Previous studies had suggested that a human would have to eat their own weight in garlic before gaining any benefits.

But the new research suggests half a raw clove would be enough, rising to four and half cloves if cooked.

Although garlic is best known for its ability to stave off heart disease, scientists have also been examining its role in cancer.

They suspect it can counter the effects of particles that cause bowel cancer, but want to know which parts of the plant are actively involved in the process.

Rex and Christine Munday, a husband and wife research team based in New Zealand, were looking at what is thought to be one of the key ingredients - a substance called diallyl disulfide.

It causes the gut to produce enzymes that can clear it of cancer-causing particles.

Their findings are reported in New Scientist magazine and will be published in the journal Nutrition and Cancer.

The two of them gave rats varying doses of disulfide, and found that it increased levels of the enzyme by up to 60% when given in amounts equivalent to a moderate daily intake in humans.

"It's been recognized that garlic is an inducer of these enzymes, but previous studies have all been with doses at meaningless levels," Rex Munday told the magazine.

"They implied you'd need to eat your own weight in garlic to achieve beneficial effects."

Instead, the Mundays found that in rats the benefits kicked in at between 0.075mg and 0.3mg of disulfide per kilogram of body weight, or half a clove of garlic for the average human.

Lesley Walker, head of science information at the Cancer Research Campaign, said: "It's an interesting study, but people shouldn't get too excited about it."

This was because the research was performed on rats and did not look specifically at bowel cancer, but at a substance that can reduce the risk of bowel cancer.

She said it would take a much a larger study to prove any benefits, but there was no harm in eating plenty of garlic as eating plenty of fruit and vegetables reduces the risk of cancer.

"It's lovely to think that eating half a clove of garlic reduces the risk of bowel cancer, and if you like garlic then go for it - but don't necessarily be surprised if you then develop cancer."

Diallyl disulfide was first proven to have the ability to slow the growth of bowel cancer in 1995.

Dr Sujatha Sundaram, a researcher at Pennsylvania State University, found that it caused human bowel cancer tumor cells to shrink and die when transplanted into mice.

Dr Sundaram was also responsible for finding another compound found in garlic that slowed the growth of breast cancer in rats.

RAW Garlic For Parasites and Viral Infections

The following article is abstracted from the European producers of a freeze-dried garlic preparation that is used for the animal industry. It is a translation from German so the grammar is not terrific in some areas. The article explains why nearly every commercial garlic preparation that you purchase is virtually worthless. If you are going to use garlic you need to use fresh RAW garlic. -- Dr. Mercola

When we talk about allicin there is a group of compounds that are formed when you crush the garlic clove which are called the thiosulphanates. Of the thiosulphanates, allicin is the dominant one. About 70 to 80% of the thiosulphates is allicin.

We tend to talk about allicin as the antimicrobial agent but there is other thiosulphates in there that are also antimicrobials, but much less work is being done on them. And this is why we use the whole clove rather than trying to synthesize things like allicin.

Enteroguard

The developers call it a new antimicrobials complex for the feed industry. They developed Enteroguard from two active natural ingredients to replace the use of antibiotics at low levels that are incorporated in animal feed. Feed like pig feed, poultry fee, milk replacement for calves, because we've known for a long time and it is been recognized that having these antibiotics in feed at low levels is causing resistance problems in the human population.

So it is this cross resistance in there.

Antibiotics like Virginiamycin, Tylosiin, Spiramycin have been used at low levels in the feed as growth promoters simply in there to promote growth of the animal. But these growth promoters belong to a family of antibiotics of which there is a human equivalent. So Virginiamycin is a Streptogramin in the antibiotics category. An example of this on the human side is synercid.

So the possibility then or the potential then is the cross resistance into the human population where you build up a reservoir of organisms that then have resistance.

So in Europe in January of 1999, these six growth promoters were banned across the whole of the EEC. They could not be used as growth promoters. They allowed them four months into which to work out their stocks, then that was it.

