From the Guidelines
Garlic does not have a clinically significant effect on lowering Low-Density Lipoprotein (LDL) cholesterol levels, as evidenced by independent clinical trials. The use of garlic preparations for the treatment of hyperlipidemia has been marketed, but studies have shown that it does not have a beneficial effect on the lipid profile 1. A placebo-controlled, double-blind clinical trial in 30 children with familial hyperlipidemia using a commercially available garlic extract found no clinically important effect on the lipid profile or any other cardiovascular risk factor 1. Some studies have shown that other dietary alterations, such as substitution with soy-based protein, dietary enrichment with rapeseed or canola oil, and the use of plant stanol and sterol esters, may have a more significant impact on lowering LDL cholesterol levels and improving overall lipid profiles 1. Key points to consider when managing hyperlipidemia include:
- The importance of rigorous clinical trial evidence to support the use of complementary medicines and dietary supplements
- The potential benefits of other dietary alterations on lipid profiles
- The need for a comprehensive approach to cholesterol management, including prescribed medications, a heart-healthy diet, regular exercise, and lifestyle modifications.
From the Research
Effect of Garlic on Low-Density Lipoprotein (LDL) Cholesterol
- The effect of garlic on LDL cholesterol has been studied in various trials, with some showing a reduction in LDL levels and others showing no significant effect 2, 3, 4, 5, 6.
- A study published in the Archives of internal medicine in 2007 found that raw garlic and garlic supplements had no statistically significant effects on LDL-C concentrations in adults with moderate hypercholesterolemia 2.
- In contrast, a study published in The Journal of nutrition in 2001 found that aged garlic extract supplementation was effective in lowering plasma concentration of LDL cholesterol by 10% in hypercholesterolemic men 3.
- A meta-analysis published in Nutrition reviews in 2013 found that garlic preparations were effective in reducing total serum cholesterol by 17 ± 6 mg/dL and LDL cholesterol by 9 ± 6 mg/dL in individuals with elevated total cholesterol levels 4.
- Another study published in the Journal of the American College of Cardiology in 2000 found that garlic powder had no significant effect on LDL cholesterol levels in moderately hypercholesterolemic subjects 5.
- A more recent meta-analysis published in the Journal of health, population, and nutrition in 2024 found that garlic consumption significantly reduced LDL-C levels (WMD = -0.44mmol/L, 95%CI = -0.57 --0.31, P < 0.001) in patients with dyslipidemia 6.
Factors Influencing the Effect of Garlic on LDL Cholesterol
- The effect of garlic on LDL cholesterol may be influenced by factors such as the type of garlic preparation used, the dose and duration of treatment, and the individual's initial cholesterol levels 3, 4, 6.
- Subgroup analyses have shown that older adults (>50 years) may be more susceptible to the protective effects of garlic on LDL cholesterol levels 6.
- The type of garlic preparation used may also influence the effect on LDL cholesterol, with garlic oil showing a greater reduction in TC and LDL-C compared to garlic powder 6.