Effects on cardiovascular risk factors of a low- vs high-glycemic index Mediterranean diet in high cardiometabolic risk individuals: the MEDGI-Carb study

Giuseppina Costabile; Robert E Bergia; Marilena Vitale; Therese Hjorth; Wayne Campbell; Rikard Landberg; Gabriele Riccardi; Rosalba Giacco

doi:10.1038/s41430-024-01406-y

Effects on cardiovascular risk factors of a low- vs high-glycemic index Mediterranean diet in high cardiometabolic risk individuals: the MEDGI-Carb study

Eur J Clin Nutr. 2024 Jan 24. doi: 10.1038/s41430-024-01406-y. Online ahead of print.

Authors

Giuseppina Costabile¹, Robert E Bergia², Marilena Vitale³, Therese Hjorth⁴, Wayne Campbell², Rikard Landberg⁴, Gabriele Riccardi³, Rosalba Giacco⁵

Affiliations

¹ Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy. giuseppina.costabile@unina.it.
² Department of Nutrition Science, Purdue University, West Lafayette, IN, USA.
³ Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy.
⁴ Department of Biology and Biological Engineering, Food Science and Nutrition, Chalmers University of Technology, Gothenburg, Sweden.
⁵ Institute of Food Sciences, National Research Council, Avellino, Italy.

PMID: 38267533
DOI: 10.1038/s41430-024-01406-y

Abstract

Background: The role of dietary Glycemic Index (GI), independently of fiber intake, in modulating cardiovascular disease (CVD) risk among non-diabetic individuals has not been fully elucidated.

Objective: To evaluate the effects of a low- versus a high-GI diet, based on a Mediterranean dietary pattern, on cardiometabolic risk factors in individuals at high CVD risk, participating in the MEDGI-Carb intervention study.

Subjects and methods: 160 individuals, aged 30-69 years, BMI 25-37 kg/m², with a waist circumference >102 cm (males) or >88 cm (females) and one feature of the metabolic syndrome, participated in a multi-national (Italy, Sweden, USA) randomized controlled parallel group trial. Participants were assigned to a low GI (< 55) or high-GI MedDiet ( > 70) for 12 weeks. The diets were isoenergetic and similar for available carbohydrate (270 g/d) and fiber (35 g/d) content. Fasting metabolic parameters were evaluated in the whole cohort, while an 8-h triglyceride profile (after standard breakfast and lunch) was evaluated only in the Italian cohort.

Results: Blood pressure and most fasting metabolic parameters improved at the end of the dietary intervention (time effect, p < 0.05 for all); however, no differences were observed between the low- and the high-GI MedDiet groups (time x group effect; p > 0.05 for all). Conversely, the low-GI diet, compared with high-GI diet, significantly reduced the 8-h triglyceride profile (p < 0.017, time*group effect) that was measured only in the Italian cohort. However, it induced a reduction of plasma triglycerides after lunch (tAUC) that was of only borderline statistically significance (p = 0.065).

Conclusions: Consuming a low-GI in comparison with a high-GI MedDiet does not differentially affect the major cardiometabolic risk factors at fasting in individuals at increased cardiometabolic risk. Conversely, it could reduce postprandial plasma triglycerides.

Clinical trial registry number: NCT03410719, ( https://clinicaltrials.gov ).

Associated data

ClinicalTrials.gov/NCT03410719