You hear a lot about the importance of getting enough protein in your diet. No wonder! Protein is one of the three macronutrients, along with carbohydrates and fats, your body needs to function. When you break protein down into its building blocks, you’re left with its compounds called amino acids It’s these amino acids your muscles use to create new proteins, including new muscle protein.
Not everyone requires the same amount of dietary protein. If you weight train or do extended periods of endurance exercise, you need more protein than a sedentary person because your muscles sustain more damage and need the amino acids for repair and for growth. It’s not just fitness junkies and bodybuilders who can benefit from a diet moderately high in protein, some research suggests older people can too. Just recently, a study showed that a diet higher in protein may help older adults regain functionality and the ability to do the things they enjoy.
Getting Older People Off the Couch
If there’s one thing that improves physical function, it’s exercise, but it’s not easy to get older people who may be overweight or obese and who have already lost some of their ability to function to start working out. Can a high-protein diet help these folks get off the couch and help them lose weight? That’s what researchers wanted to know. Here’s what they did.
They assigned 67 obese adults aged 60 and older to one of two groups. One group followed a standard weight loss diet while the other ate an alternative diet with a similar number of calories, but the alternative diet contained a higher amount of protein at every meal. Beforehand, they measured the participants’ physical functioning and gave them a “functionality” score. After 3 and 6 months, they measured their physical functioning again along with their weight and BMI.
The results? Adults who ate the diet higher in protein lost more weight than the group who ate a standard weight loss diet. Plus, their physical function score improved. In other words, older adults who ate a high-protein diet were more successful at losing weight AND improving their functionality. Remember, none of these adults took part in an exercise program. Imagine how much better their results might have been had they strength trained too. Of course, because they lost weight and their functionality improved, they probably felt more like exercising and were more capable of doing it than they were before.
How Older Adults Can Benefit from More Protein
By the time you reach your 60s, you’ll have lost a significant amount of muscle mass compared to when you were 20. Not only do you lose muscle mass throughout life, once you enter late middle age, but your body also becomes more resistant to building new muscle, a phenomenon called anabolic resistance. In fact, you lose between 0.5% and 2.0% of your muscle mass each year after the age of 50. This loss consists of a loss of muscle fiber number and size. Research suggests that anabolic resistance may be partially overcome by eating a diet higher in protein and with high-intensity strength training.
The Power of Leucine
One amino acid called leucine, one of the branched-chain amino acids seems to “set the stage” for muscle protein synthesis and getting more of it may help older people preserve muscle mass with age and avoid sarcopenia, the age-related loss of muscle tissue that ultimately leads to frailty. Leucine is the signal, in conjunction with other branch-chain amino acids, that turns on the most important pathway for muscle protein synthesis called the mTOR pathway.
So, getting protein from sources that are high in leucine, mostly meat, and dairy, may be most beneficial for preventing sarcopenia. You can still get your protein from plant-based sources, but you’ll have to plan carefully and eat more total protein from a variety of protein-rich plant foods. Soybeans, nuts, and seeds are good sources of leucine.
Other Factors that Help Preserve Muscle Tissue
Because sarcopenia is so pervasive and the consequences of losing muscle so devastating, scientists are eagerly looking for ways to prevent loss of muscle mass with age. Along the way, some interesting findings have emerged. You’ve heard about the anti-inflammatory benefits of omega-3s, especially long-chain omega-3s found in fish oil. Omega-3s in their long-chain form may also be your muscle’s best friend, especially as you age.
A small study showed that supplementing with omega-3s may help counteract anabolic resistance. In this study, older adults who took an omega-3 supplement experienced greater improvements in protein synthesis than those who took corn oil. Although you can get omega-3s from plant-based foods like walnuts, flaxseeds, and chia seeds, this kind is short-chain and may not offer the same benefits. Only a small percentage of short-chain omega-3s are successfully converted to the long-chain form, less than 5%. So, fatty fish is your best source of the long-chain form of omega-3.
We’ve heard about the role vitamin D plays in bone health, but it helps preserve muscle function as you age as well and many people don’t get enough of it. Symptoms of vitamin D deficiency include fatigue and muscle weakness. Since vitamin D plays an important role in muscle health, a number of studies have looked at whether vitamin D helps preserve aging muscles. Unfortunately, the results have been inconsistent. Some research suggests benefits while others do not. At this point, it’s not a good idea to take large quantities of vitamin D in hopes of preserving your muscles, but you should have your doctor check your vitamin D level to make sure it’s within range.
Finally, of utmost importance is the necessity of working your muscles against resistance. You never completely lose the ability to stimulate new muscle growth, regardless of age. Studies involving nursing home residents shows they, too, can build muscle size and strength.
The Bottom Line
Protein not only helps with weight loss in older people, but it may also improve the ability to function as well. Make sure you’re getting enough protein in your diet based on your age AND you’re strength training.
References:
Consultant 360. “High Protein Diet Could Improve Physical Function in Older Adults” April 2016.
Applied Physiology, Nutrition & Metabolism; Sep2014, Vol. 39 Issue 9, p987.
Today’s Dietitian. Vol. 17 No. 4 P. 16. April 2015.
Nutr Rev. 2011 Nov;69(11):675-89. doi: 10.1111/j.1753-4887.2011.00443.x.
- Nutr. January 2006. vol. 136 no. 1 277S-280S.
American Pharmacists Association. “Leucine for Sarcopenia”
Mol Aspects Med. 2005 Jun;26(3):203-19.
Berkeley Wellness. “Does Vitamin D Help Maintain Muscle?”
Mol Aspects Med. 2005 Jun;26(3):203-19.
J Gerontol A Biol Sci Med Sci. doi:10.1093/gerona/glv210.
Clin Interv Aging. 2013; 8: 443-448. published online 2013 Apr 23. doi: 10.2147/CIA.S42136.
The New York Times. “Study Finds That Weight Training Can Benefit the Very Old”
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