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Garlic needs no introduction—mostly because it announces itself. But the bulb that you use as a secret ingredient in all your favorite recipes has a secret double life as health-boosting “superfood.” In the same family as leeks, chives, onions, and shallots, the small but mighty garlic bulb has a robust history. In fact, the father of modern medicine Hippocrates prescribed garlic to treat a range of conditions. But how well does Allium sativum (that’s garlic’s scientific name) hold up to modern health concerns? Very, and there are studies to prove it.
Forms of garlic
You may have never considered that garlic has several forms. We interact primarily with fresh, raw garlic, the kind we chop or crush for recipes. (This would also include those handy jars of pre-minced garlic.) Garlic powder is ground, dehydrated garlic, and is common in spice cabinets. Aged garlic extract is a concentrated liquid form found in supplements.
Research on the health benefits of garlic looks primarily at one form per study. And different forms of garlic supplementation have different benefits, so it’s important to choose the right one if you’re boosting your garlic intake for a specific reason. For the health benefits of A. sativum outlined below, we’ve noted which form researchers used to achieve the outcomes.
Benefits of garlic
The health benefits of garlic are impressive enough to make the bad breath a non-concern. Though we mostly know garlic as a flavorful ingredient, it has historically been seen mostly as medicinal in use (Rivlin, 2001). The ancient Babylonians, Egyptians, and Greeks who used the bulbs as medicine may not have known why it worked, but researchers have figured out garlic’s health benefits come from sulfur compounds that form when the cloves of fresh garlic are mashed, crushed, or chopped. Allicin is the most well-known of these compounds, but others called diallyl sulfide, diallyl disulfide, diallyl trisulfide, and s-allyl cysteine also play vital roles in the health benefits outlined below:
Improves heart health
There’s a lot to unpack here. You’ve probably seen garlic pills in supplement or health stores marketed specifically to boost your heart health. There’s good reason for that. Garlic and garlic supplements may boost cardiovascular health by helping with several different cardiovascular diseases. Studies show that garlic powder improves cholesterol levels in patients with mildly high cholesterol, and aged garlic extract lowers systolic blood pressure in patients with hypertension (abnormally high blood pressure) (Sobenin, 2008; Ried, 2005). Systolic blood pressure is considered a greater concern for heart disease risk than diastolic blood pressure.
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Eating one clove of garlic a day might even help prevent thrombosis, the formation of a blood clot in a blood vessel. In one study, consuming one clove of raw garlic daily for 16 weeks was enough to drastically reduce thromboxane (Ali, 1995). This substance causes blood clots and constricts blood vessels. Research also suggests that garlic can help with atherosclerosis, a cardiovascular disease characterized by the build-up of plaques on artery walls, by preventing the plaque accumulation (Orekhov, 1997). This could be especially important in patients with a high heart rate (HR), as elevated HR increases the risk of plaque rupture (Dominguez-Rodriguez, 2011).
Treatment with garlic powder may also lower the risk of heart attack over a 10-year period, but the study was small, and more research needs to be done to confirm these effects of garlic (Sobenin, 2010).
Garlic is a powerful ally to your immune system. Research has shown that raw garlic has antiviral, antifungal, and antibacterial effects, though many of these disappear when the cloves are cooked since the allicin is destroyed (Bayan, 2014). Remember how we said allicin is well-known? Well, that might have something to do with it. It also helps the compound’s reputation that participants in a clinical trial who were given garlic supplements containing allicin reduced the number of times they got the common cold by 63% compared to the placebo group (Josling, 2001).
There’s also some indication that garlic may decrease your cancer risk and play a role in cancer prevention, though more research is needed in this area. Preliminary studies on the effects of organosulfur, a compound found in garlic, and cancer cells from breast cancer and colon cancer have been promising (Petrovic, 2018; Sengupta, 2004).
May improve athletic performance
Garlic has a long history in high-level athletic arenas. In fact, it was taken by Greeks in the original Olympic games as a “performance-enhancing” agent (Rivlin, 2001). But how well does that hold up to modern science? We’re not really sure yet. There’s some indication that garlic may help with fatigue, but more research needs to be done in humans to fully understand if and how garlic can boost performance (Morihara, 2007).
Detoxifies heavy metals
Heavy metal toxicity is a dangerous condition caused by our soft tissue absorbing too much of one (or more) of a number of metals like mercury, lead, and cadmium. It can result in abdominal pain, weakness, nausea, diarrhea, and chills. One study looked at how garlic affected workers in a car battery plant with chronic lead poisoning. After four weeks of garlic supplements, their lead levels had dropped by 19%, and the garlic was safer and as effective as the drug d-penicillamine at reducing symptoms (Kianush, 2012).
