Exactly. There's simply not enough data to prove or disprove the hypothesis. What's the proposed mechanism? Because if you chose 7 American men born in the 19

Exactly. There's simply not enough data to prove or disprove the hypothesis. What's the proposed mechanism? Because if you chose 7 American men born in the 1940s at random and then discovered that 3 had died of heart disease, I don't think anyone would be falling over themselves looking for an explanation. Animal studies on simulated environments would be more useful. As would quantitative work on other astronauts who've experienced intermediate environments for longer periods. (There've been enough astronauts in LEO for statistically significant results).