Everyone knows that eating lots of garlic keeps pesky vampires away. While that may be the stuff of Bram Stoker’s imagination, a new study shows that eating garlic and onions can ward off a real demon — breast cancer.
While several studies have explored the links between onion and garlic consumption and the risk of colorectal, stomach, and prostate cancers — finding that these foods lowered the risk of developing these cancers — very little research has looked at these foods and breast cancer.
That was the goal of a team of researchers from the University of Buffalo in New York State. They found that the consumption of onion and garlic among women in Puerto Rico led to significantly lower risks of developing breast cancer.
Gauri Desai, a doctoral candidate in epidemiology at the Univeristy of Buffalo, led this new study. The team sought to investigate the effect of onion and garlic consumption on breast cancer by looking at the population of women in Puerto Rico. There were two reasons for choosing this population: Puerto Rico has lower breast cancer rates compared to the mainland U.S., and Puerto Ricans consume lots of a traditional sauce called “sofrito,” which consists largely of garlic and onion.
Desai and the team used hospital and clinic records to identify 314 women ages 30-79 that had breast cancer between 2008 and 2014. The researchers also included 346 control participants who were matched based on age and residential area.
The control group participants had no history of cancer. The study used a food frequency questionnaire to find out about dietary patterns and onion and garlic intake, including the consumption of sofrito.
The study was published in the August edition of the journal Nutrition and Cancer.
The study relates an inverse association between moderate and high total onion and garlic consumption and breast cancer cases, compared with low consumption of these two vegetables.
The authors of the study write, “Sofrito intake, when examined alone, was inversely associated with breast cancer; for those consuming sofrito more than once/day, there was a 67% decrease in risk, compared to never consumers.”
The authors added that the study was unique because of the way Puerto Ricans consume onions and garlic in sofrito. That made it relatively easy to isolate those two vegetables and how much they are consumed. Using garlic and onions in other recipes, as is more typical in other cultures and areas, would have been far more difficult to quantity.
Why do onions and garlic have this effect?
This study was unique both in its subject but also in that it was done in Puerto Rico. The study’s co-author, Jo Freudenheim, Ph.D, noted, “There is very little research on breast cancer in Puerto Rico.” The incidence is far lower than in the U.S.
The study didn’t aim to find the mechanisms by which onion and garlic intake could affect the potential development of breast cancer, but the authors put forth some thoughts. The researchers wrote they suspect the flavonols and organosulfur compounds abundant in onions and garlic may be responsible for the anticancer effects.
In particular, the S-allylcysteine, diallyl disulfide, and diallyl sulfide in garlic and the alkenyl cysteine sulphoxides in onions have shown “anticarcinogenic properties in humans, as well as in experimental animal studies,” says Dr. Lina Mu, an associate professor of epidemiology and environmental health at the Buffalo university, and the study’s senior author.
The study notes that these potential links between onions and garlic and lower rates of cancer merit further research.