Another new study using the data on Women from the WHI.

Dietary protein intake in midlife in relation to healthy aging - results from the prospective Nurses' Health Study cohort

https://pubmed.ncbi.nlm.nih.gov/38309825/

Conclusions: Dietary protein intake, especially plant protein, in midlife, is associated with higher odds of healthy aging and with several domains of positive health status in a large cohort of female nurses.

Dietary protein intake is important, full stop. The difference between animal, dairy and plant protein was not significant. Considering this was the Harvard nurses study, where they were also analyzing diet, fats, CVD, HRT some participants may have leaned to plant protein. All the other caveats about using food frequency questionnaires, etc but more protein leads to healthier weights and lower risk of chronic diseases.
Good to have a study on aging women and protein rather than only young male bodybuilders.

Podcast review of study: https://podcasts.apple.com/us/podca...i=1000656656386

If "the difference between animal, dairy and plant protein was not significant", why do they conclude that "Dietary protein intake, especially plant protein, in midlife, is associated with higher odds of healthy aging and with several domains of positive health status in a large cohort of female nurses."?

Because it's from Walter Willett, and he's notoriously pro-vegetarian, anti-meat. See previous discussion thread here .. Harvard has been Anti-Meat for 30 years.

Might be worth noting that the conclusions are based on computer-generated associations using questionnaire data, and not "live" observations

Also, people who eat plants probably have a "healthy user bias". Something that confounds a lot of nutrition studies. Another factor is that protein is expensive, so higher socioeconomic status might be a factor. All things that made drinking wine look a lot healthier than it really is. I tend to think that protein consumption is healthy so I can't be too upset over their conclusions.

I too believe protein consumption is healthy, but plant proteins cause me autoimmune joint and skin problems that animal proteins do not.

Thanks Doreen, true, I was referring to that Harvard/Willet bias for seeing positive "plant based" results from an observational study of self reported food frequency questions.
While you could also say the bigger story is that women who ate "higher protein" , about 23% protein or almost 100 grams, ate less, weighed less, and aged healthier based on 11 tests, both physical and cognitive. Versus the women who ate less protein, about 13% or only 58 grams. The baseline diet and health status was 1984 vs 2014/16. Only 7.6% of nurses (who are educated, know health care, etc) were considered healthy 30 years later!
But the numbers pulled out of this huge WHI database appear to support the concept that Protein Leverage works well for older women. (they were age 50-79 in 1984) [ See Prof Raubenheimer and Simpson recent study on "Weight Gain during the menopausal transition "]. Also 12-13% protein is the current US consumption that has likely contributed to the obesity seen now.

This is what the "higher protein" cohort was able to do over 30 years…eat less, weigh less, age healthier. To me, that seems clearer than plant protein being "better" than the other two proteins.

Am I reading this correctly? The nurses were between 50 and 79 in 1984 when they started this? They would have been between 80 and 109-111 at the end of the study in 2014/16.

Please tell me that's a typo... (which is fine. I make typos all the time, and don't notice them until sometimes weeks or months later when the thread comes up again).

I'm just trying to figure out how many of the nurses would have even still been alive in 2014/16 if they were already at least 50 in '84, especially if they were trying to show a correlation between protein consumption and post-menopausal health.

Also, if it's not a typo, how much of the results had to do with the oldest nurses being so old that they were in nursing homes by then - since nursing homes are notorious for serving very low protein/high carb diets.



Also this:



Definitely contributed to the obesity problem.

I don't doubt that there's a lot of people getting even less protein than 12-13%, especially if you average in those of us doing LC and body builders who consume at least the recommended 50%, perhaps more. It's being replaced by fats (seed oils) along with more and more starchy carbs in the typical food consumption pattern of so many people.