Study: protein -rich diet and durability

Reference

levine me, suarez yes, brandhorst s, et al. A low protein intake is associated with a significant reduction in IGF-1, cancer and the overall mortality in the 65-year-old and younger, but not in the older population. cell metabolism . 2014; 19 (3): 407-417.

Design

Protein consumption about food was examined in a US population cocition and searched for connections with the overall mortality and the disease-specific mortality.

participant

The examined cohort consisted of 6,381 adults aged 50 and over from NHANES III, a cross -sectional study representative nationwide. The average age was 65 years old and was representative of the US population in terms of ethnicity, education and health characteristics.

diet details

The test subjects took an average of 1,823 calories a day, of which the majority came from carbohydrates (51 %), followed by fat (33 %) and protein (16 %), with the majority of it (11 %) from animal protein. The percentage of the calorie intake from protein was used to categorize the subjects in a group with a high protein content (20 % or more of the calories in protein), a group with moderate protein content (10–19 % of the calories from protein) and a group with a low protein content (less than 10 % of the calories in protein).

target parameter

mortality was followed by the National Death Index until 2006, which indicates the time and the cause of death. The 18-year follow-up period comprised a total of 83,308 people with a total mortality of 40 %; 10 % were due to cancer, 19 % to cardiovascular diseases and 1 % to diabetes.

most important knowledge

Members of the study cocas locations aged 50–65 years, which reported on a high protein recording, recorded an increase in total mortality by 75 % in the following 18 years and a 4-fold increased risk of cancer. These associations were either abolished or weakened when the proteins were of vegetable origin. Conversely, a high protein recording in respondents over the age of 65 was associated with lower cancer and a lower overall mortality. For those who were eating protein, a five-way increase in diabetes mortality was recorded in all age groups. These results suggest that a low protein intake in middle age, followed by moderate to high protein consumption in older adults, can optimize health and durability.

effects on practice

This data suggests that people should change their eating habits in two important ways. First, patients under the age of 65 should be advised against taking protein -rich diets, in particular diets with a high animal protein content. They should be encouraged to switch to vegetable protein. Second, patients over 65 should be encouraged to consume more protein, as this reduces overall and cancer mortality, provided there is no high risk of diabetes.

The increased risk of diabetes, which was observed in the population of middle-aged diets in protein-rich diets, was striking: subjects without diabetes at the beginning of the course had a 73-fold increase, while those in the group with moderate protein intake had a 23-fold risk diabetes mortality. These increased risk rates can be somewhat imprecise due to the low sample size; There were only 21 diabetes deaths in people who had no diabetes at the beginning of the course, and only one of the group with a low protein content.

The insulin-like growth factor 1 (IGF-1) was significantly lower for the 50- to 65-year-olds with low protein recording, while the difference between the effects of protein and protein-low diets on IGF-1 was insignificant.

The differences in mortality reported in this study are not low. The researchers found that consumption of an animal protein -rich diet in middle age the risk of dying cancer is four times higher than with someone who feeds on the protein; This is an increased risk, comparable to smoking.

The study was actually more complex than shown in the summary. It also included separate cell studies with yeast and animal studies with mice to examine the same questions. The influence of a protein -rich diet on the progression of the cancer was confirmed in mice that melanoma cells were implanted. The tumors of the mice with low -protein diet grew significantly slower and remained significantly smaller in the course of the experiment.

In order to test the hypothesis that older subjects who feed protein arms are malnourished because they have difficulty taking amino acids, an experiment was carried out in which both young and old mice were given either protein -rich or low -protein diets. Old mice that received a protein -rich diet for 30 days increased in weight. Old mice, but not young mice that were fed with a protein -poor diet, lost 10 % of their weight on the 15th day, which confirms the conclusion that the effects of protein or protein -low diets can vary with age.

mice were also used to test the hypothesis that the growth hormone receptor and the insulin -like growth factor 1 together promote the progression of cancer. Melanoma cells were implanted together with normal control animals in mice with growth hormone receptor (GHR) and IGF-1 deficiency. Tumor growth was much slower with the mice that no GHR had or who were missing IGF-1.

The protein intake was also tested on mice that had been implanted breast cancer. On the 18th day after the implantation, differences could already be seen. The tumor incidence was 100 % of the mice with the protein -rich diet and only 70 % in the mice with the protein -poor diet. At the end of the experiment on the 53rd day, the tumors in the mice with a low protein diet were 45 % smaller.

yeast was used to test the hypothesis that began to form after the view of human data and indicates that the amino acid level is connected to the lifespan. Hefe was bred in media with different amino acid concentrations. On the fifth day of the experiment, the yeast, which was exposed to high amino acids, had a three to four times higher mutation rate. Up to the eighth day, the number of surviving cells had decreased by yeast, which was bred in high concentrations of amino acids.

The strong connection between protein consumption, IGF-1, illness and mortality observed in this study was not observed in some previous reports; The age effect may not have been taken into account. Saydah (2007), for example, reported no increase in the overall, heart or cancer mortality when comparing the lower quarters with the highest quarters of protein consumption in the Nhanes III data.

The fact that the amount of animal proteins constitutes a significant proportion of the connection between the overall protective and the overall and cancer mortality agrees with other current reports on the connection between the consumption of red meat and deaths from all causes and cancer. Fung et al. reported in 2010 that a low -carbohydrate diet is associated with an increased total mortality.

Sinha et al. Data from the cohort of the National Institutes of Health Diet and Health Study with half a million people aged 50 to 71 and reported that the consumption of red and processed meat was associated with an increased overall mortality, cancer mortality and mortality by cardiovascular diseases.

Pan et al came to the same conclusion in 2012 after analyzing data from 37,698 men in the Health Professionals Follow-Up Study and 83,644 women in the Nurses' Health Study. They reported that eating red meat was associated with an increased risk of overall, cardiovascular and cancer mortality. After the documentation of 23,926 deaths during the after -observation period of 2.96 million people, Pan et al. Calculated that the total reliability risk rose by 13 % for every daily unpublished red meat. In the case of processed red meat, one serving per day increased the overall risk by 20 %. These researchers estimated that the replacement of 1 portion of red meat per day was associated with a risk of death by other foods (including fish, poultry, poultry, legumes, legumes and whole grain products).

The idea that a diet with a high proportion of red meat is associated with mortality is not new.

Although these new nutritional suggestions are simple, we will not surprise us if supporters of various popular nutritional plans resist. A number of common nutritional strategies, including the Atkins diet and the Paleolithic Diet as well as others, can increase the protein consumption of a trailer to an extent that if the conclusions of this study are true, the health of a person can have a negative impact and increase the risk of diabetes. Cancer and early mortality.

Anyone who advocates a meat -rich diet for people under the age of 65 should be ethically obliged to either find a mistake in this paper or to find a higher -level justification for such a diet that outweighs the effects of a high protein content on long -term survival. This idea that protein consumption should vary with age is a new concept that is not yet known to the public and its explanation will be tedious. It could be a good idea to print out a copy and read the entire article yourself before trying to speak to your patients.