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A Swedish study has found that low carbohydrate/high fat diets help short term weight loss, but the loss is not maintained over the long term. In fact, the diet increases blood cholesterol, which has a major impact on risk of cardiovascular disease. The study looked at 25 years of data from a regional and national dietary intervention to reduce fat intake. The intervention decreased cholesterol levels. The program then switched to a popular high fat/low carbohydrate diet that, in turn, raised cholesterol levels. Body mass index (BMI) increased over the 25 years, regardless of either diet; both the increase in BMI and cholesterol levels increased cardiovascular risk.
"Associations among 25-year trends in diet, cholesterol and BMI from 140,000 observations in men and women in Northern Sweden", Nutrition Journal, June 10, 2012
A U.S. study using functional magnetic resonance imaging (fMRI) sheds light on why sleep-restricted individuals find unhealthy foods more attractive and rewarding. fMRI of the brains of 25 normal-weight men and women showed that the sight of unhealthy food during a period of sleep restriction activated reward centers in the brain that were less active when participants had adequate sleep. Researchers said food intake data from the study showed that participants ate more overall and consumed more fat after a period of sleep restriction compared to regular sleep. “The brain imaging data provided the neurocognitive basis for those results," they said.
"Sleep restriction increases the neuronal response to unhealthy food stimuli", Presentation, annual meeting of the Associated Professional Sleep Societies, June 10, 2012
Lack of sleep damages the areas of the brain where decisions are made about eating healthy or unhealthy foods, a University of California researcher reports. Graduate student Stephanie Greer says her findings may explain the connection between sleep deprivation and obesity. For the study, functional magnetic resonance imaging (fMRI) was used to examine the brains of 23 healthy adults after a normal night’s sleep and a night of sleep deprivation. Scan results showed that sleep deprivation significantly impaired brain activity in the frontal lobe, a region critical for controlling behavior and making complex choices, such as the selection of food to eat.
"Sleep deprivation disrupts human brain reactivity in response to food desire", Presentation, annual meeting of the Associated Professional Sleep Societies, June 10, 2012
A study by U.S. and Italian researchers finds that people who have significantly restricted their caloric intake for an average of seven years have healthier, younger hearts. The researchers studied 22 people who restricted their calorie intake but ate healthy diets, and 20 people who ate a standard Western diet. Average age was about 51. The study focused on changes in heart rate variability, a measurement that tells a lot about the way the autonomic nervous system affects the heart. In the study, those who restricted their calorie intake over long periods of time had higher heart rate variability, and thus a reduced risk of cardiovascular disease.
"Caloric restriction may reverse age-related autonomic decline in humans", Aging Cell, June 06, 2012
A 14-month U.S. study based on interviews with 1,000 smokers aged 25 and older found that those who quit smoking tended to consume more fruits and vegetables. Smokers who consumed the most fruit and vegetables were three times more likely to be tobacco-free for at least 30 days at follow-up 14 months later than those consuming the lowest amount of fruits and vegetables. The held true even when adjustments were made to take into account age, gender, race/ethnicity, education, household income and health orientation. Though the researchers acknowledged that their findings from telephone interviews were “observational” only, they said they "may have identified a new tool that can help people quit smoking."
"A Longitudinal Evaluation of Fruit and Vegetable Consumption and Cigarette Smoking", Nicotine & Tobacco Research, June 06, 2012
A multinational team of researchers has determined that an ingredient in milk – nicotinamide riboside – boosts the activity of the gene SIRT1, which benefits metabolism and longevity. In a mouse study, animals that took nicotinamide riboside in fairly high doses while eating a high-fat diet burned more fat and were protected from obesity. Thanks to a boost in endurance, they also become better runners. The researchers suggested that the milk substance seems to offer the same benefits as resveratrol, and could help in achieving slimmer waistlines and perhaps longer lives.
" The NAD precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet induced obesity", Cell Metabolism, June 05, 2012
Staying healthy needn’t be a complicated affair, according to five multinational studies. In reviews of scientific literature, researchers found, for example, that frequently eating fresh fish reduces the risk of colorectal cancer, one of the deadliest forms of cancer. A meta-analysis of 14 studies found that unconventional smoking cessation aids, like acupuncture and hypnotherapy, were a significant help in quitting smoking. Other simple steps toward a healthier life: regular teeth cleaning to improve cardiovascular health and using low-dose aspirin to reduce cancer risk.
"Fish Consumption and Colorectal Cancer Risk in Humans: A Systematic Review and Meta-analysis", The American Journal of Medicine, June 04, 2012
A 2.5-year study of middle-age and older postmenopausal women found that soy supplements had no significant impact on overall mental abilities. The study’s lead author said there were no large effects, either positive or negative, on cognition. Soy and soy-based products contain estrogen-like compounds called isoflavones; some women take soy supplements as an alternative to estrogen s a postmenopausal therapy. The researchers did note that women in the study who took soy supplements showed a greater improvement in visual memory (memory for faces). This could be important, they noted, but "the finding needs to be replicated in future studies."
"Long-term soy isoflavone supplementation and cognition in women: A randomized, controlled trial", Neurology, June 04, 2012
U.S. researchers have found that reduced temperatures activate brown fat to burn calories and reduce obesity. The researchers also found that the chemical ephedrine, used as a decongestant and bronchodilator and lately as a weight loss drug, has no impact on brown fat, though it does burn calories, albeit with some side effects like increased blood pressure. For the study, ten people received ephedrine injections or a placebo, or wore cooling vests. Both methods burned the same number of calories, but the cooling vest activated brown fat with fewer side effects.
"Cold but not sympathomimetics activates human brown adipose tissue in vivo", Proceedings of the National Academy of Sciences, June 04, 2012
An Australian study involving 2,013 people with high blood pressure and pre-diabetic metabolic syndrome found that consumption of dark chocolate lowers both blood pressure and cholesterol. Participants in the study had no history of cardiovascular disease and were not receiving anti-hypertensive therapy. Researchers said daily intake of 100 g (3.5 oz.) of dark chocolate reduced cardiovascular events by 85 in a population of 10,000 over ten years. To be effective, the chocolate needs to be dark and at least 60-70 percent cocoa, or formulated to be enriched with polyphenols.
"The effectiveness and cost effectiveness of dark chocolate consumption as prevention therapy in people at high risk of cardiovascular disease: best case scenario analysis using a Markov model", British Medical Journal (BMJ), May 31, 2012
Supplementing the diets of older people with DHA – an omega-3 fatty acid found in fish like salmon and anchovies – prevents the accumulation of a toxic molecule in the retina that causes vision loss, Canadian research has found. The toxin (A2E, a constituent of the toxin lipofuscin) doubles as people age, but the researchers found in lab tests with mice that DHA (docosahexaenoic acid) stopped the accumulation of the toxin. The researchers have launched a clinical study involving people with age-related macular degeneration to see if certain genetic markers for the disease will respond better to increasing amounts of DHA in their diets.
"Dietary Docosahexaenoic Acid Supplementation Prevents Age-Related Functional Losses and A2E Accumulation in the Retina", Investigative Ophthalmology & Visual Science, May 30, 2012
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