There are still left two, that they are trying to get rid of but the main grouping is gone. At that stage people became interested in our equivalent to see if it would work in this big feed industry where they produce one half to one million tons of feed at a time. And looking for that growth enhancement of the animals as well as some disease protection in there. That is where we came in.

Enteroguard is a combination of two potent plant derived antimicrobials.

And what I would like to do is to take you through individually the two active ingredients in there in terms of why we selected them and what are known about them. The first one is allicin from garlic and I'll come on to that one in a minute, but the second one is also a natural and it's cinnamaldehyde from the oil of cinnamon.

The researchers first came across allicin about 10 years ago. They screened over 200 natural plant substances for antimicrobials activity. They determined allicin from garlic to be a potent sulfur containing antimicrobial. Its chemical name is thiosulphonate. Its only found in small concentrations in a group of food plants called the Allium group which contains onions as well as garlic. But the largest concentration of alliin is actually found in garlic which is why they selected garlic as the source of allicin.

This is the structure of allicin or diallyl thiosulphonate. In some ways it almost resembles an antibiotic- two cysteine derived molecules on the ends, but it is this S-S double bond which is the very potent part of the molecule that gives it its very strong antimicrobials activity.

Why Do They Actually Freeze Dry The Garlic?

This comes down to the fact that if you take a garlic clove and you peel it very carefully and you smell it. There is very little smell. But as soon as you crush it...boom! You get an instantaneous smell. This is a clean smell, that is allicin that is produced.

And the reason is that in garlic itself you don't find allicin but what you do find is a precursor molecule called alliin. And alliin is found within the garlic clove within the mesophyl cells and also in the garlic clove you then find around the phloem in the cells around the vascular bundle you find an enzyme called alliinase.

And these two are physically separated within the cell. When you crush it these two come into contact and immediately the combination of the two produce allicin, and the other thiosulphonates.

Thiosulphonates As A Group Are Antimicrobials

Allicin constitutes between 70 to 80% of those thiosulphonates because they provide the total antimicrobial activity. One interesting thing is that the amount of enzyme is almost the same as the amount of alliin. This is very unusual because enzyme systems usually require very little enzyme to make a conversion. But in garlic it is absolutely stocked with the enzyme.

So the same amount of enzyme there is, is equivalent to is alliin; which is one of the reasons you get that instantaneous conversion. And the conversion of all the alliin to allicin in the garlic occur within 20 seconds. When you crush it.

As far as the plant is concerned, the plant uses this as an antimicrobials because you can imagine the garlic clove which becomes the seed of the plant. If it is invaded by bacteria or a single cell pathogen will start to break down the cells. So when the cells start to break down you get alliin and alliinase coming together locally with a little puff of allicin and boom you knock out the protozoa or bacteria or yeast.

The developers import garlic from China as the soil is very rich in sulfur there, which contributes to increase activity. The product has been analyzed at the University of Bonn in Germany which found one of the highest garlic concentrate in tems of alliin content.

Imported Frozen Garlic From China

They make sure it raised in an area and a way that gives it the highest alliin content, but they then hand peel the garlic so in the fields there are 700 women sitting at tables gently peeling the cloves by hand. Now you could get a machine to do this but it would cause too much allicin to be released through cell damage which causes the alliin to react with the alliinase.

Then allicin over a period of days will actually start to break down. So after it is hand peeled they blast freeze it. It is frozen very quickly. It goes into these big stores where they pump cold air into it at -30 degrees and they are frozen solid. It is then imported from China to a factory in UK as frozen garlic cloves.

It is shipped in 12-ton containers where they keep it frozen all the way through. They then take those frozen cloves and put them through a machine that chops them three or four times, some of the small cloves are not chopped at all. This chopping just helps in moisture removal. Then this garlic then goes into a freeze-drying facility.

It is put into trays and put straight into the freeze dryer. And the freeze dryer removes all that moisture in a virtual vacuum. So in a vacuum at -30 degrees C the moisture doesn't actually turn into a liquid. It goes straight off as moisture to gas. It is rather like frozen CO2. When that is warmed it doesn't go a liquid phase it comes immediately into a gas phase.

