Before we get into the physiological effects of garlic, I would like to say that I am not a chemist; neither am I a botanist, biologist nor medical doctor. But I can read and I do love garlic enough to read everything about it I can. I am merely trying to pass on, to you the results of what I have read and otherwise learned in order to help stimulate enough of an interest in you for further study. Don't just take my word for it, Google it yourself and see where your research takes you.

I was also immensely fortunate to be able to attend all four Garlic is Life Symposia from 1998 through 2003 where research scientists from several disciplines came from all over came to deliver lectures to their peers and attend the lectures of all the other scientists. There have never before or after been any other meetings that brought together so many multi-degreed scientists to discuss their findings amongst their peers. These people formed a sort of allium intelligensia and bonded quite well with each other over the 3-4 days of each symposium. The information in this section mostly comes from these lectures and personal conversations with these esteemed and honored scientists who have done the objective studies that have shown the real effects garlic has on health when used in different ways. They didn't have an agenda, just a willingness to learn as much as they could about this wonderous bulb.
Click here to read all about the Garlic is Life Symposia

Unfortunately, not all studies are as objective as these, sometimes vested financial interests of the pharmaceuticals industry sponsor studies with the apparent intent to show garlic to have no health benefits and thus seek to undermine the confidence of the public in garlic. There was a study done at a famous Minnesota health clinic a few years ago that purported to show garlic had no health benefits because no changes were measured after consuming the pills. What they did not mention was that the pills they used in the study did not dissolve and therefore the subjects of the study received no garlic. The proper conclusion should have been that the particular pill used did not work because it did not dissolve - a fact well known to other researchers as well. Instead, they drew the conclusion that garlic has no health benefits, in spite of the thousands of other studies which prove otherwise.

There is another more recent study publicized on Yahoo in February, 2007 making similar claims. I have been too busy to look into it yet but I already know anything that flies into the face of so many thousands of objective studies to suddenly show dramatically different results needs to be looked into more closely. Many thousands of people have died from taking prescription medications,even according to the labels but no one has died from eating garlic - think about it.

I find this sort of pseudoscience to be repugnant. The average American does not have enough information about this and will probably take their word for it rather than try to find out more about it. That's what this webpage and the ones on the Health Benefits of Garlic and Garlic Pills and Oils are all about - to help the public learn the facts so they can make up their minds in a more informed manner.

If you find disagreement with the contents of this section, please leave us your comments, as we plan to update this section with the latest information as it becomes available to us. We would not knowingly or intentionally misinform anyone. Where possible, we will cite the specific source of our information and urge you read it to help you be better informed. If you are aware of research papers that you do not see discussed here, please either forward them to us or tell us where we may obtain copies so that we can update our data base.

We realize we are in the middle of a controversial subject area and wish to help you to make intelligent choices based on having the maximum amount of information. We are not trying to practice medicine, give medical advice or anything of the kind. Around our place, we just happen to like the flavor of garlic and are overjoyed that information exists to show that it has beneficial effects on our bodies. Our goal is to inform others about the research that indicates these benefits and let researchers defend their own findings.

The Chemistry of garlic is an incomplete science. We are just beginning to appreciate the complexity of chemical reactions that take place inside the cloves themselves and what happens when it is crushed, cooked or otherwise processed in some way. The more we discover about it, the more we find that we don't yet understand and may not within our lifetimes. Even the tiniest clove contains the potential for an almost unlimited number of compounds that can be generated by interacting with it in a number of ways. We will not be using chemical formulae and graphic illustrations of chemical structures as most people don't understand them anyway, but we try to keep our discussion at the lay person's level so that understanding is maximized. It is not our purpose to bedazzle anyone with complicated jargon in order to make ourselves look smart, our goal is to help people better understand what is happening in the simplest way possible.

Garlic is deceptively simple at first glance, basically containing only two compounds separated by cellular walls within the clove. But when you add the fact that garlic is a living thing that complies with its own rules for survival rather than just inert matter, things begin to get complicated. Nothing in nature is truly inert, not even rocks.

