Part II: Exercise + Protein—Perfect Partners in Mortality Protection
Many medical experts believe the RDA for protein doesn’t fully protect older adults from loss of muscle mass and then, early mortality (see Part I, "Protein: The Mortality Protector. Are You Getting Enough?").
But what if older adults want more than just avoidance of frailty? What if the goal is to live longer with vigor?
The answer: Eat the right proteins and exercise."Adequate protein alone only slows loss of muscle mass."As a Society for Sarcopenia, Cachexia, and Wasting Disease expert panel concluded, "Adequate protein supplementation alone only slows loss of muscle mass. Exercise [both resistance and aerobic] in combination with adequate protein and energy intake is the key component of the prevention and management of sarcopenia [age-related extensive loss of muscle mass and function]."
Here is what you need to know about partnering your exercise and protein for strength and long-term health.
Aerobic Exercise for More Muscle
Aerobic exercise is good for much more than the heart. Research shows it can increase muscle size and/or muscle protein synthesis in older adults:
- Women, average age 71, who exercised 3 or 4 times a week for 12 weeks on a stationary cycle had significant increases in quadriceps muscle size after training, in one small study.
- Women and men up to 87 years old who trained 3 times a week for 16 weeks on a stationery cycle had a 22% increase in muscle protein synthesis compared to a control group taught flexibility exercises in another small study.
- Older men, average age 69, who took a 45-minute moderately paced walk, the equivalent of a "walk on the beach," increased their muscle metabolism and muscle protein synthesis by more than 100% in another small study.
Resistance Training Is Never Futile
Resistance training—exercising a muscle or muscle group against an external resistance, such as in weightlifting—at an older age has been proven to produce powerful results: boosting muscle strength, muscle size, and whole body fat-free mass.
- Nearly 200 men and women aged 65+ who did leg press and leg extension training either for 12 or 24 weeks demonstrated significant changes in lean body mass, muscle fiber size, leg strength, and physical function"Every one of the nearly 200 older adults who did leg press and leg extension training improved in muscle strength or function."(the 24-week group showing greater improvements)—and, notably, in this study every participant demonstrated one or more of the above changes. The researchers concluded: "There are no non-responders to the benefits of resistance-type exercise training on lean body mass, fiber size, strength, or function in the older population. Consequently, resistance-type exercise should be promoted without restriction to support healthy aging. "
Importantly, resistance exercise increases the rate of muscle protein synthesis, in one small study 112% on average after 3 hours, 65% after 24 hours, and 34% after 48 hours/2 days.
The Unbeatable Combo
Knowing that both resistance and aerobic exercise increase muscle protein synthesis, active older adults might ask is: Do I really need to up my protein to meet the new age-adjusted guidelines if exercise will also do the job?
It’s advisable. Some studies show that after the same resistance training, older adults have significantly lower increases in muscle protein synthesis and/or muscle size than their younger counterparts.
The ideal appears to be, as study researcher R. Rizzoli points out, "the combination of optimal protein intake and exercise…[which] produces a greater degree of muscle protein accretion than either intervention alone. "
What, then, is the optimal protein choice to combine with exercise for more muscle mass?
Why Whey Wins
Most research on muscle protein synthesis in older adults has focused on whey protein. Derived from milk, whey is rapidly digested, absorbed by the body better than other protein sources (a perfect 100 on the Digestible Indispensable Amino Acid Score), and rich in the amino acid leucine, which plays a key role in stimulating muscle protein synthesis"A growing number of experts are re-evaluating protein quality based on its digestibility in the body."(see Part I). In addition, whey contains all other essential amino acids. A growing number of medical professionals, including the medical experts recommending the new protein guidelines for older adults and a FAO (Food and Agriculture Organization of the United Nations) expert panel, are re-evaluating protein quality based on these factors.
Some head-to-head studies compare whey to casein, another protein derived from milk that has many of whey’s benefits but is digested more slowly. Whether or not there’s resistance training, whey wins:
- When 48 older men (average age 74) consumed either 20 grams of whey or 20 grams of casein or casein hydrolysate without any resistance training, the whey group had significantly more muscle protein synthesis.
- When 14 older men (average age 72) took either 20 grams of isolated whey protein or micellar casein after leg-resistance exercises, all the men had muscle protein synthesis, but the whey group had a much greater response.
The Whey To Maximize Muscle
What’s the most effective whey dosage to maximize muscle synthesis after older adults exercise? Is 20 grams, the quantity shown to be effective in both studies above, the optimal number?
- One small 2012 study offers early illumination."The 40-gram whey group had a 30%+ increase in muscle protein synthesis compared to the 20-grammers."After 37 men, average age 71, did resistance exercise and then took 0, 10, 20, or 40 grams of whey protein isolate, the 20 and 40 gram groups had significantly greater muscle synthesis than those who took 10 or no whey at all. In addition, the 40-gram group had a 30%+ increase in muscle protein synthesis compared to the 20-grammers. The researchers concluded: "These data suggest that… exercised muscles of older adults respond to higher protein doses. "
Vegans and folks who are dairy intolerant need another whey to go. What are their optimal options for building muscle mass?
