A study published this month on Cell Metabolism1 reveals that a diet high in meat proteins increases the risk for health-related diseases, whereas a diet rich in plant proteins does not show the same adverse effects.
The team guided by Dr. Longo at the University of Southern California analyzed a nationally representative study sample of 6,381 subjects from the National Health and Nutrition Examination Survey (NHANES) III program with an average age of 65 years. Considering the entire group, a high and moderate protein diet was positively correlated with diabetes-related mortality, but not cancer mortality. When the population was divided into two groups – 50-65 years and 65 and older- , the protein intake showed different effects on subjects’ health. Subjects in the midlife group, consuming a high protein diet had a 74% increase in the risk of all-cause mortality and four-times increase in the risk of cancer mortality compared to the low protein group. In contrast, a high protein diet did not have the same negative effects on elderly subjects. Elderly subjects consuming a high protein diet had a reduction in both all-cause (23%) and cancer mortality (60%), when compared to a low protein diet. This may be due to the fact that elderly people have impaired digestive and nutrient absorption abilities that can cause malnutrition and frailty; therefore a higher protein intake is beneficial at older ages to prevent diseases.
The authors link the effect of protein consumption on mortality to the insulin-like growth factor 1 (IGF-1) , showing that in humans an increase in IGF-1 is correlated with an increased risk of cancer in subjects 50-65 years old with a high protein diet. Instead, IGF-1 levels decrease in elderly subjects. They also performed experiments in mouse models demonstrating that a low protein diet is responsible for smaller melanoma and breast cancer cell derived tumors with circulating levels of IGF-1 correlating with the protein content in the diet. However, the mechanism of IGF-1 involvement in protein intake and mortality is not well elucidated.
Despite the lack of a well-defined mechanism, this study demonstrates that a low protein diet in middle age people is beneficial for preventing cancer mortality through “at least, in part, regulating circulating IGF-1″. These findings are important in a country, the United States, where adults consume 1.0–1.3 g grams of proteins/kg of body weight/day, instead of the 0.7 to 0.8 g of proteins/kg of body weight/day recommended by the Food and Nutrition Board of the Institute of Medicine. According to previous reports, this study also shows that plant proteins, such as legumes, do not have the same unfavorable effect of animal proteins; in contrast, their intake has beneficial effects at all ages!
Beans might be healthier than hamburgers!
1. 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; 19 (3): 407-417 DOI: 10.1016/j.cmet.2014.02.006
Apart from the above mentioned facts about legumes, there is an endless list of advantages and health benefits that legumes offer the human body. The regular consumption of legumes can reduce cholesterol levels in the blood, regulate levels of blood glucose, lower blood pressure and improve the function of the colon in the body.
Vitamins such as Vitamin B1, Vitamin B6 and Vitamin K can be found in most legumes. It is also beneficial to note that beans such as pinto beans, black beans, kidney beans and lima beans can provide the human body with over 20% of the daily vitamin value per serving.
Proteins found in meat, on the other hand, cause a dehydrating effect in the body and promote fat storage. When protein is broken down, the body releases calcium phosphate which increases urine levels of uric acid as well as calcium which can then both cause kidney stones.
The next time you prepare you plate of food, add more green and make sure less meat is seen!
I’m from South Africa and figure that a diet derived from a doctor this side would probably suit me more so I follow the paleo diet by Prof Tim Noakes on occasion and funny enough he suggests that legumes aren’t actually good for you and disregards them completely. I get that a high protein diet isn’t all that good for you but maybe something more balanced with vegetables and leaner low cholesterol meats would be more ideal? Just a thought?