How Healthy Is Garlic?

by | Aug 4, 2010
Garlic

Garlic

People often say that garlic has medicinal properties. Some claim it lowers blood pressure, others swear it helps cholesterol and reduces clotting, and some even think it protects against cancer. I’ve also heard that garlic is “healthier” 10-15 minutes after it has been crushed or minced. Is any of this true?

The Science of Single Foods

As someone who regularly reads the scientific literature on the health benefits of food I can assure you that this is not an easy question to answer. The problem is that the effect of any single food on human health is likely to be small at best, and small effects are very difficult to detect with reliability. Studies must be incredibly well-designed to contribute anything of value to our understanding of how a food works in the human body. Also, many studies must be taken together in context for the data to be evaluated properly.

I have been researching this garlic question on and off for months and feel only slightly more confident today than I did when I started. To summarize, there are a good number of studies addressing the health value of garlic, but very very few of them are well-designed and published in reputable journals. The problem with having a large number of poor-quality studies is that results are often conflicting and difficult to interpret. Thus, when another scientist comes in to do a meta-analysis (pooling data from many studies and re-analyzing it for stronger statistics) the findings are usually inconclusive.

However, inconclusive findings do not enable me (or anyone) to say there is no benefit. What I can say is that more research is needed and if there is a benefit it is likely to be small. (How unsatisfying is that?!). But personally I would still recommend eating garlic for health. Why?

Small Benefits Are Important

Although we cannot say exactly why garlic is good for you, it is almost certainly not bad for you. Moreover, although it is difficult to attribute a particular health benefit to a single food, we do know that people who eat the most vegetables tend to be healthier than people who fewer.

Many nutrition scientists are beginning to suspect that the benefit of foods like garlic are primarily relevant in the context of a whole diet and cannot be evaluated independently. This means that it is less important that the individual studies I mentioned earlier are inconclusive, because they are likely not sensitive enough to evaluate the complex interactions of whole foods and food combinations on human physiology.

The Best Reason To Eat Garlic

The most important thing you can do for your health is eat a diverse diet of natural, unprocessed foods. Garlic is an amazing ingredient that imparts a unique and wonderful taste to the food it is cooked with. If you like garlic and it encourages you to eat your vegetables, then it’s good for you.

If it makes you feel slightly better knowing that it may help your heart or reduce inflammation, that’s awesome but less important.

What About The Crush?

If you do hope garlic can add to your health, is there any benefit in crushing it early? Probably.

Scientists have long suspected that the active ingredient in garlic is a substance called allicin. A recent study from Queen’s University showed that it is actually a decomposition product of allicin that has the most potent antioxidant activity.

Interestingly, allicin is created from an enzyme called alliinase that is not released from plant cells until they are damaged. Alliinase is what gives garlic (and onions) their strong odor and is thought to be a self-defense mechanism for these plants. When garlic is crushed, alliinase becomes active and begins creating allicin. As allicin is created and breaks down, the antioxidant potential of garlic is dramatically increased. Optimal antioxidant levels are created about 10 minutes after garlic is crushed.

It has not yet been shown that this increased antioxidant activity is a benefit to humans, but the principle is compelling enough to try to remember to crush your garlic a little early. If you are anything like me though, this feat is almost impossible. Apparently garlic hasn’t done that much for my memory.

What are your favorite reasons to eat garlic?

Originally published March 27, 2009.

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29 Responses to “How Healthy Is Garlic?”

  1. Greg says:

    Best reason to eat garlic? I propose that the best reason is to fight off Vampires. Vampires hate garlic because it gives them bad breath, and when they bite people they don’t want to have bad breath. Thanks for you view on this though, Darya.

  2. Healthyliving says:

    How interesting. I loved your post and the discussion about how to peel garlic a few months ago, and didn’t really have any idea that the benefits of garlic were more than its wonderful flavor. And who knew there was this much science about garlic.

  3. Aurore says:

    I LOVE garlic. I eat it almost every day, both cooked and raw. I eat it mainly for the flavor, but when I eat it raw it’s because, for myself, it has proven itself to fight away viruses. If I start to feel a little sick (itchy throat, cough, runny nose, etc…) I eat a few raw cloves of garlic and 98% of the time, the sickness never comes. But as you said Darya, it has to be mixed in with a healthy, varied diet to make a difference on your health. Eating garlic while you are sick and then bingeing on pizza, pasta or ice-cream will not help you.

    • Darya Pino says:

      Isn’t that the beauty of vegetables? That we can get so much from them in so many different ways. You remind me of another difficult thing about large studies, they largely ignore individual variability.

  4. doug says:

    Um, it tastes good.

  5. Karin says:

    And by the way Darya I didn’t mention before how much I love your new place here!! The site is beautiful, and I love the pictures at the top. Who did it for you?
    As for the garlic, I had no idea it had so much potential health benefit. I like fresh garlic because it adds so much irreplaceable flavor; but hey, I take the other benefits too!

  6. Scott says:

    Thanks for this post- very informative, cuts out all the uber-crunchy dogma of so many vegan-magical witch doctors. Personally I love garlic, and I love knowing that if might be really good for me!

