Soy and Human Health

• The Astonishing Functional Food: Soy Protein and Soy Constituents
• Soy Protein and Coronary Heart Disease
• Soy and Digestive Tract Health
• Soy Foods in Chronic Renal Disease
• How Can Soy Help Diabetes?
• Soy Protein Enhances Energy, Stamina and Sport Performance
• Soy and Cancers
• Soy and Breast Cancer
• Soy and Menopausal Symptoms
• Soy and Pre-Menstrual Syndromes
• Soy and Bone Health
• Losing Weight Healthily with Soy
• Soy and Urological Cancer
• Soy Lecithin and Human Health
• Clinical Abstracts on Soy
• Soy Clinical Reviews in Reputable Medical Journals: 1995-2002

Soy Protein Enhances Energy, Stamina and Sport Performance

We all could use more energy and vitality. Whether you need more energy to keep up with your children/grandchildren, or to win an Olympic Gold Medal, soy can help. Key nutritional qualities of soy protein have been identified that improve energy, stamina and sports performance, particularly, lean muscle mass, strength, endurance and recovery times. These qualities are highlighted here.

NINE reasons why soy protein will help you feel great:

1. Soy helps stimulate the release of anabolic hormones that promote muscle formation.

   The result is increased lean body mass and decreased fat mass. Soy protein contains higher amounts of arginine than whey, casein, egg white, or beef protein on a per gram basis. Arginine plays a key role in stimulating release of anabolic hormones that promote muscle formation. Arginine is recognized as a semi-essential amino acid for good health although it is readily synthesized from ornithine. Because it enhances wound healing and has an immuno-enhancing effect, many investigators consider arginine to be a "conditionally-essential amino acid" in the stressed state (1, 2). Studies show that arginine has a pharmacologic action that may account for some of the anabolic activities and improvement in immune function observed in animals and humans who have received diets supplemented with arginine (3,4). For athletes, arginine may play a key role in muscle formation, reduction of physiological stress, and in helping to maintain a strong and healthy immune system. Numerous studies in world-class Olympic athletes have documented these effects. (5-7).

2. Soy increases your VO2 max thus helping you sustain high-intensity exercise for a longer period.

   VO2 max has become a buzz word in the sports nutrition arena today. But what is it exactly and why is important? VO2 max is defined as the maximal oxygen uptake for a subject exercising under a set of defined conditions. To obtain this measurement, each subject is exercised to an increasing level while they breathe into a spirometer that measures how much oxygen is taken in. Max VO2 is measured as the region where work continues to increase but oxygen uptake levels off or even declines slightly. The VO2 max is important in determining a person's capacity to sustain high-intensity exercise for longer than 4 to 5 minutes. Studies have shown that soy consumption over a 4-month period resulted in significant improvements of VO2 max (8).

3. Soy provides branched chain amino acids for sustained endurance.

   The "Critical Cluster" branched chain amino acids are used as an energy source during exercise (9). The amino acids that make up the "Critical Cluster" include the branched chain amino acids Leucine, Isoleucine and Valine as well as Glutamine and Arginine. EnerFlex provides significant amounts of these amino acids. In the first 20 minutes of moderate to intense exercise performance, muscle glycogen is used as the primary energy source and provides glucose for muscle fueling. After this initial 20-minute phase of exercise, fatty acids and the branched chain amino acids are used as major energy sources. During endurance activity nitrogen is removed from the branched chain amino acids and converted to alanine. Alanine is transported from the muscle to the liver via the bloodstream where it is converted to glucose. Glucose from the liver returns to the muscle to supply energy for fueling and power performance.

   Glutamine and Arginine are considered essential during metabolic stress. Glutamine is the primary carrier of nitrogen to skeletal muscle and other tissues. It boosts protein synthesis, helps buffer lactic acid buildup that occurs during exercising. It also reduces central nervous system fatigue. Several studies have shown that the arginine plays a key role in stimulating the release of anabolic hormones that promote muscle formation. It is also a precursor to nitric oxide, which promote healthy blood vessels. These amino acids are important in the building, the growth and recovery of the muscle. Furthermore, several of the amino acids in the "Critical Cluster" will help strengthen the immune system.

