- Fresh or capsuled? Researcher studies garlic’s potency as a supplement
- Are garlic capsules really as healthy as eating raw garlic?
- Does Garlic (Or Its Supplements) Have Health Benefits?
- What Is Garlic?
- Is There Any Research?
- Is it safe?
- What are the benefits of garlic?
How Much Should You Take?
Large scientific boards make several recommendations about garlic dosage. The Mayo Clinic cites the European Scientific Cooperative on Phytotherapy’s recommendation for prevention of atherosclerosis as 3 milligrams to 5 milligrams allicin (3,000 micrograms to 5,000 micrograms allicin) or one clove or 0.5 gram to 1 gram of dried powder.
The World Health Organization recommends 2 grams to 5 grams of fresh garlic, 0.4 gram to 1.2 grams of dried garlic powder, 2 milligrams to 5 milligrams of garlic oil, 300 milligrams to 1,000 milligrams of garlic extract, or some other formulation that yields the equivalent of 2 milligrams to 5 milligrams (2,000 to 5,000 micrograms) of allicin daily.
Go to the Clove
Rather than fussing over garlic supplements that may or may not contain what they claim, just enjoy the heady aroma and flavor of fresh garlic in the foods you eat. You’ll always know you’re getting the best — and the most potent — allicin you can when you add garlic to foods. Consider this:
- A typical garlic clove weighs about 3 grams.
- The amount of alliin in an average clove ranges from 24 milligrams to 56 milligrams.
- A standard clove will produce about 2.5 milligrams to 4.5 milligrams of allicin per gram of fresh weight when crushed. This means you’ll get 7.5 milligrams to 13.5 milligrams of allicin from one typical clove that weighs 3 grams.
The Bottom Line
- Aim for about 5 milligrams of allicin per day.
- Use supplements that state the amount of “allicin release” rather than “allicin yield” or “allicin potential.”
- When reading supplement labels, note that the amount of allicin is often listed in micrograms (mcg) rather than milligrams (mg). There are 1,000 micrograms in 1 milligram, so a supplement that contains 5,000 micrograms of allicin has 5 milligrams of allicin, which meets the European Scientific Cooperative on Phytotherapy’s recommendation of 3 milligrams to 5 milligrams of allicin.
- A supplement may contain 500 milligrams of dried garlic bulb, which is equal to 0.5 gram. This falls into the low end of the World Health Organization’s recommendation for dried garlic powder. Remember that dried powder contains just a small amount of allicin. Other compounds make up the rest of the tablet.
But why exactly should you stink up your breath with garlic? One of the specific benefits is that it may help lower cholesterol. On the next page you’ll learn what role garlic plays in the bloodstream.
Want more information about garlic? Try:
- Vegetable Recipes: Find delicious recipes that feature garlic.
- Nutrition: Find out how garlic fits in with your overall nutrition plans.
- Vegetable Gardens: Grow a full harvest of great vegetables this year.
- Gardening: We answer your questions about all things that come from the garden.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.
or capsuled? Researcher studies garlic’s potency as a
By SARA SELIC
What good is garlic? And to reap any benefits, should you eat it in its odiferous fresh form or will a stink-free capsule suffice? Christopher Gardner, PhD, a researcher at the Stanford Center for Research in Disease Prevention, is on a mission to find out.
Thanks to a grant from the National Institutes of Health, Gardner is conducting the most rigorous study ever to address a lingering controversy in the nutritional-supplement field: whether fresh garlic and garlic supplements — a widely consumed herbal supplement — lower cholesterol as claimed.
Food service workers carefully peel garlic in preparation for an unusual study conducted by Christopher Gardner. Gardner and his team are comparing the effectiveness of garlic taken in supplement form to garlic eaten fresh. Study volunteers must agree to eat a number of garlic-infused specialty sandwiches. PHOTO: COURTESY OF CHRISTOPHER GARDNER
In preparation for the study — which is seeking volunteers and entails eating gourmet sandwiches six days a week — Gardner’s staff spent two weeks peeling, mashing and measuring 150 pounds of fresh garlic. That’s on top of the weeks they spent taste-testing a dozen custom-made sandwiches ranging from Portobello mushroom to chicken quesadilla.
