Another weak study takes aim at protein

Beef steak on the grill with flames

Another day and another observational nutrition study that doesn’t contribute to a meaningful health discussion.

The American Journal of Clinical Nutrition: Dietary proteins and protein sources and risk of death: the Kuopio Ischaemic Heart Disease Risk Factor Study

This time the study was from Finland where researchers recruited 2,600 men in the 1980s and followed them for an impressive 22 years. Once again, however, they assessed their dietary intake once on enrollment and never again. One dietary assessment in 22 years. How accurate does that sound to you? Right away we should realize that we are dealing with the lowest possible quality data and we need to question the results.

Yet, here is the best part. According to the abstract, “intake of total protein and animal protein had borderline significant associations with increased mortality risk.” What’s another way to say “borderline significant associations”? No association. It simply was not statistically significant. It was a null result with no significant increased mortality risk associated with increased animal protein consumption. We have written before how nutritional epidemiology studies with low hazard ratios (below 2.0) may be statistically significant but are rarely clinically significant as the results are likely to be statistical noise and false. In this study, however, it wasn’t even statistically significant let alone clinically significant.

When they specifically looked at meat, there was a weak statistical association at 1.23, still not strong enough to have much meaning. Add to these poor statistics the healthy user bias and other confounding factors, and it should be clear that this study does not provide any meaningful contribution to nutritional science.

Why do journals continue to publish these observational studies? I wish I knew the answer to that question. In today’s world of increasing confusion regarding “What should I eat?”, studies like this only confuse the issue more than help it.

We will continue to call for higher-quality evidence and will continue to point out the problems with these low-quality studies. We are glad you are listening, and we hope the journals will start listening as well!

Thanks for reading,
Bret Scher, MD FACC

Earlier

WHO pulls out of EAT-Lancet event after criticism from Italy

The low-fat house of cards

How much protein should you eat for a longer life?

Videos about meat