Current research shows that garlic may have some real health benefits, such as protection against the common cold and the ability to help lower blood pressure and cholesterol levels
“Let food be thy medicine, and medicine be thy food.”
Those are famous words from the ancient Greek physician Hippocrates, often called the father of Western medicine.
He prescribed garlic to treat a variety of medical conditions — and modern science has confirmed many of these beneficial health effects.
Here are 11 health benefits of garlic that are supported by human research.
Garlic is a plant in the Allium (onion) family. It is closely related to onions, shallots, and leeks.
Each segment of a garlic bulb is called a clove. There are about 10–20 cloves in a single bulb, give or take.
Garlic grows in many parts of the world and is a popular ingredient in cooking, due to its strong smell and delicious taste.
However, throughout ancient history, the main use of garlic was for its health and medicinal properties (
Its use was well documented by many major civilizations, including the Egyptians, Babylonians, Greeks, Romans, and Chinese (
Scientists now know that most of garlic’s health benefits are caused by sulfur compounds formed when a garlic clove is chopped, crushed, or chewed.
Perhaps the most well-known compound is allicin. However, allicin is an unstable compound that is only briefly present in fresh garlic after it’s been cut or crushed (
Other compounds that may play a role in garlic’s health benefits include diallyl disulfide and s-allyl cysteine (
The sulfur compounds from garlic enter your body from the digestive tract. They then travel all over your body, exerting strong biological effects.
Garlic is a plant in the onion family that’s grown for its distinctive taste and health benefits. It contains sulfur compounds, which are believed to be responsible for some of those health benefits.
Calorie for calorie, garlic is incredibly nutritious.
A single clove (3 grams) of raw garlic contains (
- Manganese: 2% of the daily value (DV)
- Vitamin B6: 2% of the DV
- Vitamin C: 1% of the DV
- Selenium: 1% of the DV
- Fiber: 0.06 grams
This comes with 4.5 calories, 0.2 grams of protein, and 1 gram of carbs.
Garlic also contains trace amounts of various other nutrients.
Garlic is low in calories and rich in vitamin C, vitamin B6, and manganese. It also contains trace amounts of various other nutrients.
Garlic supplements are known to boost the function of the immune system.
A large, 12-week study found that a daily garlic supplement reduced the number of colds by 63% compared with a placebo (
The average length of cold symptoms was also reduced by 70%, from 5 days in the placebo group to just 1.5 days in the garlic group.
Another study found that a high dose of aged garlic extract (2.56 grams per day) reduced the number of days sick with cold or flu by 61% (
However, one review concluded that the evidence is insufficient and more research is needed (
Despite the lack of strong evidence, adding garlic to your diet may be worth trying if you often get colds.
Garlic supplements may help prevent and reduce the severity of illnesses like the flu and common cold, but more research needs to be done before any conclusions can be made.
Cardiovascular diseases like heart attack and stroke are responsible for more deaths than almost any other condition (
High blood pressure, or hypertension, is one of the most important factors that may lead to these diseases.
Human studies have found garlic supplements to have a significant impact on reducing blood pressure in people with high blood pressure (
In one study, 600–1,500 mg of aged garlic extract were just as effective as the drug Atenolol at reducing blood pressure over a 24-week period (
Supplement doses must be fairly high to have the desired effects. The amount needed is equivalent to about four cloves of garlic per day.
High doses of garlic appear to improve blood pressure for those with known high blood pressure (hypertension). In some instances, supplements may be as effective as regular medications.
Garlic can lower total and LDL (bad) cholesterol.
For those with high cholesterol, garlic supplements appear to reduce total and LDL cholesterol by about 10–15% (
Looking at LDL (bad) and HDL (good) cholesterol specifically, garlic appears to lower LDL but has no reliable effect on HDL (
High triglyceride levels are another known risk factor for heart disease, but garlic seems to have no significant effects on triglyceride levels (
Garlic supplements seem to reduce total and LDL (bad) cholesterol, particularly in those who have high cholesterol. HDL (good) cholesterol and triglycerides do not seem to be affected.
