The Prot-Age Study: Evidence that We Need More Protein as We Age

by Nils Osmar. January 2, 2022. Medical Disclaimer

The PROT-AGE study (Evidence-based Recommendations for Optimal Dietary Protein Intake in Older People) was published in the Journal of the American Medical Directors Association. The entire study can be read at this link.

It calls into question some of the ideas that are widely promoted in the anti-aging community.

Some quotes from the study:

New evidence shows that older adults need more dietary protein than do younger adults to support good health, promote recovery from illness, and maintain functionality.
Older people …need more protein to offset inflammatory and catabolic conditions associated with chronic and acute diseases that occur commonly with aging.
To help older people (>65 years) maintain and regain lean body mass and function, the PROT-AGE study group recommends average daily intake at least in the range of 1.0 to 1.2 g protein per kilogram of body weight per day. Both endurance- and resistance-type exercises are recommended at individualized levels that are safe and tolerated, and higher protein intake …is advised for those who are exercising and otherwise active.
Most older adults who have acute or chronic diseases need even more dietary protein ... Older people are vulnerable to losses in physical function capacity, and such losses predict loss of independence, falls, and even mortality.
Thus, future studies aimed at pinpointing optimal protein intake in specific populations of older people need to include measures of physical function.

My thoughts:

There’s general agreement among anti-aging researchers that proteins, particularly proteins that are rich in the amino acid leucine, activate an important enzymatic process called mTOR, also known as the growth pathway.
There’s also a general agreement that low protein diets (and/or diets high in plant-based foods) activate AMPK, the longevity pathway – while high protein diets (and diets high in leucine, found mainly in animal-sourced foods) activate mTOR, the growth pathway.
Animals which are either fed low protein diets, or fasted regularly (another way of activating AMPK), do tend to live significantly longer than their litter-mates who that are free to eat whatever they want, whenever they want, and often consume more calories and protein throughout their lives, keeping mTOR activated.
Should we therefore stop eating all animal based foods – eat only plants – restrict calories permanently – and eat low protein diets indefinitely as the foundation of longevity?
In my opinion, no. But there could be a benefit in doing all of these things periodically – switching between high mTOR activation and high AMPK activation, but keeping AMPK activated at least 2/3rds of the time, and having days in which we eat more animal protein, alternating with more plant-based days.
There’s evidence that sarcopenia actually starts for most people by the time they’re forty. (According to this article, it can begin affecting people “in their thirties and beyond.”) So it’s possible that we may need to begin increasing our protein intake – at least part of the time – much earlier than has been commonly thought, in order to stave off the progression of the disease.

“What Would James Clement Say?”

In his book “The Switch”, author James Clement talks about the importance of switching back and forth between diets that (mostly) trigger mTOR and diets that (mostly) trigger AMPK. He recommends doing so every few months, but says it could be done on a different schedule.

For example, following his recommendations, we might activate mTOR for four months out of the year and activate (mostly) AMPK the other eight months. For example, you might eat lots of protein (and leucine) in the summer months, then eat lower protein, plant-based foods the rest of the year.

Some people have taken this idea to an extreme, and not necessarily benefited from doing so. In some recent interviews like the one below, Clement talks about running into people at anti-aging conferences who had looked strong and healthy a year or two before but are now literally wasting away, looking weak and sickly, showing signs of early sarcopenia.

Why? Because they had read somewhere that “AMPK is the longevity pathway,” and concluded that “mTOR is bad, AMPK is good”, and that it therefore must be “good” to have AMPK activated full time.

This is very similar to the path followed by people who eat CRON (Calorie Restriction with Optimal Nutrition) diets (permanently), and people who go low-protein permanently. Both approaches show promise of (possibly) slowing down aging and lengthening the lifespan, but they could leave us with lives most people would not want, wasting away in nursing homes.

When I visualize extreme longevity and say that it’s my goal, I’m picturing being as healthy and active as I am now. I’ve known people who became stuck in nursing homes and literally listed away, often, it appeared, because they had stopped eating healthy diets that were rich in protein. That’s not a life I’d ever want for myself.

Taking breaks from eating ample fats, proteins, and other nutrients now and then strikes me as an excellent idea, whether the breaks are for a few hours now and then or for weeks or months; but doing so permanently strikes me as a dangerous approach for the reasons outlined in the Prot-Age study. I agree with Clement that AMPK should be activated most of the time.

What I’m Doing

Like everyone else, I’m doing my best to figure it out. At this time, I’m correlating my highest protein intake with my workout days. I work out on Mondays,Wednesdays and Fridays.
I get up in the morning on those three days, take a few supplements, then work out.
This morning was typical: I got up at 7 a.m., had some tea, took a few supplements, then worked out from 10 till 11. I then had a high protein, high leucine, animal based meal (some chicken salad, heavy on the chicken). My next meal was some yogurt with blueberries and whey. I’ll shift over to more plant-based meals this afternoon. Tomorrow’s Thursday, one of my fasting days; I may fast till dinner or fast all day.
Doing it this way, I’ve been able to lose fat, gain muscle and improve energy.
For more information, see the Rekindle Protocol page: