Environmentally responsible food choices can improve nutrition but may also increase exposure to harmful substances. This is the finding of a study examining how a shift in the Finnish diet toward more plant-based foods would affect nutrition, nutrient intake, and exposure to foodborne contaminants.
A recent report published in THL’s Tutkimuksesta tiiviisti (Research Briefs) series assessed the impacts of two transition pathways: in the smaller shift, meat and dairy products were reduced by one-third; in the larger shift, by two-thirds. In both scenarios, the total energy intake remained the same, and animal-based products were replaced with plant-based alternatives in line with nutritional recommendations.
According to the study, dietary quality improved in both transition pathways when meat and dairy were replaced with fish, legumes, whole grains, and vegetables. This change supports not only health but also climate goals, as the environmental impact of plant-based food production is lower than that of animal-based production.
Nutrient intake deficiencies
However, deficiencies were observed in the intake of vitamins A and D, thiamine (vitamin B1), riboflavin (vitamin B2), and among women, also folate and iron. Young women may receive insufficient iron, as the iron in the transition diets is primarily non-heme iron, which is less readily absorbed.
The dietary shift slightly increased estimated exposure to harmful chemical substances such as lead, inorganic arsenic, methylmercury, aflatoxins, and ochratoxins.
Although the health risk is low for most of the population, exposure levels for some substances exceed the thresholds considered safe in previous risk assessments and may cause health effects. Exposure to methylmercury increases health risks especially for women of reproductive age, which can be avoided by following fish consumption recommendations. The risk from aflatoxins can be reduced by favoring domestic products over imported foods.
A comprehensive approach is needed
The study shows that dietary changes can support health and environmental goals, but it is also important to ensure adequate nutrient intake and manage exposure to harmful substances. Special attention is needed when applying new, stricter nutritional recommendations.
Dietary changes have broad impacts – they simultaneously affect nutrient intake, absorption, environmental burden, and exposure to harmful substances. Therefore, from the perspective of food security and nutrition, a comprehensive assessment and guidance are needed.
The report published in the Finnish Institute for Health and Welfare’s research series is based on the JUST-FOOD project (2019–2025) funded by the Academy of Finland. From the Finnish Food Authority’s risk assessment unit, Research Professor Johanna Suomi and Researcher Liisa Uusitalo participated in the project.