Do you want to live longer? If you’re like most people, your answer is probably, “Yes!” And, you probably want to live not only a longer life, but also a healthier one. If so, you don’t have to look very far to find claims about how to improve—no, “optimize”—your health. Want to reverse chronic disease? Extend that youthful glow? Live to 115… or forever? Lots of fitness influencers, authors, and p...