Silk Amino Acids: Promising Results

As the name implies, silk amino acids (SAAs) are derived from the protein in silk. The protein is hydrolyzed to produce polypeptides (short protein chains) comprised mainly of the amino acids alanine, glycine, serine, valine, and threonine. While each of these amino acids provide specific benefits in the body individually, research shows that supplementing them together in this unique form delivers a plethora of benefits.

Although you may think that silk amino acids are brand new, they are actually not all that new. You may have actually used them without even realizing it. But instead of consuming them as you would in a supplement, you probably put them on your hair or skin. SAAs are popular in the cosmetic industry and can be found in shampoos and cosmetics. That's because they can penetrate hair and skin and help to moisturize them. But don't go guzzling your shampoo. You can now get SAAs in supplement form.

The most recent study on SAAs comes from Korea and shows that six weeks of silk amino acid supplementation in mice showed some impressive changes in performance and hormone levels. The Korean scientists reported that the mice getting silk amino acids for six weeks more than doubled their exercise endurance. Having better endurance not only means that you can go harder and longer during your cardio workouts, but it can also boost your weight workouts. Mainly it can help you to complete more reps with a given weight. The end result can lead to greater muscle growth and strength gains as well as enhanced fat loss.

The mice getting the silk amino acids also increased their muscle mass by 15% as compared to a control group. The increased muscle mass was concomitant with increased fat loss. In other words, silk amino acids may help to simultaneously gain muscle and lose body fat. This may be due to the fact the mice supplemented with silk amino acids had boosted their testosterone levels by more than double during exercise. Having higher testosterone levels during workouts can increase muscle strength and muscle growth. Plus, they simultaneously decrease their exercise cortisol levels to almost half. Since cortisol interferes with testosterone's anabolic actions, lower cortsiol further facilitates the muscle strength and growth-promoting properties of testosterone.

Other studies have shown that silk amino acids also offer health benefits. They have even been found to lower blood cholesterol, triglyceride, and glucose levels, as well as act as a potent antioxidant.

Jim's Take-Home Message:

Silk amino acids look very impressive on paper. However, up to now all of the research has been done in animals. How well these benefits carry over to humans is currently hard to tell. On a hypothetical supplement scale of 1-10, I would rank silk amino acids somewhere around a 7. They certainly aren't a "must-have" supplement at this stage, but there could be some potential benefits of them. My ranking is on the low side because I have not seen the results yet in enough people to confirm if silk amino acids deserve an 8 or 9. But I'll keep you updated as the results come in.

References:

Shin, S., et al. Silk amino acids improve physical stamina and male reproductive function of mice. Biol Pharm Bull. 2010 Feb;33(2):273-8.

Kim, H., et al. Dietary silk protein, sericin, improves epidermal hydration with increased levels of filaggrins and free amino acids in NC/Nga mice. Br J Nutr. In press, 2012.

Jung, E. Y. Feeding silk protein hydrolysates to C57BL/KsJ-db/db mice improves blood glucose and lipid profiles. Nutrition Research 30:783-790, 2010.

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