Protein-Heavy Diets Deadly For Middle-aged Adults

High protein diets, particularly if that protein comes from meat, may be lowering the lifespan of middle-aged adults, according to a recent study.

The study, published in Cell Metabolism, investigated the effect a high protein diet has on lifespan and quality of life.

According to the study, over 6800 American adults were surveyed in a U.S. national survey that focuses on health and diet. After a significant wait period, answers and medical histories were then compared, allowing researcher to drawn some alarming conclusions.

Individuals 50 to 65 years old with protein-heavy diets, the researchers found, were four times more likely to die from cancer or diabetes and twice as likely to die from any health issue at all within the next two decades. Those who consumed moderate amounts of protein also showed increased risks of cancer, but not nearly as high.

Some in the scientific community are likening this observation to the adverse effects of smoking, where heavy smoking habits contribute not only to a significant rise in cancer risk, but a rise in risk of death by many other conditions that lead to death as well.

However, unlike smoking, the researcher found that past the age of 65, the adverse effects of a high protein diet practically reverse. In seniors, a high protein intake was linked to a 60 percent reduced risk of dying from cancer and a nearly 30 percent risk of dying from any ailment.

Most interestingly, both negative and positive attributes of a high protein diet seemed to disappear all together when the course of high protein intake was primarily plant-based (IE- peanuts).

While researchers didn't attempt to explain this phenomenon, aiming only to provide evidence of their occurrence, they did explain that high amounts of protein intake (at least 20 percent of an individual's caloric intake came from a protein source) have been linked to a restriction of growth hormone activity in organisms in past studies. This indicates that growth hormones may have a significant influence over mortality.

Of course, more research must be conducted to find the causes of these associations.

The study was published in Cell Metabolism on March 4.