The study garnering a lot of attention is from the journal Cell Metabolism. They looked at self-reported diet data from NHANES. Over 6,000 men and women were tracked over 18 years. The researchers zeroed in on protein intake and concluded those with the highest protein intake had higher relative risk for cancer and cardiovascular disease from ages 50 to 65. Their hypothesis is that protein increases a hormone IGF-1 and that this increases disease risk but it’s not as clear-cut as it sounds. Remember my husband and the hockey/business conclusion?
All protein isn’t created equal
The headlines zeroed in on meat, cheese and milk not exactly the foods any nutritionist worth his or her degree is going to base a food plan on. We have also seen data showing that fish and poultry reduce relative risk. And the current study found plant sources of protein (legumes and nuts) didn’t raise relative risk (in humans more on that later). So it’s clear that all protein isn’t created equal. I would go further to say not only is red meat different from plant protein but how do we lump McDonalds in with grass-fed organic meat? Foods are not simply protein or carbohydrates but combinations with some components heathy and others harmful.
It’s dangerous at one age, beneficial at another?
Two other parts of this study sort of put the simple conclusion that protein is bad on its head. First, you turn 65 and protein isn’t only OK- this study showed that the low protein group is more likely to die of cancer after your 65th birthday. Then a rodent study was thrown in. We read about mice with higher protein diets (and implanted with melanoma cells) having a higher risk of death than lower protein but here’s the catch in the critters.. animal and plant protein had similar results here.
What to do
First, let’s remind ourselves that when it comes to body composition and weight, recovery from illness and growth protein is beneficial (I have “research” to show you if you’d like). My advice for clients who are concerned is that we need protein in our diets but it should come from good sources. Protein at breakfast is crucial for appetite control, it's also helpful at lunch but dinner? We don't need animal protein there and that's a great time for a good carb (quinoa, sweet potato) and a copious amount of veggies. Aside from the hoopla about raw kale and thyroid function, vegetables are always good. Also. be aware of restaurant protein portions- you and the 6 foot 6 man get the same amount, leave some over or take it home keep protein to the size of an iPhone max.
As for the scientists I mentioned earlier, the smoking comparison was purely hype. No part of this study compares the protein data to the smoking research so that’s questionable even irresponsible. And one of the lead researchers on this study Dr Longo is involved with a company that makes meat replacement products. So much for credibility.
Did you hear about this study? Did it make you reconsider your protein intake? What sources of protein do you include in your diet?