I’ve always loved garlic. On everything. I never thought about the potential benefits garlic might have – I simply enjoyed it for the spicy, robust flavor it gave to every dish it joined. Then I came across a meme on facebook that claimed all sorts of miraculous things that garlic can do. I was intrigued. Could garlic really do everything this source-less meme said it could?
It sounded like a challenge to find the truth behind each of these claims. Challenge accepted. And, unlike this meme, I will actually share my sources with you so you can verify for yourself. I encourage anyone to leave extra sources in the comments, but beware – anyone who tries to post pseudoscience will be publicly shamed and stand as an example of what not to do when attempting science. 😉
To help give a brief overview of each item on the list, I have color coded each item in the following way:
Green – Seems legit, though further study is always helpful.
Black – Unknown or mixed results.
Red – Decidedly false.
Blue – Duplicate or broadly termed item made to inflate the list and make it look more impressive.
1. High Cholesterol. According to this study, a garlic supplement lowered the mean cholesterol level of human participants by 11.5%. In this study, a garlic supplement lowered the total cholesterol level of rats significantly.
2. Athlete’s Foot. This study showed that ajoene, a garlic-derived organic trisulphur, cured 100% of athlete’s foot in human subjects after a mere two weeks. Furthermore, the subjects had no recurrence of fungal infection for 90 days afterward.
3. Poor Digestion. This is a very broad term because digestion encompasses so many different processes in the body. I found this study that stated a high intake of garlic essential oil reduced gas (methane production) by 17.5% in ruminants. This study found that giving broiler chickens garlic did not aid in the digestibility of the meat end product. Really, I didn’t find anything specifically on poor digestion related to garlic intake, so this claim remains unknown.
4. Low Energy. Just like poor digestion, low energy is a broad term. I looked up everything I could think of relating to low energy: sleep patterns, kinetic ability, fatigue, and endurance. I did find this study that suggested aged garlic extract helped combat physical fatigue in rats, but the method of action seemed unknown and I couldn’t find any follow up studies to determine the exact mechanism.
5. Blood Sugar. I’m taking this to mean plasma glucose. This study suggested that diallyl disulfide, the major organosulfur compound of garlic, increased plasma glucose levels within an hour of ingestion. In non-geek terms, blood sugar increases.
6. Blood Cholesterol. I’m sure the maker of this meme probably forgot that the first thing they listed was cholesterol. But hey, why not list it twice to make the miracle list even longer and more impressive? See #1.
7. Colon Cancer. This review of thirteen different studies on the subject found no evidence for garlic reducing the chances of colorectal cancer. In fact, it suggests garlic supplements may increase the risk for colorectal cancer. Ouch.
8. Chronic Bronchitis. I couldn’t find one scientific study that found any benefits to garlic in the treatment of bronchitis, either acute or chronic.
9. Yeast Infections. No benefits were found in this study when garlic was used in Candida-positive women.
10. Respiratory problems. This study found that purified aged garlic extract reduced airway inflammation in mice, but if you look at #25 you’ll see that garlic can also become an allergen that causes acute respiratory problems.
11. Boosts the immune system. Holy broad terms, batman! While technically correct in it’s sweeping coverage, as many papers including this review have shown, garlic is composed of many different compounds, some of which can be easily altered depending on preparation. Overall, yes, but it’s disappointing to see such a broad term used in a list that also encompasses specific uses. I’m going to count this one as a double and point you to… well… every other number on here because most of them have something to do with the immune system.
12. Increase absorption of iron and zinc. Now here’s a great example of being specific AND being true! See this study for more details.
13. Coughing. Another repeat. See #10.
14. Antioxidants. While garlic has been found to have some antioxidant properties, many studies including this one have not been able to find antioxidants in the blood stream after a human ingests raw garlic.
15. Breast Cancer. A specific garlic derivative aided in cell death of breast cancer cells according to this study. This study also observed the effect a garlic derivative had on the death of breast cancer cells.