From the moment a garlic bulb matures and its leaves die down, chemical changes are constant as each clove within the bulb begins the slow cycle to become a multi-cloved bulb itself. In a few months or so, depending on variety, each clove will send up its first little spike of a leaf in search of sunlight and generate roots that reach out and down seeking nutrient-laden water that it can osmose into itself and use the energy within the clove or sunlight to convert into new life. That very action itself would seem to imply some sort of intelligent plan, complete with systematic alternatives, that it follows, apparently knowingly-but that is an entirely different subject that we will not go into. We will attempt to look only at the chemical changes without trying to examine any subtle reasons why garlic does what it does.

If you slice open a clove of garlic, you will see that it is composed of cells separated by cellulose walls. Thanks to research conducted in 1951 by two Swiss chemists, Dr. Arthur Stoll and Dr. Ewald Seebeck, we know these cells contain either a cysteine-based sulfur rich amino acid, called alliin, which is stored in the mesophyll cells that make up most of the clove, or a protein-based enzyme called alliinase, that is stored only in the vascular bundle sheaths that run vertically up through the cloves, which reacts spontaneously with Alliin on contact, hence the need to be kept apart by the cellular walls. The clove had little or no discernible smell until you sliced it allowing these two compounds to mix and form a sulfenic acid which almost spontaneously condenses down to form thiosulphinates, mostly allicin. Among researchers, there are several other complicated chemical names for allicin. It is the allicin that is thus formed by chemical action that has the familiar garlic smell.

Raw garlic contains a few lipids (one or two tenths of a percent). Oil is not formed until garlic is crushed and steam distilled and then degrades down into the oily mix of sulfurous compounds, described above. The more time that elapses after crushing, the more complex the compounds become and the less sulfurous they smell. The simpler sulfur compounds have the most smell and the most anti-bacterial action. The polysulphides which are among the last breakdown products of allicin have the least taste and smell and the least immediate antibiotic effects, but are responsible for many of garlics other physiological effects. It is the allicin which is garlic's natural protection from pests and diseases and when we eat the fresh garlic it protects us also. Then it breaks down into other compounds which are helpful in different ways. Garlic just keeps on going and going and going.

Cooked garlic and garlic oil capsules will have broken down almost all the way and that makes a difference to us as they have different effects on the human body and its ailments. As doctor Wargovich at Houston's M.D. Anderson Hospital once put it, "If it doesn't stink, it doesn't work". There is no way to avoid the aroma of garlic about oneself if one wants it to work. As we say around our place, Garlic breath is better than no breath. Get used to it and educate your friends who find the smell of garlic offensive. Bad (garlic) breath is better than bad health. Even the so-called deodorized garlic pills or capsules, if they are any good, will cause a garlic smell to exude from your pores and breath as the garlic works its way through your circulatory system, lymphatic system and lungs, even if there is no garlic residual in your mouth and throat. You might as well develop a good sense of humor about it and if you lose a superficial friend or two, consider it their loss, not yours. If they are more concerned about your aroma than being alive and healthy, are they really the kinds of friends you want anyway?

In their wonderfully informative book, "Garlic", Nature's Original Remedy - published by Healing Arts Press of Rochester, Vermont, Stephen Fulder and John Blackwood point out that the Swiss researchers Stoll and Seebeck found wide variation in the sulfur content of garlic bulbs they obtained from 12 different parts of Europe. The samples varied from 500 mg/kg of sulfur to as much as 3720 mg/kg. It seems that the more sulfur in a bulb, the greater is its potential to produce allicin. Monsignor David Greenstock , head of Biology at St. Albans College, Valladolid, Spain found similar differences in bulbs grown in different parts of Spain and noted that those grown organically had a higher level of sulfur. However, the book doesn't say whether all test garlics were of the same variety or anything about soil types and climate, so it would be interesting to see some more work done in this area. Inquiring minds want to know for sure.

These trace minerals are an important part of garlic's health benefits as research shows that deficiencies or imbalances of them can lead to or contribute to hundreds of health problems. Mineral deficiencies are said to cause or contribute to everything from age spots and osteoporosis to arthritis and muscular dystrophy. How many trace minerals, and in what amounts garlic contains them, is a direct function of their presence in the soil in which garlic is grown. Organic and biodynamic growers regularly test their soil for trace minerals and replenish those with low values. Garlic grown with artificial fertilizers in depleted soils will contain smaller amounts of them than garlic grown organically in soils that have had trace minerals replenished by conscientious growers. If trace minerals are not present in the soil, garlic cannot contain them. The content of every plant on this planet is a direct function of what is in the soil in which it is grown and the water and air it is supplied.

