One common method used by dietitians, medical professionals, and researchers to assess individuals’ diets and their impact on health is through self-reporting. While this approach can be helpful, there is a risk of inaccuracies in the data collected through methods such as dietary records or questionnaires.
To address these limitations, a recent study focused on analyzing metabolites in blood as potential biomarkers for evaluating dietary patterns objectively. Metabolites are molecules like amino acids and peptides that are produced during metabolic processes or afterward.
Andrea J. Glenn, an assistant professor of nutrition at NYU Steinhardt School of Culture, Education, and Human Development, explains, “By analyzing metabolites in blood in controlled feeding studies, we may potentially use these as biomarkers of dietary patterns in the future. This method could offer a more accurate assessment compared to self-reported data.”
The study analyzed metabolites in plasma samples from participants in two trials who were following the portfolio diet. This diet is designed to lower cholesterol levels by emphasizing plant-based foods such as soy protein, nuts, plant sterols, and viscous fiber.
During both trials, participants received all the required foods as part of the diet plan at weekly clinic visits for four weeks. Plasma samples were collected at the beginning of the study, at week two, and at week four to monitor changes in metabolites.
In the first trial, 34 participants were divided into three groups: a portfolio diet group, a control diet group, and a control diet combined with a cholesterol-lowering medication. In the second trial, 25 participants were assigned to either the portfolio diet group or the control group.
The results of the study, published in the European Journal of Clinical Nutrition, revealed significant changes in metabolites for participants following the portfolio diet. Across both trials, 52 metabolites associated with plant-based diets and low saturated fat content showed notable changes, indicating adherence to the portfolio diet.
While these findings are promising, further research is required to confirm these metabolites as reliable biomarkers for assessing dietary patterns. Andrea J. Glenn, the lead author of the study, emphasizes the need for additional studies to validate these results.
More information:
Glenn, A.J., et al, Metabolomic profiling of a cholesterol lowering plant-based diet from two randomized controlled feeding trials, European Journal of Clinical Nutrition (2025). DOI: 10.1038/s41430-025-01625-x, www.nature.com/articles/s41430-025-01625-x
