By Curtis Alexander, Pharm.D.
Summary: The benefits of garlic include antibiotic and possible antiviral activity, no resistance shown from bacteria like traditional prescription antibiotics and some antioxidant activity. Using garlic as a way to lower cholesterol appears to be more controversial.
Dear Curtis: People always point out the health benefits of garlic. But, in your opinion, is it really as great as they claim. And, are the benefits of garlic supplements the same as eating raw garlic?
My Answer: While supplement manufacturers and pharmaceutical companies are searching for the next breakthrough that they can patent, sometime Mother Nature has something that is better than anything we could ever come up with. Garlic may just be one of those natural foods that you and I should be eating more of.
Especially after you look at what the scientific evidence shows about garlic:
1. Natural Antibiotic Activity
In one study at the National University of Health Sciences researchers obtained allicin, the major component of garlic, from garlic tablets. They then tested microgram quantities (1 milligram is 1000 micrograms; so we are talking extremely small amounts here) and found that even these small amounts were enough to inhibit VRE (vancomycin-resistant enterococci).
In case you didn’t know vancomycin is one of those antibiotics that is considered a big-gun and a last resort. Now, with the overuse of typical antibiotics the medical community is starting to see a lot more resistance to even our last resort drugs.
Another dangerous strain of bacteria is known as MRSA (methicillin-resistant Staphylococcus aureus). Allicin is also showing signs in the lab of being able to eradicate this dangerous strain. At the University of East London researchers used liquid and cream formulations of allicin and found it was a potent inhibitor of MRSA. Including those strains of MRSA resistant to mupirocin – a common antibiotic used to treat MRSA in hospitals.
SIDENOTE: These studies were performed in vitro (in the lab) not in vivo (in humans).
2. Low, or no, resistance
With current antibiotics we are always worried about the bacteria eventually mutating and becoming resistant. But with garlic it doesn’t look like the body ever develops any sort of resistance to the anti-bacterial effects of garlic.
Of course, more testing needs to be performed. But right now that is a huge advantage over other antibiotics.
3. Cold and flu prevention
Garlic isn’t just an antibiotic. It appears as though it has some antiviral properties as well. As in, preventing, and maybe even treating, the common cold and flu. While the studies out there aren’t definitive there have been some positive news.
For example, one double-blind, placebo-controlled survey (this is the gold standard of clinical studies) showed that there was a statistical difference between the incidence and duration of a cold or flu in volunteers who took a garlic supplement versus those who didn’t.
In short, the volunteers who took a garlic supplement saw significantly fewer colds during cold season. If they did get a cold, the number of days it lasted was significantly shorter.
Right now we don’t know if it is true antiviral acitivity, or if garlic ‘revs up’ your own immune system to protect you better. Either way, it’s apparent that garlic can improve your cold and flu defense.
SIDENOTE: The main study supporting garlic’s use to prevent colds and flu was performed at a pro-garlic facility. However, I thought the design of the study was solid and trust the results.
4. Garlic is an antioxidant
In 1995 scientists from The College of Medicine at the University of Saskatchewan found that Garlicin (a commercially available garlic supplement) showed a concentration-dependent lowering of hydroxyl radicals. In short, the more Garlicin they gave, the more antioxidant activity they saw.
The question is, are free radicals as big of a deal as we once thought? I tend to think they are and anything you can do to keep your free radical load down is a positive thing. It was clear from this study that a garlic supplement can do that.
The study did not look at raw garlic, but I would think the results would hold true in that case.
Controversy About Garlic
Some readers have asked my why I didn’t include cholesterol lowering as one of garlic’s benefits. Frankly, I don’t think the evidence supports the use of garlic for lowering cholesterol.
However, I have reviewed some of the studies and I will say that the study design, in my opinion, was faulty. For example, they gave raw garlic in a sandwich.
First of all, if you are designing a study the participants diets should not have changed during the study. Secondly, there is some evidence to show that adding grains to a persons diet can raise cholesterol.
Despite my problems with the study I still think the cholesterol-lowering effects of garlic have been overstated.
If you have any information that you think would change my mind please pass it along.