4. Soy can help reduce muscle injury/inflammation and help improve recovery time.

   Managing oxidative stress has become a real issue in the arena of sports nutrition today. People under conditional stress, such as athletes training hard and people with an active lifestyle produce free radicals which have been known to contribute to higher levels of upper-respiratory infections and muscle inflammation, therefore increasing recovery time. In a recent study at Ohio State University, male subjects were fed either soy protein or whey protein (10). The group consuming soy protein showed a rise in plasma total antioxidants status while the group fed whey did not experience any increase. This rise in plasma total antioxidants status was associated with the reduction of muscle enzymes in the blood indicating less oxidative stress and damage occurring in the muscle tissues. Thus, soy may help to reduce muscle injury and inflammation, hence shortening recovery time. Athletes can then train sooner and harder.

5. Soy protein decreases post-exercise fatigue

   Studies in Olympic athletes indicate that athletes consuming a soy protein-rich diet experience a decrease in fatigue after training sessions. Studies with the Romanian Olympic Rowing Team showed that an intake of soy protein at 1.5 g per kg body weight in addition to the regular intake of protein in the diet (2.0 g/kg body weight) may be responsible for reduced fatigue post exercise performance (5).

6. EnerFlex can enhance your current protein regimen.

   EnerFlex's protein quality is equal to whey, casein or egg white sources and will enhance your nutrition used in combination or alone. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is the gold standard for measuring amino acid content and purity (11). EnerFlex is made of soy protein that scores a 1.0 which is the highest score a protein equal in protein quality to whey, casein (milk) and egg protein (which all have scores of 1.0 also). Red meat typically scores a 0.92, thus is not as good as EnerFlex, whey, casein or egg proteins. Soy protein meets or exceeds the essential amino acid requirements of both children and adults (12-16,17,18). It is highly digestible, readily absorbable, and maintains positive nitrogen balance when fed as the sole protein source, even at minimum intake levels (16).

7. Soy decreases metabolic stress on your kidneys from a high protein diet.

   One of the concerns that sports performance experts have is whether or not high protein intakes will negatively effect kidney function. Many athletes consume a higher protein intake to enhance performance. Body builders or strength athletes as well as endurance athletes (19,20) have higher protein needs than non-athletes in order to facilitate muscle building and re-synthesis of muscle after a long endurance event. Recently, researchers (21,22) have documented that the type of dietary protein affects kidney function. Studies in both humans and animals indicate that consumption of a soy protein diet promotes a decrease in the glomerular filtration rate reducing the workload of the kidney. In studies in Romanian Olympic Swimming and Rowing Teams and in Chinese Olympic Team athletes, soy supplementation at 1.5 g per kg body weight showed no detrimental effects on kidney function (5-6). Key studies with Romanian Olympic athletes indicated that urinary excretion of mucoproteins was reduced by as much as 5 to 46% when soy protein was used as a supplement at 1.5 g per kg body weight in addition to the regular intake of protein in the diet (2.0 g/kg body weight) (6,7). These observations further support the theory that soy protein decreases metabolic stress on the kidney.

8. Soy promotes strong bones and connective tissues.

   Strong bones and connective tissue are vital for optimal sports performance and longevity. Accumulating evidence suggests that soy protein consumption promotes strong bones and connective tissues (23-25).

9. Soy can lower your risk of heart disease and may lower risk of certain cancers.

   In addition to enhancing sports performance, soy has many other health benefits. You really can't go wrong by adding soy to your regimen. For men, soy lowers risk of cardiovascular disease, promotes prostate health, and protects colon tissues. For women, soy reduces menopausal/menstrual symptoms and promotes healthy breast, bone, heart, endometrial and skin/hair/nails tissues. These benefits are thought to come from the isoflavones found in soy protein and the soy protein itself.