Garlic (Allium sativum) is a popular ingredient used worldwide for its strong taste and potential health benefits. It has been part of human diets for centuries, dating back to ancient Egyptians (who gave garlic daily to pyramid workers). Recent studies show garlic may help with heart health, boost the immune system, regulate blood sugar, protect the liver, and provide other health benefits.

Garlic belongs to the same plant family as onions, shallots, and leeks. Much of its power comes from sulfur compounds (such as allicin) that form when you chop or crush a garlic clove. These compounds give garlic its strong smell and are thought to be behind many of its health benefits. Below we summarize some of the main research findings on the potential benefits of garlic and how to include it in your diet.

Fact
Ancient Egyptian workers who built the pyramids were given garlic to help boost their stamina and prevent infections.

Health Benefits of Garlic

Here are some of the key potential health benefits of garlic according to research, starting with benefits that have the strongest evidence.

1. Supports Heart Health

Garlic is most known for its potential heart health benefits. Several large studies have found that garlic may help lower blood pressure—especially in people who already have high blood pressure (1, 2). By reducing high blood pressure, garlic may help prevent serious heart problems.

Research has also found that garlic may slow the buildup of plaque (fatty deposits) in the arteries. Clinical studies have shown it can reduce plaque accumulation, help arteries remain more flexible, and protect against coronary artery disease (3, 4).

Additionally, garlic has been linked to improved blood circulation and better blood vessel function (5, 6).

The effect of garlic on cholesterol levels shows mixed results. Some studies suggest it can modestly lower total and LDL (higher risk) cholesterol and increase HDL (beneficial) cholesterol. Other studies find little or no effect. These differences may be due to the type of garlic used (fresh, aged extract, or powdered), the amount taken, and how long it was used (7).

However, there is promising evidence that garlic may reduce certain inflammation markers, which in turn supports heart health (4).

Summary
Regular garlic consumption may help control high blood pressure, promote healthier arteries, and reduce harmful inflammation linked to heart disease. Its cholesterol-lowering effects vary between studies, but overall, research suggests garlic is beneficial for heart health.

2. Helps Regulate Blood Sugar

Garlic appears to have positive effects on blood sugar control, especially for people with type 2 diabetes or insulin resistance (when your body doesn’t respond well to the effects of the insulin it makes). Reviews of clinical studies show that garlic supplements may significantly lower fasting blood glucose (blood sugar measured after not eating for several hours) and HbA1c (a marker of longer-term blood sugar control) (8, 9).

For women with polycystic ovary syndrome (PCOS) or metabolic syndrome (a group of conditions that increase heart disease risk), garlic may improve insulin resistance and fasting glucose levels (10).

Summary
Garlic helps improve how your body processes sugar, which may be especially helpful if you have diabetes or other conditions affecting insulin function.

3. Benefits for Metabolic Health

By helping regulate blood pressure, blood sugar, and cholesterol, garlic may have broader positive effects on metabolic syndrome (a cluster of conditions that increase your risk of heart disease, stroke, and type 2 diabetes). Several clinical studies have found that garlic supplements may decrease waist size, lower blood fats called triglycerides, and increase beneficial cholesterol in people with metabolic syndrome (6, 11).

Garlic may also increase adiponectin (an important hormone that supports metabolism and helps insulin work better) (12, 13).

4. Enhances Immune Function

Garlic has been used as a natural immune booster for many years. Studies show it may stimulate important immune cells (like natural killer cells and γδ-T cells), helping your body fight infections (14).

Some clinical trials report that garlic supplements may reduce how often people catch colds or flu and/or make these illnesses less severe (15).

More recently, fortified garlic extract was shown to reduce the need for supplemental oxygen on certain treatment days in hospitalized COVID-19 patients (16).

Garlic’s immune benefits likely come from its ability to reduce harmful inflammation, activate important immune defenses, and slow the growth of certain germs.

5. Antimicrobial & Antifungal Effects

Allicin is released when garlic is crushed, and it is one of the main compounds responsible for its germ-fighting activity. In one clinical trial with 30 people, a garlic-based mouth rinse significantly lowered levels of Streptococci mutans (a bacteria that cause cavities) (17).

In another carefully designed clinical trial, a 1.8% garlic-lemon solution worked as effectively as a standard 3% sodium hypochlorite solution (a common disinfectant) in cleaning infected root canals (18).