The level of selenium in garlic is at least 9 parts per million and is said to be higher than in almost any other plant. Selenium is also found in seafood and liver. A December 1996 issue of the Journal of the American Medical Association reports that researchers at the University of Arizona found that patients who received a daily dose of selenium had 63% fewer cases of prostate cancer, 58% fewer cases of rectal cancer and 45% fewer cases of lung cancer compared to a group that received placebos. There were also 50% fewer cancer deaths than in the placebo group. But the researchers cautioned that the study needs to be replicated as the initial intent of the study was to measure whether selenium would help prevent skin cancer - and it did not.

Among the transient compounds formed when allicin breaks down into oil are dimethyl disulfide - which gives cabbage its taste, propenyl disulfide - which gives onions their smell, and propenyl sulphenic acid - which is the substance in onions that causes tears to flow when you slice or peel them. These compounds occur in much smaller quantities in the breakdown of allicin than they do in the other vegetables mentioned but they give you some idea of the kinds of compounds that can form just from crushing a clove of garlic. Please bear in mind that these compounds, too, are temporary and through chemical reactions with food substances, saliva and digestive juices, rapidly turn into other compounds.

A Few Special Garlic Compounds

There are a few compounds of special interest, mostly Diallyl disulfide (DADS) and Diallyl trisulfide (DATS), both fat-soluble, which have been shown to have anti-cancer activity. There are many studies showing these compounds are involved in most of garlics' benefits.

There's also some interest in S-allyl cysteine and S-allylmercaptocysteine, both water-soluble compounds that are contained in Kyolic brand aged garlic extract that also have shown some antitumor activity as well. Numerous studies sponsored by Kyolic in hospitals have shown beneficial effects in other areas as well, such as lower cholesterol and blood pressure, etc. Other researchers point out that in order to demonstrate even minimal results, very large amounts (way above normal daily usage amounts,) must be used and that the sulfides (DADS and DATS) produce results at normal consumption levels.

There are some practical ways you can increase the amounts of these chemicals in the garlic you use. Pickling garlic (whole, sliced, cubed or crushed) in vinegar causes S-allyl cysteine to form and the longer you store it, the more is formed up until about 5 years. By then, it's pretty potent and so's the vinegar it's in as they both show the same level of S-allyl cysteine (SAC) after about 60 days. I'm not sure whether it has to be refrigerated or not, but I refrigerate mine, just to be safe. You might want to make a big batch, because pickled garlic is so good it is hard to keep it very long and it just gets better and increases its SAC with age. What a great way to take medicine - pickled garlic.

It's a good idea to let the sliced, cubed or crushed garlic set and self-marinate for about 10 minutes in order to ripen before putting it into the vinegar so that the allicin has a chance to maximize and enhance the flavor and potency of the garlic, whether you pickle it or roast it or whatever processing you do. Like Chinese mustard, it takes the allicin a few minutes to build character before using.

A good way to maximize the amounts of Diallyl Disulfide (DADS) and Diallyl trisulfide (DATS) is to roast the chopped garlic in an oven or microwave it as the heat converts the allicin mostly into DATS and DADS as well as a few other things. Boiling them in water in a covered dish for 20 minutes does the same thing, but you lose a little through steam - you lose a lot if the pan is uncovered. Surprisingly, much of the DADS and DATS are retained by boiling the chopped, ripened garlic in milk. The boiled milk also retains some DADS and DATS in the milk solids, presumedly they would go into the lymphatic system since they are fat-soluble.

Complicating the picture are the conflicting findings of research teams funded by different organizations and not surprisingly, their findings always seem to favor their company's products. Still, we try to sift through things and present as balanced a report as we can. We try to find ways the average person can maximize the benefits of garlic.

There's more to come, please be patient with me while I learn. I'm trying to upgrade this page to reflect the state of the art knowledge of garlic chemistry as understood by the top researchers who meet at the Garlic is Life! Symposium in Tulsa every fall.

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