Onions and garlic are key ingredients in sofrito, a condiment that’s a staple of Puerto Rican cuisine. They may also be a recipe for reducing the risk of breast cancer, according to findings of a study led by researchers from the University at Buffalo and University of Puerto Rico.
“We found that among Puerto Rican women, the combined intake of onion and garlic, as well as sofrito, was associated with a reduced risk of breast cancer,” Gauri Desai, study lead author, said in a news release.
Desai is a doctoral epidemiology student in the UB School of Public Health and Health Professions.
Those who consumed sofrito more than once per day had a 67% decrease in risk compared to women who never ate it. The idea for the study stemmed from previous scientific evidence showing that eating onions and garlic may have a protective effect against cancer.
“Studying Puerto Rican women who consume a lot of onions and garlic as sofrito was unique,” Desai said. He said total intake of onions and garlic, not sofrito alone, was associated with breast cancer risk.
Women in the American territory tend to consume more onions and garlic than in Europe and the U.S., due largely to the popularity of sofrito, Desai said. Onions and garlic also are eaten regularly in “guisos” (stews), as well as in bean- and rice-based dishes in Puerto Rican cuisine.
“Puerto Rico has lower breast cancer rates compared to the mainland U.S., which makes it an important population to study,” Desai said.
Study co-author Jo Freudenheim, chairwoman of epidemiology and environmental health at UB, said university researchers worked with those in Puerto Rico to understand why rates there are lower than in the rest of America, as well as why rates there are continuing to increase while they are decreasing in the rest of the U.S.
Onions and garlic are rich in flavonols and organosulfar compounds. In particular, Desai said, garlic contains compounds such as S-allylcysteine, diallyl sulfide and diallyl disulfide, while onions contain alkenyl cysteine sulphoxides.
“These compounds show anticarcinogenic properties in humans, as well as in experimental animal studies,” said Lina Mu, the study’s senior author and an associate professor of epidemiology and environmental health at UB.
Study participants were enrolled in the Atabey Study of Breast Cancer, a case-control study named after the Puerto Rican goddess of fertility. The study was conducted between 2008 and 2014 and included 314 women with breast cancer and 346 control subjects.