High BCAAs in your blood look like a symptom, not a cause
Two genetic analyses, one in about 250,000 people, found the traffic running mostly from insulin resistance to higher circulating amino acids. Neither gave anyone a supplement.
What the study found
High blood BCAAs look like a readout of metabolic health, not a cause
Two genetic analyses ran the arrow both ways. Higher insulin resistance raised circulating branched-chain amino acids, and a bidirectional study in about 250,000 people found the traffic mostly running that way. None of this is about supplements; it is about what your own body carries.
The caveat · European-ancestry samples only
Genetic proxies for circulating levels are not a stand-in for swallowing a supplement, and neither study gave anyone one. Both draw on European-ancestry samples, and the UK Biobank cohort is healthier than the general population. Neither rules out a smaller effect running the other way.
What we don't know
Genetic proxies for circulating levels are not a stand-in for swallowing a supplement, and neither study gave anyone one. Both draw on European-ancestry samples, and the UK Biobank cohort is healthier than the general population. Neither rules out a smaller effect running the other way.