Eating More Species Cuts Mortality Risk by 9% Per Additional Food Species
A 7,210-person PREDIMED cohort study finds each additional food species consumed reduces all-cause mortality risk by 9% in high-risk older adults.
Summary
Researchers analyzed dietary species richness (DSR) — the count of unique plant and animal species consumed — in 7,210 older Spanish adults at high cardiovascular risk. Over a median 6-year follow-up, each additional food species consumed was associated with a 9% reduction in all-cause mortality risk, and similar reductions in cardiovascular, cancer, and other-cause deaths. DSR ranged from 16 to 57 species (median 48) and was only moderately correlated with Mediterranean diet adherence, suggesting food biodiversity captures a distinct dietary dimension. The findings support dietary recommendations that emphasize variety across biological species, not just food groups, as a practical longevity strategy.
Detailed Summary
The concept of 'food biodiversity' — eating a wide variety of species from across the plant and animal kingdoms — is gaining traction as both a personal health and planetary sustainability strategy. This study is among the first to rigorously quantify its association with mortality in a large, high-risk population.
Researchers used data from the landmark PREDIMED trial, enrolling 7,210 older Spanish adults (median age 67, 58% women) with high cardiovascular risk. Dietary species richness (DSR) was calculated cumulatively over the study period using annual food frequency questionnaires, counting the number of unique plant and animal species each participant consumed. Cox regression models adjusted for a comprehensive set of confounders were used to assess associations with all-cause and cause-specific mortality.
Over a median follow-up of 6 years, 425 deaths occurred — 103 from cardiovascular disease, 169 from cancer, and 153 from other causes. Every additional food species consumed was associated with a hazard ratio of 0.91 for all-cause mortality, 0.93 for CVD mortality, 0.92 for cancer mortality, and 0.91 for other-cause mortality. These are striking, consistent reductions across all death categories.
Importantly, DSR was only moderately correlated with Mediterranean diet adherence scores, indicating that food biodiversity is a meaningfully distinct dietary metric — not simply a proxy for eating a Mediterranean diet. This suggests that species variety may confer independent benefits, possibly through broader phytonutrient diversity, gut microbiome enrichment, or reduced dietary monotony.
Caveats include the observational design, which cannot establish causation, and the reliance on self-reported food frequency questionnaires. The cohort was limited to older, high-cardiovascular-risk Spanish adults, which may limit generalizability. Nonetheless, the findings offer a compelling, actionable message: diversifying the species on your plate may meaningfully extend lifespan.
Key Findings
- Each additional food species consumed was linked to a 9% lower all-cause mortality risk (HR 0.91).
- CVD, cancer, and other-cause mortality all showed similar 7–9% risk reductions per additional species.
- Dietary species richness ranged from 16 to 57 species (median 48) across 7,210 participants.
- DSR was only moderately correlated with Mediterranean diet scores, suggesting it captures a distinct dietary dimension.
- 425 deaths occurred over 6 years in this high-cardiovascular-risk cohort.
Methodology
Prospective cohort analysis of 7,210 PREDIMED participants followed for a median of 6 years. Dietary species richness was calculated cumulatively from annual food frequency questionnaires. Cox proportional hazards regression with full confounder adjustment was used to assess mortality associations.
Study Limitations
Observational design precludes causal inference, and dietary data relied on self-reported food frequency questionnaires subject to recall bias. The cohort was restricted to older, high-cardiovascular-risk Spanish adults, limiting generalizability to younger or lower-risk populations.
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