Study shows garlic may shrink tumors

Drs. Arabinda Das (left) and Pierre Giglio combine their talents with other colleagues to research potency of plant derivatives to combat deadly brain tumors.

Allium sativum, or what we know as garlic, has been trumpeted for its health benefits over the centuries. Some benefits appear to be true, while some remain in the category of folklore arising from humans eating and using the herb for 7,000 years.

According to the National Institutes of Health, studies have found garlic “possibly effective” for reducing high blood pressure, atherosclerosis (or “hardening of the arteries), reducing the risk of developing colon, rectal or stomach cancer, and treating fungal infections of the skin.

The NIH stresses, however, that garlic is possibly ineffective for other diseases that it has been crediting in helping, such as diabetes, high cholesterol and cancers of the lungs and breasts.

But there’s even more exciting news about garlic coming right out of the Holy City.

Researchers at the Medical University of South Carolina have found that a compound in garlic may be effective at shrinking brain tumors, notably the most aggressive and lethal kind, glioblastoma. The cancer represents 17 percent of all primary brain tumors and, to date, remains incurable.

Drs. Arabinda Das and Pierre Giglio are among a team that found direct evidence that the compound DATS, or diallyl disulfide, which is found in garlic, is effective in blocking the pathways of the proliferation of cancer cells and, ultimately, may reduce tumor growth.

Their study found a 60 percent to 74 percent rate of shrinkages of tumors, the result of which left the research team “cautiously thrilled.”

Giglio says those kind of results are rare.

By comparison, Giglio says the only drug used to treat the tumors, Avastin, produces rates of 30 percent to 40 percent shrinkage.

“In the clinic, I declare victory when I don’t see any change in the tumor,” says Giglio. “When you get a response that cuts the tumor down by that sort of percentage, I can’t stress how exciting it would be if that would translate to a clinical truth. This paper showed the efficacy, and it was quite stunning.”

As with all research, Giglio cautions that it will take time for the results to be translated for clinical use and that “what works in the lab sometimes does not work in the clinic.”

Das said it has long been known that plant derivatives have beneficial effects in many diseases. Plant derivatives that are or will be studied include lemon, mushroom, green tea, turmeric, soybeans and ginger.

“We have been working on several of these, which are known to have anti-tumorigenic properties, and garlic compound is one of the agents, among many, we have chosen to study,” says Das.

According to a release from MUSC, the research team tested the garlic-derived organo-sulfur compound DATS in two ways.

They applied it directly to glioblastoma cells taken from tumors removed from patients.

They also placed these cells in immunosuppressed mice using a method in which the altered tumor cells are implanted in the tumor site of origin. It’s a technique advantageous for its ability to mimic local tumor growth and pathways of metastasis.

Giglio said it seems that glioblastoma cancer cells have multiple pathways within them that allow them to grow, divide quickly, invade the brain and form blood vessels for themselves.

“In a nutshell, they have a lot of strategies that allow them to evade the body’s immune defense systems, evade the treatments that we may give and, most importantly, develop a resistance to the treatments that we give,” says Giglio.

Das says the DATS compound seems to have a selective effect on the cancerous cells and not the normal cells. Researchers want to explore all mechanisms by which the compound may be working against cancer cells.

The response rate suggests it works in more than one pathway to block the cancer, he said.

“We demonstrated shrinkage of tumors in these animals and showed that DATS reduced division of cells within the tumors and worked against multiple proteins and pathways that promote tumor growth,” Das said.

From this work, research projects include working to develop a highly purified DATS capsule for a phase I study, which will hopefully take place within the next year.

While the researchers caution that it’s premature to say garlic consumption will help lower the risks of gliobastoma and other cancers, they do have advice on how to eat it.

To take advantage of any potential anti-cancer benefits from garlic now, they say it’s important to cut and peel a piece of fresh garlic and let it sit for 15 minutes before eating or cooking it. This time allows for the release of the enzyme alliinase that produces the anti-cancer compounds.

Also, they warn eating too much garlic may cause diarrhea, allergies and internal bleeding and, of course, bad breath.

Reach David Quick at 937-5516 or dquick@postand