No Sign of Benefits in a Study of Higher Protein Intake in Older Individuals
One of the many theories regarding the cause of sarcopenia, age-related loss of muscle mass and strength, is that impaired processing of the essential amino acid leucine is a significant cause. If this is the case, then leucine supplementation should help to some degree. Similar suggestions have been made for a few other aspects of aging - that we should assign a modest fraction of the blame to the typically lower protein intake observed in older people, as tissues find themselves lacking sufficient raw materials needed to maintain themselves. The study here suggests that this is not the case, or at least that the contribution of reduced protein intake is small in comparison to the other mechanisms of degenerative aging.
Regardless of whether an adult is young or old, male or female, their recommended dietary allowance (RDA) for protein is the same: 0.8g/kg/day. Many experts and national organizations recommend dietary protein intakes greater than the recommended allowance to maintain and promote muscle growth in older adults. However, few rigorous studies have evaluated whether higher protein intake among older adults provides meaningful benefit.
"It's amazing how little evidence there is around how much protein we need in our diet, especially the value of high-protein intake. Despite a lack of evidence, experts continue to recommend high-protein intake for older men. We wanted to test this rigorously and determine whether protein intake greater than the recommended dietary allowance is beneficial in increasing muscle mass, strength, and wellbeing."
The clinical trial, known as the Optimizing Protein Intake in Older Men (OPTIMen) Trial, was a randomized, placebo-controlled, double-blind, parallel group trial in which men aged 65 or older were randomized to receive a diet containing 0.8-g/kg/day protein and a placebo injection; 1.3-g/kg/day protein and a placebo injection; 0.8-g/kg/day protein and a weekly injection of testosterone; or 1.3-g/kg/day protein and a weekly injection of testosterone. All participants were given prepackaged meals with individualized protein and energy contents and supplements. Seventy-eight participants completed the six-month trial.
The team found that protein intake greater than the RDA had no significant effect on lean body mass, fat mass, muscle performance, physical function, fatigue or other well-being measures. "Our data highlight the need for re-evaluation of the protein recommended daily allowance in older adults, especially those with frailty and chronic disease."
Link: https://www.eurekalert.org/pub_releases/2018-04/bawh-emp040218.php
That is quite contrary to my experience. However, the study didn't mention exercise. On days I go to the gym I boost protein intake to 1.2 - 1.5g/kg. Without out exercise, especially strength training, no one can combat sarcopenia. Here is my proof:
https://youtu.be/Ae9tarc5tmM
Studies of the traditional Okinawan's report that the hard-working farmers ate on average <40 grams of protein in total per day.
So they somehow managed to be the longest-lived on the planet eating about .7g/kg.
https://issuu.com/pdfdoc/docs/okinawan_longevity_food/4
As part of my "program" to combat sarcopenia...I use a supplement of 9 essential amino acids that are supposed to be 99% utilized...and in theory at least NOT contain extras I don't want. One of the aminos is leucine.
My anectdotal experience is that this helps maintain musculature to some extent.
Otherwise it's mostly veggies and fish (wild salmon).
I also use some gelatin...strontium citrate...magnesium...calcium...Vit D...try to keep moving so I can continue to do my own maintenance...etc. Keep moving...keep weight down. Don't fall on your butt and die.
My 94 year old mother has probably fallen 10 times in the last 10 years (rough guess)...it's whether you can still function after a fall that matters. No way can she get up off the ground...but she is so short she doesn't have far to fall.
I go out for walks in fairly remote places (for around here) and have slipped on ice and so forth a few times...so far I've just gotten up and continued on. As one gets older...one's reaction time is slowed...you can be on the ground before you know it. At 6 feet....it's a long way down.
Life as an older person is like playing russian roulette on a daily basis....try to win the game?
As a followup...I think the issue is more what attitude you tend to have towards your later years. I was once 40-50 lbs heavier and found that I was losing the ability to function...so I lost the weight and have kept it off. Still 20 lbs overweight...but I EXPECT to be able to get up from the ground...do repairs (car/computer/house) and yard work...be able to get out and walk at least.
I find my energy to do things has decreased some...strength is somewhat diminished...but I can still do the things I've typically done...maybe a little slower though.
Keeping ones brain functioning is most important...doing repairs and so forth is actually very challenging work....diagnose...find a way to repair or replace...don't make things worse.
Some as they get older try to just quit moving and vegetate as if that will preserve functioning...but it's more like use it or lose it?
Dr Valter Longo explains how high protein intake activates the growth hormone receptor, which in turn increases the levels of insulin and insulin-like growth factor1 (IGF-1), whose altered concentrations are associated with diabetes and cancer, respectively. Leucine, for example, can activate TOR-S6K, a set of genes that accelerate ageing. His recommendation is to consume low but sufficient proteins; 0.31 to 0.36 grams per pound of body weight per day and to eat 30 g in a single sitting to maximise muscle synthesis.