Those who began the study with higher total cholesterol levels, and who continued taking garlic over a longer term, saw the most benefit. Garlic powder and aged garlic extract were more effective in reducing total cholesterol levels, while garlic oil best lowered triglyceride, or total lipid levels.
Overall, compared to placebo, garlic in all forms reduced total cholesterol by 5.4 percent and triglycerides by 6.5 percent. Doctors concluded that garlic therapy should benefit those who have higher chances of heart disease.