They use this process as a gentle method of removing water. Now with the moisture removed, the alliin and the alliinase are separated and totally inactive because they can only react in the presence of moisture. So they can then take the dried clove out of the freeze dryer and mill them into a powder.

If the garlic were milled while the moisture content was still high in the garlic then they would react to produce allicin and the allicin would disappear in a few days. This is the problem with all the garlic products that are on the market. There is no allicin left.

For when they milled their product there was moisture in it. When Enteroguard is taken in by the animal or the human as it is rehydrated as it makes its way down the digestive track is becomes active the alliin reacts with the alliinnase and allicin is produced just where you want it in the gut.

The allicin appears to be effective against

E. coli.
Staphylococcus aureus

Clostridium perfringens

Salmonella spp.

However the lactic organisms and the enterococci are virtually unaffected by garlic. Why is this good? Because this group contains the beneficial bacteria in the gut. So here you have an organism that is anti yeast and anti fungi, anti gram negative and gram positive bacteria, and yet against a group of very beneficial organism it doesn't have any activity.

Not only does garlic kill pathogenic bacteria but it also kills rotavirus infection which is responsible for many cases of diarrhea. At concentrations of 20 parts per million garlic totally protects these mammalian cells from being invaded pathogenic viruses.

It has also been helpful in protoza infections like Cryptosporidium parvum. It was first discovered in the USA in 1971 in the following 22 years in has become absolutely endemic on the dairy farms; 90% of all dairy farms are infected by Crypto. And as soon as you get 100+ dairy cows on a unit all of them are infected.

Even in these cow/calve operations where the calves are raised with their mothers out in the fields, 40% of them are infected because the heifers before they are weaned they shed these oocysts through their saliva into the pastures and these little oocyst just stay around and the next generation gets them.

It is the single major cause of contaminating the human water supply.

The Enteroguard is now sold to vets in the USA for Rotavirus and Crypto.

During the First World War, garlic was the major battle field wound dressing. They made a paste of it and rapped wounds with it. So when the antibiotics were developed all the publications on garlic stopped.

Allicin is active interracially in the gut and once absorbed it is quickly converted into diallyl suphides in the liver. Diallyl sulphides have low antimicrobials activity and these are then expressed through the urine, through the breath and through the skin. The diallyl sulphides is the smell you get when you cook garlic or when you eat lots of garlic.

But the allicin is the clean smell you get when you crush it which is a different smell than the diallyl sulphides which is stronger in smell and what you get when you cook it. Allicin is a cascade molecule and as it breaks down there have been 150 different breakdown molecules from a molecule of allicin. So you get allicin slowly degrading into other molecules which themselves react with each other to form molecules which may be very active against protozoa like giardia and trichomonous.

Garlic also appears to be very active against Helicobacter pylori.

Toxicity

You would have to eat ten to twenty grams per kilo weight which means you would have to eat a trunk load of garlic to have any toxic effect.

Mode Of Action

How does it kill bacteria cells? This is what is called the macroeffect. What we know is that allicin disrupts the cell membrane biosynthesis. It inhibits DNA polymerases and inhibits RNA synthesis. So it is disrupting the whole enzyme system that is responsible for cell replication.

Allicin also destroys the SH groups in proteins. These sulfur containing groups are found in thiol enzymes which are a large part of the physiology of lower organisms- bacteria, virus, and protozoa. Antibiotics tend to target a single metabolic pathway in an organism and take apart this pathway. Now as far as the bacteria is concerned a single gene mutation with just the random mutations that go on all the time, can often find an alternative way from getting from A to B. When an antibiotic destroys that ability from getting from A to B the cell is killed.

So when this cell has a successful mutation then resistance is accomplished. When you take something like an allicin which is affecting groups which are found in many enzymes in the lower organisms, they are being destroyed.

But these enzymes are building proteins that go into the cell membrane, or proteins are part of other enzyme systems that are then used in the DNA polymerase and the RNA polymerase synthesis system. And they are the building blocks of all sorts of proteins. Now it is impossible for the bacteria to spontaneously find its way around all these different enzyme systems and to find alternative ways of doing it. So they can't get resistance with natural compounds like allicin.

