Interesting new research article over at Cell Metabolism on the subject:
From the summary, edited for reader-friendliness,
Branched-Chain Amino Acid Supplementation Promotes Survival and Supports Cardiac and Skeletal Muscle Mitochondrial Biogenesis in Middle-Aged Mice
Here, we show that a BCAA-enriched mixture (BCAAem) increased the average life span of mice. BCAAem supplementation increased mitochondrial biogenesis [growing new mitochondria] and *sirtuin 1 expression in primary cardiac and skeletal myocytes [cells] and in cardiac and skeletal muscle, but not in adipose tissue [fat cells] and liver of middle-aged mice, and this was accompanied by enhanced physical endurance. Moreover, the reactive oxygen species (ROS) [free radicals] defense system genes were upregulated, and ROS production was reduced by BCAAem supplementation. These data reveal an important antiaging role of BCAAs mediated by mitochondrial biogenesis in mammals.I guess that means BCAAs are "heart healthy" -yikes-!!! Don't tell the USDA about this, it'll cause too much cognitive dissonance.
The BCAAs are leucine, isoleucine and valine. They are three of the eight essential amino acids that we must get from diet as our body cannot form them from other components. Dairy and red meat are good sources of BCAA's, as well as whey protein and eggs. Unlike grains and legumes, dairy, red meat, and eggs do not contain compounds designed to discourage their consumption. Like lectins, gluten, etc., but that's a topic for another post.
For those who are looking to build muscle through resistance exercise, Martin Berkhan over at LeanGains has posted about the positive effects of BCAA intake pre-workout in an otherwise fasted state. Just do a search for BCAA to find his post.
*Sirtuin 1 is downregulated in cells that have high insulin resistance and inducing its expression increases insulin sensitivity, suggesting the molecule is associated with improving insulin sensitivity.