A longer article on branched chain amino acids (BCAA) and mouse longevity from Singularity Hub: "First and foremost, the work is in mice. Yes, mice are one of the most common test animals for longevity, and yes, the same BCAA cocktail also worked with yeast cells (another common test organism), but none of that means that humans are guaranteed to benefit. Second, the mice used were all males, and as we've seen with previous work in longevity, some techniques simply do not translate from one sex to another. Third, only 30 mice were used in the BCAA test group (30 in the control as well). That's simply not a very big sample. ... Finally, we should point out that while the Italian experiment showed a 12% increase in median lifespan, the range of lifespans didn't improve nearly as much. Maximum longevity for the BCAA mice was 1043 days compared to 979 days in the control group - a more modest 6.5% increase. If we look at the top 10% of mice in each group, the BCAA mice only improved 4.5% (981 compared to 938). In other words, while the amino acid treatments helped the mice live longer as a group, they didn't produce any super old mice."