Soy protein may present possibilities:
- A primarily textured soy protein-based diet was found just as effective in building muscle as a beef-based diet in one small 2002 study of 21 older men, average age 65, doing 12 weeks of resistance training. The men had 14%-38% gains in all muscle groups trained, and there were no significant differences between the meat and vegetarian groups. This did contradict the findings of a 1999 study by the same research lab,"In one of two studies, a soy protein-based diet was as effective as a meat diet in building muscle."in which 19 men aged 51−69 did similar training while eating a meat or a vegetarian diet, and the meat eaters had much greater gains in fat-free mass and skeletal muscle mass. The researchers suggested that the different outcomes might be due to protein consumption: In the "meat wins" study, all the men’s total daily protein intake had been under .45 grams per pound of their body weight—close to the RDA for protein (.36 grams/pound), which research shows may result in skeletal muscle atrophy (see Part I). In the "soy = meat" study, all the men ate.46 grams — .53 grams of protein per pound of body weight, numbers right in line with the revised recommendations for older adult protein consumption (see Part I). The researchers concluded: "This… may indicate that [in this study] total protein intakes were adequate to meet the demands of protein synthesis. " There may be other explanations too—it's early to tell.
A vegan path, untested in older adults (in fact, no vegan path combined with resistance exercise has been tested in older adults), may be pea protein:
- During 12-weeks of resistance training, 151 men aged 18−35 either took 50 grams of NUTRALYS® pea protein daily (25 grams twice a day); 50 grams of whey, or a placebo/sugar mixture."There were no differences in muscle thickness between the pea and the whey protein groups."Afterwards, the pea protein group had significantly greater thickness in their biceps muscles compared to the placebo group, and there were no differences in muscle thickness between the pea and the whey protein groups. Note that Roquette, which makes the NUTRALYS® brand, helped fund the 2015 study, and three of the study authors were employed with the company.
That said, pea protein is rich in the muscle protein stimulator leucine, and recent research shows that…
Fruits & Veggies Might Help Prevent Frailty
- When researchers compared fruit and vegetable intake in 2,689 women aged 18−79, the women in the highest quartile (group of four)"Independent of exercise, older men and women who ate more fruits and vegetables were less likely to be frail."of produce consumption had significantly greater skeletal muscle mass, independent of age and protein consumption, than the group consuming the least. Average protein intake in the 2013 study was 81 grams/day. The researchers concluded: "The results… suggest that the optimal diet for maintenance of muscle mass should contain not only protein but also… fruits and vegetables. "
- Korean men and women 65+ who were in the highest quintile (group of 5) of fruit and vegetable eaters of the 823 men and 1,089 women studied had a significantly lower risk of sarcopenia. In this 2014 study, men’s lowered sarcopenia risk was associated with high vegetable consumption, high fruit consumption, and combined high vegetable and fruit consumption. In women, lower sarcopenia risk was linked to high fruit consumption alone.
Neither study proves that eating more produce prevents sarcopenia—while the researchers did adjust for exercise,"High fruit and vegetable consumption helps prevent heart attacks and extends lives."other healthy lifestyle elements might produce these positive results. Still, since there’s a significant body of evidence that fruit and vegetable consumption plays a major role in heart attack prevention and in long-life expectancy, why not include 5 — 7 daily servings of fruits and vegetables for possible muscle mass-induced mortality prevention?
Like much of life, the takeaways from research are open to interpretation. Many of the above studies included very few subjects, which calls into question the reliability of results, and sometimes the studies measured different fitness outcomes, complicating fair comparisons.
That said, this is largely the research we have to date, and the international group of medical experts setting new protein recommendations used many of these small-subject studies, published in respected journals, as foundational research for their conclusions. If we can take the research we have at face value, 5 valuable takeaways emerge to help older adults—and perhaps middle-aged adults as well—stay strong and healthfully extend their lives:1Consuming the PROTO-Age Group expert panel’s recommendation of .45 — .54 grams of protein per body weight each day (see charts in Part I), unless you have kidney disease. In Part III (to come), learn about some of the most protein-rich foods.2Exercising 3−5 times a week, doing a combination of aerobic and resistance training. Even aerobic exercise consisting of 45 minutes of moderate walking was shown to make a difference.3Taking 20 — 40 grams of protein containing leucine after weightlifting or other resistance training: 20 grams minimum for better muscle protein synthesis and 40 grams for maximum results.4Supplementing with whey—the quickly digested, easily absorbed, and leucine-rich protein—right after resistance training. Other vegetarian and vegan options appear above.5Eating 5 — 7 servings of fruits and vegetables daily.
Stay strong based on the science. See Part III for the protein-rich foods to stay powerful, and stay tuned to Honest Health News for real reports on living healthfully longer.Exercise and Protein: Perfect Partners for Mortality Protection. Click To Tweetby