Garlic is something of an acquired taste but one that many people enjoy and use in their cooking. What is more, garlic is very good for you. We have already looked at the health benefits of garlic, many of which it derives from the presence of a compound called allicin. So what is allicin and what exactly can it do for our health?
What is Allicin?
Allicin is a sulfur compound found in garlic with a number of potential medical benefits. In garlic, it acts as the plant’s defense mechanism to protect against pests. When the plant gets injured, it produces the compound through an enzymatic reaction.
An enzyme called allinase is converted to allicin and this compound is toxic to pests like insects, fungi and other harmful microorganisms.
Allicin was originally isolated and then studied in 1944 by Chester Cavallito. While garlic has been extensively studied, relatively little research has taken place regarding the health benefits of allicin itself. Nevertheless, studies have found that allicin has a number of medicinal properties including antioxidant, antimicrobial, anti-cancer and hypolipidemic actions.
Allcin is the compound responsible for the familiar pungent odor of the garlic plant and herb. In fact, allicin is not sold in purified form because of its offensive odor and its instability. When extracted from garlic, allicin quickly loses much of its medicinal prowess and is turned into other sulfurous compounds.
Allicin is not sold in its purified form because it is not stable and gives off an offensive odor. Allicin extracted from garlic can quickly lose its beneficial properties. Diallyl trisulfade (DATS) is produced with allicin extracted by hydrolysis. This is used to treat a wide range of conditions from cancer, to bacterial infection and cardiac arrhythmia.
A review of the health benefits of garlic and allicin supplements recently found that supplements had less benefit than garlic that is consumed fresh. The review also found that owing to bioavailability, non-coated supplements were more beneficial than enteric-coated ones. (1)
If you would like to find out more about the health benefits of allicin, please read on.
The Health Benefits of Allicin
Studies have found that allicin has a number of beneficial actions that may positively impact human health. For example, allicin has demonstrated beneficial effect on the heart because of its antiplatelet, hypolipidemic and circulatory properties. Studies have also found the compound has anticancer, chemopreventive and antimicrobial properties.
Aged garlic has also demonstrated additional benefits including brain and liver health properties but allicin itself may be limited by its instability and biavailability.
Despite the relatively few studies into the health effects of allicin, there are several potential uses including heart health, cancer prevention, bone health, immune health and skin health benefits.
Let us take a more detailed look at some of these studies.
May Reduce Cholesterol
According to research, allicin can have a beneficial effect on the heart because of its ability to reduce cholesterol and blood pressure levels. High cholesterol and blood pressure are both factors known to increase the risk of heart disease.
A handful of studies have revealed that allicin might help reduce cholesterol levels in humans.
One of the earliest studies, published back in 2001, looked at the effects of garlic powder supplements on 46 participants with high cholesterol. The participants, who were also put on a low fat diet, were either given a garlic powder tablet containing 9.6 mgs of allicin or a placebo for 12 weeks.
The results were promising. By the end of the 12-week study, the group that took the allicin supplements had a significant reduction in LDL cholesterol levels compared with those who had taken the placebo. In addition, HDL (the good kind) cholesterol levels were not affected. (2)
A meta-analysis, published in 2013 found that compounds present in garlic helped reduce both total and LDL cholesterol levels when supplements were taken for two months or more. In addition, the authors found that treatment with garlic supplements were linked to a 38% reduction in coronary events at the age of 50. (3)
One study, published in 2013, involved 210 patients who were wither given garlic tablets, a beta-blocker or a placebo. The researchers found that the group who had taken garlic supplements had a significant reduction in blood pressure levels compared to both the beta-blocker and placebo groups. (4)
There is also some evidence that allicin might help prevent atherosclerosis. Atherosclerosis is a common heart disease involving the build up of plaque in the arteries. This plaque is made up of various substances including cholesterol, fat and calcium. Over time, it hardens and narrows the arteries limiting the flow of oxygen-rich blood around the body.
One study, published in 2017, looked at the effects of allicin on 62 patients with coronary heart disease. the patients were divided into two groups and treated with allicin or with aspirin. After 12 weeks, the researchers found that the patients treated with allicin experienced a reduction in Hcy levels which could reduce the risk of atherosclerosis. (5)
The researchers concluded that allicin might be a useful treatment for preventing atheroslerosis and cardiovascular disease.
