Could a Yogurt-a-Day Help Keep Breast Cancer Away?

Researchers have been studying potential causes of breast cancer, the most common cancer in women other than skin cancers, for decades. And there’s a new hypothesis: Could harmful bacteria in our bodies be one cause of breast cancer?

by Lara DeSanto Health Writer

If its running list of benefits—digestion aid, immunity booster, bone builder—aren’t enough to convince you, there’s yet another reason to become yogurt’s biggest fan.

While it’s still unproven, new evidence supports the idea that harmful bacteria may trigger inflammation in the body that could cause breast cancer, according to the study published in Medical Hypotheses. And the researchers from Lancaster University in England think they’ve come up with a simple way to prevent this: Yogurt.

"There is a simple, inexpensive potential preventive remedy, which is for women to consume natural yogurt on a daily basis,” the researchers write.

Why? Because yogurt contains so-called “good bacteria,” called lactose-fermenting bacteria, or microflora, according to the news release. This kind of good bacteria is also found in the breasts of mothers who have breastfed. Researchers believe the bacteria is protective because breastfeeding lowers the risk of breast cancer by 4.3% yearly.

Other research has also shown that eating yogurt is linked to a lower risk of breast cancer, possibly because of the displacement of harmful bacteria that occurs when you eat the good stuff.

Plus, it’s well-established that inflammation can lead to a host of other major issues in the body. For example, inflammation can lead to gum disease, which has been linked to several types of cancer—including breast cancer.

“The stem cells which divide to replenish the lining of the breast ducts are influenced by the microflora, and certain components of the microflora have been shown in other organs, such as the colon and stomach, to increase the risk of cancer development,” the researchers say. "Therefore, a similar scenario is likely to be occurring in the breast, whereby resident microflora impact on stem cell division and influence cancer risk."

Other Ways to Prevent Breast Cancer

While throwing back a yogurt-a-day to prevent breast cancer is promising, it isn’t 100% proven. Here are some tried-and-true ways to reduce your risk of breast cancer, according to the American Cancer Society (ACS):

  • Get enough physical activity. Not surprisingly, research shows that moderate to vigorous physical activity is associated with lower risk of breast cancer. Aim for the recommended 150 minutes of moderate-intensity physical activity (like brisk walking) or 75 minutes of vigorous-intensity activity (like hiking uphill or going for a run) per week.

  • Limit or avoid drinking alcohol. Another thing research is clear about: Alcohol ups your risk of breast cancer. The ACS recommends women drink no more than 1 drink per day (meaning 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of hard liquor).

  • Breastfeed if you’re able and willing. Women who choose to breastfeed for at least a few months have a reduced risk of breast cancer, research shows.

  • Eat a Mediterranean-style diet. And yes, another way to reduce your breast cancer risk that’s being studied involves your diet. Some studies show that a diet full of fruit and veggies, fish, and low-fat dairy may help lower your risk. While the data isn’t as clear on this tactic, there are plenty of other research-backed reasons to adopt a healthy diet, so there’s certainly no harm in making that a goal as well. And yogurt could definitely be a part of it.

  • Cancer Stats in Women: Cancer Facts for Women. (2019). National Cancer Society.

  • How to Reduce Risk of Breast Cancer: Can I Lower My Risk of Breast Cancer? (2019). American Cancer Society.

  • Yogurt and Breast Cancer Study: Medical Hypotheses. (2020). “Hypothesis: Bacterial induced inflammation disrupts the orderly progression of the stem cell hierarchy and has a role in the pathogenesis of breast cancer.”

  • Yogurt and Breast Cancer Study News Release: Why eating yoghurt may help lessen the risk of breast cancer. (2020). Lancaster University.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at