A study of 90 overweight smokers suggests that garlic supplements have no effect on a number of heart disease risk factors.
Taking garlic powder supplement for three months resulted in no changes in cholesterol levels, C-reactive protein levels (which indicate arterial inflammation), or levels of other blood substances that indicate how well blood vessel walls are working.
Some studies have found that garlic supplements may help lower blood cholesterol and blood pressure, but other studies have failed to find these benefits.
One-third of the study participants were randomly assigned to take 2 grams of garlic supplement each day. Another third took 40 milligrams of Lipitor each day, and the rest were given placebos. There were no clear differences between the garlic group and the placebo group.