Men's health and evolution: what the evidence says

Which chapters of the book cover men's health?

• Chapter 16Aging WellThe whole body over a lifetime: the cells that age and occasionally turn cancerous, and the organs that fail at the end.
• Chapter 15Women's Bodies Across the Life CourseThe female reproductive axis across a lifetime, from first period through pregnancy to the transition and the decades after it.

Which popular claims about men's health hold up?

• Should men take testosterone after 40?

  False.

  ●●●StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.

What do the graded recommendations say about men's health?

• Raise your ceiling●●●Evidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.Topic 8
• Adults: know the three signs●●●Evidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.Topic 16
• Keep people close●○○Evidence grade: Emerging. Early, small, animal-only, or actively contested.Topic 21
• Drink less●●●Evidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.Topic 22
• Move most days, and let some of it be hard●●●Evidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.Topic 28
• Aim for a stable, moderate body composition in both sexes●●○Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Topic 32
• Treat endocrine disruptors as a reasonable precaution, not a proven cause●○○Evidence grade: Emerging. Early, small, animal-only, or actively contested.Topic 32
• Build and keep strength●●○Evidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.Topic 35

What does the body expect, and what does it get now?

The mismatch cards of the reference topics behind these chapters, as the library states them.

• Topic 32: The Reproductive Paradox

  ●●○ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.

  The reproductive axis, from the hypothalamic pulse generator to ovaries and testes, and the post-reproductive life course built around it.

  What it expects

  Steady energy availability, first births while fertility is at its peak, kin nearby to subsidize weaned children, and a lifetime of relatively few ovulatory cycles (Topic 22).

  What it gets

  Energy surplus or deficit rather than balance, a mean first birth at 27.5 in the United States, grandparents in other cities, and an industrial chemical environment nobody has fully characterized.

  What happens in the gap

  Ovulation stops in women who look healthy, obesity disturbs the same loops from the opposite side, sperm counts and testosterone drift downward across cohorts, and the biological window opens and closes on a schedule the social one ignores.