Resistance to the allicin in garlic can't be induced. When you think about it, is makes sense for as far as a plant is concerned it just needs a simple mechanism which will kill microorganisms without allowing them to develop resistance for if they develop resistance them the plant will be destroyed. It would no longer be around after 10,000 years. Garlic is around so there are no resistant pathogens that have developed that are resistant to allicin.

Why Doesn't The Garlic Harm Mammalian Cells

If you take a mammalian cell, we don't use S-H compounds extensively used. Additionally S-H group can be protected. Glutathione is known to protect groups. You can demonstrate this in a test tube. You can take a sulfur containing enzyme. This mechanism of protection is the same for the lactic acid organisms. So they have developed the same protective mechanisms. If this was not so then in the garlic eating nations they would have eradicated their lactic acid bacteria long ago, which is certainly not the case.

So in summary with Allicin you have a broad spectrum of activity against bacteria, virus, and protozoa.

No resistance can be built up so it is an absolutely safe product to use.

It has no effect on mammalian cells, and no effect on the lactic acid bacteria.

Dr. Mercola's Comment:

Garlic is one food that you should be eating every day. Dr. Klinghardt and I are very impressed with its ability to optimize bowel flora and kill pathogenic organisms.

It is important to note that the garlic MUST be fresh. The active ingredient is destroyed within one hour of smashing the garlic. Garlic pills are virtually worthless and should not be used. When you use the garlic it will be important to compress the garlic with a spoon prior to swallowing it if you are not going to juice it. If you swallow the clove intact you will not convert the allicin to its active ingredient.

One problem, of course, is the smell, but generally a few cloves a day are tolerated by most people. If one develops a socially offensive odor then all you do is slightly decrease the volume of garlic until there is no odor present.

Related Articles:

Oregano, Other Essential Oils Destroy Strep Pneumonia Cells

Garlic Lowers Heart Disease Risk

Garlic Keeps the Ticks Away

Garlic May Prevent Cancer

Evidence Mounts For Garlic's Antimicrobial, Cholesterol-Lowering Effects

Garlic the wonder food

Garlic and its cousins (onions, chives and scallions) are probably the most intriguing of all vegetables. Garlic lowers cholesterol, reduces the risk of heart disease, fights infection and boosts immunity. And, as if that weren't enough, the data is strong for the prevention of cancers of the digestive system, including the esophagus, stomach, colon and rectum. The National Cancer Institute is sponsoring a huge clinical trial on garlic's ability to prevent stomach cancer. But why wait years for the results of this clinical trial?

Many publications have shown that garlic supports the cardiovascular system, while earlier trials suggest it may lower cholesterol and triglyceride levels in the blood.

Garlic and cancer

Human population studies suggest that eating garlic regularly reduces the risk of esophageal, colon and stomach cancer.(4,5) This may be partly due to garlic’s ability to reduce the formation of carcinogenic compounds.

Parts of China have the misfortune to have an inordinately high rate of cancer of the esophagus and stomach. Scientists at the Nanjing Cancer Institute compared the incidence of several cancers among thousands of people who ate lots of allium vegetables versus thousands who ate little or none. ('Lots' in this case means at least once per week while 'little' means less than once per month.)

85% reduction for those who ate lots of scallions
75% for onions
70% for garlic
43% for chives

83% reduction for those who ate lots of onions
78% for scallions
69% for garlic
60% for chives

Studies indicate that eating garlic seems to protect against colorectal cancer as well.

Dr. Lenore Arab and colleagues from the University of North Carolina at Chapel Hill analyzed 18 studies looking at garlic eaters.

The average intake of the consumers of raw or cooked garlic was 18.3 grams per week (about six cloves).

Based on 6 studies, the findings suggest "high consumption of raw or cooked garlic decreases the risk of colorectal cancer from 10% to nearly 50%," the researchers write(6).

Garlic and heart disease

Recent studies (7) have uncovered what is perhaps
garlic's most important health benefit: lowering the risk of heart disease.

