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Garlic (Allium sativum L.) is a plant that is used for its many powerful medicinal benefits and as a pungent herb in cooking. Raw garlic has been used as a medicine for centuries. Recent scientific research has shown that garlic has many health benefits such as boosting your immune system, improving cardiovascular health, helping to fight colds and flu, and reducing inflammation.

Garlic has a strong anti-bacterial properties. According to a study published in the Journal of Antimicrobial Chemotherapy, a compound in garlic named diallyl disulfide is 100 times more powerful than two common types of antibiotics for fighting the bacteria Campylobacter. The garlic compound was able to destroy the bacteria in just a fraction of the time taken by the antibiotics. (35)

You can use raw garlic as a medicine by chopping or crushing cloves from the garlic bulb and eating it. Some people prefer to buy garlic supplements or garlic pills to help boost their health and prevent some of the side effects of consuming raw garlic.


However you choose to supplement your diet with garlic, you will find that garlic benefits your overall health.

In this article, I will look at what science says about how to use garlic as a medicine. You will learn how to use raw or dried garlic to boost your immunity and protect yourself against cold and flu infections.


Nutritional Value of Garlic

Garlic is closely related to onions, shallots, chives and leeks. Each segment of a garlic bulb (or head) is called a clove. There are about 10–12 cloves in a single bulb or head.

Mincing 1 small clove of garlic yields about ½ teaspoon and 1 large clove yields about 1.5 teaspoons.

Garlic is a very nutritious food and is low in calories. In fact, you may be surprised to learn about the nutrition facts of garlic.

Just 3 garlic cloves contain the following vitamins, minerals, and nutrients: (1)

    •    8 mg vitamin C (5% recommended daily intake)

    •    1 mg vitamin B6 (6% RDI)

    •    16 mg calcium

    •    36 mg potassium

    •    13 mg phosphorus

    •    8 mg omega-3 fatty acids

    •    3 g carbohydrates

    •    13 calories

As well as the above nutrients, garlic also contains traces of vitamins A and K, as well as B-group vitamins.

Medicinal Components of Garlic

The health benefits of garlic are mostly due to chemical compounds that have an antioxidant effect in the body.

The main medicinal property of garlic is a compound called allicin. A review of the therapeutic effects of garlic stated that allicin is the principal bioactive chemical in raw garlic. This is a sulfur-based compound that has an anticancer, anti-hypertensive, and antimicrobial effect. Allicin becomes active when garlic bulbs are chopped or crushed.

Garlic also contains compounds with well-known medicinal properties such as phenolic compounds, flavonoids, and antioxidants.

Garlic bulbs also contain omega-6 and omega-3 polyunsaturated fatty acids. They play a central role in the normal development and functioning of the brain and central nervous system

Medicinal Health Benefits of Garlic (Raw and Dry)

Let’s look in more detail at science-based research that sheds light on the health benefits of eating raw garlic or taking garlic supplements.



Garlic Can Boost Your Immune System

Consuming fresh garlic gives your immune system a powerful boost. Although many people choose garlic supplements like aged garlic extract to increase immunity, there is evidence that active compounds have the same effect.

A study found that eating a meal containing fresh garlic has an immediate effect in boosting the body’s immune system. 17 volunteers ate a meal that had 5 g crushed garlic (about 2 garlic cloves). 3 hours after consuming the meal, blood tests revealed that taking garlic had a positive impact on the immune system. 

Research into the immune-boosting potential of fresh garlic and garlic compounds show that garlic benefits your immune system. Researchers discovered that consuming fresh garlic stimulates the production of T-cells – a type of white blood cell that has an important role in a healthy immune system.

There is even evidence to suggest that the antibacterial properties of fresh garlic also boost the effectiveness of antibiotics. 

The health benefits of raw garlic for colds and your immunity come from eating fresh, raw garlic because you get the active compound allicin.

