Once again, a study that seems to contradict years of medical literature is making splash headlines. The study, 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 is being portrayed in the media with headlines like “Eating large amounts of meat, cheese may be as deadly as smoking.”
Now for some perspective: The study was essentially 2 studies. One was an analysis of data from a pre-existing survey (NHANES III; one of the largest American-based national surveys of health and nutrition), assessing 6381 adults over the age of 50.
There are many problems with the analysis. Study issues aside, let’s just look at the conclusions (read these carefully).
- For those aged 50-65, high protein intake was associated with a 75% increase in overall mortality and 4-fold increase in cancer mortality.
- If the protein was plant based, the association with cancer and mortality was abolished or greatly reduced.
- For patients over 65, high protein intake was associated with reduced cancer and overall mortality.
These results just don’t make sense! How can there be such horrible numbers for people aged 50-65, and then have the opposite results for those over 65?
The second study was a mouse study where tumors were placed in mice, and then they were fed diets with various amounts of protein. Results from this simply cannot be applied to humans.
New studies that contradict current wisdom deserve to be looked at, but should not be used to change what we do until they can be confirmed with good science.
In the meantime, don’t abandon high protein diets, but be mindful of portion size because total calories do matter. Get your protein from organic sources including meat, chicken, fish and plant sources, along with plenty of fresh low glycemic fruits and vegetables. If you have any questions, contact your Cenegenics Nutrition Counselor who will be happy to assist you.