Is adherence to a healthful plant-based diet associated with a lower mortality risk and chronic disease among UK adults?

By Bhavana KunkalikarReviewed by Lily Ramsey, LLMMar 31 2023

In a recent study published in the JAMA Network Open Journal, researchers examined the correlation between adherence to a healthful plant-based diet and mortality risk.

Study: Association of Healthful Plant-based Diet Adherence With Risk of Mortality and Major Chronic Diseases Among Adults in the UK. Image Credit: marilynbarbone/Shutterstock.com

Background

The global popularity of plant-based diets (PBDs), defined by a limited or complete absence of eggs, fish, dairy products, and meat, is rising. This phenomenon can be attributed, to some extent, to the possible health advantages that individuals may experience by adhering to PBD.

These benefits include a decreased likelihood of developing cardiovascular disease (CVD), diabetes, and mortality. Research suggests that a healthy PBD involving limited intake of animal-based foods and processed plant-based foods is linked to a reduced likelihood of developing type 2 diabetes, CVD, and overall mortality. However, a comprehensive assessment of plant-based diet quality in relation to risk of mortality and major chronic diseases is lacking.

About the study

The present study assessed the potential correlation between healthful and unhealthful PBD patterns and their association with mortality rates and major chronic diseases.

The UK Biobank involves a prospective study encompassing a population-based sample of over 500,000 persons aged between 40 and 69 years recruited from 2006 to 2010. The study's participants must have attended one of the 22 assessment centers in England, Wales, and Scotland. At these centers, they underwent a thorough baseline assessment.

The study utilized the Oxford WebQ instrument to develop two distinct indices: the healthful PBD index (hPDI) and the unhealthful PDI (uPDI). These indices were established by analyzing the average food consumption derived from at least two 24-hour dietary evaluations.

The hPDI and uPDI were evaluated based on a scoring system that assigned positive scores to healthy plant foods and negative scores to less healthy plant foods and animal-derived foods.

The uPDI was scored oppositely to the hPDI. The food group intakes exceeding zero portions were categorized into quartiles. The individuals involved in the study were categorized into quartiles based on the amount of each food group they consumed and subsequently received a score ranging from 2 to 5.

Results

126,394 individuals out of the 502,411 participants had accessible data from at least two dietary recalls at baseline, along with pertinent covariates. The present study's subsample comprised 70,618 females and 55,776 males.

The average age of the group was 56.1 years. Over a follow-up period ranging from 10.6 to 12.2 years, this study observed 5,627 deaths, 6,890 CVD cases, 8,939 cancer cases, and 4,751 fracture cases.

The study population exhibited normal distribution in both hPDI and uPDI scores, ranging from 31 to 84 and 28 to 82 points. Individuals exhibiting higher hPDI scores had a greater likelihood of being female, possessing a lower body-mass index (BMI), being of advanced age, reporting no medication intake, having no chronic health conditions, exhibiting lower alcohol consumption, and having a higher level of education in comparison to those with lower hPDI scores.

The study utilized multivariable-adjusted models to determine the association between hPDI scores and all-cause mortality. The results indicated that persons with higher hPDI scores exhibited a 16% lower likelihood of all-cause mortality than those with lower scores.

In contrast, individuals who obtained higher scores on the uPDI scale exhibited a 23% increased likelihood of experiencing mortality from any cause. The study found that increased adherence to hPDI was linked to a 7% reduction in the likelihood of developing cancer.

Conversely, individuals with elevated uPDI scores exhibited a 10% greater risk of developing cancer. No significant correlations were observed between hPDI or uPDI and frequently diagnosed prostate, breast, and colorectal cancers.

Multivariable models revealed that increased hPDI scores were linked to decreased risks of total ischemic stroke, myocardial infarction, and CVD with corresponding hazard ratios of 0.84, 0.86, and 0.92. Elevated uPDI scores positively correlated with increased susceptibility to ischemic stroke, myocardial infarction, and total CVD, as evidenced by hazard ratios of 1.23, 1.17, and 1.21, respectively.

The study found no significant correlations between uPDI or hPDI and the likelihood of experiencing a hemorrhagic stroke. The results of our analyses indicated a lack of significant correlations between uPDI or hPDI and the risks of total and site-specific fractures.

Conclusion

The study findings indicated that adopting a healthful PBD reduces risks of total CVD, cancer, and overall mortality. Conversely, an eating regimen primarily composed of plant-based foods with increased consumption of sugary beverages, snacks, desserts, refined grains, potatoes, and fruit juices was linked to an elevated risk.

The study also noted that prioritizing the consumption of nutritious plant-based foods can enhance overall health and furnish evidence in favor of adopting a wholesome PBD for CVD  prevention, regardless of an individual's genetic predisposition to the disease.

Further research is required to evaluate the association between PBDs and the risk of significant chronic illnesses in more diverse ethnic, racial, and cultural groups.