A pediatrician who has looked closely at the scientific evidence says that dehydration is simply not the common problem, not even remotely the global epidemic, some researchers (and water vendors) keep saying it is. Yet people are constantly being told to drink eight glasses of water a day. The truth is that people are hydrated by almost any liquid they drink – beer, coffee, tea, etc. – and an awful lot of foods they eat, including fruits and vegetables. Says Dr. Aaron E. Carroll: “Contrary to many stories you may hear, there’s no real scientific proof that, for otherwise healthy people, drinking extra water has any health benefits.”
"No, You Do Not Have to Drink 8 Glasses of Water a Day", The New York Times, August 24, 2015
The authors of a U.S. study that analyzed data on the relationship between exercise and obesity say there is no doubt physical activity is beneficial to humans, but “there is limited evidence to suggest that it can blunt the surge in obesity.” In other words, they argue, limiting calorie intake, with or without exercise, is the only way to shed pounds. A large number of clinical trials have shown that exercise plus calorie restriction achieves the same weight loss as calorie restriction alone. The key reason? Increasing your physical activity tends to increase your appetite. That leads to eating more food, and gaining – or simply not losing – weight.
"Physical activity does not influence obesity risk: time to clarify the public health message. ", International Journal of Epidemiology, August 20, 2015
Compounds known as resolvins, maresins and protectins formed from oily fish have been shown to reduce inflammation. Synthetic versions of the compounds have been tested successfully in lab dishes and in animals. But a new U.S. study comparing synthetic fish oil compounds found in supplements to those naturally occurring in fish finds that the synthetic versions are not nearly as absorbable or digestible by the human gut as natural versions. That means they are less likely to offer any anti-inflammatory benefits that would reduce the risk of heart disease. After rigorous testing, the researchers “found no evidence” that fish oil capsules play any role in reducing inflammation.
"Bioactive products formed in humans from fish oils. ", Journal of Lipid Research, August 19, 2015
A low rather than a high dose of the antioxidant resveratrol prevents tumor growth in mice and alters metabolic pathways in human tissues, a study by British and U.S. researchers has found. Earlier studies looked at the impact of high doses of resveratrol, a compound found in red grapes and wine, on cancer prevention. This study analyzed the effects of a lower daily dose – the amount of resveratrol found in a large (250 ml, or 8.5 ounce) glass of red wine – compared to a dose 200 times higher. The researchers cautioned that drinking a glass of wine a day will not necessarily prevent cancer. The problem: you can’t separate resveratrol in wine from the alcohol which itself can be cancer-inducing. Much more research is needed, they said.
"Cancer chemoprevention: Evidence of a nonlinear dose response for the protective effects of resveratrol in humans and mice. ", Science Translational Medicine, August 19, 2015
Postmenopausal women whose diet includes a lot of refined carbohydrates are at greater risk for depression, U.S. researchers report. The scientists studied factors such as dietary glycemic index, glycemic load, types of carbohydrates, and instances of depression in survey data compiled among 70,000 women between 1994 and 1998. Higher dietary GI scores and consumption of added sugars and refined grains were associated with increased risk of depression, while dietary fiber, whole grains, vegetables and non-juice fruits were linked to a decreased risk. The findings suggest potential therapeutic strategies for treating depression among post-menopausal women.
"High Glycemic Index Diet as a Risk Factor for Depression: Analyses from the Women’s Health Initiative. ", American Journal of Clinical Nutrition, August 18, 2015
No one disputes the health benefits of vitamin-rich spinach, but a new U.S.study says an extract of the green leafy vegetable delivers an extra health punch: satiety, or a reduced appetite. Researchers studied the impact of thylakoid-rich spinach extract on the satiety, food intake, lipids and glucose of thirty men and thirty women, all categorized as either overweight or obese. Blood tests were taken before breakfast, after extract (Appethyl) consumption, after lunch and later after dinner. Researchers noted a drop not only in hunger but also in the desire for salty. The findings suggest that taking thylakoids might be useful for people with high blood pressure and associated weight problems.
