High-protein diets look more harmful than not

A few years ago, it seemed that everyone was talking about the Atkins diet, a low-carb and high-protein approach to losing weight. Protein was touted as the dieter’s holy grail: It would lead to weight loss while still maintaining muscle mass. The Atkins diet was even voted one of the best diets of 2014 by U.S. News and World Report. New scientific data, however, could make high protein diets a thing of the past.

A recent study in Cell Metabolism showed that individuals who ate more protein were 74 percent more likely to die during the study period, especially of diabetes, than those who ate less protein.

The study also found that protein helps regulate the growth hormone IGF-I. This regulation is necessary, but too much regulatory activity can lead to cancer. After individuals turn 65, they have less and less IGF-I, causing muscles to deteriorate. For this reason, researchers have found that it is important to have a diet that is low in protein during middle age in order to lower chances of cancer. After middle age, it is best to ramp up protein intake to prevent physical weakness.

But what kind of protein are we talking about? Scientists found that proteins in plants did not have the same negative effects of animal proteins. This suggests that it is important to get more protein from plants than from other sources.

Such advice appears to be sorely needed in America, where the average person consumes nearly twice the recommended protein amount. The optimal amount of protein for those who are middle aged can be obtained by calculating 0.8 grams of protein per kilogram of body weight.

Diets that are considered low in protein contain 10 percent protein at most, whereas those moderate in protein contain less than 20 percent, and those high in protein contain greater than 20 percent protein. The study focused on 6,318 middle-aged adults who ate varying amounts of protein. Surprisingly, adults with a diet consisting of a moderate amount of protein had a threshold greater chance of dying from cancer than those who had low protein diets. When individuals changed from a moderate to low protein diet, they were an impressive 21 percent less likely to have early deaths. Also, more IGF-I corresponded to a significantly higher chance of dying with cancer for those on high protein diets than those on low protein diets.

A similar experiment was carried out among mice, and scientists discovered that mice who ate less protein suffered less from cancer. Furthermore, if the mice did develop cancer, they had tumors nearly half the size of those who ate more protein.

With so much recent research in the field of nutrition, it can be difficult to choose what recommendations to adopt when we decide on our meals each day, and there are many other factors at play besides protein content. By consuming low levels of protein, though, you can diminish the chance that precancerous cells will lead to cancer.