A healthful plant-based diet is associated with higher physical and mental well-being among older adults independent of circulating CRP

Plant-based diets have been found to be environmentally sustainable as well as beneficial for health. Observational research showed that higher plant-based diet quality improves well-being in adult women, however this relationship has not yet been established for men and women of older ages. It has been hypothesized that such effects may be due to anti-inflammatory properties of plant-based diets. In that case, especially older adults, often suffering from chronic inflammation, may profit from a more plant-based diet. Therefore, we investigated the relation between plant-based diets and well-being in older adults of both genders and tested whether the effects are influenced by circulating high-senstivity C-reactive protein (hsCRP) levels. We used the data of the population-based Lifelines Cohort Study (n=6,635, mean age=65.2 years) and a subsample in which hsCRP was measured (n=2,251, mean age=65.2 years). We applied a plant-based diet index measuring adherence to a healthful (hPDI) and an unhealthful (uPDI) diet based on FFQ data. The RAND-36 questionnaire was applied as measure of quality of life, from which we derived physical (PCS) and mental component scores (MCS). Older adults with the highest adherence to a healthful plant-based diet had respectively 14% and 12% greater odds for high physical well-being and mental well-being. Meanwhile, higher adherence to uPDI was associated with respectively 19% and 14% lower odds for high physical and mental well-being. We observed an additive but no mediating effect of hsCRP on the association between plant-based diets and well-being. We conclude that in older men and women, adherence to a healthful plant-based diet and circulating levels of inflammation are independently associated with physical and mental well-being.