An report in this week’s Proceedings of the National Academy of Sciences calculates several environmental costs of raising cows for meat and milk, poultry and pork for meat, and chickens for eggs. According to the report, per calorie of food that we consume, dairy, poultry, pork, and eggs have similar environmental costs. Compared with their average, beef production generated five times more greenhouse gases, needed six times more fertilizer and 11 times more irrigation water, and used 28 times the land. The same four costs for growing potatoes, wheat, and rice were two-fold to six-fold lower than the nonbeef foods in land use, greenhouse gas emissions, and fertilizer use, and about the same for irrigation water.
Every day, millions of Americans use the Nutrition Facts labels on food packages to make healthy choices. The U.S. Food and Drug Administration has recently proposed changes to make the labels even more useful. It’s an important move that could help curb the skyrocketing number of Americans with type 2 diabetes, osteoarthritis, and other weight-related conditions. The proposed new label will list information about added sugars, update daily values for sodium and dietary fiber, list the amount of potassium and vitamin D, and remove the “Calories from Fat” category while continuing to list types of fat. For foods that come in larger packages but could be consumed in one sitting, manufacturers would have to use a two-column label showing calorie and nutrition information for both a single serving and the entire package. These changes are a step in the right direction, but don’t go far enough with sugar, ingredient listing, and nutrient claims.
A study published in this month’s Journal of Nutrition suggests that drinking caffeinated beverages, having the occasional alcoholic drink, and eating a healthy diet may help preserve memory and thinking skills long into old age. In particular, foods that are part of the Mediterranean diet—fruits, vegetables, nuts, fish, olive oil, and whole grains—show promise for preserving memory and preventing Alzheimer’s and other forms of dementia.
A new study that linked eating more protein to lower risk of stroke isn’t the last word on the subject. But that doesn’t make dietary protein any less vital, especially in older adults who are at greater risk for malnutrition and illness. How much protein is enough? Current guidelines for adults of any age recommend 0.8 grams of protein per kilogram of body weight. Do older people need more protein than younger ones? That’s still an open question.
Resveratrol, an antioxidant found in red wine and certain foods, has been touted as a natural way to slow aging and fight cancer, obesity, heart disease, and diabetes. As promising as it sounds, we don’t really know how resveratrol affects humans, since most studies have been conducted on animals and microbes. A study out this week from the Johns Hopkins University School of Medicine found no link between consumption of resveratrol from food and rates of heart disease, cancer, and death in a study of older men and women living in Italy’s Chianti region. The disappointing results don’t mean that resveratrol and other molecules like it won’t help extend the lifespan or protect against the development of aging-related diseases. Higher doses may be needed to do that. What’s needed now are trials to determine if taking high-dose resveratrol supplements is safe.
Fish and shellfish are great sources of lean protein, and many types are rich in heart-healthy omega-3 fatty acids. But there’s a catch: some species of fish contain worrisome amounts of methylmercury, a toxin that’s especially dangerous to developing brains. That’s why women who are or could become pregnant and young children shouldn’t eat high-mercury fish such as swordfish, shark, king mackerel, and tilefish. A new study hints that eating too much—or the wrong kind—of salmon and tuna can also boost mercury levels. But the study also offered reassurance: 95% of the nearly 11,000 people surveyed, including those who ate fish often, had blood mercury levels in the safe zone.
A sugar-laden diet boosts the chances of dying of heart disease even among people who aren’t overweight. So says a major study published online this week in JAMA Internal Medicine. Over the course of the 15-year study, individuals who took in 25% or more of their daily calories as sugar were more than twice as likely to die from heart disease as those whose diets included less than 10% added sugar. Overall, the odds of dying from heart disease rose in tandem with the percentage of sugar in the diet—and that was true regardless of a person’s age, sex, physical activity level, and body-mass index (a measure of weight). Sugar-sweetened beverages such as sodas, energy drinks, and sports drinks are by far the biggest sources of added sugar in the average American’s diet. They account for more than one-third of the added sugar we consume as a nation. Other important sources include cookies, cakes, pastries, and similar treats; fruit drinks; ice cream, frozen yogurt and the like; candy; and ready-to-eat cereals.
A landmark clinical trial done in Spain, known by the acronym PREDIMED, continues to support the health benefits of following a Mediterranean-style eating pattern. Last year, PREDIMED researchers reported that Mediterranean-style eating—rich in fruits, vegetables, and healthy plant oils—prevents heart attacks, strokes, and death from heart disease. This week in The Journal of the American Medical Association, they report that a healthy Mediterranean-style diet can also help prevent peripheral artery disease (PAD), a form of “hardening of the arteries.” It’s an important finding, since as many as 12 million Americans have PAD. It can cause leg pain when walking that goes away with rest (called intermittent claudication); a weakening of the aorta, the main pipeline that delivers blood to the body; pain after eating; erectile dysfunction; and other problems.
Diverticulitis, an unpleasant condition that occurs when tiny pouches inside the large intestine become inflamed, can cause intense lower abdominal pain, diarrhea, constipation, a fever, and sometimes a good deal of rectal bleeding. Following a liquid diet for a while can help treat it, but antibiotics, and sometimes even surgery, may be needed. A new study in JAMA suggests that these treatments may be overused.
University of Michigan researchers reviewed the results of 80 studies of diverticulitis and its treatment. While the team agreed that antibiotic use and surgery are sometimes necessary, it concluded that there should be a lesser role for aggressive antibiotic or surgical intervention for chronic or recurrent diverticulitis than was previously thought necessary. Some studies suggest that exercising, controlling weight, and eating a high-fiber diet can prevent diverticular disease. It can also bring relief from constipation, better cholesterol control, and make for more filling meals. Adults should get 25 to 30 grams of dietary fiber every day. It’s best to get it from high-fiber foods, such as beans, whole grains, vegetables, and fruits. Some people need a fiber supplement.
Could tea be a health beverage? Eleven new studies in the American Journal of Clinical Nutrition highlight the many ways that tea may improve health: Tea drinking appears to lower the risk for heart disease and stroke, may strengthen bones, and appears to improve mood, concentration, and performance. Natural compounds called polyphenols in tea might protect against several cancers, including those of the prostate, GI tract, lungs, breast, and skin, and may also increase metabolism and promote weight loss. Those possible benefits apply to tea, not tea extracts condensed into pills. If you’re a tea drinker, enjoy your favorite brew with the added satisfaction that it may be good for your health. If you aren’t, there’s no reason to start.