However, if you want to avoid bad breath from garlic, taking high-quality garlic supplements also have a positive effect on your immune system.

When taking garlic to improve immunity you need to avoid these common mistakes.

Garlic Can Help Fight Flu and Cold Infections

Increasing the amount of garlic in your diet can help fight off the common cold and flu infections.

A study published in 2016 found that supplementing your diet with aged garlic extracts (AGE) can help to reduce the severity of cold and flu. During the trial, 120 healthy adults took 2.56 g aged garlic extract supplements for 3 months. Researchers found that people who took garlic supplements during the “flu season” experienced fewer and less-serious symptoms.

Another study examined the effect of garlic supplements containing allicin on 146 volunteers. During the months of November to February, people in the group taking the garlic supplements were less likely to get a cold. If they did become ill, the length of the cold or flu infection was shorter.

The reason why garlic helps to prevent cold and flu infections is because garlic extracts could enhance immune cell function. This helps to build up the body’s defenses to lessen the severity of upper respiratory infections such as cold and flu.

Eating Raw Garlic Can Improve Your Heart Health

One of the many benefits of eating garlic is that medicinal compounds in garlic have a protective effect on your heart.

A review of research published between 2013 and 2016 on the benefits of garlic extracts found that overall, garlic protects against heart disease.

Another review of the garlic benefits on heart health in 2017 reported that taking garlic can both prevent heart disease and treat symptoms of heart disease.

Also do these 5 easy things to reduce your risk of a heart attack.

Medicinal Compounds in Garlic Help to Lower Blood Pressure

One of the ways that using garlic as a medicine protects your heart is that it helps to lower hypertension (high blood pressure).




A review of 20 trials in using garlic extract supplements for blood pressure found them to be effective. After reviewing the results from over 970 individuals, researchers reported that garlic capsules can help to reduce both systolic blood pressure and diastolic blood pressure. In some cases, taking the garlic extracts lowered blood pressure by up to 8.7 mm Hg. (14)

Please see my other article to find out other ways to reduce high blood pressure naturally.

Garlic Supplements and Raw Garlic May Lower Cholesterol

Garlic also protects your cardiovascular system because sulfur compounds in garlic help to lower cholesterol.

A 2018 review of 14 high-quality research papers found that most studies showed that garlic extracts lower cholesterol. Notably, garlic helped to reduce levels of LDL (“bad”) cholesterol. This is the type of cholesterol that scientists say is damaging to your arteries and heart. 

Other studies have shown that combining 20 g fresh garlic (about 6 cloves) with a tablespoon of lemon juice can help to significantly lower cholesterol levels. 

There are more ways to reduce cholesterol that you may never have thought of.

Garlic Can Help Reduce Blood Glucose Levels

Regularly taking garlic extract supplements can help to lower blood glucose levels. Taking garlic can also help you manage the symptoms of type 2 diabetes.

A comparison of studies into the antidiabetic effect of garlic found that garlic supplementation helps to reduce blood glucose levels. Taking garlic supplements up to 1.5 g daily helped to lower fasting blood glucose in 1-2 weeks. 

Some trials found that tablets of dry garlic powder were effective in controlling diabetes symptoms. Other trials found that garlic capsules enhanced with allicin were also effective in managing type 2 diabetes. 

Studies using rats found that aged garlic extracts have a strong antidiabetic effect. Scientists noted that AGE extracts were just as potent as fresh garlic in helping to lower blood sugar glucose.


You can also try some of these foods to manage type 2 diabetes.

Garlic Has Anti-Inflammatory Properties

Inflammation is connected with many chronic diseases. Science-based research has revealed that aged garlic extracts (AGE) can help to prevent chronic disease due to its anti-inflammatory potential.

In one study, 51 adults were given AGE supplements with a dose of 3.6 g garlic extract daily. After 6 weeks of consuming the powdered garlic extract, inflammatory markers in blood test results were lower. Researchers concluded that this anti-inflammatory effect could have the potential to prevent chronic diseases in obese individuals. (19)

Medicinal Properties in Raw Garlic Fight Fungal Infections

The medicinal properties of allicin in garlic can also treat fungal infections in your body.




