Life Extension Magazine November 2010
Halt Age-Related Muscle Loss
Novel Plant Protein Blend Helps Maintain Functional Strength
By Robert Haas, MS
Without protein supplementation, more than half of all adults could eventually face the progressive, age-related loss of vital muscle tissue known as sarcopenia.
Vegetarians and those following a cholesterol-restricted diet may be at a higher risk of protein deficiency that could lead to this degenerative condition that results in a 5-10% loss of muscle mass per decade after age 40. Sarcopenia increases the risk of falls, injuries, and loss of functional capacity.1
At the beginning of the 21st century, sarcopenia was responsible for 1.5% of total health care expenditures in the United States, with an annual cost of $18.5 billion.2 Mainstream doctors rarely discuss this health threat with their patients because most lack the training to successfully prevent or treat the condition.
In this article you will learn about a plant-based protein supplement enriched with branched-chain amino acids and glutamine that can help avert age-related muscle loss and promote recovery from exercise. This supplement contains a proprietary blend of pea, rice, and artichoke proteins and mixes with water to make an instant low-fat, cholesterol-free drink with a biological value and digestibility score equal to whey and egg protein.
Unlike most protein drink mixes on the market, this cutting-edge formula contains no common allergens like dairy or egg, and provides cholesterol-lowering beta-glucan fiber and the prebiotics agave inulin and FOS to support digestive health and immune function.
Why Aging Individuals Need More Protein
Research has firmly established the anabolic (tissue-building) effect of protein supplementation on muscle mass in aging humans, with and without exercise.3-5 Contrary to popular belief, clinical studies reveal that older adults can benefit from higher amounts of high-quality protein each day even more than active younger people.6-9
Although protein synthesis and skeletal muscle mass are regulated by a host of factors, the fundamental prerequisite for muscle protein synthesis is dietary-derived amino acids. Surprisingly, the recommended daily intake (RDI) for protein established by the Institutes of Medicine is the same for all adults—0.8 grams per kilogram of body weight. This translates into 58 grams for an aging adult weighing 160 pounds.
Yet considerable evidence reveals that the protein requirement for healthy older adults is 1.0-1.3 g/kg body weight,10-12 which translates into 73-94 grams for an aging adult weighing 160 pounds. This contradiction indicates the federal government’s protein intake recommendation is up to 38% less than what published scientific studies indicate is needed.
Clinical research suggests that eating a diet rich in cholesterol-free, high-quality vegetable protein can lead to favorable changes in cardiovascular risk profiles in adults of all ages. For example, a recent study found that overweight, hyperlipidemic men and women (ages 21-70) who were fed a reduced-calorie diet abundant in high-quality vegetable protein achieved similar weight loss but superior reductions in blood pressure and LDL-cholesterol compared to a matched group of adults fed a high-carbohydrate, lacto-ovo vegetarian diet (containing low-fat dairy and eggs).13
A new proprietary plant protein product enriched with branched-chain amino acids and glutamine has a perfect PDCAAS (protein digestibility corrected amino acid score) of 1.0 (100%), which is equal to the PDCAAS of whey and egg.14 The PDCAAS has been adopted by Food and Agriculture Association (FAO) and World Health Organization (WHO) as the preferred standard for measurement of protein value in human nutrition.15
Converting Ingested Proteins into Body Proteins
When proteins are ingested, they are transformed in your cells through a process known as “protein synthesis” into vital structures that make up a considerable amount of your anatomy. Aging results in a reduction in cellular protein synthesis within our body.
Fortunately, just a modest bout of physical activity in older individuals may be able to restore the ability of insulin to stimulate muscle protein synthesis.16
A more recent study found that amino acid supplementation with 15 grams/day of essential amino acids for three months increased muscle synthesis and lean body mass in older women.17 Study investigators concluded, “The acute anabolic response to essential amino acids supplementation is maintained over time and can improve lean body mass, possibly offsetting the debilitating effects of sarcopenia.”
Shore Up Aging Muscles with Branched-Chain Amino Acids
The branched-chain amino acids (BCAAs)—leucine, isoleucine, and valine—are essential amino acids that play important metabolic roles, particularly during exercise and in the maintenance and growth of skeletal muscle. BCAAs account for 35% of the essential amino acids in muscle proteins and can serve as an energy source for muscle tissue during exercise.
Leucine, the most metabolically active branched-chain amino acid (BCAA) promotes muscle tissue synthesis.18-20 Notably, leucine is a potent activator of a signaling pathway in human skeletal muscle that favorably modulates insulin sensitivity and the body’s anabolic drive.21,22
While it is widely acknowledged that aging muscle becomes progressively resistant to the stimulatory effects of normal postprandial concentrations of leucine,23 several animal studies show that this deficit can be overcome by feeding supplemental leucine with typical mixed nutrient meals.24-26 These findings emphasize the tremendous potential of taking supplemental leucine with meals in order to maximally stimulate muscle protein synthesis.27
Glutamine: An Essential Energizer
Glutamine is the most abundant free amino acid in the body and accounts for more than 60% of all free amino acids in plasma and muscle tissue.28 L-glutamine easily crosses the blood-brain barrier. Once in the brain, glutamine is converted into L-glutamic acid, which the brain can use for fuel should glucose, the brain’s preferred energy substrate, be in short supply.29
Glutamine is intimately involved in a number of key metabolic functions, including as an energy source for endothelial, intestinal, and lymphocytic cells,30,31 a regulator of nitric oxide synthesis by endothelial cells,32 and a transport molecule to carry toxic ammonia from peripheral tissues to the liver for conversion to urea.30
In catabolic states of injury and illness, glutamine becomes conditionally essential (requiring intake from food or supplements).30,33 Extensive study has shown that glutamine is useful in treatment of serious illnesses,34-36 injury,37 infection,38,39 and mitigating treatment-related side effects of cancer,40,41 as well as promoting wound healing in postoperative patients.30,42
Legumes for Vegetarian-Based Protein
Research has shown that consumption of high-quality vegetable protein exerts numerous beneficial effects in aging humans. A recent study found that compared to consuming 15 grams whey or milk protein (casein), ingesting 15 grams pea protein provided greater postprandial (after-meal) satiety.43 This is important for those seeking to reduce their calorie intake of fats and carbohydrates.
Another study using an in vitro gastrointestinal digestion model suggested that pea protein has potential to reduce elevated blood pressure.44
Pea protein contains more glutamine than whey or egg protein, with comparable BCAA values to whey, egg, and casein. It also contains more arginine than these ‘gold standard’ animal proteins. Arginine is essential for nitric oxide synthesis, which promotes healthy endothelial function and blood vessel dilation and relaxation.45
Although numerous studies have established the value of consuming whey protein to boost tissue levels of the antioxidant glutathione, research scientists very recently discovered that compared to glutathione, pea protein hydrolysate exhibited a significantly higher ability to inhibit fatty acid oxidation and to chelate free radical-causing metals.46