Consumption of red meat — beef, pork and lamb — can be part of a healthy diet, according to the USDA nutrition recommendations. But as with many things, you might want to enjoy it in moderation.

Consumption of just two servings of red meat weekly is linked to a higher risk of developing type 2 diabetes, researchers report today in the American Journal of Clinical Nutrition. Conversely, lowering red meat intake by substituting plant-based protein sources like beans and nuts was associated with a lower risk of the disease.

The findings, based on data from 216,695 participants followed for up to 36 years, are not surprising. But they confirm considerable previous research indicating that while red meat has nutritional value, our bodies can take only so much before heart disease, cancer and other chronic diseases become more likely.

"It's okay to eat meat, but limit the amount and choose healthier types to reduce the risk of heart disease," Stephen Hu, MD, a cardiologist at Scripps Clinic Carmel Valley, said in a previous overview of research on the topic. "Eating too much red meat comes with health risks and is not part of a healthy diet. Red meat is high in cholesterol, saturated fats and sodium. It should be eaten in a limited fashion."

Stark statistics

The details from the new study:

• Each additional daily serving of unprocessed red meat was linked to a 24% higher risk of type 2 diabetes.
• Each additional daily serving of processed red meat was linked to a 46% higher risk.
• People who ate the most red meat had a 62% higher risk compared with those who ate the least.
• Substituting one daily serving of plant-based protein for red meat lowers the risk of type 2 diabetes by 20%.

These associations don't prove cause-and-effect, and they are generalized to the study population — your mileage may vary, and many other factors can affect health. Regular physical activity, good sleep and a healthy diet overall can greatly up the odds of a long life—and a healthy, productive, enjoyable one.

But the take-home message is clear:

"Given our findings and previous work by others, a limit of about one serving per week of red meat would be reasonable for people wishing to optimize their health and well-being," said the study's senior author, Walter Willett, MD, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.

A largely avoidable disease

About 10% of Americans have diabetes, and 90% or more of them have type 2 diabetes, which is a largely preventable condition that usually develops later in life and is caused, in many cases, by unhealthy lifestyles and behaviors. Rates are higher among many minority groups and seniors, and prevalence has soared in recent decades in the US and globally. Diabetes is the seventh leading cause of death in the US.

Diabetes is often, though not always, accompanied by obesity, whose rates are also rising. Diet is a key factor in both conditions. Among the prevention strategies often cited by exerts to help ward off these and other chronic conditions: Avoid highly processed food, whether meat, cereal, boxed or frozen items, or otherwise, given all the hidden salt, sugar and unpronounceable ingredients that contribute to weight gain and poor heart health.

Other studies have found processed meat — hot dogs, salami, bacon and the like — to be much worse for health than lean cuts of unprocessed meat.

That doesn't mean you should eat T-bones with abandon.

"Our findings strongly support dietary guidelines that recommend limiting the consumption of red meat, and this applies to both processed and unprocessed red meat," said the new study's first author, Xiao Gu, PhD, a research fellow in nutrition at Harvard T.H. Chan.

The message seems to be getting across. As I coincidentally wrote earlier this week, Americans are already eating less beef, per person, than in past decades, though the reasons may include factors beyond diet.

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