Effects of lacto-vegetarian and vegan diets on glycemic responses and metabolite profiles in healthy adults: a randomized trial using continuous glucose monitoring and targeted metabolomics

Zhu, X., Gayathri, R., Sriram Manasa, V., Abirami, K., Bhupathiraju, S. N., Mohan Anjana, R., Givens, D. I. ORCID: https://orcid.org/0000-0002-6754-6935, Wijeyesekera, A. ORCID: https://orcid.org/0000-0001-6151-5065, Sudha, V., Mohan, V. and Vimaleswaran, K. S. ORCID: https://orcid.org/0000-0002-8485-8930 (2025) Effects of lacto-vegetarian and vegan diets on glycemic responses and metabolite profiles in healthy adults: a randomized trial using continuous glucose monitoring and targeted metabolomics. Clinical Nutrition, 49. pp. 138-148. ISSN 1532-1983 doi: 10.1016/j.clnu.2025.04.018

Abstract/Summary

Background Our previous studies have demonstrated that dairy products protect against type 2 diabetes (T2D) and improve cardiometabolic health outcomes. Given that continuous glucose monitoring (CGM) and metabolomics analysis capture different aspects of T2D, this study investigated the effects of dairy and non-dairy products on the glycemic and metabolite profiles in healthy adults following lacto-vegetarian and vegan diets. Methods A parallel randomized feeding trial with 30 participants compared isoenergetic vegan and lacto-vegetarian diets. All participants wore CGM sensors for 14 days to track glucose concentrations. Anthropometric and biochemical characteristics were also measured. In a subgroup of 13 individuals, fasting and postprandial blood samples were collected on days 1 and 15 for metabolomics analysis. Results Our CGM data showed higher mean glucose concentrations in the vegan group over 14 days compared to the lacto-vegetarian group (p = 0.0399), after adjusting for age, sex, body mass index, and baseline glucose concentrations. Metabolomics analysis from day 1 to day 15 showed increased postprandial phenylalanine (Phe; p = 0.0189) in the vegan group, while the lacto-vegetarian group showed increased acetyl carnitine (C2; p = 0.00704) and decreased argininosuccinic acid (p = 0.0149). Conclusions Our pilot CGM data suggest a lacto-vegetarian diet may offer better glycemic control, potentially explained by our preliminary metabolomics findings. The increased Phe observed in the vegan group may be explained by a hypothetical mechanism in which higher glucose induces oxidative stress, whereas the increased C2 from dairy in the lacto-vegetarian group may protect against oxidative stress, contributing to lower glucose concentrations. However, larger, longer-term studies with more diverse populations, along with in vitro investigations into biomolecular mechanisms, are needed to confirm these findings.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/122530
Identification Number/DOI	10.1016/j.clnu.2025.04.018
Refereed	Yes
Divisions	Interdisciplinary Research Centres (IDRCs) > Institute for Food, Nutrition and Health (IFNH) Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Human Nutrition Research Group
Publisher	Elsevier
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