The Claim

Testosterone levels are not significantly associated with the risk of Ascaris lumbricoides infection or with parasite load across all age groups, indicating that the relationship between reproductive hormones and immune function is specific to the parasite species and not a universal biological phenomenon.

Source: Amazonian Shuar testosterone levels are related to parasite infection: Immunocompetence Handicap Hypothesis Implications

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
42score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

Testosterone levels do not correlate with the likelihood of being infected by Ascaris lumbricoides worms or with the number of worms present, regardless of age. This suggests that hormonal influences on immune responses vary depending on the type of parasite.

See the scientific wording

Testosterone levels show no significant association with Ascaris lumbricoides infection risk or parasite load at any age, suggesting that the interaction between reproductive hormones and immune function is parasite-species specific and not a general effect.

Why this might work

Testosterone does not change how the body responds to Ascaris worms because the immune cells that fight these worms do not react to testosterone. Even when testosterone levels go up or down, the body still fights Ascaris the same way, so infection risk and worm numbers stay the same.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Amazonian Shuar testosterone levels are related to parasite infection: Immunocompetence Handicap Hypothesis Implications

    The study found that testosterone levels didn’t affect whether boys or men got roundworms or how many worms they had — but it did affect a different worm (whipworm) in teens. This means hormones don’t affect all worms the same way.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.