Eating More PUFAs May Lower Your Breast Cancer Risk. What Are They?

Breast cancer is one of the most common cancers in the United States. Some risk factors, like genetics, are not in your control. However, your diet and lifestyle are breast cancer risk factors that you do have some power to change.

For example, research has suggested that eating more fruits and vegetables might be linked to a lower risk of getting breast cancer while consuming more alcohol may increase your risk.

A new study published in Menopause found that eating a nutrient—polyunsaturated fatty acids (PUFAs)—might also be linked to a reduced risk of breast cancer.

What Are PUFAs?

There are four major dietary fats in food: saturated fats, trans fats, monounsaturated fats, and polyunsaturated fats.

Mono- and polyunsaturated fats (the latter of which are known as PUFAs) are among the healthier fats found in the foods that we eat. Eating more of these fats—which are found in olive oil and nuts—has been linked to positive heart, eye, and brain health benefits.

On the other hand, research has shown that consuming more trans and saturated fats (like butter, pastries, and bacon) may have negative effects on our health (especially our heart health).

“[PUFAs] are simply fats that contain more than one double bond in their chemical backbone, which makes them more flexible than saturated fats that are solid at room temperature and monounsaturated fats, which have only one double bond,” Melissa Azzaro, RDN, LD, a registered dietitian and podcast host at Hormonally Yours, told Verywell.

How Are PUFAs Linked to Breast Cancer Risk?

While some studies have suggested that a higher intake of omega-3 PUFAS might be linked to a reduced risk of breast cancer, the results have been mixed.

Most of the studies that have been done on the connection have used data from postmenopausal women—those who have gone through menopause.

For the recent study, the researchers wanted to see if there was also a link between PUFA intake and breast cancer risk in premenopausal women—those who have yet to go through menopause.

To find out, they did a case-control study using almost 1,600 women in China who had breast cancer, and the same number of controls who did not.

The researchers assessed the participants’ dietary intakes by looking at how they responded to a food frequency questionnaire, as well as noting whether they were pre- or postmenopause.

The researchers found that:

• A higher intake of omega-3 PUFAS from marine sources like fish and total omega-3 PUFA intake was linked to a lower breast cancer risk.
• Specifically, there was a 49% lower risk associated with dietary alpha-linolenic acid intake, and a 32% risk reduction associated with intake of EPA and DHA.

These associations were strongest for the premenopausal women as well as the women who had estrogen receptor (ER)-positive, progesterone receptor (PR)-positive, and ER-positive PR-positive tumors.

The Power of PUFAs

Sarah Gold Anzlovar, MS, RDN, LDN, owner of Sarah Gold Nutrition, LLC, was not involved in the new research but told Verywell that the study had a few interesting findings, including the fact that overweight and obese women saw a significantly lower risk for breast cancer with more omega-3 intake.

“This suggests that there are dietary habits women can implement to improve health outcomes without focusing on weight loss,” she said.

“What’s great about the results of this study is that there was a reduced risk of breast cancer from total omega-3 intake—which includes both fish and plant-based sources,” she added. “If you don’t love fish or don’t have access to it regularly, you can focus on eating the plant-based sources of omega-3s.”

In a press release, Chrisandra Shufelt, MD, president of the North American Menopause Society, said that the study “highlights the effect of lifestyle habits and, specifically, dietary intake of polyunsaturated fatty acids on breast cancer risk. Lifestyle or diet is known to contribute to up to one-third of the risk for breast cancer.”

Shufelt also noted that people can “affect their risk of developing breast cancer by making dietary changes to include fruits and vegetables, fiber, and whole grains and avoiding high-fat animal and dairy products.”

While the study has given us more insight into the benefits of omega-3 fatty acids, Azzaro said that “it doesn’t change the recommendations already in place” for consuming these fats.

Azzaro said that it is recommended to “eat fatty fish 2 to 3 times a week and to include a variety of nuts and seeds regularly”—though most Americans are not meeting these guidelines.

More Research Is Needed, but PUFAs Are Still Beneficial

While the results are promising, the study had a few key limitations:

• It only looked at a relatively small number of participants and all of them were from one part of the world.
• The researchers also relied on data about food intake that was self-reported, which is not always the most accurate.

These limitations highlight why we need more research with bigger and more diverse populations to find out if PUFAs are really beneficial for reducing breast cancer risk.

While cancer prevention is certainly a goal, researchers are also hoping to find out whether PUFAs would be beneficial for people who already have breast cancer.

A pilot clinical trial on 10 women between the ages of 45 and 67 found that the women with breast cancer who ate two ounces of walnuts per day for about two weeks experienced positive genetic changes related to cancer development and growth.

The study’s findings were encouraging, but it was very small. Like with the more recent study, we still need larger and longer-term studies on cancer risk and PUFAs before we could make any firm conclusions.