6. Soy Protein Isolate benefits for Bodybuilders
Animal research suggests some great advantages of using soy protein isolate as a bodybuilding supplement. Research has shown that the isoflavone daidzein found in soy-protein isolate might have a gender specific normalizing effect on sex-hormone production. Lab animals experienced testosterone and growth hormone excretion as well as muscle growth in males, while the female animals experienced a decrease in these hormones and fat loss.
Daidzein is a key isoflavone found in soy that acts as a potent phyto-estrogen. It is structurally a very weak "pseudo-estrogen" (about 1000 times weaker than the body's primary estrogen estradiol). This is good news to the bodybuilder because weak estrogens like daidzein will compete with stronger estrogens like estradiol for available receptor sites to "bind" to. By binding to the receptor sites daidzein then "blocks" the stronger estrogens from binding to and activating receptor sites. With the daidzein isolflavone attached, estrogen receptor sites remain inactive. This inactivity further minimizes the negative effects of estrogen in the body. Many researchers believe this effect is the reason soy protein is linked to a reduction in the risk for many forms of breast, endometrial, and prostate cancer. This mechanism works similarly to the prescription drug Nolvadex (tamoxifen citrate)--an anti-estrogen staple in the bodybuilding community.
Research also indicates that the soy-protein isolates may reduce nitrogen loss and keep you in a positive nitrogen balance to better facilitate muscle growth. The human body can only repair and build muscles when it has a positive nitrogen balance.
Of particular interest to the bodybuilder is Soy Isolates high concentration of the amino acids glutamine and arginine. These two aminos are extremely important to a body builder for their ability to release growth hormone, aid in immune system functions, and for their ability to speed muscle cell recovery.
Glutamine (per 100g)
Soy 10.5g
Milk Protein 8.8g
Whey 4.9g
Many bodybuilders understand the importance of the essential amino acid L- glutamine to their muscle building supplementation. What many bodybuilders don't know is that soy protein isolate has the highest concentration of glutamine among protein sources-over twice that of whey protein! (7) Glutamine has been used for years in hospitals to speed muscle cell recovery and improve maintenance of muscle mass during periods of starvation, infection, and exercise trauma. (8) Glutamine supplementation has been shown to promote muscle glycogen accumulation, which has been linked to an increase in muscle protein synthesis. (10) Glutamine has also shown the ability to increase muscle cell volume through the process of cellular hydration. (11) Glutamine supplementation in as little as 2 grams per day has been shown to increase plasma growth hormone levels. This increase in growth hormone has been shown to help shift the fuel for muscle from glucose to fatty acids. (9) Research has suggested that a bodybuilder should consume between 8 - 15 grams of glutamine each day. Supplementing 3-5 grams of glutamine 3 times per day has been shown to elicit a positive response without stimulating the excretion of glutamine in the urine.
Arginine (per 100g)
Soy 7.6g
Beef 6.3g
Egg 5.8g
Cassein 3.7g
Whey 2.9g
L-Arginine is another important amino acid with respects to body building. Arginine plays several roles in the body such as fighting mental and physical fatigue, but its main job is to assist with growth. This amino acid promotes the release of two highly anabolic hormones, insulin and growth hormone. Arginine promotes gains further by assisting in recovery from post workout muscle trauma through its ability to speed tissue healing. This amino acid aids in the detoxification of the liver by removing ammonium from the body. Arginine has also shown the ability to lower LDL cholesterol and triglyceride levels in the blood. Arginine is used in the medical treatment of angina, congestive heart failure, male infertility and wound healing. Soy isolate protein contains higher amounts of this important amino acid than any other protein source.
As a hard training bodybuilder, your body needs protein every 2 -2 1/2 hours even if you may not think you need it. The human body does not store protein long term as it does for fat and carbohydrates. Instead, your body holds amino acids in three pools that provide the body's necessary protein for fuel. These pools are constantly in a state of flux and are replenished either from dietary protein or the breakdown of muscle. It is extremely important to keep these amino acid pools topped off through the feeding of protein every 2 - 2 1/2 hours. When feeding stops, there is a fall in protein synthesis and a rise in protein breakdown. This translates into a loss of lean body mass after extended periods without protein.
7. Soy Protein Isolate for Dieters
For years, bodybuilding gurus have recommended the use of soy protein for pre-contest bodybuilders who need to shed body fat while keeping as much lean muscle as possible. Normally when the body is forced into a low calorie diet program, it reacts by slowing down your metabolic rate. This will make it increasingly more difficult to lose body fat. Soy-protein isolate helps lessen this effect through several different pathways. First, soy-protein isolate has been found to enhance endogenous production of thyroid stimulating hormone (TSH), thyroxin (T4), and triiodothyronine (T3). Thyroxin is the main player in the regulation of your metabolic rate. The more thyroxin you have the faster your metabolism will be. A faster metabolism insures that more of the food you eat will be used as fuel and less will be stored as fat, an important advantage to any dieter.
