diagnosed with the disease survive to five years. A weekly intake of selenium in the top 25 percent of consumption cut the risk of developing pancreatic cancer in half. Those whose vitamins C, E, and selenium intake was in the top 25 percent of consumption were 67 percent less likely to develop pancreatic cancer.
"Dietary antioxidants and the etiology of pancreatic cancer: a cohort study using data from food diaries and biomarkers", Gut, July 23, 2012
Although children in the U.S. are drinking less milk these days, a new study finds the drop in consumption is not related to the steep increase in drinking low-nutrition sugary drinks. Milk drinking dropped between 5th and 8th grade, according to researchers who studied the long-term dietary habits of 7,445 students who were kindergartners in a 1998 -1999. Among the same group, consumption of sugary sodas and flavored fruit drinks doubled. But the researchers noted that changes in children's milk and 100-percent-juice consumption were not significantly related to changes in their consumption of sweetened beverages over time. The conclusion? Sweetened beverages did not replace other caloric beverages in children's diets.
"Beverage Displacement between Elementary and Middle School, 2004-2007", Journal of the Academy of Nutrition and Dietetics, July 22, 2012
Medical experts who determine the recommended daily allowance (RDA) of vitamin C are using inappropriate evaluation techniques to come up with faulty conclusions, according to a U.S. review of recent scientific literature. Specifically, the researchers found, the RDA of vitamin C could be doubled – to an optimum 200 mg a day, instead of 75 to 90 mg – to safely saturate cells and tissues for the greatest possible health benefit, they said. The problem is that medical experts insist on evaluating vitamin C in the same way they do pharmaceutical drugs, using phase 3 randomized placebo-controlled trials. This “almost insures they will find no beneficial effect,” the researchers said. “We need to get past that.”
"Authors' Perspective: What is the Optimum Intake of Vitamin C in Humans?", Critical Reviews in Food Science and Nutrition, July 18, 2012
Research has shown that vitamin D insufficiency and obesity are individual risk factors for insulin resistance and diabetes. But new U.S. research shows that when you combine the two, the odds of insulin resistance rise to an even greater degree. Obese individuals in the study who had healthy levels of vitamin D were 20 times more likely to have insulin resistance than the overall study population. But obese individuals who also had low levels of vitamin D were 32 times more likely to have insulin resistance. Further research could help determine whether vitamin D supplements would reduce insulin resistance.
"Joint Effects of Obesity and Vitamin D Insufficiency on Insulin Resistance and Type 2 Diabetes", Diabetes Care, July 17, 2012
An analysis of health data from nearly 133,000 middle-aged and older Chinese men and women found that vitamin E intake from both diet and supplements were associated with a lower risk of liver cancer, the third most common cause of cancer mortality in the world. The association was consistent among participants with and without self-reported liver disease or a family history of liver cancer. "We found a clear, inverse dose-response relation between vitamin E intake and liver cancer risk," the authors wrote. Nuts, seeds, and vegetable oils are among the best natural sources of vitamin E.
"Vitamin Intake and Liver Cancer Risk: A Report From Two Cohort Studies in China", Journal of the National Cancer Institute, July 17, 2012
|