The Stanford study differs greatly from the dozens of garlic studies conducted over the past four decades, Gardner explained.
While previous studies tested different garlic preparations with inconsistent and often inadequate potency, the Stanford researchers know the exact chemical composition of the garlic preparations they’re using and will monitor this throughout the study with periodic chemical analyses. And unlike previous studies, which tested just one garlic type, the Stanford study will evaluate the effects of two top-selling garlic supplements along with fresh garlic.
“This study goes far beyond the other trials, because we know exactly what we’re giving participants,” said Gardner, assistant professor of medicine. “These results should help set the record straight.”
For centuries, garlic has been touted for its disease-fighting properties. The most commonly claimed benefit is reduced cholesterol, although garlic is also said to reduce blood pressure, boost antioxidants and reduce the risk of certain cancers. Seeking such benefits without eating (or smelling like) garlic, millions of Americans take garlic supplements — pills containing powdered garlic or aged-garlic extract.
Meanwhile, researchers sought to determine whether garlic deserves its reputation. More than two dozen studies in the 1970s and ‘80s claimed to prove that garlic lowers cholesterol, but the studies were later criticized for poor design. They involved too few participants or didn’t include a control group, for example. When more-rigorous studies were conducted in the 1990s, most concluded that garlic offered little to no significant benefit.
Gardner said the question remains unsettled because chemical analyses conducted by Larry Lawson, PhD, a biochemist and co-investigator for Stanford’s study, revealed serious flaws in the formulations of the garlic supplements used in past studies. The key issue is allicin, an enzyme that is garlic’s active ingredient.
When a person eats fresh garlic, allicin is released by chewing or mincing the herb. It’s more challenging to get allicin from a garlic pill, however. In some cases, if the pills dissolve in the stomach, the garlic enzyme needed to produce allicin becomes inactivated.
Some pills, meanwhile, have an enteric coating, and these pills often pass through the body undissolved. “The problem is, all these studies didn’t really test garlic — they tested garlic supplements,” Gardner said. “That’s not the same as eating garlic.”
To select the fresh garlic for the study, Gardner traveled to Gilroy, Calif., the nation’s “garlic capital.” An eight-person team spent two weeks peeling and mashing the garlic, then scooping it into 5-gram containers.
The premeasured garlic portions will be spread onto the gourmet “study sandwiches” that participants in the “fresh garlic group” must eat six days a week.
All other participants must eat the sandwiches as well, but minus the garlic. The six types of sandwiches used in the study were chosen in taste tests from a larger sample all custom-prepared by a chef. “This isn’t your typical clinical trial. It’s a lot of fun,” Gardner said.
Participants in the Stanford study — 200 healthy adults with moderately elevated cholesterol — will consume the sandwiches along with study tablets for six months. Random assignment will be used to determine which combination of sandwich and pill will be given to each participant in the trial.
Participants’ cholesterol, blood pressure, blood-clotting ability and antioxidant levels will be monitored periodically.
Volunteers must be between ages 30 and 65 and in good health but have moderately elevated cholesterol (LDL of 130-190). And, they must agree to eat their allotted “study sandwiches” six days a week.
“We only want people who like our sandwiches,” Gardner said, adding, “We’ve gone to enormous lengths to make sure they’re excellent.”
Interested volunteers should call 725-5018 for more information.
Are garlic capsules really as healthy as eating raw garlic?
As is often the case, the easy way doesn’t really work. As mentioned earlier, to activate the garlic’s healing compound, you need to ingest raw, crushed garlic. No pill, powder or dried form can match the therapeutic potential of garlic in its natural state.
Most garlic pills contain no allicin and the alliinase enzyme to produce allicin will not be activated in the stomach because stomach acid will destroy it.
Then there are enteric coated garlic tablets that hope to dissolve slowly and their contents open up in the less acidic intestines to produce allicin. But this depends upon transit time and pH. Sometimes enteric coated capsules open up in the stomach or pass all the way through the digestive tract undissolved.
The smelly phosphorus gas disappears when garlic is dried, processed or cooked, but so do some of the health benefits.Dried garlic retains anti-oxidant properties and can help fight free radicals – but never to the same extent as raw garlic does. If you struggle with raw garlic, just remind yourself that chewing it has been proven to be as effective as taking penicillin in some cases.
