Every week, we’re bringing you a roundup of the latest health and wellness news to hit the wire. This week, we look at controversial new research that suggests pumping the brakes on red meat may be premature, in addition to other studies that show how nuts can help keep pounds at bay and how overtraining strains the brain.

A green light to eat red meat?

A food fight is brewing over new research published in the Annals of Internal Medicine, which concluded that the years-old advice to cut back on red meat and processed food to reduce your risk of chronic diseases such as heart disease and cancer is not backed by good scientific evidence.

The health benefits from eating less beef and pork are small, researchers concluded, with their advantages so faint that they can only be discerned when looking at large populations and are not sufficient to tell individuals to cut back or eliminate meat.

“The certainty of evidence for these risk reductions was low to very low,” Bradley Johnston, Ph.D., an epidemiologist at Dalhousie University in Canada and leader of the international group publishing the research, told The New York Times.

The new analysis is among the largest such evaluations attempted and could sway how scientists conduct nutrition research and issue future dietary guidelines.

However, it was met with staunch criticism by public health researchers from the American Heart Association, the American Cancer Society and the Harvard T.H. Chan School of Public Health, who argued that the research ignored a vast body of randomized studies showing that compared with plant sources of protein, red meat increases blood levels of LDL (bad) cholesterol and triglycerides, which consistently predict a higher risk of cardiovascular disease.

The report was based on three years of analysis by a group of 14 researchers in seven countries. The groups reviewed 61 articles reporting on 55 populations with more than 4 million participants. They also looked at randomized trials linking red meat to cancer and heart disease, as well as 73 articles that examine links between red meat and cancer incidence and mortality. In each study, the scientists found the links between red meat, disease and death were small and the quality of the evidence was low to very low.

The news raises more doubt about dietary guidelines, which have long urged people to eat less red meat.

While consumption of red meat has declined since the 1970s, replaced largely by poultry, researchers say their surveys show that most omnivores are unwilling to give it up completely.

For its part, the American Cancer Society said that it still believes red meat is a risk, just one that this particular group believes is “acceptable for individuals.”

Nuts to keep the pounds away

Just a small handful of nuts a day—about a dozen almonds or 10 walnuts—could slow the weight gain that comes with age, according to a new study in BMJ Nutrition, Prevention & Health covered by NPR.

Researchers looked at the diet of more than 280,000 adults taking part in three long-term research studies, and they asked participants how often they ate a serving of nuts to see what effect the snack had on weight gain.

On average, U.S. adults put on 1 pound of weight every year, said Deirdre Tobias, D.Sc., co-author of the study. However, the people who most consistently ate nuts gained on average only about half a pound a year.

Of course, some of that difference can be attributed to the participants eating nuts instead of other less healthy snacks such as pastries, crackers and donuts. And the protein, fiber and healthy fat take longer to digest, keeping people feeling full longer.

Overall, they found a consistent nut intake of half an ounce a day was associated with a 23 percent lower risk of putting on 10 or more pounds or becoming obese over four years.

Body tired, brain tired?

Endurance sports are generally good for your health, but overdoing it can have adverse effects on your brain, according to a new report in Cell Biology covered by ScienceDaily.

When researchers imposed an excessive training load on triathletes, they showed a form of mental fatigue, including reduced activity in a portion of the brain important for making decisions. They also acted more impulsively, favoring immediate rewards instead of bigger ones that would take longer to achieve.

The study suggests that both mental and physical effort require cognitive control and that this process works overtime in endurance athletes to help control the automatic process that would make them stop when muscles or joints hurt.

 

Photo credit: amirali mirhashemian, Unsplash