Another way soy accelerates fat loss is with its unique concentration of amino acids. Soy-protein isolate has the highest concentration of amino acids in what is called the "critical cluster". This cluster of amino acids contains the three branch chain amino acids (BCAA's) and two essential aminos - glutamine and arginine. These critical amino acids help a bodybuilder spare muscle while losing body fat during a pre-contest diet. Any time you diet, your body tries to break down muscle glycogen in an effort to provide the body with more calories. In fact, your body will often try to use broken down muscle for fuel before it uses stored body fat. This is called muscle catabolism or muscle breakdown. These three branch chain amino acids are the first amino acids that are used for fuel when your body begins muscle catabolism. If you have a high amount of these branch chain amino acids in your diet, your body will first use these for fuel before it breaks down your stored muscle.
8. The Health Benefits of Soy Isolate
Now that we know that soy is a quality protein source, what health benefits can soy protein bring to its consumer? The intake of soyfoods has long been associated with a reduced risk for certain cancers. Research has suggested that phytic acid and protease inhibitors, two of the nonnutritive compounds in soybeans, contribute to the observed anticarcinogenic effects of consuming soy. (1) Residents of the United States and the United Kingdom, as a whole, consume the smallest amounts of soyfoods but have the highest instances of breast and prostate cancer. Japanese residents in comparison are the largest consumers of soyfoods and have the lowest instances of these cancers. (3) Researchers point to the isoflavones genistein and daidzein, which are found exclusively in soy and soy protein isolate, as the major components behind soy's anti-carcinogenic effects.(2)
Soy protein isolate has shown the ability to promote bone health, which in turn aids in the prevention of Osteoporosis. Osteoporosis is a chronic disease characterized by a decrease in bone density, which results in abnormally porous and fragile bones. It has been suggested that a high protein diet may increase the excretion of calcium in the urine, which can lead to this health condition. Studies have shown that not all proteins have the same effect on calcium excretion. Compared with animal protein, soy does not result in an increased loss of calcium in the urine thus promoting a more optimal calcium balance. (4) In addition, the isoflavones in soy protein have been shown to increase both bone mineral content and bone mineral density which will improve the health of abnormally porous bones.(5)
Soy protein isolate has shown the ability to effectively lower LDL cholesterol and triglyceride levels in the blood. Experts agree that these cholesterol-lowering effects can be achieved through the consumption of as little as 25 grams of soy isolate protein each day. The experts point to the high levels of the amino acid arginine for this lipid lowering effect. (6) LDL cholesterol is one of the primary factors behind progressive atherosclerosis. This medical condition is caused by the progressive build up of plaque that clogs blood flow in the arteries.
Soy protein has also shown the ability to improve kidney function. While scientists agree that the high protein intake of bodybuilders is necessary for proper muscle building and repair, they also agree that this diet will place additional stress on the kidneys. Studies of both humans and animals have shown that soy proteins filter more easily in the kidneys thereby reducing their workload. In 1993, a study was performed on the Romanian Olympic swimming and rowing teams. In this study, the athletes were supplemented with 1.5 grams per kg of bodyweight of soy protein along with their dietary protein (2 grams per kg of bodyweight) per day. This additional protein showed no detrimental effects on kidney function and actually showed from 5 to 46 percent improvement in kidney function.
References
(1)(2) Messina M, Messina V. Increasing use of soyfoods and their potential role in cancer prevention. J Am Diet Assoc 1991;91:836-840
(3) American Cancer Society. Cancer Facts & Figures-1996.
(4)(5)(6)Ross PD. osteoporosis: Frequency, consequences and risk factors. Archives of Internal Med 1996's 156.1399-1411.
(7)(8)(9) Bulus, N., Pysysiological Importance of Glutamine. Metabolism Vol.38, No.8, August 1989.
(10)(11) Parry-Billings, M. Effects of changes in cell volume on the rates of glutamine and alanine release from rat skeletal muscle in vitro. Biomedical Journal, 276, 1991.
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http://notmilk.com/acidblood.html
It concludes imo to have a balance not just one not just the other but a balance with more of soy vs meat.
Acidic Blood: Heart & Bone Disease
Food proteins are broken down by the human body into their
building blocks, amino acids. The amino acids are then used
to build new proteins. Proteins consist of 28 amino acids.
