Onions And Garlic May Reduce The Risk of Breast Cancer, Says Study

Are you one of those women who can’t enjoy a meal that doesn’t include either onion or garlic? If so, then you’re in luck. According to new research, regularly eating either of these foods can help to protect you against breast cancer.

According to the American Institute of Cancer Research, onions and garlic – which are part of the allium genus food group – contain certain compounds that help to halt the progress and growth of cancer cells (1). Additionally, various research has found that both of these foods contain anti-cancer properties. In fact, they have been linked to reducing either the risk or destroying cancer cells associated with lung, brain, and prostate cancers, as well as reducing the occurrence rate of precancerous tumors in the large intestine. With that said, it’s no wonder that the two foods may protect against breast cancer as well.

The study 

The study, which was published in the journal Nutrition and Cancer, focused on the country of Puerto Rico, whereby researchers analyzed the health benefits of onions and garlic. The researchers were both from the University at Buffalo and the University of Puerto Rico.

The reason for the study is that Puerto Rico consumes large amounts of both garlic and onions. This may have something to do with the fact that one of the country’s staple foods is sofrito. This is a mix of garlic, onions, peppers, and tomatoes cooked in olive oil. Additionally, Puerto Rico also has “lower breast cancer rates compared to the mainland U.S., which makes it an important population to study.”, as explained by Gauri Desai, lead study author of the study, in a statement

“This study was a collaboration between my colleagues here at UB and at the University of Puerto Rico to help us understand why rates there are lower than in the rest of the U.S., and why rates there are continuing to increase, while they are decreasing in the rest of the [U.S.].” added study-co author Jo Freudenheim, Ph.D.

Sofrito and breast cancerbreast cancer | Longevity LIVE

The researchers gathered more than 600 women. These women had been enrolled in the Atabey Study of Breast Cancer, which was a case-control study. 314 of the women, aged between 30 and 79, had breast cancer. The other 346 were control participants who were matched based on age and residential areas.

The control participants had no history of cancer, apart from non-melanoma skin cancer. Over a period of six years (2008 to 2014), the researchers analyzed the diet and health of each group. They did so through the frequent use of food questionnaires to monitor the development of breast cancer would develop. They made sure that the questionnaires also included questions about their total onion and garlic intake, including their sofrito consumption. Additionally, the team also made sure to adjust for factors such as age, family history, as well as smoking status.

The results

The researchers found that Puerto Rican women who ate more sofrito were facing a lower risk of developing breast cancer.

“For those consuming sofrito more than once/day, there was a 67% decrease in risk, compared to never consumers.” wrote the authors of the study.

The researchers believe that the cause for this stemmed from the fact that both onions and garlic contain anti-cancer properties. Onions contain alk(en)yl cysteine sulphoxides, while garlic offers S-allylcysteine, diallyl sulfide, and diallyl disulfide

“These compounds show anticarcinogenic properties in humans, as well as in experimental animal studies.” explained Lina Mu, senior study author and an associate professor of epidemiology and environmental health at UB. 

That said, the researchers do acknowledge that the study does have its limitations. 

“Although the recipe for sofrito varies to some extent, other ingredients, such as bell peppers, tomatoes, cilantro, and black pepper are usually added. Since we did not adjust our models for these ingredients, we cannot be sure that our results were due to the sole effect of onions and garlic.” As mentioned by the researchers.

What other benefits do onions and garlic provide?

As mentioned, onions and garlic are part of the allium genus food groups, which makes them rich in flavor. In addition, they’re also rich in certain compounds that can provide the body with a number of benefits.

Alzheimer’s Disease

In addition to a number of other effective tips, cooking with more garlic and onions may also help to reduce one’s risk of developing Alzheimer’s disease.

Both garlic and onions contain antioxidants that can help protect against oxidative damage. That said, there is an idea that this may also serve to protect against dementia. In fact, research published in the Journal of Neurochemistry found that aged garlic extracts, which contain the active compound S-allyl-L-cysteine (SAC), may be used in the development of future drugs to treat Alzheimer’s disease.


Onions contain the flavonoid quercetin, and according to the National Arthritis Foundation, this compound helps to alleviate pain and swelling in arthritis sufferers (2).

Additionally, a study published in the journal BMC Musculoskeletal, which involved over 1000 healthy female twins, found an association between a diet rich in allium vegetables and fewer signs of early osteoarthritis in the hip joint amongst the women.

garlic and rainbow eatingBlood Sugar

It’s important to control your blood sugar, especially if you have diabetes or pre-diabetes. That said, you may want to start by adding more onions and garlic to your diet.

According to a meta-analysis published in the Journal of Medicinal Food, onions contain compounds that may help to fight off the development of diabetes. Additionally, an animal study done on diabetic rats found that garlic helps to significantly lower their blood sugar, as well as cholesterol and triglyceride levels.

Bone Health

Onions support bone health by increasing bone density, which then reduces the likelihood of fractures and breaks. It also may help to prevent osteoporosis.

Research from the Department of Family Medicine at the University of South Carolina found a 5% improvement in overall bone density amongst perimenopausal and postmenopausal women who ate onions at least once a day.

Cardiovascular Health

Cardiovascular diseases continue to be the biggest cause of mortality worldwide. Thankfully, cooking more onions and garlic may help curb these rates.

As mentioned, onions contain the flavonoid quercetin, which helps to address all the risk factors that contribute to heart disease. This includes inflammation, and elevated levels of cholesterol and blood pressure (3, 4). Additional research has also found that garlic supplements help to do the same in reducing blood pressure and LDL cholesterol. Garlic extract has also been found to help to remove plaque buildup in arteries, which then greatly reduces the risk of heart disease.


Both onions and garlic can help to ward off infections as they each contain antibacterial and anti-fungal properties. They also contain phytonutrients, which helps to strengthen the body’s immune system.

In fact, research has found that a daily garlic supplement not only helped to reduce the number of colds by 63%, but it also reduced the number of days sick with cold or flu by 61% (4, 5).

Healthy Onion and Garlic Recipes

Here are a few of our favorite recipes that contain both onions and garlic:

Roasted Vegetable Parcels

Healthy Home-Made Hummus

East African Pea, Tofu And Lentil Curry Bunny Chow