Garlic (Allium sativum) is an incredibly popular ingredient around the world, mostly for its health benefits and pungent taste and odor. It has been consumed for centuries, dating back to ancient Egyptians (who fed garlic daily to the workers of the pyramids). Modern studies indicate garlic may support heart health, enhance the immune system, regulate blood sugar, protect the liver, and more.

Garlic belongs to the same family of plants as onions, shallots, and leeks. Much of its power comes from sulfur-base compounds—such as allicin—that form when the garlic clove is chopped or crushed. These compounds are what give garlic its strong odor and are believed to be responsible for many of its health attributes. Below we summarize some of the primary research findings on the potential benefits of garlic and how to include it in your diet.

Fact
The Builders of ancient Egypt were documented to have been given garlic to help sustain stamina and prevent infections.

Health Benefits of Garlic

Here are some of the key potential health benefits of garlic according to research, beginning with areas that have substantial evidence to those needing further study.

1. Supports Heart Health

Garlic is most notably known for its potential cardiovascular effects. Several large studies have concluded that garlic may help lower systolic and diastolic blood pressure—especially in those with high blood pressure (1, 2). By lowering high blood pressure, garlic may help prevent severe heart-related events.

Research has also found that garlic may reduce the progression of plaque (atherosclerosis) in the arteries. Clinical trials have shown it can reduce plaque buildup, promote more elastic arteries, and help protect against coronary artery disease (3, 4). Additionally, garlic has been associated with improved circulation and blood vessel function (5, 6).

The impact of garlic on improving cholesterol is mixed. Some research indicates it can modestly lower total and LDL (“bad”) cholesterol and raise HDL (“good”) cholesterol. Other studies find little to no effect. Likely the differences result from the type of garlic (fresh, aged extract, or powdered), dosage, and duration (7). Still, there is promising evidence that garlic may decrease certain markers of inflammation, which in turn supports heart health (4).

Summary
Consuming garlic regularly may help manage high blood pressure, promote healthier arteries, and reduce harmful inflammation associated with heart disease. Its cholesterol-lowering potential can vary, but overall, it shows strong potential for heart health.

2. Aids in Blood Sugar Regulation

Garlic appears to have positive effects on blood sugar regulation, particularly for individuals with type 2 diabetes or insulin resistance. Systematic reviews of clinical trials show that garlic supplementation may significantly lower fasting blood glucose and HbA1c (a marker of longer-term blood sugar) (8, 9).

For women with polycystic ovary syndrome (PCOS) or metabolic syndrome, garlic may improve insulin resistance and fasting glucose (10).

Summary
Garlic helps enhance glucose metabolism, which may be especially helpful in those with diabetes or other insulin-related issues.

3. Advantages for Metabolic Health

By helping regulate blood pressure, blood sugar, and cholesterol, garlic may have broader positive effects on metabolic syndrome (MetS). Several randomized trials conclude that garlic supplements may decrease waist circumference, lower triglycerides, and increase HDL (“good”) cholesterol in individuals with MetS (6, 11).

Garlic may also lower certain inflammatory markers and improve antioxidant capacity, including increasing adiponectin (a crucial hormone that boosts insulin sensitivity) (12, 13).

4. Enhances Immune Function

Garlic has traditionally been used as a natural immune enhancer for many years. Studies show it may stimulate key immune cells (e.g., natural killer cells, γδ-T cells), helping the body fight off infections (14).

Some clinical trials report that garlic supplementation may lessen how often people catch colds or flu and/or reduce their severity (15). More recently, fortified garlic extract was shown to reduce supplemental oxygen needs on certain treatment days in hospitalized COVID-19 patients (16).

Garlic’s immune benefits likely stem from its ability to reduce harmful inflammation, activate crucial immune defenses, and slow the growth of certain microbes.

5. Antimicrobial & Antifungal Effects

Allicin forms when garlic is crushed and is one of the primary compounds responsible for its antibacterial activity. In one clinical trial of 30 subjects, a garlic-based mouth rinse significantly lowered levels of mutans streptococci (a cavity-causing bacterium) (17). Also, in a double-blinded randomized clinical trial, a 1.8% garlic-lemon solution was comparable to 2.5% sodium hypochlorite in disinfecting infected root canals (18).

