The benefits of garlic: Letting the research speak for itself

In a 1985 issue of Scientific American, in an article entitled "The Chemistry of Garlic and Onions," Eric Block, Ph.D., wrote: "The world has always been divided into two camps: those who love garlic and onions" and those who don't.

Among today's garlic researchers there are at least two camps, as well, the garlic-extract people and the powdered-garlic people:

The garlic-extract school-of-thought. These scientists believe that aged garlic extract contains a variety of organosulfur compounds, other than alliin/allicin, that are the most important and medicinally beneficial garlic-based components.

The powdered-garlic school-of-thought. On the other hand, these scientists believe that alliin/allicin, and other sulfur compounds, are the key ingredients present in powdered-garlic preparations, components which account for most of the beneficial effects associated with garlic and garlic supplements.

Let's begin a dialogue in which we let the research speak for itself:

Garlic-extract research.

Prostate cancer. In a study which appeared in a recent 1997 issue of the American Journal of Clinical Nutrition, New York City's Memorial Sloan-Kettering's John T. Pinto, Ph.D., and colleagues, looked at the effects of major water-soluble compounds derived from aged garlic extract (S-allylcysteine and S-allylmercaptocysteine) on cultured (test-tube) human prostate cancer cells.

The study found: 1) "Within 30 minutes of exposure" to either of the compounds, proteins that are usually "hopped up" (present at heightened levels) as prostate tumors grow were suppressed; 2) intracellular levels of the reduced (antioxidant) form of glutathione were increased; and 3) a special enzyme (ornithine decarboxylase) which helps produce those "bad-guy" proteins was blocked.

Breast cancer. A series of studies by Pennsylvania State University's J.A. Milner, and colleagues (Carcinogenesis, 1992 & 1993 and Journal of Nutrition, 1996) reported that aged garlic extract significantly prevented [blocked] breast cancer in both the beginning (initiation) and later (promotion) stages. The compound, S-allylcysteine (SAC), by itself, also reduced the initiation of breast cancer.

Bladder cancer. In a recent experimental study by Donald L. Lamm, M.D., and colleagues (Cancer, May 15, 1997) at West Virginia University, mice with bladder cancer were given either aged garlic extract or a salt-water placebo solution. The resuits were positive, leading the authors to conclude: "the significant antitumor [effectiveness] of [aged garlic extract] warrants further investigation and suggests that [this compound] may provide a new and effective form of therapy for transitional cell carcinoma of the bladder."

Other cancer studies. Including the above three studies, there are a total of 49 studies (since 1983) pointing to the anti-cancer effects of aged garlic extract and its constituents. Among these are 17 breast cancer studies, seven on colon cancer, and five on bladder cancer.

Powdered-garlic research.

Anti-cancer results have also been suggested, as early as 1957, in a report in Science by Austin Weisberger and Jack Pensky, which indicated that "[a compound similar to allicin] may have tumor-inhibiting effects when malignant cells are placed directly in contact with this compound prior to inoculation."

Much more recently, a 1991 study by Michael J. Wargovich presented at the Second International Garlic Symposium looked at organosulphur compounds derived from garlic, such as diallylsulfide (DAS) and S-allylcysteine (SAC) [also found by Pinto in aged garlic extract] and gastrointesinal cancer - colorectal and esophageal.

In this rat study, both compounds successfully prevented colorectal cancer, and DAS specifically "protected rats from developing esophageal cancer." Wargovich concluded that these compounds seem to block cancer at the early initiation stage.

Stomach/urinary cancer. In 1997, K. Polasa and K. Krishnaswamy published a powdered-garlic study in Cancer Letters, in which rats exposed to urinary cancer-causing chemicals (mutagens) were given powdered garlic.

The results were positive, with the authors reporting that "`there was a significant reduction in the excretion of [cancer-causing agents, suggesting a cancer-protective effect] by carcinogen-exposed rats fed [powdered] garlic."

Population-based garlic research. Several population-based studies on people in China, Italy, Iowa, and California have shown that adding garlic to the daily diet can reduce the risk of certain types of cancer, such as stomach and colon cancer.

So there is the briefest of samples as to the studies that are out there, and thus begins our dialogue on research that's on the "frontiers of science." BN