EAT-Lancet Healthy Reference Diet: environment and heart-friendly?

A recent study posted in the Journal of the American Heart Association aimed to construct a diet score measuring adherence to the healthy reference diet (HRD) and to explore its association with cardiovascular events and environmental benefits.

Study: Adherence to the EAT‐Lancet Healthy Reference Diet in Relation to Risk of Cardiovascular Events and Environmental Impact: Results From the EPIC‐NL Cohort. Image Credit: BONDARTPHOTOGRAPHY/Shutterstock.com

Background

Eating healthy is a buzzword among environmentally- and health-conscious individuals globally.

The Healthy Reference Diet (HRD) is an eating plan designed with such considerations in mind. A new paper reports how far individuals who follow the HRD experience reduced cardiovascular risk along with the environmental impact of their actions.

Introduction

Poor-quality diets, linked to high sodium intake and low consumption of whole grains and fruit, are associated with cardiovascular disease risk. At the same time, the current eating practices are environmentally unsustainable for the growing global population.

Up to a third of greenhouse gas (GHG), production and almost three-quarters of freshwater consumption occurs during food production, mostly while raising meat and dairy animals.

Shifting toward healthy and sustainable diets could benefit both public and planetary health.”

The HRD, proposed by the EAT‐Lancet Commission on Healthy Diets From Sustainable Food Systems, is heavy on fruit and vegetables, with whole grains, legumes, nuts, and unsaturated fats, with low amounts of saturated fats, red meat, and sweeteners. Small to moderate quantities of fish, poultry, starchy vegetables, and dairy are included.

The EAT-Lancet report predicted a drop in premature adult mortality risk by about a fifth to a quarter, but this has been little studied in practice.

In the present study, a nuanced vs a binary approach was used to assess adherence to HRD over a spectrum of dietary choices and its association with cardiovascular and environmental impact.

The study investigated data from approximately 35,500 participants in the EPIC‐NL (European Prospective Investigation into Cancer and Nutrition‐Netherlands) study. The investigators used food frequency questionnaires to explore the participants’ adherence to the HRD, expressed as a score.

They then linked this score with records of illness and death from national and death registries, as well as life cycle assessments to examine the environmental impact.

Eutrophication, which refers to the enrichment of water bodies with nutrients at excessive levels, causing algal bloom and reducing the available oxygen for aquatic life forms, was measured for the latter purpose, as well as soil acidification, via the entry of sulfur dioxide or its equivalent, causing the loss of biodiversity.

What did the study show?

Participants with high HRD adherence were mostly female, with normal body mass, better education, non-smoking habits, and lower consumption of calories per day when compared with the least adherent participants.

Over the next 15 years (median), there were over 4,000 cardiovascular events and over 2,300 coronary heart disease events. Overall, there were ~840 strokes.

The researchers found that individuals with a high degree of adherence to the HRD had a reduced risk of cardiovascular risk. The risk of cardiovascular disease was reduced by 14%, while that of coronary heart disease was reduced by 12%.

Greenhouse gas (GHG) emissions were reduced in those with high HRD adherence, while land use was reduced by ~4%. Freshwater and marine eutrophication decreased by 0.5% and 3.3%, respectively. Acidification of the soil was ~8% less, while blue (irrigation) water use was higher by a third.

What are the implications?

High adherence to the HRD resulted in better health outcomes overall. Both cardiovascular risks and coronary heart disease risks were lower among those with the closest adherence.

Even with total stroke, the magnitude of associations remained similar to that of the above conditions, though it fell short of statistical significance.

Similarly, the impact of the HRD on the environment was non-negligible, with significant thought small reductions in the number of nutrients being allowed to enter marine and freshwater, less soil acidification by over fifteenth, lower GHG emissions, and a decline in land use.

The findings using this refined HRD score reflect those of earlier studies, except for the lack of association with stroke in one earlier study. This could be a chance finding, given the small number of cases in that study, however.

The risk reduction for cardiovascular events also corroborates the findings of earlier researchers based on the Mediterranean and other health-promoting diets.

Observed diets may still be suboptimal, and further improvements toward the HRD may have larger effects on environmental impact indicators.”

Socio-economic changes, along with better food supply chain and waste management, will be essential for producing significant environmental changes.

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.