Garlic also boasts notable antifungal properties. A garlic derivative, ajoene, was found to be equally effective as terbinafine cream in treating ringworm (19). In another clinical trial, a garlic paste was as effective as clotrimazole for treating oral yeast infections (20).

6. Offers Antioxidant Protection

Garlic contains several antioxidant compounds, such as organosulfur compounds and phenolic acids. Systematic reviews indicate that garlic supplementation can raise total antioxidant capacity (TAC) and reduce free radicals like malondialdehyde (MDA) (21, 22).

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

7. Promotes Liver Health

Studies of non-alcoholic fatty liver disease (NAFLD) show that garlic can lower liver fat and improve liver enzymes in 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 supplementation improved arterial oxygen levels and reduced mortality in some individuals (25).

8. May Aid in Cancer Prevention

Multiple research studies links increased garlic consumption with a lower risk of certain cancers, especially those of the digestive tract. Meta-analyses indicate that garlic consumption may be tied to reduced gastric and colorectal cancer risk (26, 27). Garlic’s sulfur compounds—allicin, diallyl disulfide, and diallyl trisulfide—may trigger tumor 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 gastric cancer (28). Another randomized trial found that aged garlic extract may slow early colon polyp growth, implying possible prevention of precancerous lesions (29).

While some studies do not replicate these findings—long-term observational data can differ—overall evidence supports a protective role for garlic in certain cancers (30).

Summary
Research links garlic consumption with reduced risk of stomach and colon cancers. Its sulfur compounds may encourage tumor cell death and slow tumor development. Some findings are mixed depending on the garlic form, dosage, and study design.

9. Facilitates Wound Healing

Topical (on the skin) and dietary garlic may support wound healing by enhancing circulation and immune factors. One clinical trial found that applying a 30% garlic ointment on surgical wounds led to faster recovery and less noticeable scarring compared to standard ointment alone (31).

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

10. Promotes Oral Health

Garlic’s antimicrobial properties also aid oral hygiene. In a study comparing garlic, tea tree oil, and chlorhexidine, garlic significantly reduced mutans streptococci (17).

Long-term use of garlic extracts may help gum disease as well. In an 18-month trial, aged garlic extract reduced periodontal pocket depth in people with periodontitis (33).

11. Helps With Weight Management

Some research points to garlic aiding modest weight or fat reductions. In one randomized clinical trial on NAFLD patients, garlic powder supplementation led to small but noteworthy decreases in body weight and body fat mass (34).

By improving insulin sensitivity and lowering oxidative stress, garlic may support a healthier metabolic environment for gradual weight loss—especially in conjunction with diet and exercise (35).

12. Assists in Hormonal Balance

Garlic appears particularly beneficial for women with PCOS by boosting insulin sensitivity and lowering androgens (10). Through its metabolic improvements and inflammation reduction, garlic may help stabilize certain hormonal imbalances.

13. Bone & Joint Health

Some findings suggest garlic’s anti-inflammatory properties may be protective for bones, especially in women susceptible to osteoporosis after menopause. Garlic is believed to decrease pro-inflammatory factors that can damage bone density (36).

In a knee osteoarthritis study, garlic supplementation decreased stiffness and enhanced comfort in overweight or obese women, likely by minimizing joint inflammation (37).

14. Supports Neurological Health

Due to garlic’s antioxidant and anti-inflammatory properties, it may also favorably influence brain health. A systematic review of herbal medicine for Alzheimer’s disease highlighted garlic for its potential to reduce neuro-inflammation (38).

Large human trials on garlic and dementia risk are still limited, but animal data suggest garlic may cut oxidative damage in the brain and safeguard mental function.