16. Cold and flu. Garlic may or may not be responsible for the reduced severity of cold and flu symptoms, but it also has definitively been shown in this study to have no effect on the incidence of colds or flu.
17. Leukemia. This study shows that certain components of garlic can stop the proliferation of cancer cells.
18. Anti-fungal. This study found that garlic derivatives allicin and garlic extract inhibits growth in fungal cells.
19. Vaginitis. Oh, dear. Another double and a broad term. See #9.
20. Toothaches. Pure wives tale. I couldn’t find even one study that found garlic to help toothaches.
21. Warts. This study found that 96% of patients treated with lipid garlic extract had a complete healing response for their recalcitrant multiple common warts symptoms. What’s more, no recurrence was found in the garlic-treated group.
22. Stomach. Too broad to tackle succinctly. What about the stomach? Digestion has already been covered in #3.
23. Diabetes. This review talks about the anti-diabetes properties of various garlic derivatives. This study goes over the effects of garlic on postprandial blood glucose levels and intestinal sucrase and maltase activities – all decreased by garlic.
24. Parasites. This study suggests that garlic can be a powerful anti-parasite in guppies and other freshwater fish. Although somewhat effective, this study showed that garlic wasn’t nearly as powerful as pumpkin extract or ivermectin at eradicating the nasal botfly. This study found that allicin treatment wasn’t effective in treating parasitic infections in commercially raised chickens.
In all, this meme touches on some of the awesome qualities of garlic, but I cannot in good conscience promote ANYTHING it claims for multiple reasons. Number one – I am no doctor. I have a degree in Biology with a focus on genetics and microbiology. I speak the language of medicine, though I am not trained in its many particulars. While I can read through all of these abstracts, studies, and reviews and understand them, I am not a source of medical knowledge.
Number two – different garlic preparations have different properties and vastly different outcomes. If you actually read through even half of the studies I linked to, you’ll have noticed that there are many different compounds present in raw garlic. For instance, allicin has some antioxidant properties, but it has not been detected in serum or urine after ingestion of raw garlic. Garlic powder must be prepared at a suitable temperature and is associated with some toxicity. No major studies on the efficacy of garlic oils have been reported. The composition of aged garlic extract is such that it has increased sulfur compounds with the loss of allicin. Basically, there is A LOT of variability in the contents of garlic preparations. None of these studies mentioned were predicated on a person eating raw garlic – they were all conducted with very specific by-products of garlic processing.
What does all that mean? It means that eating raw garlic may or may not give you the benefits you just read about because those specific things tested in the studies may or may not be present and in usable form in raw garlic.
Number three – this was just a few hours worth of research that I did. I no longer have access to all of the full articles, so this brief research probably missed many small nuances that are only present in the full texts. There’s always more to the story, like the fact that some toxicity has been reported with garlic use, especially when taken as an encapsulated supplement. Exact doses are very case-dependent, and toxicity levels vary from species to species, person to person. Did you know that even small amounts of garlic are toxic to cats and dogs? Garlic also has known interactions with other drugs, including the ability to make birth control less effective.
Why did I even bother going through pointing out what was true, what was false, and what was inconclusive if I’m not going to stand by any of it as it relates to the miraculous claims of this meme? Because I simply wanted to point out that this meme, while certain aspects of it are scientific, is broadly pseudoscientific in nature. One cannot take a couple truths, stir it in with a bunch of unknowns or complete falsities, and expect the end result to retain scientific accuracy. This meme contains a few nuggets of science, but is overwhelmingly false despite that.
What’s my point? Use your reasoning skills when you come across things like this meme on the internet. Research the claims for yourself. Don’t accept anecdotal websites and sources as truth – dig deeper. Peer-reviewed studies are the best sources for any medical information and advice. If something sounds too good to be true, it probably is. And finally… talk to you doctor! Your doctor has most likely heard all of the pseudoscience surrounding various alternative medicines, and will be able to present you with well-researched information to counter or enhance your own findings.
To end this blog, I leave you with this.