The Claim

Long sleep duration (≥9 hours per night) is not associated with a reduced risk of ischemic heart disease, indicating that increasing sleep beyond the optimal range of 7–8 hours per night does not provide additional cardiovascular protection.

Source: Causal association between sleep duration, daytime napping, sleep disorders and ischemic heart disease: A systematic review and meta‑analysis of Mendelian randomization studies

What the research says

Challenges is higher

Challenge is ahead, but a single strong supporting study can change this.

Supports
0score
Challenges
39score

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

Sleeping more than 9 hours a night doesn’t make your heart healthier—once you’re getting 7 to 8 hours, sleeping longer won’t lower your risk of heart disease.

See the scientific wording

Long sleep duration (≥9 hours per night) is not associated with a reduced risk of ischemic heart disease, suggesting that simply sleeping more does not confer cardiovascular protection beyond the optimal range of 7–8 hours.

What the research says

1 study

  1. Study: Causal association between sleep duration, daytime napping, sleep disorders and ischemic heart disease: A systematic review and meta‑analysis of Mendelian randomization studies

    The study found that sleeping more than 8 hours actually lowers the risk of heart disease, but the claim says it doesn’t help — so the study says the claim is wrong.

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.