A recent study of 6,381 adults aged 50 and over from the NHANES III suggests that whether or not to consume high amounts of protein may vary according to one’s age.
A recent study of 6,381 adults aged 50 and over from the NHANES III suggests that whether or not to consume high amounts of protein may vary according to one’s age.During the study, subjects consumed 1,823 calories on
average per day, of which the majority came from carbohydrates (51%) followed
by fat (33%) and protein (16%) with most of it (11%) derived from animal
protein. The percent of calorie intake
from protein was used to categorize subjects into a high-protein group (20% or
more of calories from protein), a moderate-protein group (10-19% of calories
from protein) and a low protein group (less than 10% of calories from protein).
Key Findings
Mortality was followed via the National Death Index until
2006, which provides timing and cause of death.
The 18-year follow-up period covered 83,308 total person-years with 40%
overall mortality; 10% was due to cancer, 19% cardiovascular disease, and 1%
diabetes. Members of the study aged
50-65 in the high protein category reported a 75% increase in overall mortality
and a 4-fold increase in cancer death risk during the following 18 years. These
associations were either abolished or attenuated if the proteins were plant-derived.
Conversely, high protein intake was associated with reduced cancer and overall
mortality in respondents over 65. There was a 5-fold increase in diabetes
mortality across all ages for those consuming high-protein diets. These
results suggest that low protein intake during middle age followed by moderate
to high protein consumption in older adults may optimize health span and
longevity.
Practice Implications
These data suggest that people should shift their dietary
patterns in two key ways. First, patients younger than 65 should be discouraged
from eating high-protein diets, especially diets high in animal protein. They
should be encouraged to shift toward vegetable protein. Second, patients over
65 should be encouraged to consume more protein as it reduces overall and
cancer mortality unless at high risk for diabetes.
Reference
Levine ME, Suarez JA, Brandhorst S, et al. Low protein intake is associated with a major
reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not
the older population. Cell Metab, 2014;19(3): 407-417
