In an investigation at Penn State University, garlic lowered total cholesterol in subjects with high cholesterol by 7 percent. (Additional research has shown that every 1 percent drop in total cholesterol results in a 2 percent drop in coronary-disease risk.) Other studies have generated less impressive results, but there are still significant indications that garlic may have a positive impact on cholesterol levels and heart health. Many studies have used the equivalent of one-half to one clove a day. If that's a turnoff, take a supplement—one clove equals about 4 grams. Impaired blood clotting is the one notable side effect, so if you notice increased bruising, consult your physician.