Q. As a physician I usually enjoy your column. But I have some serious questions about your claims about garlic.
What is the evidence that “Egyptian physicians used garlic”? You have stated that as if it were fact? Is there any actual record of this? Even if they did, is that a good reason for us to use it? How do you know that garlic can help prevent blood clots or that it has cancer fighting properties?
I enjoy the flavor of garlic in my food, but I am skeptical about its ability to prevent cancer or heart attacks. Please back up your statements.
A. The Ebers Papyrus from 1550 BC mentions 22 herbal remedies containing garlic. Hippocrates prescribed it for a wide variety of ailments including chest pain.
Just because Egyptians and Greek healers used it doesn’t necessarily mean it has medicinal value. Modern studies show, however, that this flavorful herb contains chemicals with anti-platelet action (Pharmacology, online, Jan. 28, 2009). As a physician you understand that such activity reduces the risk of blood clots that could cause heart attacks.
Garlic and Cardiovascular Health:
A study published in the journal Nutrition (Sept, 2014) demonstrated that an aged garlic extract:
“reduced atherogenic markers and thus may have a cardioprotective effect beyond the gold standard medication in patients with mild hypercholesterolemia.”
An article titled “Role of Nutraceutical in Hypolipidemic Therapy” published in the journal Frontiers in Cardiovascular Medicine (May, 2015) noted:
“Overall, garlic, even without a significant lipid-lowering effect, could have other protective effects on the cardiovascular system for its ability to reduce blood pressure and platelet aggregation, but this needs to be better investigated in large controlled trials.”
Another article titled “Prevention of Cardiovascular Diseases by Garlic-Derived Sulfur Compounds” published in the Journal of Nutritional Science and Vitaminology (Jan. 8, 2016) concluded:
“Taken together, garlic may prevent thrombus formation [blood clots] during CVD [cardiovascular disease] through different mechanisms involving anti platelet, vasodilative, lipid-lowering, and anti-atherosclerotic effects.”
Garlic vs. Cancer
In the test tube, garlic blocks tumor promotion. Epidemiology in China shows that when it is part of the diet cancer incidence drops dramatically. A review of the potential therapeutic effects of garlic in Avicenna Journal of Phytomedicine (Jan-Feb. 2014) concluded that:
“…garlic may be the most potent food having cancer preventive properties. Garlic has a variety of anti-tumor effects, including tumor cell growth inhibition and chemopreventive effects.”
To maximize the anti-cancer effect, it should be crushed or chopped at least 10 minutes before it is cooked.
Action Against Parasites:
Leishmaniasis is a nasty infection from a protozoan parasite Leishmania. Biting flies can spread this disease and it is challenging to treat. An article in the Journal of Evidence Based Complementary and Alternative Medicine (online, Dec. 30, 2015) offered this:
“The current drugs for treatment of leishmaniasis possess many disadvantages; therefore, researchers are continuously looking for the more effective and safer drugs. The aim of this study is to review the effectiveness, toxicities, and possible mechanisms of pharmaceutical actions of different garlic extracts and organosulfur compounds isolated from garlic against Leishmania spp. in a variety of in vitro, in vivo and clinical trials reports…In summary, garlic with immunomodulatory effects and apoptosis induction contributes to the treatment of leishmaniasis.”
The Bottom Line:
We think garlic represents an amazing addition to the diet. We prefer it fresh in food, but some people cannot tolerate the taste or the smell, so an extract may be worthwhile for them.
We have only scratched the surface of the potential benefits of garlic. Research is ongoing and we may yet learn that it has antibacterial, anti fungal and anti diabetic activity. Since it cannot be patented it is highly unlikely that any drug company will spend money to demonstrate to your satisfaction the healing power of garlic. Nevertheless, we think there is a LOT of goodness in garlic!