A large study examines what blood proteins and metabolites might reveal about the long-term health links of a plant-forward diet.
Study: Plasma multi-omics signatures of the EAT-Lancet diet and associations with health outcomes. Image Credit: udra11 / Shutterstock
A recent study published in the journal Communications Medicine found that adherence to the EAT-Lancet diet and related blood-based molecular profiles were associated with chronic disease risk and modeled life expectancy. The findings point to possible roles for immune regulation and lipid metabolism, but do not establish that dietary changes prevent disease or extend life.
The EAT-Lancet diet is a plant-forward eating pattern designed to support human health and environmental sustainability. Previous research has linked plant-based foods to lower risks of major chronic diseases and death, but the biological changes associated with this dietary pattern remain unclear. Studying those changes could inform precision nutrition research.
About the study
Researchers analyzed dietary data from 204,938 UK Biobank participants aged 40 to 69 at recruitment. Smaller groups had the blood-protein and metabolite data needed for the molecular analyses. The team also considered participants’ medical histories, lifestyle factors, body measurements, and other health information.
Participants completed at least one questionnaire about what they had eaten during the previous 24 hours. Some completed additional questionnaires, allowing the researchers to estimate their usual intake. The team used these responses to score adherence to the EAT-Lancet diet, then examined subsequent diagnoses and deaths across 45 health outcomes.
The researchers measured proteins and metabolites in blood samples and identified groups of markers associated with higher diet scores. They examined whether these molecular profiles were associated with subsequent health outcomes and explored biological pathways that might help explain the findings. Additional analyses tested whether the broad pattern persisted when the researchers changed the dietary scoring criteria, restricted the sample to people with repeated dietary assessments, or excluded outcomes arising early in follow-up.
Results
During an average follow-up of 14 years, higher EAT-Lancet diet scores were associated with lower risks of several conditions. The clearest associations for the diet score involved lung cancer and chronic obstructive pulmonary disease.
The researchers identified a diet-related profile containing 163 proteins and another containing 37 metabolites. These profiles showed stronger associations with several health outcomes than the self-reported diet score. They may also reflect health-related changes beyond diet, so the stronger associations do not establish that blood tests measure dietary adherence more accurately.
The protein profile was associated with lower risks across a range of conditions, with the strongest association with lung cancer. The metabolite profile showed its strongest inverse association with diabetes. Both profiles pointed to processes involving inflammation, immune regulation, and lipid metabolism.
The metabolite profile was also associated with higher risks of Parkinson’s disease and death from nervous system disorders. The authors cautioned that these findings do not show that adhering to the EAT-Lancet diet increases neurological risk. Changes related to an illness before diagnosis, medication use, or other health factors could influence the blood markers.
Among the foods included in the diet score, fruits, dairy products, vegetables, and nuts contributed substantially to the observed associations. Higher fruit intake was linked to lower risks of stroke and lung cancer, while starchy vegetables and tubers were associated with lower mortality from respiratory diseases. These analyses cannot establish that any individual food caused the differences.
At age 45, people with the highest diet scores had about three months more modeled remaining life expectancy than those with the lowest scores. Comparisons based on the molecular profiles produced larger estimated differences. These figures describe differences between groups, not additional years a person could expect to gain by adopting the diet.
The researchers also examined whether specific blood markers could help explain the associations between diet scores and health outcomes. Proteins involved in immune activity and metabolites related to fats and inflammation emerged as possible intermediates. These statistical analyses suggest avenues for further research but cannot confirm the mechanisms.
Conclusion
Blood-based molecular profiles may provide information on the biological changes associated with adherence to the EAT-Lancet diet and future disease risk. They complement dietary questionnaires, which remain necessary to identify what people eat.
The observational design cannot rule out other explanations for the findings. The molecular profiles were measured only once, and the UK Biobank sample was predominantly White. Studies with repeated measurements and more diverse populations, along with research capable of testing causal mechanisms, are needed before these profiles can guide personalized dietary advice.
