Source: Science Daily - Top Health A study involving more than 270,000 people has linked higher blood levels of the amino acid tyrosine—a popular brain supplement—to a shorter lifespan in men. Using both observational data and genetic analysis, researchers concluded that elevated levels of tyrosine could potentially reduce male life expectancy by nearly a year, though no significant effect appeared in women. Tyrosine is is sold as a supplement for boosting focus and mental...