Researchers found that the allicin in fresh garlic can kill off Candida albicans pathogens in lab experiments. The results showed that garlic has the potential to be used as a powerful antifungal treatment. (20)

A 2017 study from Brazil found that taking garlic extract supplements can also fight fungal infections in the body. The researchers added that consuming garlic extract can also reduce inflammation. (21)

Garlic Has Antioxidant Properties That Help Protect Your Liver

The antioxidant and anti-inflammatory compounds in garlic extracts can have a therapeutic effect on the liver.

One trial examined the effect of garlic powder on people with nonalcoholic fatty liver disease. 110 men and women were divided into 2 groups and one group received 400 mg garlic powder twice a day. The study revealed that taking garlic powder supplements regularly reduced body weight in people with nonalcoholic fatty liver disease. (22)

Other studies have shown the potential to use garlic supplements to improve liver function that has been damaged by alcohol use. (23)

Please check out this article to learn about other foods that can protect your liver.


Garlic Supplements Can Protect Your Brain

A daily dose of dry garlic extract has a neuroprotective effect and may prevent the onset of degenerative brain diseases.

One clinical trial using rats found that aged garlic extracts helped prevent inflammation in the brain. This effect of garlic compounds helped to minimize cognitive dysfunction and improve short-term memory. Researchers said that supplementation with garlic extracts could improve cognitive function in the elderly. 

Another trial found that the sulfur compound in garlic, allicin, helped to protect the brain from oxidative stress. Garlic extracts could prevent brain damage in the event of a stroke. 

Eat Garlic to Treat Gastric Ulcers

The antibacterial potential of allicin in garlic can help to treat gastric ulcers and other digestive issues.

Most peptic and gastric ulcers are caused by the Helicobacter pylori strain of bacteria. A small clinical trial in 2016 on 15 humans with gastric ulcers found that raw garlic helped to kill off gastrointestinal bacterial infections. The study showed that taking 2 cloves of garlic twice a day has anti bacterial effect against H. pylori infection.

In another study of over 8,000 people with H. pylori infections, it was found that those who consumed raw garlic cloves regularly have lower levels of H. pylori bacteria. Other studies have shown that garlic powder capsules can also have an antiulcer effect

If you need to get rid of heartburn or soothe discomfort caused by a gastric ulcer, please read my article on how to treat heartburn.

Garlic Can Strengthen Bones in Menopausal Women

Osteoporosis is a common condition that affects menopausal women. Taking good quality garlic supplements regularly can help to reduce the effects of the menopause on bone density.

A randomized controlled trial found that women who regularly consumed garlic showed improvement in their signs of osteoporosis. Women took 2 garlic tablets every day for 30 days. After one month, blood tests from the women taking garlic supplements showed an increase of antioxidants and fewer signs of osteoporosis. (28)

Raw Garlic Has Anticancer Properties

There are many scientific studies showing that garlic extracts have the potential to protect against many types of cancer. Garlic is one of the top 14 foods that protects against cancer development.

For example, the National Cancer Institute reports that many population studies show a connection between increased intake of garlic and a lower risk of cancer. Among the types of cancers that raw garlic has a protective effect on are stomach, colorectal, breast, pancreas, and esophagus cancer. It has also been reported that cooked garlic also has an anticancer effect.

Researchers say that the potential of garlic in preventing certain types of cancer could be due to the antibacterial effect. Other reasons why consuming raw or cooked garlic can prevent cancer are because it can prevent cancer cells from multiplying or help boost DNA repair.

However, there is not enough research or evidence to recommend a specific dose of garlic to take for cancer prevention.

Garlic Pills vs. Raw Garlic – Which One is Better?

