Broccoli Sprout Powder Could Improve Some Lipid and Glucose Parameters in Patients with Type 2 Diabetes
Bahadoran Z, Mirmiran P, Hosseinpanah F, Rajab A, Asghari G, Azizi F. Broccoli sprouts powder could improve serum triglyceride and oxidized LDL/LDL-cholesterol ratio in type 2 diabetic patients: A randomized double-blind placebo-controlled clinical trial. Diabetes Res Clin Pract. 2012;96(3):348-354.
Type 2 diabetes is associated with a rise in dyslipidemia and lipid peroxidation, both of which promote atherosclerosis. Several natural products derived from cruciferous vegetables with a high antioxidant content have shown favorable effects on mitigating this process, including broccoli (Brassica oleracea var. italica) sprouts. A recent phase I study showed that broccoli sprouts had beneficial effects on the lipid profiles of patients with type 2 diabetes; though the study was uncontrolled, of a short duration, and had a small sample size. This parallel, randomized, double-blind, placebo-controlled trial studied the effects of broccoli sprout powder (BSP) on lipid parameters in patients with type 2 diabetes. In addition to statin therapy, the combination of fibrates, niacin, or omega-3 fatty acids has often been used to treat hypertriglyceridemia in patients with type 2 diabetes.
Patients were recruited via referrals to the Iranian Diabetes Society and the endocrine clinic of the Taleghani Medical Center in Tehran, Iran. Patients were 18-60 years of age and had a clinical diagnosis of type 2 diabetes for at least 1 year. They were excluded if they had any severe physical impairment; were pregnant or lactating; took insulin injections; or consumed estrogen, vitamin K antagonists, or antioxidant supplements. Eighty-one patients were randomly assigned to 1 of 3 groups: group A (n=27), who received 10 g/d of BSP (Cyvex Nutrition, Inc.; Irvine, California); group B (n=29), who received 5 g/d of BSP; or group C (n=25), who received a placebo (5 g of corn starch powder colored with chlorophyll) that was claimed to have been indistinguishable from the treatments. The 10 g dose of BSP provided 225 μmol/l of glucosinolates and isothiocyanates daily and the 5 g dose of BSP provided 112 μmol/l of glucosinolates and isothiocyanates daily. All treatments were taken for 4 weeks with a beverage after meals (to reduce gastrointestinal [GI] symptoms).
Blood samples and 3-day dietary recalls were performed at baseline and 4 weeks. Blood was analyzed for fasting blood glucose (FBG), total cholesterol (TC), triglyceride concentration (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and oxidized LDL (Ox-LDL). Ratios of Ox-LDL/LDL-C, the atherogenic index of plasma (AIP; log TG/HDL-C), TC/HDL-C, and LDL-C/HDL-C were calculated.
No differences in anthropometric measures, medication, total energy, or nutrient intake were seen between groups. Nine patients (n=4 from group A; n=3 from group B; and n=2 from group C) dropped out of the study due to GI discomfort, flatulence, increased defecation, flushing, or being lost to follow-up. This left a total of 72 patients who were included in the final analysis (n=23, group A; n=26, group B; and n=23, group C).
At the end of 4 weeks, FBG, TC, and LDL-C decreased significantly in both groups A and B, compared to their respective baselines.
BSP showed beneficial effects on several lipid and blood glucose parameters, including FBG, TG, LDL-C, and the AIP. TG is a potent and independent predictor of coronary heart disease (CHD), and a 1 mmol/l increase in serum triglycerides has been independently related to a 14% and 37% increased risk of CHD in men and women, respectively. In this study, there was an 18.7% decrease in serum TG (representing close to a 0.5 μmol/l reduction). Similarly, the Ox-LDL/LDL-C ratio has been shown to be a significant and independent marker of cardiovascular risk. The higher dose of BSP induced a 13.5% decrease in the Ox-LDL/LDL-C ratio, which may be associated with a decreased risk of atherogenic complications in patients with diabetes; indeed, the AIP in this group fell by 52%. The mechanism of action of BSP on lipid parameters is not clear, but it may involve either reduced fat absorption or decreased gene expression and activity of key lipogenic enzymes.
Future studies should increase the duration of treatment and the frequency of testing during the study, as well as test additional dosages and inflammatory parameters. Also, future studies would be improved by analysis, characterization, and confirmation of the glucosinolate and isothiocyanate content of the test nutritional product.