The consumption of cheese and meat is as bad for the heath as smoking for middle-aged adults, a new study finds.
The next time you pick up that large piece of chicken wing or a big cheese cube, remember it's as bad as smoking an entire cigarette. Yes! Researchers of a new study found that consuming a high protein diet during middle age increases chances of pre mature death by two folds. Additionally, the chances of dying from cancer are higher by four times.
"There's a misconception that because we all eat, understanding nutrition is simple. But the question is not whether a certain diet allows you to do well for three days, but can it help you survive to be 100?" said corresponding author Valter Longo, in a press statement.
Researchers highlight that proteins attained from animal sources like milk, meat and cheese can be more harmful to middle-aged adults.
The current study is not debunking the idea of popular protein-rich diets like Paleo and Atkins because the right amount of proteins a person should consume a day remains a controversial topic. However, this is the first study that looks into how the biology of the human body changes, consequently changing its nutritional requirements. What's good for you at one age may be damaging at another.
The new study was conducted on 2,253 people whose levels of the growth hormone IGF-I were recorded directly. Findings of the study revealed that for every 10 ng/ml increase in IGF-I, those on a high-protein diet were 9 percent more likely to die from cancer than those on a low-protein diet. The findings were in line with past research associating IGF-I levels to cancer risk. Middle-aged adults who consume high-protein diets are also several times more likely to die of diabetes.
The main responsibility of proteins is to control the growth IGF-I, a hormone that helps the body grow. However, previous studies have linked excessive proteins to cancer susceptibility. The findings of this new study support recommendations from several leading health agencies to consume about 0.8 grams of protein per kilogram of body weight every day in middle age.
However, the same doesn't apply for people aged 65 and above. After reaching 65, the IGF-I level in the body decreases, leading to potential frailty and muscle loss. Researchers found that a high protein diet can actually prove to be beneficial for people above 65 years of age.
"The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality, through a process that involves regulating IGF-I and possibly insulin levels," said co-author Eileen Crimmins, the AARP Chair in Gerontology at USC. "However, we also propose that at older ages, it may be important to avoid a low-protein diet to allow the maintenance of healthy weight and protection from frailty."
Additionally, researchers also found that plant-based proteins, such as those from beans, don't have the same mortality effects as animal proteins.
The study was funded by NIH/NIA grants and a USC Norris Cancer Center pilot grant. Findings were published online in Cell Metabolism.
