While some studies have suggested that drinking wine or eating grapes can slow the effects of some cancers, you’d need to consume such great quantities that the benefits would likely be outweighed by the effects of the alcohol or the weight gain, a study conducted at Petah Tikva’s Sharon Hospital shows.

Previous studies have concluded that eating grapes and drinking wine can suppress and slow the spread of cancer in both mice and humans. (Others have also pointed to possible heart benefits.) The new study, reported by Israel Hayom this week, demonstrates how exactly this happens.

Conducted by Professor Meir Galdati, Dr. Michael Bergman, and Dr. Gal Shahaf, the study tested cultures of large intestine cancer cells, to which an active ingredient found in grape skins, resveratrol, was added. The addition of resveratrol resulted in 30 to 40 percent slower growth of cancer cells. The higher the concentration of resveratrol added, the more the growth of the cancer cells was slowed.

Yet the researchers did not rush to declare eating grapes and drinking wine an appropriate method for preventing cancer. “Although there is proof of the existence of mechanisms within wine and grapes [that slow the growth of cancer cells], and consumption of grapes is a good thing, there are still the ramifications of gaining weight and diabetes,” Dr. Herzl Salman, who heads an internal medicine ward at Sharon hospital, told Israel Hayom.

According to Salman, “the study was conducted in laboratory conditions, with very high concentrations of the [resveratrol] substance. The lowest concentration we used would be found in roughly 750 grams of grapes, and the highest concentration, in 3 kilograms of grapes.” In other words, he said, the amount of grapes one would have to eat to derive an anti-cancer benefit “could lead to weight gain, or diabetes.”

Similarly, said Salman, red wine consumption might be helpful, but “then there are the possible dangers involved in drinking alcohol.”

“The active ingredient delays the development of the cancer cells in two ways,” said Salman.

Addition of resveratrol, he said, “causes a decrease in the release of materials responsible for inflammatory immunological response,” slowing the development of the cancerous growth.

“In addition, the cells we studied showed an increase in a substance called TNF, which causes the destruction and rotting of cancer cells.”