Does Garlic (Or Its Supplements) Have Health Benefits?
An FDA household survey in 2002 showed that garlic was the second most commonly used dietary supplement (after echinacaea) . Considering the fact the same survey showed that 73% of English speaking non-institutionalized adults in the USA used dietary supplements, we can safely conclude that that’s a whole lot of garlic.
I am all in favour of using garlic as a culinary spice but is there science to back up the role of garlic as a functional food?
What Is Garlic?
Garlic (Allium sativum L) is a member of the lily family along with chives, onions, shallots and leeks. It is a perennial that grows up to 2 feet high and came originally from Asia. China produces about 75% of the worlds supply of garlic. The city of Gilroy, California prides itself as the ‘garlic capital of the world’ and is the leading US producer of garlic.
There are two main subspecies of garlic:
- hardneck garlic and
- softneck garlic.
Garlic can be consumed in a myriad of ways:
- garlic cloves,
- essential garlic oil (0.2 to 0.5% of garlic cloves),
- garlic powder,
- garlic oil macerates (garlic cloves ground into vegetable oils),
- garlic extract,
- black garlic
- aged garlic extract
- capsules and
Two forms of garlic deserve a special mention:
This is ordinary garlic that has been allowed to ferment. The fermentation process gives the garlic the characteristic dark color and the sweet taste.
Aged Garlic Extract:
This results from storing sliced garlic in 10-20% ethanol for 18 months. The process is believed to decrease the content of allicin and increase the content of allylcysteine, selenium and s-allylmercaptocysteine. It also has less odor than fresh garlic.
References to the medicinal properties of garlic date back to the writings of the Zoroastrians in the 6th century BC. Garlic was part of the therapeutic armamentarium in ancient Egypt, Greece, Rome, traditional Chinese medicine and native American medicine.
It was used by gravediggers in the 18th century to fend off the plague and by soldiers in World War II to prevent gangrene.
Louis Pasteur himself confirmed the antibacterial activity of garlic in 1858.
It would be remiss of me not to mention vampires in relation to garlic especially as I am writing this article less than a kilometre form the home of Bram Stoker.
Garlic contains over 100 compounds that may act synergistically. It is high in organosulfur content with allylsulfur being responsible for some of the key health benefits which comprises 1% of the dry weight of garlic. Key among the bioactive are allicin and quercetinquercetin.
Is There Any Research?
There are 5532 publications related to garlic which includes 222 human clinical trials. This compares favourably to ginger which has 3000 publications and 186 clinical trials to boost of.
Does Allicin Have Medicinal Properties?
Often times when sitting with patients , I tell them that there is only one thing that they need to remember from the entire consultation. Sometimes I even write down the key message on a prescription pad and sign my name to it and tell them that they can use if for reference after the consultation. I find this helpful for example, when someone first learns of a diagnosis of HIV and I want them to know that they will be fine but know that they will doubt my words in the dark of the night.
The following is the key message from this article. Feel free to forget everything else I have written but the following is a very practical message that everyone needs to know.
Allicin (allyl 2-propenethiosulfinate) is one of the key bioactive ingredients in garlic. It is produced from the breakdown of s-allyl cysteine-S-oxide (alliin).
Studies showed that as little as 60 seconds of microwave heating or 45 minutes of oven heating can block garlic’s ability to inhibit in vivo anticancer activity. Allowing crushed garlic to “stand” for 10 minutes before microwave heating for 60 seconds prevented the total loss of anticarcinogenic activity. Why?
The key to using garlic for health is to chop, peel or slice garlic and allow it to stand for 10 minutes. This allows the alliin to form allicin via the so -called allinase reaction. Once the allicin is formed, it does not deteriorate during cooking.
It is not just red wine that needs to breathe, garlic needs to breathe too.
Does It Reduce Blood Pressure?
Allicin acts both as a vasodilator and as an angiotensin converting enzyme inhibitor which provides a biological basis for possible anti-hypertensive effects.
A 2015 systematic review published in Phytomedicine evaluated the effect of garlic on hypertension .
They identified a total of seven relevant randomized, placebo-controlled trials. Compared with placebo, garlic had a significant lowering effect on both systolic BP and diastolic BP.
