Tier 2 — strong

Dietary polyamine intake and all-cause and cause-specific mortality in Japanese adults in the Takayama study

Chisato Nagata, Keiko Wada, Michiyo Yamakawa, Yuma Nakashima, Masaaki Sugino, Tomoka Mori

British Journal of Nutrition 2024 131(2):343-350

Bibliography

PubMed: PMID 37964604
DOI: 10.1017/S0007114523002465
Funding: Partially supported by the Ministry of Education, Culture, Sports, Science, and Technology, Japan (No. 20014006).
Competing interests: The authors declared no conflicts of interest.

Study snapshot

Design	Population-based prospective cohort
Model	Japanese adults aged 35 years and older
Sample	29,079 (13,355 men; 15,724 women)
Intervention	No intervention; habitual dietary polyamine intake estimated from a validated food-frequency questionnaire
Duration	16 years
Endpoints	All-cause mortality; Cancer mortality; Cardiovascular mortality; Other cause-specific mortality

What the study showed, in plain terms

This large Japanese cohort did not reproduce the inverse mortality associations reported in Bruneck and NHANES. Dietary spermidine was not significantly associated with lower all-cause or cause-specific mortality.

Key findings

No overall mortality benefit was detected. In women there was a suggestive positive association between the highest versus lowest spermidine quartile and cancer mortality (HR 1.38, 95% CI 0.99-1.93; trend p=0.02), which is not sufficient to establish harm but is important counter-evidence.

What this study can and cannot tell us

Observational dietary assessment from baseline FFQ, potential residual confounding and exposure misclassification. The study evaluates food intake, not isolated spermidine supplementation, and the female cancer-mortality estimate crossed 1.0.

Editorial review

Reviewed by the Biohack Blueprint research team

Khaled Mahmoud