Food biodiversity and total and cause-specific mortality in 9 European countries: An analysis of a prospective cohort study

Author summary Why was this study done? Facilitating populations to transition to diets that are both nutritious and sustainable is a key challenge for human and environmental health. Dietary (between food group) diversity is increasingly advocated within the framework of dietary recommendations and food-based dietary guidelines.</p> Food biodiversity, defined as the variety of plants, animals, and other organisms that are consumed between and within food groups globally, is a potential lever for improved public and planetary health. Nevertheless, scientific evidence is a prerequisite to understand the associations between metrics of food biodiversity and major health outcomes.</p> Thus far, evidence regarding the positive association between dietary species richness (DSR), i.e., the absolute number of unique species consumed by an individual, and micronutrient adequacy of diets is limited to low- and middle-income countries (LMICs).</p> What did the researchers do and find? This study assessed the relationships between DSR and all-cause and cause-specific mortality in the large and diverse European population that constitutes the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, including 451,390 adults from 9 European countries with 46,627 recorded deaths between 1992 and 2014. In addition, this study provides a picture of the usual consumption of food and beverage species across 9 European countries.</p> Higher DSR was inversely associated with total mortality rate and cause-specific deaths due to cancer, heart disease, respiratory disease, and digestive disease, independent of other established components of diet quality. Overall, self-reported total energy intake was derived from a narrow range of species.</p> What do these findings mean? Our findings add to the evidence base on the relevance of food biodiversity, both between and within food groups, as a basis for public health strategies championing dietary (species) diversity in European countries.</p> These findings will play a key role in communications about the merits of biodiversity stewardship, in the context of ongoing European/global debate on nutritious and sustainable diets for a stable Earth system.</p> Background Food biodiversity, encompassing the variety of plants, animals, and other organisms consumed as food and drink, has intrinsic potential to underpin diverse, nutritious diets and improve Earth system resilience. Dietary species richness (DSR), which is recommended as a crosscutting measure of food biodiversity, has been positively associated with the micronutrient adequacy of diets in women and young children in low- and middle-income countries (LMICs). However, the relationships between DSR and major health outcomes have yet to be assessed in any population.</p> Methods and findings We examined the associations between DSR and subsequent total and cause-specific mortality among 451,390 adults enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) study (1992 to 2014, median follow-up: 17 years), free of cancer, diabetes, heart attack, or stroke at baseline. Usual dietary intakes were assessed at recruitment with country-specific dietary questionnaires (DQs). DSR of an individual's yearly diet was calculated based on the absolute number of unique biological species in each (composite) food and drink. Associations were assessed by fitting multivariable-adjusted Cox proportional hazards regression models. In the EPIC cohort, 2 crops (common wheat and potato) and 2 animal species (cow and pig) accounted for approximately 45% of self-reported total dietary energy intake [median (P-10-P-90): 68 (40 to 83) species consumed per year]. Overall, higher DSR was inversely associated with all-cause mortality rate. Hazard ratios (HRs) and 95% confidence intervals (CIs) comparing total mortality in the second, third, fourth, and fifth (highest) quintiles (Qs) of DSR to the first (lowest) Q indicate significant inverse associations, after stratification by sex, age, and study center and adjustment for smoking status, educational level, marital status, physical activity, alcohol intake, and total energy intake, Mediterranean diet score, red and processed meat intake, and fiber intake [HR (95% CI): 0.91 (0.88 to 0.94), 0.80 (0.76 to 0.83), 0.69 (0.66 to 0.72), and 0.63 (0.59 to 0.66), respectively; P-Wald < 0.001 for trend]. Absolute death rates among participants in the highest and lowest fifth of DSR were 65.4 and 69.3 cases/10,000 person-years, respectively. Significant inverse associations were also observed between DSR and deaths due to cancer, heart disease, digestive disease, and respiratory disease. An important study limitation is that our findings were based on an observational cohort using self-reported dietary data obtained through single baseline food frequency questionnaires (FFQs); thus, exposure misclassification and residual confounding cannot be ruled out.</p> Conclusions In this large Pan-European cohort, higher DSR was inversely associated with total and cause-specific mortality, independent of sociodemographic, lifestyle, and other known dietary risk factors. Our findings support the potential of food (species) biodiversity as a guiding principle of sustainable dietary recommendations and food-based dietary guidelines.</p>