Plant-Based Diet Linked to Lower Risk of Multiple Diseases

The Lancet Healthy Longevity published an analysis of data from more than 400,000 adults from six European countries, where researchers assessed how plant-based dietary patterns are associated with the risk of multimorbidity - the simultaneous development of at least two chronic diseases from the cancer + cardiometabolic disease group (diabetes and CVD). The result: the higher the adherence to a plant-based diet, the lower the risk of both individual conditions and their "combos", and this was true for both people under 60 and 60+. In the UK Biobank subsample, participants with the highest adherence had a 32% lower risk of multimorbidity than those who adhered to a plant-based diet less well. The work was carried out with the participation of the University of Vienna, IARC (France) and Kyung Hee University (Republic of Korea).

Background of the study

Multimorbidity – the simultaneous presence of at least two chronic diseases in a person – is rapidly becoming the norm in ageing societies. In Europe, its prevalence is estimated to reach 20-40% in middle age and up to ≈80% in the elderly; this is a consequence of increasing life expectancy and advances in diagnostics and therapy, which is why more and more people are living “with several diagnoses at once”. The combination of cancer and cardiometabolic diseases (diabetes, CVD) is particularly difficult: it worsens quality of life, complicates treatment and increases costs for healthcare systems. Therefore, large cohorts – EPIC and UK Biobank – have been studying for several years not cancer or heart attack separately, but rather the trajectories leading to their combination.

Against this backdrop, there is growing interest in lifestyle factors that “work on multiple fronts.” Plant-based dietary patterns are a convenient candidate: they are rich in fiber, polyphenols, and unsaturated fats, while simultaneously “easing” the metabolic, vascular, and inflammatory risk contours. But an important caveat of recent years is the quality of the plant-based diet. Studies distinguish between a healthy plant-based index (vegetables, fruits, whole grains, legumes, nuts) and an unhealthy one (refined grains, sweets, sweetened beverages): the former is consistently associated with a lower risk of CVD and death, the latter is not. In parallel, data has accumulated that ultra-processed foods (UPF), including “plant-based” imitators, can increase the risk of multimorbidity in cancer and cardiometabolic diseases - another argument to look deeper than the “plant-based” label.

Until recently, the question remained open: do plant-based diets “work” in the same way at different ages - in people under 60 and 60+; and do they affect the transition from one major diagnosis to multimorbidity? A new study in The Lancet Healthy Longevity closes this gap: using data from >400,000 participants from six European countries, the authors showed that a more plant-based plate is associated with a lower risk of not only individual diseases, but also their “combos”, and this is true both before and after 60 years. The results are supported by press reports from the University of Vienna and reviews of popular medicine, which emphasize the practical value of healthy plant-based patterns in the prevention of multimorbidity.

The practical implications of this shift in research are a shift away from “one disease, one advice” to universal prevention strategies that simultaneously reduce the likelihood of several major outcomes. From a health policy perspective, this fits neatly with the goals of sustainable diets: plant-based patterns are not only associated with better health outcomes, but also reduce the ecological footprint, which supports their inclusion in national guidelines with an emphasis on whole foods and minimization of ultra-processing.

How was this tested?

The researchers combined data from two large cohorts, EPIC and UK Biobank, covering Italy, Spain, the UK, Germany, the Netherlands and Denmark. Diet was described using integral indices of the “vegetation” of the diet, after which morbidity trajectories were tracked: first cancer or cardiometabolic disease, then their combination (multimorbidity). The key question was whether a plant-based diet “works” the same way in middle age and old age; the answer was yes, a link was observed in both age groups.

Key findings

• Less multimorbidity. A more plant-based diet is associated with a reduced risk of cancer + diabetes/CVD combinations; in the UK Biobank, up to -32% with the highest adherence.
• The effect is not “only for the young.” Risk reduction was similar in those <60 and ≥60 years.
• The quality of plant foods matters. Across studies, it is the healthy plant-based diet (vegetables, fruits, whole grains, legumes, nuts) that produces the best associations; the “unhealthy” plant-based diet (refined grains, sweets, UPF) may provide no benefit or be associated with greater risk - and this is not always consistent across cohorts.

Why is this important?

Multimorbidity is a rapidly growing problem in ageing societies: the same person lives with several chronic diseases, which worsens quality of life and complicates treatment. New work suggests that a shift to a plant-based plate may be a universal preventive strategy for both midlife and old age. This is consistent with recent European news and educational materials: plant-based diets reduce the ecological footprint and are associated with better long-term health outcomes.

What is a "healthy" plant-based diet?

• The base that works:
  • vegetables and fruits of different colors;
  • whole grains;
  • legumes (lentils, beans, chickpeas, soybeans/tofu/tempeh);
  • nuts and seeds;
  • olive oil/other "good" fats in moderation.
• What is less:
• red and processed meats;
• skins/fatty sausages, super-sweet drinks;
• ultra-processed plant imitations (some burgers/sausages) - "plant" does not always mean "healthy". In a number of studies, it was UPF that increased the risk of multimorbidity.

How to interpret

This is an observational analysis - it shows associations, not strict causality. Within the meta-framework, there is heterogeneity between cohorts (EPIC vs UK Biobank): in one set, the signals for an "unhealthy" plant-based diet are strong, in the other - not. In practice, this means that the quality of the diet is more important than the "plant-based" label, and the results themselves should be verified by intervention trials.

Practical conclusions

• Move toward 80/20: 70-80% of calories from whole plant foods; small portions of quality animal products are still appropriate (fish, yogurt) - strict veganism is not required.
• Create a half-quarter-quarter plate: half vegetables/fruit, a quarter each of protein (legumes/tofu/fish/poultry) and whole grains.
• Minimize UPF: read the ingredients, avoid sugar "under different names", trans fats and "endless" lists of additives - this will work better than simply replacing meat with "plant" sausage.
• Think about age, but don't put it off: the study showed benefits up to 60 and beyond, so it's never too late to start.

Context and what other sources say

The signals in favor of plant-based patterns are accumulating: reviews and cohorts link them to lower risks of mortality and “major” chronic diseases; in parallel, individual studies show that ultra-processed foods are, conversely, associated with an increased risk of multimorbidity. The new paper fits into this puzzle, adding an important layer—analysis by age and multimorbidity outcome.

Limitations and open questions

• Observational design: residual confounding (income level, habits, medicine) cannot be completely excluded.
• Measuring diet: Diet questionnaires inevitably contain errors; "vegetation" indices simplify the real complexity of diet.
• Tolerability: Results - about Europe; in other regions the composition of plant-based diets and background disease risk are different.
• Plant-Based Quality: Frontier - Separate whole plant foods from ultra-processed ones and test them separately.

What will science do next?

The authors and commentators call for randomized interventions (not necessarily “rigid” ones – a shift in diet towards whole plant foods is enough) with rigorous endpoints: new cases of cancer/CVD, transitions to multimorbidity, intermediate biomarkers (lipodomics, glycemic and inflammatory panels). A separate vector is the economy and ecology of diet: plant-based patterns are both healthier and more environmentally friendly, which is important for updating national recommendations.

Source of research: Córdova R., Kim J., Thompson SA, et al. Plant-based dietary patterns and age-specific risk of multimorbidity of cancer and cardiometabolic diseases: a prospective analysis. The Lancet Healthy Longevity, 20 August 2025; DOI: 10.1016/j.lanhl.2025.100742.