"Acute Effects of a Spinach Extract Rich in Thylakoids on Satiety: A Randomized Controlled Crossover Trial. ", Journal of the American College of Nutrition, August 18, 2015
Diets that restrict fat consumption are much more effective at reducing overall body fat, U.S. researchers have found in a small clinical study. Nineteen obese adults lived in a metabolic ward for two 2-week periods. Researchers monitored and controlled every bite of food they ate. In each period they ate either a carb-restricted diet or a fat-restricted diet. Measurements of how much fat each participant ate and burned were taken, and the data were used to calculate the rate of body fat loss. Body fat lost with dietary fat restriction was greater compared with carbohydrate restriction, even though more fat was burned with the low-carb diet. The researchers cautioned, for a variety of reasons, against making sweeping conclusions about how to diet from the study.
"Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity. ", Cell Metabolism, August 14, 2015
Researchers, nutritionists and even governments have bought into the hypothesis that skipping breakfast leads to a waterslide-fast descent into obesity. The notion probably gained traction because many scientists relied heavily on observational studies linking breakfast skipping to weight gain, ignoring evidence from randomized controlled studies. Researchers at a New York City hospital, however, recently conducted a small clinical trial. Three groups of participants ate either a bowl of oatmeal, a bowl of cornflakes, or nothing at 8:30 every morning for four weeks. The only group that lost weight by the end of the study was the group that skipped breakfast. The researchers hope their findings might have an impact on upcoming federal nutritional guidelines.
"The science of skipping breakfast: How government nutritionists may have gotten it wrong", The Washington Post, August 10, 2015
Using data compiled from half a million people, Chinese scientists conducted an observational study that found that regularly eating spicy foods reduces the risk of death from cancer, ischemic heart disease and respiratory disease. Earlier studies had shown that fresh chilies, which contain capsaicin, have anticancer, anti-inflammatory and antihypertensive effects. The researchers followed a total of 487,375 participants aged 30 to 79 who completed a questionnaire about their health and consumption of spicy foods, red meat, vegetables and alcohol. During follow up, frequent consumption of spicy food was linked to a 14 percent reduced risk of death.
"Consumption of spicy foods and total and cause specific mortality: population based cohort study", The British Medical Journal, August 04, 2015
Americans are not only not eating enough fiber, they’re not eating enough different types of fiber, according to U.S. researchers. Proper daily fiber intake -- 38 grams for men, 25 for women – regulates the digestive system and helps control cholesterol, blood pressure, glucose, insulin and excess weight. To get the right amount of fiber, people should eat the recommended quantities of fruits and vegetables. But they should also expand beyond plant-based fiber sources, to fiber that has been added to food in the manufacturing process. Some examples include fiber-fortified bread, cereals, yogurt and pasta.
"Consumers should seek a variety of fiber sources to get the maximum health benefits", News release, symposium presentation at IFT15: Where Science Feeds Innovation, July 28, 2015
Scientists have been accumulating evidence for some time that excessive time spent TV viewing, automobile commuting, or sitting at home or on the job – i.e., sedentary behavior – is linked to adverse health outcomes. But U.S. researchers who analyzed health survey data on 4,910 adults found that sitting and doing nothing was not linked to poorer diets. They did find a significant correlation between physical activity and better overall diet quality, and concluded that physical activity should be encouraged along with adherence to dietary guidelines. But they suggested that sedentary behavior and dietary quality should be targeted independently.
"Accelerometer determined sedentary behavior and dietary quality among US adults. ", Preventive Medicine, July 25, 2015
A U.S. research team that analyzed national survey data and information from the USDA determined that Americans will buy organic broccoli from American or foreign suppliers but they’re willing to pay a significant premium for organic American broccoli. Packages of organic broccoli must label them as such, but they also must show a “country-of-origin” label. This has confused consumers because they’re not sure if the overseas broccoli meets USDA organic standards. Americans will pay as much as $1 more a pound for U.S. organic broccoli than for broccoli from China and Mexico, and 32 cents more a pound for broccoli from Canada.