We manufacture 19 amino acids in our livers. Nine essential
amino acids must be obtained from the foods we eat. Many
people believe that animal and plant proteins are exactly
the same. That is not true.
One of those "essential" amino acids is methionine.
One needs methionine for many human metabolic functions
including digestion, detoxification of heavy metals, and
muscle metabolism. However, an excess of methionine can be
toxic and create that acid condition in your blood.
The center atom of methionine is sulfur. That's the problem.
Eat foods containing too much methionine, and your blood
will become acidic. The sulfur converts to sulfates and weak
forms of sulfuric acid. In order to neutralize the acid, in
its wisdom, the body leaches calcium from bones.
"Dietary protein increases production of acid in the blood
which can be neutralized by calcium mobilized from the
skeleton." {American Journal of Clinical Nutrition, 1995;
61,4}
Animal proteins contain more methionine than plant proteins.
Let's compare cow's milk to soymilk:
Methionine in 100 grams of soymilk: .040 grams
Methionine in 100 grams of whole milk: .083 grams
Methionine in 100 grams of skim milk: .099 grams
Now, let's compare 100 gram portions of tofu to meat:
(All of the meat products are lean and without skin)
Silken soft tofu: .074 grams of methionine
Hamburger: .282 grams of methionine
Hard boiled egg: .392 grams of methionine
Roast ham: .535 grams of methionine
Baked codfish: .679 grams of methionine
Swiss cheese .784 grams of methionine
Roast chicken: .801 grams of methionine
Why do nations with the highest rates of bone disease also
have the highest milk consumption rates? The highest rates
of osteoporosis are to be found in Denmark, Holland, Norway,
and Sweden.
We are told to consume 1000 milligrams per day of calcium.
Inuit Eskimos consume 3500 milligrams of calcium each day,
and by age 40 are crippled.
THE KEY TO OSTEOPOROSIS
It's not how much calcium you eat. It's how much calcium you
prevent from leaving your bones.
WHY DOES CALCIUM LEAVE BONES?
In 1988, N.A. Breslau and colleagues identified the
relationship between protein-rich diets and calcium
metabolism, noting that protein caused calcium loss. His
work was published in the Journal of Clinical Endocrinology
(1988;66:140-6).
A 1994 study published in the American Journal of Clinical
Nutrition (Remer T, Am J Clin Nutr 1994;59:1356-61) found
that animal proteins cause calcium to be leached from the
bones and excreted in the urine.
MORE SUPPORTING EVIDENCE:
"Osteoporosis is caused by a number of things, one of the
most important being too much dietary protein." {Science
1986;233, 4763}
"Even when eating 1,400 mg of calcium daily, one can lose up
to 4% of his or her bone mass each year while consuming a
high-protein diet." {American Journal of Clinical Nutrition
1979;32,4}
"Increasing one's protein intake by 100% may cause calcium
loss to double." {Journal of Nutrition, 1981; 111, 3}
"The average man in the US eats 175% more protein than the
recommended daily allowance and the average woman eats 144%
more." {Surgeon General's Report on Nutrition and Health,
1988}
"Consumption of dairy products, particularly at age 20
years, were associated with an increased risk of hip
fractures... metabolism of dietary protein causes increased
urinary excretion of calcium." {American Journal of
Epidemiology 1994;139}
Can it get worse? Absolutely.
The Framingham Heart Study is the largest and most exciting
heart study in the history of mankind. Some of the
highlights of this exhaustive 50 year study:
In 1960, Cigarette smoking was found to increase the risk of
heart disease.
In 1970, high blood pressure was found to increase the risk
of stroke.
During the 1980's, high levels of HDL cholesterol were found
to reduce risk of death from heart disease.
In the 1990's, homocysteines were identified as key factors
in heart attack deaths.
Homocysteines are normal breakdown products of METHIONINE
and are believed to exert a number of toxic effects in the
body. I recently spoke with the senior investigator of the
Framingham heart study, William Castelli, M.D. (E-mail:
[email protected]) Dr. Castelli has suggested that
an elevated homocysteine level is a risk factor for heart
disease. The first evidence of this was published in the
American Journal of Cardiology (Glueck, 1995;75:132Â*6).
Two recent publications resulting from Framingham data
indicate a positive correlation between cardiovascular
disease mortality and blood serum levels of homocysteine.
Bostom AG, et. al, Nonfasting plasma total homocysteine
levels and all-cause and cardiovascular disease mortality in
elderly Framingham men and women. Arch Intern Med 1999;
159:1077-1080.
Bostom A.G., et. al, Nonfasting plasma total homocysteine
levels and stroke incidence in elderly persons: the
Framingham Study. Ann Intern Med 131[5], 352-355, 1999.
