Consumption of Garlic, Coriander, and a Combination of the Two Improved the Lipid Profiles of Patients with Hyperlipidemia
Hyperlipidemia is a major cause of cardiovascular disease (CVD). The retention of lipid-containing compounds such as low-density lipoprotein (LDL) in coronary arteries results in decreased blood flow to the heart. High-energy diets low in omega-3 and omega-6 fatty acids and the lack of physical activities have attributed to an increase in CVD. Nutraceuticals such as garlic (Allium sativum, Amaryllidaceae) and coriander (Coriandrum sativum, Apiaceae) reportedly lower blood lipid levels and improve CVD symptoms. These authors conducted a single-blind, randomized, placebo-controlled clinical trial to investigate the individual and combined effects of garlic and coriander seed powder on lipids, body mass index (BMI), and blood pressure of patients with hyperlipidemia.
The study was conducted at the Cardiac Rehabilitation Center of Hayatabad Medical Complex Hospital in Peshawar, Khyber Pakhtunkhwa, Pakistan. Eighty males and females aged 40 to 80 years met the following inclusion criteria: hyperlipidemia with CVD, total cholesterol >200 mg/dL, and serum triglyceride (TG) level >150 mg/dL. The patients were randomly assigned to take garlic powder (GP), coriander seed powder (CSP), a mixture of equal amounts of GP and CSP, or nothing (control group). The supplements were taken at a dose of 2 g daily for 40 days. The patients were followed for an additional 20 days. Blood lipid levels, BMI, and blood pressure were measured at baseline and at days 20, 40, and 60 days of the study.
Male-to-female ratios were 2:5 in the GP group, 4:3 in the CSP group, 5:2 in the GP-CSP group, and 5:2 in the control group. The baseline average age of all patients ranged from 46.42 to 65.28 years, and BMI averaged from 26.21 kg/m2 to 30.39 kg/m2. Total cholesterol (TC) at baseline ranged from 217 mg/dL to 241 mg/dL; TG levels ranged from 194.28 mg/dL to 292.14 mg/dL, high-density lipoprotein cholesterol (HDL-C) ranged from 41 mg/dL to 43.57 mg/dL, and LDL-C ranged from 123.17 mg/dL to 148.85 mg/dL. Systolic blood pressure (SBP) ranged from 137.14 mm Hg to 140 mm Hg; diastolic blood pressured (DBP) ranged from 83.57 mm Hg to 88.57 mm Hg. Blood glucose levels averaged from 126 mg/dL to 240 mg/dL.
During the study, BMI reached its highest average (30.64 kg/m2) in the control group at day 60 and its lowest average (26.11 kg/m2) in the GP-CSP group at day 40. Although the average BMI tended to decrease in the three treatment groups over time, after day 40, a nonsignificant increase was observed. The authors point out that the efficacy of garlic in reducing BMI may be attributed to its sulfur-containing compounds that reduce the production of fatty substances. Coriander, they say, is rich in dietary fiber, which helps reduce body weight.
The greatest decrease in total cholesterol was seen in the GP group, followed by the GP-CSP group, during the 40-day intervention period. In the follow-up period; however, a significant increase in total cholesterol was seen in the GP group (P<0.05), with nonsignificant increases observed in the CSP and GP-CSP groups. In the control group, total cholesterol levels increased throughout the 60-day study. Among the garlic and coriander groups, the greatest reductions in TG levels were seen in the GP-CSP group, and the smallest improvements were seen in the CSP group. TG levels increased slightly, but not significantly, in the CSP and GP-SCP groups during the 20-day follow-up period. In the control group, TG levels were lower at day 60 compared with baseline.
A significant improvement was seen in HDL-C levels in the three intervention groups (P<0.05), with the greatest improvement observed in the GP group and the lowest in the CSP group. Those improvements were reversed during the follow-up period. HDL-C levels decreased in the control group from baseline to day 60. LDL-C levels, which were significantly lowered during the 40 days of intervention in the garlic and coriander groups, increased during the follow-up period. The greatest improvements were observed with the GP intervention. The control group experienced a steady increase in LDL-C values during the study. In earlier studies, hypolipidemic effects have been attributed to the flavonoids and polyphenols in coriander and to allicin and sulfur-containing compounds in garlic.
Results of blood pressure measures revealed significant decreases in SBP in all garlic and coriander groups (P<0.05), with the greatest improvements seen in the CSP group and the smallest decreases seen in the GP-CSP group. SBP did not change significantly in the control group. DPB did not change significantly in any of the four groups during the study. The antihypertensive effects of coriander may be attributed to its ability to increase urine output and excretion of electrolytes and improve kidney function.
The authors conclude that the daily consumption of garlic, coriander, or a combination of the two improved the lipid parameters of patients with hyperlipidemia.
Zeb F, Safdar M, Fatima S, et al. Supplementation of garlic and coriander seed powder: impact on body mass index, lipid profile and blood pressure of hyperlipidemic patients. Pak J Pharm Sci. September 2018;31(5):1935-1941.