Juvenon Health Journal – October 2013, No. 10
What do young body builders and athletes have in common with the over 50 crowd? More than you might think, according to research linking the consumption of high-quality protein with healthy muscles, regardless of strength or age.
Both groups are concerned about strength. However, the latter group is wrestling with an unfortunate fact of life: muscle mass declines at an alarming rate of 1 to 2 percent each year as early as age 50 onward. Muscle loss associated with aging (sarcopenia) is a widespread syndrome with an accompanying increase in illness and death.
Chronic muscle loss targets an estimated 30 percent of people over the age of 60 and more than half of the octogenarian population. Progressive sarcopenia leads to frailty and with that comes a greater likelihood of falling and an inability to do routine daily tasks.
That’s the bad news. However, there is plenty of good news out there, too. A growing body of evidence now supports protein’s ability to maintain lean muscle mass. This is important because if we can maintain lean muscle mass as we age, our coordination/balance is better, as is our ability to move and get up from stationary positions. A number of reports also support the use of dietary supplementation with balanced amino acid formulas containing branched chain amino acids (BCAAs) to prevent disability and prolong healthy life expectancy of elderly subjects. Therefore, if boomers and seniors can boost their dietary protein intake and add some weight bearing exercise, chances are better for a long, independent life.
Protein is made up of amino acids. One type of essential amino acids, called branched chain amino acids (BCAAs), increase the rate of protein synthesis and decrease the rate of protein degradation in muscle tissue. Branched chain amino acids, and in particular, the BCAA leucine, interact with the “the mammalian target of rapamycin” (mTOR), which is a signaling pathway in the cells, and serves as a central regulator of cell metabolism, growth, proliferation and survival.
For decades, dietary supplementation with amino acids has been proposed for various health conditions. Also, a trend in sports nutrition has been to supplement with BCAAs. Based on the recent progress in our understanding of how BCAA’s work, and on accumulating experimental results, the concept that dietary BCAA supplementation might have health effects is now experiencing a major revival.
BCAA Supplementation Studies
A research group in Italy recently demonstrated that long-term dietary supplementation with a specific BCAA-enriched amino acid mixture increased the average lifespan of male mice. This was accompanied by increased mitochondrial biogenesis and sirtuin 1 (SIRT1) expression and by up-regulated reactive oxygen species (free radicals) defense system, with reduced oxidative damage, both in heart and skeletal muscles of middle-aged mice.
The relevance of boosting mitochondrial function to preserve mammalian health and longevity has been recently shown by Safdar et al. Like exercise, which is another way to boost mitochondrial function, BCAA supplementation does not affect maximum lifespan, but increases the median lifespan, an indicator that specific diseases have been prevented.
Yeast (Saccharomyces cerevisiae) has also served as a good organism in which to investigate the role of amino acids in aging. It has been found that low levels of essential amino acids reduce chronological life span in yeast. Further, chronological life span has been recently studied in yeast grown in media supplemented with different amino acids. Increased availability of the BCAA’s leucine, isoleucine and valine extended chronological life span. The fact that leucine, isoleucine and valine were most important for chronological life span points to a special status for the BCAAs during aging.
Muscle Building Benefits
A promising area of preclinical research is evaluating the effects of BCAAs on skeletal muscle atrophy. Results indicate that BCAA intake may preserve muscle fiber size and improve physical endurance and motor coordination in middle-aged mice. Furthermore, an amino acid mixture enriched with BCAA was found to improve sarcopenia, i.e., the aging associated loss of muscle mass, in rats.
A variety of amino acid mixtures have also been used to restore the protein content of defective tissues, especially of skeletal muscles, in aged human subjects. A 3-month supplementation with essential amino acids increased lean body mass in aged women, without affecting kidney function. The acute anabolic response (increased muscle protein synthesis rate) to this supplementation was maintained over time, suggesting the possibility to improve skeletal muscle growth with long-term treatment.
Various BCAA dietary supplements have been reported to reduce sarcopenia in elderly subjects. In a randomized trial involving 41 subjects with sarcopenia aged 66 to 84 years, intake of a BCAA enriched formula increased muscle mass and improved insulin sensitivity. As a result, leucine enriched balanced amino acid supplements are now considered as part of the nutritional recommendations for the management of sarcopenia.
BCAAs also appear to have an impact on obesity. BCAAs, and in particular leucine, increase fat leptin secretion, decrease food intake and body weight (via mTOR signaling), and improve muscle glucose uptake and whole body glucose metabolism. Research suggests that specific mixtures of amino acids, rather than a single amino acid supplement such as leucine, may be more efficacious in lowering the blood glucose response to a glucose challenge.
Studies in wrestlers and in obese subjects have shown that BCAA supplementation exerts beneficial effects on body weight and body fat. Most recently, the population-based International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP) provided a unique opportunity to evaluate the effects of dietary BCAAs across different cultures. This high-quality study demonstrated that a higher BCAA intake is associated with a lower prevalence of being overweight or obese in middle-aged individuals from East Asian and Western countries.
Heart Health Benefits
Amino acid supplementation may also inhibit inflammatory markers in chronic heart failure patients and may represent a promising therapeutic approach, particularly in the presence of the so-called wasting syndrome. Accordingly, supplementation with a BCAA enriched formula may improve exercise capacities in elderly subjects affected by chronic heart failure, and may improve exercise capacities of aged individuals without heart failure.
BCAA Lifestyle Choices
Geriatricians have long recognized that disability, frailty, and age-related disease onset are critical issues that need to be addressed in older populations. A number of preclinical and clinical reports support the use of dietary supplementation with balanced amino acid formulas containing BCAAs to prevent disability and prolong healthy life expectancy of elderly subjects.
What is the take home message? Maintaining strength and muscle mass are especially important as we age. Exercise and consuming sufficient high quality protein are two proven ways to stay strong and independent. If you are worried about your protein consumption, you might consider supplements. Amino acids, and in particular, BCCA’s are one type of supplement that have gained popularity in sports nutrition, and look promising for older individuals. Consider consulting with a trusted healthcare professional to see if BCAA supplementation may be a good choice for your aging body.
In the coming months, the Juvenon Health Journal will continue to feature research that will help you stay informed and healthy. By offering effective, all-natural supplements and health news you can use, Juvenon provides an essential toolkit to battle aging enemies.