Might Protect Against Cancer
The consumption of garlic has ling been recommended to treat a number of conditions. Some have claimed that it can reduce the risk of cancer but studies are sparse.
A number of laboratory studies have found that allicin could inhibit the growth and spread of cancer cells but the effect of the compound on cancer in humans remains unknown. The major limitation of allicin is its instability as well as its poor bioavailability. It appears to only be most effective when allicin is exposed directly to cancer cells.
However, studies have also found that allicin could induce apoptosis and helped inhibit the growth of both murine and human cancer cells. (6) A recent study, published in 2018 found that allicin was effective against cervical cancer. (7)
More research is needed in the future before we can say with certainty whether or not allicin has a cancer preventive effect.
There is some evidence that allicin can help treat muscle injury and alleviate soreness and pain.
According to a study, published in 2008, the compound may be effective in treating muscles injured by exercise. In this study, athletes were either given allicin supplements or took a placebo for 14 days prior to a treadmill workout. The researchers found that those who took the allicin supplements experienced less soreness in their muscles following their workout than those who took the placebo. (8)
While the study involved athletes, the results suggest that the compound could be effective in reducing muscle pain and soreness in general.
Allicin and the garlic in which it is found also has excellent antimicrobial properties. A number of laboratory studies have found that allicin had antibacterial and anti-fungal activity against a variety of pathogens including Staphylococcus aureus, E.coli and Helicobacter pylori. It may also be effective against common yeast infections like candida. (9)
Might Prevent Colds and Boost Immune Function
Allicin might also help bolster the immune system and help protect against common conditions like the cold and flu.
One large study, published in 2001, looked at the effects of garlic supplements on 146 volunteers. The participants were divided into two groups and either given daily garlic supplements or a placebo for 12 weeks.
At the end of the study, the researchers found that the group given the supplements had a 63% reduction in colds compared with the control group. The garlic supplements also significantly reduced the length of the illness from 5 days to only 1.5 days.(10)
Another study later confirmed these findings. The researchers found that consuming aged garlic in a high dose significantly reduced the incidence of cold and flu. (11)
It should be noted that these studies involved taking large doses of garlic supplements as opposed to allicin specifically. It should also be noted that not all studies have found that garlic supplements were effective for preventing colds and more research is necessary.
How to Use Allicin
Eating more garlic is one way to get more allicin into your system but simply eating more garlic does not get you near the doses of allicin used in studies. One clove of garlic typically contains between 5 and 18 mg of the compound. To put this in perspective, the majority of studies have used much higher doses from 300 mg a day to as much as 1500 mg a day.
Allicin is available in supplementary form and is usually labeled as either allicin or garlic.
There are no standard recommended doses for allicin.
Studies have found that eating fresh garlic is more beneficial than taking supplements.
Side Effects and Precautions
Unfortunately, we do not have a great deal of safety data regarding allicin or garlic supplements. The lack of research means that relatively little is known about the long term use of these supplements or whether they interact with other forms of medication.
Allicin might increase a person’s risk of bleeding. It is therefore important to avoid taking allicin supplements in the weeks leading up to a scheduled surgery.
For the same reason, people using blood-thinning medications like warfarin or aspirin should avoid using allicin supplements unless they have consulted their doctor.
Allicin might reduce blood sugar levels so diabetics and those taking diabetes medication should consult their doctor before using allicin.
Alliciin can reduce blood pressure. People taking other blood pressure supplements or blood pressure drugs should avoid using allicin supplements.
There is no data regarding the safety of allicin supplements in pregnant women or nursing mothers. If you are either pregnant or breastfeeding, it is best to stay on the side of caution and avoid using allicin supplements.
Allicin is a compound found in garlic and responsible for the distinctive smell of the herb. Allicin has a number of potential health benefits. It is used to reduce cholesterol and lower blood pressure while it may also help protect against atherosclerosis,
As well as its heart health benefits, allicin might help bolster the immune system and protect against old and flu. Laboratory studies have also found that allicin had antimicrobial properties against various strains of bacteria and fungus. In vitro studies also suggest allicin may have anti-cancer potential.
You can get allicin from eating garlic and it is available in supplementary form. As yet, there are no firm dosage recommendations but studies have used looked at the effects of large doses of allcin up to 1500 mg a day.
While allicin supplements are likely safe for the majority of people, you should consult your doctor before using them. They may interact with certain medications and should be avoided by people with certain preexisting conditions.