These effects are wide-ranging and likely result from several different mechanisms.

Regular garlic consumption appears to prevent the buildup of fatty plaque in the arteries and may even shrink existing plaques, according to German researchers who recently concluded a 4-year study of 280 adults (8). People who ingested 900 mg of garlic powder daily had up to 18% less arterial plaque at the end of the study than those taking a placebo. The effect, seen in both sexes, was most pronounced in women. Plaque volume rose by 53% in women on the placebo, while it declined by 4.6% in those taking garlic.

Another benefit which has been confirmed by medical research is garlic's antibiotic activity. Studies have repeatedly confirmed that garlic is effective against bacteria, fungi and yeasts. Garlic can be safely taken for mild, recurring or chronic infections which are not dangerous. Examples include colds, infections of the mouth, ears, throat and especially candida. (9)

Garlic supplements

Many people avoid eating garlic since it can make one's breath smell pretty strong. In that case, garlic supplements are a convenient alternative.

For those who prefer it, odor-controlled, enteric-coated tablets or capsules with approximately 1.3% allicin are available. Several clinical trials which have shown benefits have used 600–900 mg (delivering approximately 5,000–6,000 mcg of allicin potential) per day in 2 or 3 divided amounts.(10,11)

Which garlic supplement should you choose? Well, that depends on whom you ask. Nutrition experts continue to debate whether aged garlic extracts are superior to standardized high-allicin extracts.

Aging is a method of preserving garlic. It was developed thousands of years ago by Chinese herbalists, who found that “steeping” garlic in vinegar for a few years actually increased the herb‘s potency. A Japanese company reinvented the process in the 1950s. In the modern version, organically grown garlic is placed in large vats of vinegar for 2 years.

Proponents say that aging the garlic in this way enhances the herb‘s antioxidant properties, prevents the rapid deterioration of important compounds, and removes the odor as well as irritants which might cause stomach upset.

Indeed, if you‘re concerned about garlic breath, an aged extract or enteric-coated tablet is the way to go. If you‘re treating an infection of some kind, a standardized high-allicin extract or the actual food is the better choice. Aging destroys garlic‘s antibiotic properties.

And if your main concern is preventing heart disease or cancer, you can choose either the food, an aged extract or a high-allicin extract.

I spend a lot of time researching the best prices for supplements on the internet and in my opinion, the best price for high quality garlic supplements can be found here.

Some individuals who are sensitive to garlic may experience heartburn and flatulence. Because of garlic's anticlotting properties, those taking anticoagulant drugs should check with their nutritionally oriented doctor before taking garlic. Those scheduled for surgery should inform their surgeon if they are taking garlic supplements.

(1). Warshafsky S, Kamer R, Sivak S. Effect of garlic on total serum cholesterol: A meta-analysis. Ann Int Med 1993;119:599–605.

(2). Silagy C, Neil A. Garlic as a lipid-lowering agent—a meta-analysis. J R Coll Phys London 1994;28:39–45.

(3). Neil HA, Silagy CA, Lancaster T, et al. Garlic powder in the treatment of moderate hyperlipidaemia: A controlled trial and a meta-analysis. J R Coll Phys 1996;30:329–34.

(4). Dorant E, van den Brandt PA, Goldbohm RA, et al. Garlic and its significance for the prevention of cancer in humans: A critical review. Br J Cancer 1993;67:424–9.

(5). Fleishauer AT, Poole C, Arab L. Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers. Am J Clin Nutr 2000;72:1047–52.

(9) SOURCE: Lin, Robert. Garlic in Medicine. Speech made to American College of Advancement in Medicine. May 14, 1992 p 46.

(10). Brown DJ. Herbal Prescriptions for Better Health. Rocklin, CA: Prima Publishing, 1996, 97–109.

(11). Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 134.

Disclaimer: Statements are made pertaining to the properties and/or functions of food and/or nutritional products. These statements have not been evaluated by the Food and Drug Administration and these materials and products are not intended to diagnose, treat, cure or prevent any disease.