Oxidative damage from free radicals contributes to the aging process.
Garlic contains antioxidants that support the body’s protective mechanisms against oxidative damage (
High doses of garlic supplements have been shown to increase antioxidant enzymes in humans, as well as significantly reduce oxidative stress in people with high blood pressure (
The combined effects on reducing cholesterol and blood pressure, as well as the antioxidant properties, may reduce the risk of common brain conditions like Alzheimer’s disease and dementia (
Garlic contains antioxidants that can help protect against cell damage and aging. It may reduce the risk of Alzheimer’s disease and dementia.
The potential effects of garlic on longevity are basically impossible to prove in humans.
But given the beneficial effects on important risk factors like blood pressure, it makes sense that garlic could help you live longer.
The fact that it can fight infectious diseases is also an important factor, because these are common causes of death, especially in the elderly or people with dysfunctional immune systems (
Garlic has known beneficial effects on common causes of chronic disease, so it makes sense that it could also help you live longer.
Garlic was one of the earliest “performance enhancing” substances.
It was traditionally used in ancient cultures to reduce fatigue and improve the work capacity of laborers.
Most notably, it was given to Olympic athletes in ancient Greece (
Rodent studies have shown that garlic helps with exercise performance, but very few human studies have been done (
In one small study, people with heart disease who took garlic oil for 6 weeks had a 12% reduction in peak heart rate and better exercise capacity (
However, a study on nine competitive cyclists found no performance benefits (
Other studies suggest that exercise-induced fatigue may be reduced with garlic (
Garlic may improve physical performance in lab animals and people with heart disease. The benefits for people without heart disease are not yet conclusive. Ultimately, more research is needed.
At high doses, the sulfur compounds in garlic have been shown to protect against organ damage from heavy metal toxicity.
A 4-week study in employees at a car battery plant (who had excessive exposure to lead) found that garlic reduced lead levels in the blood by 19%. It also reduced many clinical signs of toxicity, including headaches and blood pressure (
Three doses of garlic each day even outperformed the drug D-penicillamine in reducing symptoms.
Garlic was shown to significantly reduce lead toxicity and related symptoms in one study.
No human studies have measured the effects of garlic on bone loss.
However, rodent studies have shown that it can minimize bone loss by increasing estrogen in females (
One study in menopausal women found that a daily dose of dry garlic extract (equal to 2 grams of raw garlic) significantly decreased a marker of estrogen deficiency (
This suggests that this supplement may have beneficial effects on bone health in women.
Foods like garlic and onions may also have beneficial effects on osteoarthritis (
Garlic appears to have some benefits for bone health by increasing estrogen levels in females, but more human studies are needed.
The last one is not a health benefit but is still important.
Garlic is very easy to include in your current diet. It complements most savory dishes, particularly soups and sauces. The strong taste of garlic can also add a punch to otherwise bland recipes.
Garlic comes in several forms, from whole cloves and smooth pastes to powders and supplements like garlic extract and garlic oil.
A common way to use garlic is to press a few cloves of fresh garlic with a garlic press, then mix it with extra virgin olive oil and a bit of salt. This works as a very simple and nutritious salad dressing.
Garlic side effects
However, keep in mind that there are some downsides to garlic, such as bad breath. There are also some people who are allergic to it.
If you have a bleeding disorder or are taking blood-thinning medications, talk with your doctor before increasing your garlic intake.
Garlic is delicious and easy to add to your diet. You can use it in savory dishes, soups, sauces, dressings, and more.
For thousands of years, garlic was believed to have medicinal properties. Science is now beginning to confirm it.
If you’re currently taking blood-thinning medications, make sure to talk with your doctor before drastically increasing your garlic intake.
Just one thing
Wondering if raw garlic has more health benefits than cooked garlic? We’ve got the answer.