Association between planetary health diet and cardiovascular disease: a prospective study from the UK Biobank

The Planetary Health Diet Index (PHDI) prioritizes the well-being of both individuals and the planet but has yielded mixed results on cardiovascular disease (CVD). The aim of this study was to assess the association between the PHDI and risk of CVD.

A cohort of 118 469 individuals aged 40-69 years from the UK Biobank, who were free of CVD at 2009-12 and followed up to 2021. The PHDI was calculated using at least two 24-h dietary assessments and included 14 food groups, with a possible range from 0 to 130 points. Cardiovascular disease incidence was defined as primary myocardial infarction or stroke and obtained from clinical records and death registries. During a 9.4-year follow-up, 5257 incident cases of CVD were ascertained. When comparing the highest (89.9-128.5 points) vs. the lowest (21.1-71.1 points) quartile of PHDI adherence, the multivariable-adjusted hazard ratio [95% confidence interval (CI)] was 0.86 (0.79, 0.94) for CVD, 0.88 (0.80, 0.97) for myocardial infarction, and 0.82 (0.70, 0.97) for stroke. The association was linear until a plateau effect was reached at 80 points of adherence to PHDI. Results remained robust when excluding participants with type 2 diabetes, including only those with three or more diet assessments, or excluding CVD cases in the first 3 years of follow-up. The food group components of the PHDI more strongly associated with a reduced CVD risk were higher consumption of whole grains, whole fruits, and fish and lower consumption of added sugars and fruit juices.

In this large cohort of middle-aged and older British adults, adherence to the PHDI was associated with a lower risk of CVD. These results provide empirical evidence that this dietary pattern, thought to be environmentally sustainable, benefits cardiovascular health.