Combined Effects of Exercise and Broccoli Supplementation on Metabolic and Lipoprotein Biomarkers in Adults with Type 2 Diabetes: A Randomized Controlled Trial

Aim: To investigate the synergistic effects of exercise training and Brassica oleracea var. italica (broccoli sprout) supplementation on Apolipoprotein A-I, B-100, and J levels in men with Type 2 diabetes mellitus (T2DM). Methods: Forty-four males with T2DM were randomly assigned to four groups: Control (CG), Supplement (SG), Training (TG), and Training + Supplement (TSG) groups. Participants in the supplement groups (SG and TSG) received 10 g of broccoli supplement after meals for 12 weeks, while those in the training groups (TG and TSG) participated in a structured exercise program (resistance and aerobic), performed three times per week for 12 weeks, at intensities of 60-70% one-repetition maximum (1RM) for resistance training and 60-70% peak oxygen uptake (VO2peak) for aerobic training. Results: Circulating levels of apolipoproteins improved after 12 weeks in the TSG, TG, and SG groups. However, the TSG group exhibited the most pronounced improvements across metabolic and lipoprotein markers, reflecting an additive effect of both interventions. Specifically, the TSG group demonstrated absolute reductions in ApoB-100 (-48.30 ± 7.20 mg/dL) and ApoJ (-44.05 ± 5.76 mg/dL), along with an increase in ApoA-I (+44.92 ± 6.05 mg/dL). Main effect analysis revealed that exercise training elicited the most substantial improvements across metabolic and lipoprotein markers, with large effect sizes for glucose (η2p = 0.787), insulin (η2p = 0.640), HOMA-IR (η2p = 0.856), ApoA-I (η2p = 0.685), ApoB-100 (η2p = 0.774), ApoJ (η2p = 0.848), and HDL-C (η2p = 0.535). Supplementation showed moderate effects, particularly on HOMA-IR (η2p = 0.370), ApoA-I (η2p = 0.383), and ApoB-100 (η2p = 0.334), supporting an additive but exercise-dominant benefit. The combined intervention group (TSG) showed the most pronounced improvements across all measured outcomes, with large effect sizes for ApoA-I (η2p = 0.883), glucose (η2p = 0.946), insulin (η2p = 0.881), HOMA-IR (η2p = 0.904), and ApoJ (η2p = 0.852). Conclusions: The effects of combining training and broccoli sprout supplementation on apolipoprotein levels are likely to result from the activation of two separate pathways, one from training and the other from supplementation. This dual-modality intervention could serve as an effective complementary strategy in managing metabolic and cardiovascular risk factors for individuals with T2DM. However, the magnitude of change induced by the combination of exercise training and broccoli supplementation was largely driven by the training component, with supplementation providing complementary but less consistent benefits.