A risk-benefit assessment of moderate plant-forward dietary transitions in the Danish population

Background

Quantifying health and environmental trade-offs of plant-forward diets provides evidence to support public health decision makers and the transition to more sustainable consumption.

Methods

Moderate plant-forward substitution scenarios, based on substituting animal foods with plant foods, and an EAT-Lancet scenario were compared to usual diets in Denmark using national consumption data and a risk-benefit assessment. Net impacts from nutritional and chemical dietary risk factors were integrated on the disability-adjusted life year (DALY) and environmental impacts were quantified as carbon footprints.

Results

The EAT-Lancet scenario provided the most beneficial net health (593 [95% UI: -583 to 1544] DALYs averted annually per 100,000 females) and environmental effects; however, it was also the scenario with the highest chemical burden of disease and departure from baseline intakes. The 25% plant-forward substitution resulted in an estimated 262 [-747 to 1699] DALYs annually per 100,000 females (of which 1.5 DALYs were averted due to lowered chemical intake) and a 12% reduction in CO2eq. All substitution scenarios led to loss of DALYs except for the high protein scenarios in males. Carbon footprint reductions increased with higher proportions of substitution, reaching up to 29%. Inclusion of associations between fish and dementia and dairy and dementia drove the negative health impacts.

Conclusions

Results suggested that more plant-forward shifts may not result in health gains for the Danish population, contrary to previous studies. However, high levels of uncertainty were propagated in our models. Compared to nutritional risks, impacts from heavy metals were negligible. Selection of input data and foods being substituted play critical roles in dietary models and warrant further investigation. Co-benefits between environmental and health gains for the Danish population following plant-forward transitions could not be established nor ruled out.

Key messages

• Dietary model results had much greater associated uncertainty and opposite direction of most previous studies on sustainable diets.

• Health impacts of chemical risks in sustainable dietary transitions were much smaller than nutritional risks.