Improves bone health
Although more research needs to be done in humans, animal studies are hopeful and suggest that garlic supplements may minimize hormone-induced bone loss by boosting levels of estrogen (Mukherjee, 2004).
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Widely accessible and easy to add to your diet
Although it may not provide the same amount of health-boosting compounds as aged garlic extract, the use of garlic in your daily diet may confer some health benefits. When possible, use fresh cloves of garlic instead of jarred crushed garlic. Allicin, that compound that gets so much attention, isn’t stable (Fujisawa, 2008). That means you’ll get more of it if you’re using fresh garlic cloves and eating it not long after you chop or crush it, activating those compounds.
How to get enough garlic
Those of you who think garlic is delicious probably don’t struggle with getting plenty of it into your diet. It’s also available in many different forms, from garlic oil to powder. (Just know you’re signing up for its most notorious side effect: bad breath.) But if boosting your garlic consumption is proving to be a struggle, you can ensure you’re getting the most benefits possible from the garlic you are eating and boost your garlic intake further with supplements. Most garlic supplements come in capsule or tablet form.
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- Josling, P. (2001). Preventing the common cold with a garlic supplement: A double-blind, placebo-controlled survey. Advances in Therapy, 18(4), 189–193. doi: 10.1007/bf02850113. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/11697022
- Kianoush, S., Balali-Mood, M., Mousavi, S. R., Moradi, V., Sadeghi, M., Dadpour, B., et al. (2011). Comparison of Therapeutic Effects of Garlic and d-Penicillamine in Patients with Chronic Occupational Lead Poisoning. Basic & Clinical Pharmacology & Toxicology, 110(5), 476–481. doi: 10.1111/j.1742-7843.2011.00841.x. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22151785
- Morihara, N., Nishihama, T., Ushijima, M., Ide, N., Takeda, H., & Hayama, M. (2007). Garlic as an anti-fatigue agent. Molecular Nutrition & Food Research, 51(11), 1329–1334. doi: 10.1002/mnfr.200700062. Retrieved from https://onlinelibrary.wiley.com/doi/abs/10.1002/mnfr.200700062
- Mukherjee, M., Das, A. S., Mitra, S., & Mitra, C. (2004). Prevention of bone loss by oil extract of garlic(Allium sativum Linn.) in an ovariectomized rat model of osteoporosis. Phytotherapy Research, 18(5), 389–394. doi: 10.1002/ptr.1448. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15173999
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- Petrovic, V., Nepal, A., Olaisen, C., Bachke, S., Hira, J., Søgaard, C., et al. (2018). Anti-Cancer Potential of Homemade Fresh Garlic Extract Is Related to Increased Endoplasmic Reticulum Stress. Nutrients, 10(4), 450. doi: 10.3390/nu10040450. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/29621132
- Ried, K., Frank, O. R., & Stocks, N. P. (2010). Aged garlic extract lowers blood pressure in patients with treated but uncontrolled hypertension: A randomised controlled trial. Maturitas, 67(2), 144–150. doi: 10.1016/j.maturitas.2010.06.001. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/20594781
- Rivlin, R. S. (2001). Historical Perspective on the Use of Garlic. The Journal of Nutrition, 131(3). doi: 10.1093/jn/131.3.951s. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/11238795
- Sengupta, A., Ghosh, S., & Das, S. (2004). Modulatory influence of garlic and tomato on cyclooxygenase-2 activity, cell proliferation and apoptosis during azoxymethane induced colon carcinogenesis in rat. Cancer Letters, 208(2), 127–136. doi: 10.1016/j.canlet.2003.11.024. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15142670
- Sobenin, I. A., Andrianova, I. V., Demidova, O. N., Gorchakova, T., & Orekhov, A. N. (2008). Lipid-Lowering Effects of Time-Released Garlic Powder Tablets in Double-Blinded Placebo-Controlled Randomized Study. Journal of Atherosclerosis and Thrombosis, 15(6), 334–338. doi: 10.5551/jat.e550. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19060427
- Sobenin, I. A., Pryanishnikov, V. V., Kunnova, L. M., Rabinovich, Y. A., Martirosyan, D. M., & Orekhov, A. N. (2010). The effects of time-released garlic powder tablets on multifunctional cardiovascular risk in patients with coronary artery disease. Lipids in Health and Disease, 9(1), 119. doi: 10.1186/1476-511x-9-119. Retrieved from https://lipidworld.biomedcentral.com/articles/10.1186/1476-511X-9-119
Dr. Mike is a licensed physician and the Director, Medical Content & Education at Ro.