What food should we eat and how much? We are often not sure, and this has always been one of the main problems of healthy nutrition. Every day science is coming up with new findings and researches related to the food intake, and sometimes, these findings can be disturbing and shocking as it is with this new study.
Researchers have found that eating foods rich in animal proteins pose a great mortality risk, the risk one can compare to smoking. A study published in Cell Metabolism revealed that a diet based on animal proteins, such as cheese, meat and milk, is linked to early death in general, especially for middle-aged people, and even 74 percent of people are more likely to die of any cause (cancer, diabetes) in comparison to those who prefer low-protein diets. So, how much proteins should we eat then?
Researchers explained that due to the biological changes that occur as we age, the foods that once was good for us may pose a great risk later in life. Proteins regulate the growth hormone IGF-I, that is linked to cancer susceptibility, and these levels drop off significantly after age 65, and while intake of high protein food is very harmful, proteins also protect older adults (over 65).
“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. 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“, said co-author Eileen Crimmins.
On the other hand, plant-based proteins do not have the same mortality effects as animal-based proteins, and the scientists suggest cutting down the protein intake, though not extremely. So, according to researchers, what is a high-protein diet? The diet that derives at least 20 percent of calories from proteins, both plant-based and animal-based proteins, is a high-protein diet, while the diet that includes less than 10 percent protein is a low-protein diet.
The so called “moderate” protein diet, which includes 10-19 percent of calories from proteins, can also have detrimental effects for middle-aged people, according to the study. In the study, an average protein intake for 6,318 adults (over the age of 50) was 16 percent of total daily calories (about two-thirds of animal protein), and those adults were still three times more likely to die of cancer. The good thing is that a small decrease in protein intake in a moderate diet can reduce likelihood of early death by 21 percent.
“Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: Does it progress? Turns out one of the major factors in determining if it does, is protein intake“, said Valter Longo, corresponding author.
We know we have to be very careful about what we eat, and how much, and though scientists certainly need to conduct more research on this subject, now, we can be more sure about the advantages and disadvantages of the animal-based protein intake.
Morgan E. Levine, Jorge A. Suarez, Sebastian Brandhorst, Priya Balasubramanian, Chia-Wei Cheng, Federica Madia, Luigi Fontana, Mario G. Mirisola, Jaime Guevara-Aguirre, Junxiang Wan, Giuseppe Passarino, Brian K. Kennedy, Min Wei, Pinchas Cohen, Eileen M. Crimmins, Valter D. Longo. Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population. Cell Metabolism, 2014.
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