Garlic gets a bad review
Well, a trial conducted at Stanford University that followed almost 200 patinents has found no evidence that garlic lowers levels of LDL ("bad") cholesterol and general blood lipidity. HerbalGram's review of the study is a good summary, if you don't want to read the whole thing.
Aside from the inevitable media frenzy over this (best headline award: "Garlic stinks for lowering cholesterol"), the study does seem to be a fairly well-crafted, in vivo trial. My only quibble comes with the dose on the fresh garlic, which is very low at 4 grams (about 1 clove) daily. I usually suggest more like 4-5 cloves a day, and generally prefer the whole-plant preparations to health food store pills like Kyolic or Garlicin. In my practice, I have seen these levels of consumption have an impact on total cholesterol and LDL levels when used as part of a balanced, plant-rich, fiber-rich diet.
I think we can draw two lessons from this new information: first off, as the HerbalGram review points out, it may be that garlic has a more potent anticholesterol effect in folks who have seriously elevated levels, not just mildly elevated ones. Secondly, garlic has powerful effects on other markers of cardiovascular disease such as hypertension and vascular inflammation. It may be that, again, we are taking serum cholesterol too seriously as a causative factor in CV disease - and that garlic will reduce blood lipids only in cases where there is actual vascular damage, progressive atherosclerosis, and hypertension.
This study says nothing, of course, about garlic's power to combat infection, address colds and flus, or deal with intestinal parasites and infections - although it does detail effects on breath and body odor, thankfully.