  7. Katie says:

    My favorite part of your post was the eating diversely thing; I think its so important, and things just go downhill when we don’t have a lot of different things in our diets. Meals will also taste better if things are varied. Curious though, what kind of substitutes for garlic are out there? I mean, even though I like garlic I would like to add something to a stirfry that is like garlic, but not garlic. Like maybe ginger? Could I mince up some ginger and use it like garlic? What other options are out there…..?

    • Daniel Cowan says:

      Lemongrass comes to mind as an aromatic that could be added in a manner to garlic & ginger – I use all three.

  8. The sound and smell of garlic being chopped on the cutting board = my mom’s kitchen.

  9. Mike says:

    I count 47 garlic bulbs in that picture. Any takers?
    I do love garlic though. So do Italians. Is there any other type of food that garlic is more associated with than Italian?

  10. Mus says:

    I proved myself healthier after three days of taking fresh garlic. No more ‘jerking’ while working up to another floor. It’s amazed me. Any one can try.

  11. baahar says:

    I love garlic and eat it mostly because of its flavour. Many of our dishes are being served with yogurt+garlic. It seems that it can make any dish awesome :)
    One old uncle of mine eats raw garlic every day to regulate his blood pressure levels. Back home I used to press 1-2 cloves into a glass of milk, bring it to a boil, put some honey in and drink it when I had a bad, bronchitis like cough. The cough would be gone the other day .. but beware ! Not every garlic tastes the same. I tried the same recipe some years later with local garlic here and it was bad .. very bad.

    In my culture, most of the information about health benefits are rooted in tradition. After all, these food items (vegetables, herbs, etc.) are around for some time and scientists in the old days weren’t lying around lazily either ;) Sure, they didn’t have the technical equipment of today, but followed basic scientific procedures to gain knowledge (http://en.wikipedia.org/wiki/Medicine_in_medieval_Islam#Scientific_method). Lately I hear of more and more scientists applying modern methods to verify or falsify these statements.

    I find these things fascinating and would love to collect as much knowledge as possible. Hopefully I will be able to make time to study things that interest me so.

  12. Chris Lea says:

    I have no fear of vampires. That’s how much I like garlic.

  13. tonyboy says:

    Thinly sliced garlic. Stir fried with plain peanuts on med heat 20-30 min….add nothing…ohhhh my god…tastes awsome with beer everyday and healthy also

  14. Johnathen says:

    I hate Garlic, thank you for all the overweight people in America that have complained their entire lives about why you were overweight and wanted to promote the over use of Garlic to loose your imaginary pounds…. myself and many thousands of the younger generation are Allergic to Garlic and I cant even have a decent meal now….

    My allergy has no been promoted to throat swelling and is in the critical phase of my allergy and Allergies have never been noticed in the past 500 years of my relatives records… I am 28 years of age and this Garlic Allergy started from a young age with Garlic Powder!! now its with everything that has raw, natural and powder Garlic…

    thank you for Ruining my life and shortening my life span to suit your own selfish eating habits!!!

    if you want to loose weight and be healthy, drink V8 and reduce the food you in a meal to the size of your 2 hands put together. And, if your still hungry, then go do something else and stop looking for more food…. Remember, Mass can not be created nor destroyed it just changes FORM!!!!!

  15. khakimo says:

    Best reason by far is the allicin. Garlic is one of the most potent anti-biotics on the planet. Not to mention anti-viral and anti-fungal and another I can’t think of at the moment.

    Works very fast! MUST be raw and fresh. If the garlic has been smashed in the store (if it’s soft), the allicin will be gone and you won’t get the benefit of the allicin. Wait 10 to 15 minutes after it
    s been crushed for the allicin to form and gain potency. Use it within an hour of crushing, as after that it starts to lose potency.

    Some will look for garlic that doesn’t burn, but my experience has shown that the more it burns, the more potent it is.

    Even a toothache! No more anti-biotics that take 2 or 3 days to work! And first hold it on the tooth before swallowing it, and it will kill the pain. Some say hold it there for 45 minutes, but I find it to be much faster – some have held it there too long and actually blistered their gums.

    It works great for dogs too – saved mine many times. I had a dog that would eat a whole clove, but for most you can just chop it up and put peanut butter or canned dog food or something they like. Be sure to let the allicin form. Cats – some say yes, some say no. Just be careful and use small amounts if you want to try.

  16. Sarah says:

    Garlic is definitely healthy. I know someone in there late 90′s who eats a ton of garlic and is still really healthy.

  17. Alan says:

    I love cooked garlic but get an upset stomach from raw garlic. Online research seems to say that many of garlic’s health benefits are largely destroyed by cooking, and I’m guessing that it’s caused by the heat destroying the alliinase enzyme so that it’s no longer available to catalyze reactions. (Similar to myrosinase enzyme converting glycosides to isothiocyanates when cell walls are broken in cruciferous vegies.) So here’s my hypothetical solution: cook with plenty of garlic but after cooking add some raw green onion to the meal so alliinase is again available to catalyze the reactions. Does this sound plausible enough to be worth the small effort?

  18. Neo says:

    Try some raw garlic with your favourite cheese.
    You wont be dissapointed. Make sure you get the
    ratio garlic:cheese right though.
    Off tap!

  19. MUKESH GUPTA says:

    Dear Madam, i use to eat garlic everyday in lunch food. it is harmless in this summber…? i want to know….

    Mukesh Gupta.

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