Canadian reviewers conducted a full Cochrane analysis of garlic for the prevention of cardiovascular mortality in patients with baseline hypertension.
Only two relevant trials (with 87 participants) were identified and one of these trials was excluded due to methodological flaws (the numbers randomized to different arms of the study were not stated making it impossible to include in the meta-analysis). Neither trial reported clinical outcomes and insufficient data was provided on adverse events. No conclusion was reached (apart from the fact that some people do lousy research).
Garlic is effective at lowering BP but there is no evidence that it reduces cardiovascular risk in people with baseline hypertension.
Does it help with the common cold?
Australian reviewers published a Cochrane meta-analysis of garlic for the common cold in 2014. Only one trial of 146 participants met the inclusion criteria. The participants were randomized to either a garlic supplement (with 180 mg of allicin content) or a placebo (once daily) for 12 weeks.
The study found statistically significant reductions in the number of episodes of the common cold. Overall, the reviewers concluded that ‘there is insufficient clinical trial evidence regarding the effects of garlic in preventing or treating the common cold. A single trial suggested that garlic may prevent occurrences of the common cold but more studies are needed to validate this finding. Claims of effectiveness appear to rely largely on poor-quality evidence’.
Depending on your perspective in life, we can either say that there either say that there is a single study suggesting that garlic prevents the common cold or that there is insufficient evidence.
Does It Lower Cholesterol?
Garlic exerts an effect on HMG CoA reductase which provides biological plausibility for a possible lipid lowering effect. A 2103 review from Australian investigators is the most comprehensive meta-analysis to date of the lipid lowering effects of garlic.
A total of 39 primary trials of the effect of garlic preparations on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides were included in the review. Data crunching showed that garlic reduced total serum cholesterol by 17 ± 6 mg/dL and low-density lipoprotein cholesterol by 9 ± 6 mg/dL in individuals with elevated total cholesterol levels (>200 mg/dL), provided garlic is used for longer than 2 months. This reduction was statistically and clinically significant. There was no significant effect on HDL or triglycerides.
Medium to long term consumption of garlic helps to reduce cholesterol.
Does It Help Prevent Alzheimers and Dementia?
Studies relating garlic to the prevention of Alzheimer’s Disease or dementia are ‘only in their infancy’ according to leading experts in the field. There are 26 studies in the field but no human clinical studies. Studies in mice, rats and laboratory models suggest a number of mechanisms by which garlic may help with brain health but none of these is ready for study in humans.
There is no human science to support a role for garlic in brain health.
Does It Increase Longevity?
On one hand, we could argue that garlic is part of the Mediterranean and Asian dietary pattern which have been shown to prolong life. On the other hand, it is very difficult to quantity the relative contribution of garlic in these complex lifestyle and eating patterns. It is just one part of many things.
Garlic and particularly aged garlic has been shown to prolong longevity in senescence accelerated mice. However, interesting though this may be, it should be noted that this study dates back to 1996 and not much progress has been made on the topic in the last 20 + years.
Garlic has no credibility as a longevity agent apart.
Does It Improve Athletic Performance?
Researcher s at the Appalachian State University studied the effects of 7 days of supplementation with garlic and placebo on peripheral blood pressures, blood oxygen saturation, heart rate, oxygen consumption, and time to exhaustion during a progressive exercise test to exhaustion in humans under hypoxia. No significant differences were observed between treatments regarding oxygen consumption, exercise or resting peripheral blood pressures, blood oxygen saturation, heart rates, or exercise time to exhaustion.
Similarly, researchers from James Madison University found that acute garlic supplementation did not alter vasoreactivity, fibrinolytic potential or the fibrinolytic response to exercise in young healthy trained males but had a small effect on V02 max (a measurement of the maximum amount of oxygen that an individual can utilize during intense, or maximal exercise). However the authors questioned the clinical significance of the change in the V02 maximum.
Finally, Iranian investigators found that garlic increased the antioxidant content of saliva in 16 young male athletes (as compared to placebo) . Again it is hard to extrapolate the clinical significance of this.
There is no convincing evidence that garlic helps with exercise tolerance.
Does It Help Bone Health?
A cross-sectional study conducted in a large population-based volunteer cohort of twins showed a protective effect of dietary garlic on osteoarthritis.The authors of the study acknowledge that such studies are fraught with methodological issues.