"Consumers’ preferences for fresh broccolis: interactive effects between country of origin and organic labels. ", Agricultural Economics, July 25, 2015
U.S. researchers have developed a way to assess beverage intake and correlate it to health status. The Healthy Beverage Index (HBI), based on dietary data from 16,000 adults, takes into account 10 factors, such as total energy from beverages and total fluid requirements. It also recommends limits for subgroups, such as low-fat milk, fruit juice, and alcohol. Some components of the HBI are weighted more heavily because they contribute to good health. Water, for example, should constitute at least 20 percent of total fluid intake. The data were correlated with risk factors such as obesity/overweight, hypertension, high fasting insulin, etc. The sample population was assigned scores ranging from 0 to 100. The higher the score, the better the adherence to beverage guidelines and a healthier beverage intake pattern in both men and women. The average HBI score was 63±16.
"The Healthy Beverage Index Is Associated with Reduced Cardiometabolic Risk in US Adults: A Preliminary Analysis", Journal of the Academy of Nutrition and Dietetics, July 24, 2015
A clinical trial involving 14 healthy males found that drinking beet juice for 15 days lowered their blood pressure and dilated their blood vessels while at rest or exercising. In addition, the nitrate-rich juice helps the heart consume less oxygen during exercise, increasing endurance. The U.S. and Korean researchers concluded that exercise can be "performed at a given workload for a longer period of time before the onset of fatigue" when regularly drinking beet juice.
"Effects of Chronic Dietary Nitrate Supplementation on the Hemodynamic Response to Dynamic Exercise. ", American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, July 22, 2015
A study in mice by U.S. scientists shows that a soybean oil-rich diet is much more likely to induce obesity and other pre-diabetic symptoms than coconut oil or fructose-rich foods and beverages. Four groups of animals ate different diets, each containing 40 percent fat and the same number of calories. One diet was high in coconut oil, another had equal amounts of coconut oil and soybean oil (roughly the equivalent of the amount in the American diet). Two diets included added fructose. Mice on the high soybean oil diet showed increased weight gain, larger fat deposits, diabetes and insulin resistance, compared to the coconut oil diet. Mice on the fructose diet had less severe metabolic effects, but more negative effects in the kidney and symptoms of inflammatory bowel disease.
"Soybean Oil Is More Obesogenic and Diabetogenic than Coconut Oil and Fructose in Mouse: Potential Role for the Liver. ", PLoS ONE, July 22, 2015
Research has associated the powerful polyphenol antioxidant resveratrol, found in red wine, with a reduced risk of heart disease despite a high-fat diet. Now U.S. researchers have found that resveratrol, along with the polyphenol quercetin, may also prove to be a potent anti-cancer treatment. They developed a system to make the two water soluble and thus injectable into the blood stream. Levels in the body would thus be much higher than by eating the right foods or taking supplements. The two compounds appear to reduce the cardiac toxicity of the widely used cancer drug Adriamycin, which unfortunately can only be used for a limited time in humans. Administering the two polyphenols at the same time as Adriamycin might make it safer and increase its effectiveness.
"Combinatorial resveratrol and quercetin polymeric micelles mitigate doxorubicin induced cardiotoxicity in vitro and in vivo. ", Journal of Controlled Release, July 16, 2015
A U.S. scientist who analyzed eight years of data from a national health survey reports that Americans who eat at fast food and full service restaurants generally consume 200 more calories a day, compared to eating at home. In addition, they tend to take in more cholesterol, sodium, fat, and saturated fat. Restaurant diners tend to take in more healthy nutrients (e.g., certain vitamins, potassium and omega-3 fatty acids) than at-home or fast food diners, but they also also consume a lot more sodium and cholesterol. Fast food adds an average of 300 milligrams of sodium to the daily intake, while restaurant food adds 412 milligrams.
"Fast-food and full-service restaurant consumption and daily energy and nutrient intakes in US adults", European Journal of Clinical Nutrition, July 09, 2015
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The New York Times, August 13, 2015
Live Science, August 05, 2015
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