Garlic also has notable antifungal properties. A garlic-derived compound called ajoene was found to be as effective as terbinafine cream, which is a standard treatment for ringworm infections (19). In another study, a garlic paste was as effective as clotrimazole, which is an antifungal medication used to treat some types of yeast infections (20).

6. Offers Antioxidant Protection

Garlic contains several antioxidant compounds (substances that help protect your cells from damage), such as organosulfur compounds and phenolic acids. Systematic reviews show that garlic supplements can increase your total antioxidant capacity (your body’s overall ability to neutralize harmful molecules) and reduce damaging free radicals, like malondialdehyde (MDA) (21, 22).

One study found that short-term garlic supplementation reduced the oxidation tendency of LDL cholesterol (a risk factor for heart disease) by 34% (23).

7. Promotes Liver Health

Studies of non-alcoholic fatty liver disease (NAFLD), a condition where fat builds up in the liver, show that garlic can reduce liver fat and improve liver enzyme levels in affected individuals (24).

Additionally, fermented or aged garlic may lower certain blood liver enzymes (like ALT and GGT), suggesting improved liver function. In severe liver conditions (like hepatopulmonary syndrome in cirrhosis), garlic supplements improved blood oxygen levels and reduced deaths in some patients (25).

8. May Help Prevent Cancer

Multiple research studies link increased garlic consumption with a lower risk of certain cancers, especially those of the digestive system. Reviews of many studies indicate that eating garlic may be linked to reduced stomach and colorectal cancer risk (26, 27).

Garlic’s sulfur compounds (allicin, diallyl disulfide, and diallyl trisulfide) may trigger cancer cells to self-destruct or limit their growth.

In a high-risk region for cancer in China, a long-term randomized intervention found garlic supplements lowered the risk of stomach cancer (28). Another clinical trial found that aged garlic extract may slow the growth of early colon polyps (growths that can become cancerous), suggesting it might help prevent precancerous lesions (29).

While some studies don’t show these same benefits (long-term observation studies can give different results), overall evidence suggests garlic may help protect against certain cancers (30).

Summary
Research links eating garlic with reduced risk of stomach and colon cancers. Its sulfur compounds may help destroy cancer cells and slow tumor growth. Some findings vary depending on the garlic form, amount, and study design.

9. Helps Wound Healing

Applying garlic to the skin and eating garlic may support wound healing by improving blood flow and immune factors. One clinical trial found that using a 30% garlic ointment on surgical wounds led to faster healing and less visible scarring compared to standard treatment alone (31).

By improving circulation, garlic supplements may also help deliver oxygen and nutrients to injured tissues, supporting tissue repair (32).

10. Promotes Oral Health

Garlic’s germ-fighting properties also help with oral hygiene. In a study comparing garlic, tea tree oil, and chlorhexidine (a common mouthwash ingredient), garlic significantly reduced cavity-causing bacteria (17).

Long-term use of garlic extracts may help gum disease as well. In an 18-month study, aged garlic extract reduced the depth of periodontal pockets (spaces between teeth and gums that can harbor bacteria) in people with gum disease (33).

11. Helps With Weight Management

Some research suggests garlic may help with modest weight or fat loss. In one clinical trial with non-alcoholic fatty liver disease patients, garlic powder supplements led to small but notable decreases in body weight and body fat (34).

By improving insulin sensitivity, garlic may create a healthier metabolic environment that supports weight management (35).

12. Helps Balance Hormones

Garlic appears particularly beneficial for women with PCOS by improving insulin sensitivity and potentially lowering androgens, which are male hormones elevated in PCOS (10). Through its metabolic improvements and inflammation-reducing effects, garlic may help stabilize certain hormone imbalances.

13. Bone & Joint Health

Some findings suggest garlic’s anti-inflammatory properties may help protect bones, especially in women at risk for osteoporosis after menopause. Garlic appears to mitigate substances that can reduce bone density (36).

In a knee osteoarthritis study, garlic supplements decreased joint stiffness and improved comfort in overweight or obese women (37).

14. Supports Brain Health

Due to garlic’s antioxidant and anti-inflammatory properties, it may also benefit brain health. A review of herbal medicines for Alzheimer’s disease included garlic among plants with potential protective effects (38).

Large human studies on garlic and dementia risk are still limited, but animal research suggests garlic may reduce oxidative damage in the brain and help protect mental function. Additional research on human subjects is necessary to confirm these correlations.