Other Potential Health Benefits Benefits

Research in the following areas is still limited. While initial findings are interesting, larger and more rigorous research is needed:

  • May Support Mental Health: Chronic inflammation has been associated with depression and other mood problems, so garlic’s ability to diminish inflammation may support mental well-being. Though human data remains limited, the outlook is encouraging (38).
  • May Improve Muscle Health: Some evidence suggests garlic may aid muscle recovery and performance by reducing exercise-induced oxidative stress. One small study found that post-workout garlic intake boosted muscle glycogen replenishment during recovery (39).
    Systematic reviews on certain root-plant supplements (including garlic) suggest lower markers of muscle damage post-exercise, but more clinical data in humans are needed to confirm garlic’s full impact (40).
  • May Improve Sexual Health: Garlic might indirectly support sexual health by improving blood flow, lowering inflammation, and possibly balancing hormones. Initial clinical trials suggest certain garlic formulations enhanced some markers of erectile function in older men, possibly via better circulation (41). In men who only partially responded to ED medication, adding garlic improved treatment outcomes (42).
  • May Potentially Extend Lifespan: While it is difficult to prove direct “life extension” in humans, garlic may be an exception. Consuming garlic was found to have an impact on 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, there are a few considerations:

  • Drug Interactions: Certain forms of garlic may interact with some HIV medications and other drugs processing specific liver enzymes. Consult a healthcare provider if you use prescription medications similar to these (44).
  • Bleeding Risk: Garlic has a mild blood-thinning effect. It is generally well tolerated, but anyone on blood thinners or facing surgery should be aware that large amounts may increase bleeding (45).
  • Gastrointestinal Discomfort & Odor: Garlic can cause gas, heartburn, or a strong garlic smell. In one study, 21% of participants reported noticing a strong garlic odor (46).
  • Allergic Reactions: Garlic allergy is rare but possible, presenting with rashes, respiratory issues, or GI upset. Those allergic to other Allium plants, such as onions, should use caution (47).
Summary
Garlic is generally safe for most people. However, if you are taking specific medications, have upcoming surgery, or have allergies, talk to a healthcare professional. Excessive amounts may cause notable odor or digestive issues.

Ways to Incorporate Garlic Into Your Meals

Garlic can be easily added to many common dishes:

  • Raw Garlic: Crushing or chopping fresh garlic releases allicin, its main active compound. Allowing it to sit for 5–10 minutes before use can increase allicin formation. Add raw garlic to salad dressings, dips, or spreads.
  • Cooked Garlic: Sautéing, roasting, or simmering softens garlic’s flavor. For maximum benefits, chop it and let it rest for a few minutes before cooking.
  • Aged Garlic Extract: Aged in ethanol, this form is common in research because it’s standardized for S-allyl cysteine (SAC) and typically has a milder smell.
  • Garlic Oil or Powder: Encapsulating garlic products are an option if you dislike fresh garlic’s strong smell. Purchase from reputable brands.

High heat for extended periods can degrade beneficial compounds. Adding garlic and crushing it toward the end of cooking may preserve more of its healthful properties.

Nutritionally, a 3 g clove of raw garlic contains about 4.47 kcal, 0.19 g protein, and trace vitamins and minerals (48).

Does Cooking Garlic Take Away Its Benefits?

High heat may destroy compounds such as allicin, so using moderate cooking methods (light sautéing, roasting) can help retain some of the 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 Potent Than Fresh Garlic?

Aged garlic extracts tend to have more stable compounds like S-allylcysteine that has been notably present as a major player in studies regulating blood pressure and inflammation. Fresh garlic contains higher amounts of allicin (cooking reduces the amount of allicin). Both types may be helpful, so choose as you desire or based on someone’s needs.

Conclusion

Garlic (Allium sativum) is an incredibly nutritious ingredient famed for its culinary uses. Studies show it may help manage blood pressure, boost the immune system, support blood sugar control, and more. Whether enjoying it fresh in meals or taken as a supplement, garlic appears to have beneficial effects on multiple body systems.

Garlic, however, may cause some side effects, such as odor or digestive discomfort, and may interfere with certain medications. Individuals on blood thinners or dealing with specific health issues should check with a medical professional before taking garlic supplements.

Adding garlic to your recipes or using it in supplement form, together with a balanced lifestyle, can help you tap into the remarkable potential of this time-honored herb. With extensive evidence and ongoing research, garlic stands out in both the kitchen and your wellness routine.

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