A study in 44 postmenopausal osteoporotic women who were randomly assigned into two groups: the garlic group and the placebo group showed mixed effects on pro-inflammatory cytokines making it hard to predict the likely impact on bone.
There is insufficient information to comment on garlic an bone health.
Is it safe?
Garlic is generally regarded as safe. Side effects of garlic include garlic breath, body odour and gastrointestinal upset. Garlic is caustic and it should not be applied to skin. It can decrease the effectiveness of antiretroviral medication used for the treatment of HIV infection. It can also increase the risk of bleeding and care would be taken in people who are taking anticoagulant medication.
Other clinically important drug-drug interactions include:
- reduced effectiveness of the oral contraceptive pill
- reduced absorption of isoniazid and
- reduced effectiveness of the anti-rejection drug, cyclosporin.
Garlic is a safe, delicious and a low-calorie culinary condiment. Science suggests that it can lower blood pressure and cholesterol.
The key take home message is that garlic should be allowed to breathe prior to cooking in order to avail of any therapeutic benefits.
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What are the benefits of garlic?
Below are examples of some scientific studies published in peer-reviewed academic journals about the therapeutic benefits (or not) of garlic.
Lung cancer risk
People who ate raw garlic at least twice a week during the 7 year study period had a 44 percent lower risk of developing lung cancer, according to a study conducted at the Jiangsu Provincial Center for Disease Control and Prevention in China.
The researchers, who published their study in the journal Cancer Prevention Research, carried out face-to-face interviews with 1,424 lung cancer patients and 4,543 healthy individuals. They were asked about their diet and lifestyle, including questions on smoking and how often they ate garlic.
The study authors wrote: “Protective association between intake of raw garlic and lung cancer has been observed with a dose-response pattern, suggesting that garlic may potentially serve as a chemo-preventive agent for lung cancer.”
Organo-sulfur compounds found in garlic have been identified as effective in destroying the cells in glioblastomas, a type of deadly brain tumor.
Scientists at the Medical University of South Carolina reported in the journal Cancer that three pure organo-sulfur compounds from garlic – DAS, DADS, and DATS – “demonstrated efficacy in eradicating brain cancer cells, but DATS proved to be the most effective.”
Co-author, Ray Swapan, Ph.D., said “This research highlights the great promise of plant-originated compounds as natural medicine for controlling the malignant growth of human brain tumor cells. More studies are needed in animal models of brain tumors before application of this therapeutic strategy to brain tumor patients.”
Women whose diets were rich in allium vegetables had lower levels of osteoarthritis, a team at King’s College London and the University of East Anglia, both in England, reported in the journal BMC Musculoskeletal Disorders. Examples of allium vegetables include garlic, leeks, shallots, onions, and rakkyo.
The study authors said their findings not only highlighted the possible impact of diet on osteoarthritis outcomes but also demonstrated the potential for using compounds that exist in garlic to develop treatments for the condition.
The long-term study, involving more than 1,000 healthy female twins, found that those whose dietary habits included plenty of fruit and vegetables, “particularly alliums such as garlic,” had fewer signs of early osteoarthritis in the hip joint.
Potentially a powerful antibiotic
Diallyl sulfide, a compound in garlic, was 100 times more effective than two popular antibiotics in fighting the Campylobacter bacterium, according to a study published in the Journal of Antimicrobial Chemotherapy.
The Campylobacter bacterium is one of the most common causes of intestinal infections.
Senior author, Dr. Xiaonan Lu, from Washington State University, said, “This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply.”
Share on PinterestGarlic may contain heart-protective chemicals.
Diallyl trisulfide, a component of garlic oil, helps protect the heart during cardiac surgery and after a heart attack, researchers at Emory University School of Medicine found. They also believe diallyl trisulfide could be used as a treatment for heart failure.
Hydrogen sulfide gas has been shown to protect the heart from damage.
However, it is a volatile compound and difficult to deliver as therapy.
Because of this, the scientists decided to focus on diallyl trisulfide, a garlic oil component, as a safer way to deliver the benefits of hydrogen sulfide to the heart.
In experiments using laboratory mice, the team found that, after a heart attack, the mice that had received diallyl sulfide had 61 percent less heart damage in the area at risk, compared with the untreated mice.