Other Potential Health Benefits

Research in the following areas is still limited. While early findings are interesting, larger and more thorough studies are needed:

  • May Support Mental Health: Chronic inflammation has been linked to depression and other mood disorders, so garlic’s ability to reduce inflammation might support mental wellbeing. Though human data is limited, the outlook is promising (38).
  • May Improve Muscle Recovery: Some evidence suggests garlic might help muscle recovery and performance by reducing exercise-related oxidative stress. One small study found that taking garlic after workouts improved muscle glycogen replenishment (restoration of energy stores in muscles) during recovery (39).
    Reviews of certain plant supplements (including garlic) suggest lower markers of muscle damage after exercise, but more human studies are needed to confirm garlic’s full impact (40).
  • May Improve Sexual Health: Garlic might indirectly support sexual health by improving various body functions. Early clinical trials suggest certain garlic formulations improved some markers of erectile function in older men (41). In men who only partially responded to ED medication, adding garlic improved treatment results (42).
  • May Potentially Support Longer Life: While it’s difficult to prove direct “life extension” in humans, garlic may be an exception. Consuming garlic has been found to affect major factors, like high blood pressure, infections, and chronic disease risk. This suggests it may support healthy aging. A large Chinese study found that older adults who ate garlic at least once weekly lived longer than those who consumed it less frequently (43).

Possible Risks & Side Effects

While garlic is generally safe for most people, there are a few considerations:

  • Drug Interactions: Certain forms of garlic may interact with HIV medications (antiretrovirals). Talk to your healthcare provider if you take prescription medications (44).
  • Bleeding Risk: Garlic has been thought to have mild blood-thinning properties. However, a study of aged garlic extract specifically found no increased bleeding risk in patients taking the blood thinner warfarin (45).
  • Odor: Garlic can cause a noticeable garlic smell. In one study, 21% of participants reported a mild garlic smell (46). Some people may also experience digestive discomfort when consuming garlic.
  • Allergic Reactions: Garlic allergy is rare but possible, showing up as rashes, breathing problems, or digestive upset. Some cases of severe allergic reactions to raw garlic have been reported (47).
Summary
Garlic is generally safe for most people. However, if you’re taking certain medications, having upcoming surgery, or have allergies, check with a healthcare professional. Large amounts may cause noticeable odor or digestive issues.

Ways to Include Garlic in Your Meals

You can easily add garlic to many common dishes:

  • Raw Garlic: Crushing or chopping fresh garlic releases allicin, its main active compound. Letting garlic sit for 5–10 minutes before using it can increase allicin formation. Add raw garlic to salad dressings, dips, or spreads.
  • Cooked Garlic: Sautéing, roasting, or simmering mellows garlic’s flavor. For maximum benefits, chop it and let it rest for a few minutes before cooking.
  • Aged Garlic Extract: This form is made by aging garlic in ethanol and is common in research because it contains standardized amounts of S-allyl cysteine (SAC) and typically has a milder smell.
  • Garlic Oil or Powder: If you don’t like fresh garlic’s strong smell, encapsulated garlic products are an option. Choose products from trusted brands.

High heat for long periods can break down beneficial compounds. Adding crushed garlic toward the end of cooking may preserve more of its health-promoting properties.

Nutritionally, a 3-gram clove of raw garlic contains about 4.5 calories, 0.2 grams of protein, and small amounts of various vitamins and minerals (48).

Does Cooking Garlic Take Away Its Benefits?

High heat may destroy some of the beneficial compounds (like allicin), so using moderate cooking methods (light sautéing, roasting) can help preserve some active compounds. Chopping garlic and letting it sit for a few minutes before heating can also help maintain its healthy properties.

Is Aged Garlic More Effective Than Fresh Garlic?

Aged garlic extracts contain more stable compounds (like S-allylcysteine) that have been prominent in studies on blood pressure and inflammation. Fresh garlic has higher amounts of allicin (which cooking reduces). Both types can be beneficial, so choose based on your preferences or specific needs.

Conclusion

Garlic (Allium sativum) is a nutritious ingredient known for its culinary uses and health benefits. Studies show it may help manage blood pressure, support immune function, regulate blood sugar, and offer many other health advantages. Whether you enjoy it fresh in meals or take it as a supplement, garlic appears to benefit multiple body systems.

Garlic may cause some side effects, such as body odor or digestive discomfort, and it may interact with certain medications. If you take blood thinners or have specific health concerns, check with a healthcare provider before taking garlic supplements.

Adding garlic to your recipes or using supplements, along with a balanced lifestyle, can help you benefit from this remarkable herb. With substantial research evidence, garlic stands out as a valuable addition to both your kitchen and wellness routine.

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