You may be wondering which is the best way to increase your consumption of garlic in your diet to benefit from its medicinal properties. Is raw garlic better than taking garlic supplements?

The journal American Family Physician reports that there are a number of components in garlic that give it its health benefits. Allicin is the sulfur-containing active ingredient which forms when garlic bulbs are crushed, chopped, or chewed. 

Some studies suggest that fresh garlic extract is more effective than garlic powder. 

Many garlic supplements in the form of dried garlic powder, aged garlic extract, or garlic oil don’t contain enough allicin, if any. However, as many studies in this article have pointed out, garlic supplements do have many health benefits. 

Some people prefer to get the benefits from garlic through supplements as there are fewer side effects.

How Much Garlic to Consume – Recommended Daily Dosage

There is no standardized recommended daily dosage of fresh crushed garlic to get its medicinal benefits.

As a general guide, the World Health Organization says that consuming 1 or 2 cloves of garlic a day can benefit your health. This would be the equivalent of around 1 g of dried garlic powder or between 300 and 1,000 mg of garlic extract.

However, most people can tolerate taking 3 or 4 cloves a day of raw garlic to boost their health. For example, one study showed that taking up to 6 cloves of garlic a day can help to lower cholesterol and blood pressure.

It is best to consume raw garlic, as obviously cooking fresh garlic can destroy some of the healthy sulfur compounds. But if eating raw garlic is not your cup of tea – all is not lost. During the cooking process other sulfur containing compounds are formed that still have health benefits. But don’t microwave garlic – microwaving garlic will completely kill the allicin and its therapeutic effects.

Here is a great tip when cooking garlic to preserve its maximum healing benefits: crush the garlic and then wait 10 minutes before cooking to maximize health benefits. Allowing the crushed garlic to stand for 10 minutes before cooking further enhances formation of allicin, ensures the maximum synthesis of allicin, and also makes it more stable and resistant to the heat of cooking. Then cook it on low or medium heat for a short period of time (up to 15 minutes).

If you consume garlic supplement, there is a lot of variation among garlic products sold for medicinal purposes. The amount of allicin depends on the method of preparation, and not all garlic supplements contain the same amount of active ingredients, so it is important to read the label carefully.

How to Use Garlic

How can you start eating more raw garlic in your diet to benefit from its therapeutic properties? Here are a few ideas:

    •    Before eating raw garlic, crush 2 or 3 garlic cloves and allow to sit for 10 minutes. This allows the allicin to become activated.

    •    Use fresh, raw garlic because cooking can affect some of garlic’s medicinal properties.

    •    Mix fresh crushed garlic with plain yogurt or honey to mask the strong sulfur taste.

    •    Learn how to grow your own garlic at home to always have an abundant supply.

Side Effects of Garlic

In general, garlic is safe to take when using a few raw garlic cloves a day. However, raw garlic can cause some unpleasant side effects: (33)

    •    Bad breath and body odor

    •    Eating garlic on an empty stomach can cause gastrointestinal upset

    •    Changes in intestinal flora that result in excess gas, nausea, vomiting, or diarrhea

Although this article has discussed the medicinal uses of taking garlic, you can also use garlic as a topical application for fungal infections such as ringworm. However, you should never put chopped or crushed raw garlic directly on your skin as it may cause burns. When applied topically, the crushed garlic needs to be mixed with other ingredients, such as coconut oil, olive oil aloe vera gel or honey.

Precautions About the Use of Garlic

If you are taking medication for any of the health issues discussed in this article, you should speak with your doctor before taking garlic extract for medicinal uses.

The journal American Family Physician says that garlic can cause blood thinning, lower blood pressure, and blood glucose levels. If you take medication for blood pressure, diabetes, or blood clotting, you should use caution when taking garlic supplements. (30)

Consuming more garlic is one of the 70 habits featured in my e-book 70 Powerful Habits For A Great Health which will guide you how to take positive steps to improve your wellness and overall health.

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