In another study, published in the Journal of Agricultural and Food Chemistry, scientists found that garlic oil may help protect diabetes patients from cardiomyopathy.
Cardiomyopathy is the leading cause of death among diabetes patients. It is a chronic disease of the myocardium (heart muscle), which is abnormally thickened, enlarged, and/or stiffened.
The team fed diabetic laboratory rats either garlic oil or corn oil. Those fed garlic oil experienced significantly more changes associated with protection against heart damage, compared with the animals that were fed corn oil.
The study authors wrote, “In conclusion, garlic oil possesses significant potential for protecting hearts from diabetes-induced cardiomyopathy.”
Human studies will need to be performed to confirm the results of this study.
High cholesterol and high blood pressure
Researchers at Ankara University investigated the effects of garlic extract supplementation on the blood lipid (fat) profile of patients with high blood cholesterol. Their study was published in the Journal of Nutritional Biochemistry.
The study involved 23 volunteers, all with high cholesterol; 13 of them also had high blood pressure. They were divided into two groups:
- The high-cholesterol normotensive group (normal blood pressure).
- The high-cholesterol hypertensive group (high blood pressure).
They took garlic extract supplements for 4 months and were regularly checked for blood lipid parameters, as well as kidney and liver function.
At the end of the 4 months, the researchers concluded “…garlic extract supplementation improves blood lipid profile, strengthens blood antioxidant potential, and causes significant reductions in systolic and diastolic blood pressures. It also leads to a decrease in the level of oxidation product (MDA) in the blood samples, which demonstrates reduced oxidation reactions in the body.”
In other words, the garlic extract supplements reduced high cholesterol levels, and also blood pressure in the patients with hypertension. The scientists added that theirs was a small study – more work needs to be carried out.
Doctors at the Department of Urology, China-Japan Friendship Hospital, Beijing, China, carried out a study evaluating the relationship between Allium vegetable consumption and prostate cancer risk.
They gathered and analyzed published studies up to May 2013 and reported their findings in the Asian Pacific Journal of Cancer Prevention.
The study authors concluded, “Allium vegetables, especially garlic intake, are related to a decreased risk of prostate cancer.”
The team also commented that because there are not many relevant studies, further well-designed prospective studies should be carried out to confirm their findings.
Alcohol-induced liver injury
Alcohol-induced liver injury is caused by the long-term over-consumption of alcoholic beverages.
Scientists at the Institute of Toxicology, School of Public Health, Shandong University, China, wanted to determine whether diallyl disulfide (DADS), a garlic-derived organosulfur compound, might have protective effects against ethanol-induced oxidative stress.
Their study was published in Biochimica et Biophysica Acta.
The researchers concluded that DADS might help protect against ethanol-induced liver injury.
Preterm (premature) delivery
Microbial infections during pregnancy raise a woman’s risk of preterm delivery. Scientists at the Division of Epidemiology, Norwegian Institute of Public Health, studied what impact foods might have on antimicrobial infections and preterm delivery risk.
The study and its findings were published in the Journal of Nutrition.
Ronny Myhre and colleagues concentrated on the effects of Alliums and dried fruits, because a literature search had identified these two foods as showing the greatest promise for reducing preterm delivery risk.
The team investigated the intake of dried fruit and Alliums among 18,888 women in the Norwegian Mother and Child Cohort, of whom 5 percent (950) underwent spontaneous PTD (preterm delivery).
The study authors concluded, “Intake of food with antimicrobial and prebiotic compounds may be of importance to reduce the risk of spontaneous PTD. In particular, garlic was associated with overall lower risk of spontaneous PTD.”
Garlic and the common cold
A team of researchers from St. Joseph Family Medicine Residency, Indiana, carried out a study titled “Treatment of the Common Cold in Children and Adults,” published in American Family Physician.
They reported that “Prophylactic use of garlic may decrease the frequency of colds in adults, but has no effect on duration of symptoms.” Prophylactic use means using it regularly to prevent disease.
Though there is some research to suggest that raw garlic has the most benefits, other studies have looked at overall allium intake, both raw and cooked, and have found benefits. Therefore, you can enjoy garlic in a variety of ways to reap its advantages.