This article originally appeared on Live in the Now.
According to a surprising new study, people who wouldn’t dream of harming their health by smoking may be increasing their risk of disease and death just as much by consuming a high-protein diet. They also found consuming a low-protein diet in middle age appears to be protective against cancer.
Scientists involved in the study, published in Cell Metabolism, knew that eating a hamburger or other source of animal protein raises levels of the growth hormone IGF-1, which is a substance linked to cancer and other age-related diseases. Because of the harmful effects of IGF-1, they sought natural means of lowering it. They postulated that simply reducing protein in the diet might reduce the levels of the hormone along with the diseases associated with it. Searching to find the answer, they analyzed data gathered from 6,381 adults. The findings supported their postulation.
Harmful Effects of High-Protein Diets
People whose diets were plentiful in meat and dairy products had a four-fold greater risk of dying from cancer than those on a low-protein diet, a risk increase comparable to that of smoking. Additionally, they had a 74 percent greater risk of dying from any cause and a much greater risk of developing diabetes compared to those on a low-protein diet. While a high-protein diet helps people lose weight, it appears that the price of this weight loss is far too costly in terms of detrimental health consequences.
Beneficial Effects of Low-Protein Diets
To explore the effects of a low-protein diet, researchers studied mice that had been injected with cancer cells to produce melanoma and breast cancer. Unexpectedly, the findings showed this diet was able to stop the cancer from progressing in some of the mice and even prevent the cancer from appearing at all in a portion of the others. Additionally, the low-protein diet reduced levels of IGF-1, a benefit the researchers attributed to the protective effect against cancer. These results led to the conclusion that a low-protein diet may have value in the prevention and treatment of cancer.
What About Plant-Based Protein?
The scientists also found adverse effects of a diet high in plant protein, such as beans; but they weren’t as harmful as those from animal protein. People who consumed diets high in plant protein were three times as likely to die of cancer compared with those who consumed a low-protein diet. However, they didn’t have an increase in their overall death rate.
The Age Difference
At the age of 64, a person’s level of IGF-1 starts to decline, a condition that may lead to weight loss and an increase in frailty. The researchers advised against a low-protein diet for this age group.
What Is the Recommended Protein Intake?
Author Valter Longo said protein should comprise 9 to 10 percent of your daily caloric intake. This would equate to 35 grams of protein for a person weighing 100 pounds and 76 grams of protein for a person weighing 200 pounds. He advises lowering intake of all dietary protein, especially that from animal sources. According to the USDA, a 3-ounce serving of chicken contains 22 grams of protein.