Older adults who follow healthy dietary patterns have blood biomarker levels associated with more favourable biological processes relevant to ageing. This is shown in a study from Karolinska Institutet published in the journal BMC Medicine. The findings may contribute to a better understanding of how dietary habits are related to the body’s ageing processes.
Researchers have long known that diet plays an important role in health later in life, but the biological mechanisms underlying these associations are not yet fully understood. In the current study, researchers cross-sectionally investigated how different dietary patterns are associated with a broad range of blood biomarkers reflecting metabolism, inflammation, vascular health and neurodegenerative processes related to ageing.
The study included 1,769 people aged 60 years and over who participated in the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Participants answered questions about their dietary habits over the previous year, and researchers simultaneously analysed 54 different blood biomarkers.
Three dietary patterns
The researchers examined three dietary patterns that have previously been linked to good health: a Mediterranean-style diet, an index of overall dietary quality, and a measure of the inflammatory potential of the diet. Greater adherence to these dietary patterns was associated with favourable levels of several biomarkers. This included higher folate levels and lower levels of growth differentiation factor 15, which were observed consistently across all three patterns. Additional associations with biomarkers linked to inflammation, metabolism and neurodegenerative processes were specific to individual dietary patterns.
Photo: N/A.
“Our findings suggest that healthy dietary patterns are associated with several biological processes that are important for how we age. This reinforces the view of diet as a modifiable factor that may contribute to healthy ageing,” says Rachel Ann Da Costa , researcher at the Department of Neurobiology, Care Sciences and Society , and first author of the study.
The dietary pattern with lower inflammatory potential showed associations with the greatest number of biomarkers, particularly those linked to inflammation and metabolism. According to the researchers, this may indicate that the inflammatory properties of diet are related to several interconnected biological processes involved in ageing.
More studies needed
As the study examined associations at a single point in time, it cannot establish cause and effect. The researchers also emphasise that participants mainly consisted of older adults from the Stockholm area with relatively high levels of education, which may limit the generalisability of the findings to other populations.
Photo: Maria Yohuang.
“We now need more longitudinal and intervention studies to investigate whether changes in diet also lead to changes in the biological markers we have studied,” says Adrián Carballo-Casla , researcher at the same department and last author of the study.
The study was conducted in collaboration between researchers at Karolinska Institutet, Stockholm University, KTH Royal Institute of Technology, Stockholm Gerontology Research Center, Universidad Autónoma de Madrid and CIBERESP in Spain, as well as the University of Ljubljana in Slovenia. The study is based on data from SNAC-K. Funding was provided by, among others, the Swedish Research Council, Forte, Karolinska Institutet, the Swedish Alzheimer Foundation, the Dementia Foundation, the Foundation for Geriatric Diseases at Karolinska Institutet, the David and Astrid Hagelén Foundation, and Swedish government departments, regions and municipalities. The researchers report no conflicts of interest.
Publication
“Biological signature of dietary patterns in older adults: findings from a population-based study” , Rachel Ann DaCosta, Caterina Gregorio, Amaia Calderón-Larrañaga, Alice Margherita Ornago, Anja Mrhar, Rosario Ortolá, Claudia Fredolini, Davide Liborio Vetrano, Adrián Carballo-Casla, BMCMedicine, online 25 september 2026, doi: 10.1186/s12916-026-05202-2
Three ways of measuring diet quality
Alternative Mediterranean Diet (AMED)
A dietary pattern based on the traditional Mediterranean diet. Higher scores are awarded for a high consumption of vegetables, legumes, fruit, nuts, whole grains and fish. A high proportion of unsaturated fats and moderate alcohol consumption are also scored positively. Lower consumption of red meat and dairy products likewise contributes to a higher score.
Alternative Healthy Eating Index (AHEI)
A scientifically developed index that measures overall diet quality. Higher scores are awarded for foods such as vegetables, fruit, whole grains, legumes, nuts, fish, healthy fats and moderate alcohol consumption. Lower scores are given for high consumption of red and processed meat, sugar-sweetened beverages, trans fats and sodium.
Empirical Dietary Inflammatory Index (EDII)
A measure that estimates how diet influences inflammation in the body. In this study, a reverse version of the index was used, with higher scores corresponding to a diet with lower inflammatory potential. Components such as leafy green and dark yellow vegetables, fruit juices, coffee and tea receive higher scores, while higher consumption of red and processed meat, refined grain products and sugar-sweetened beverages results in lower scores.
