Studies Detail Breast Cancer Risk Reduction Through Healthy Dietary Patterns
Thu, April 22, 2021

Studies Detail Breast Cancer Risk Reduction Through Healthy Dietary Patterns

Breast cancer frequently affects 2.1 million women every year, according to the World Health Organization (WHO), the UN’s specialized agency that leads partners in global health responses. About 627,000 of them die from it, making breast cancer the leading cause of cancer-related deaths among women— representing approximately 15% of all cancer deaths. Breast cancer rates are higher in developed countries, but the rates are also increasing in every region across the world.

Early detection is critical to improving breast cancer outcomes and survival. Countries with weak health systems where most women are diagnosed in late stages should prioritize early diagnosis programs. Such programs are grounded on awareness of early signs and symptoms, as well as prompt referral to diagnosis and treatment. In fact, the stage of an individual’s breast cancer is a key factor in decisions about treatment, according to the American Cancer Society, a nationwide voluntary health organization.

Breast Cancer Statistics

About 5% to 10% of breast cancers can be linked to known gene mutations inherited from the individual’s mother or father, with BRCA1 AND BRCA2 genes being the most common, according to Breast Cancer.Org, a breast cancer information and support website. Women with a BRCA1 mutation have an average of up to 72% lifetime risk of developing breast cancer. The risk is 60% for women with a BRCA2 mutation. This latter is associated with a lifetime risk of about 6.8% among men, while BRCA 1 mutations are a less frequent cause of breast cancer.  

In the US, about 42,170 women are expected to die in 2020 from breast cancer. Since 2007, death rates have been steady in women below 50 years old, but continued to decline in women over 50. The overall death rate fell by 1.3% each year from 2013 to 2017. The decline in breast cancer death rates is said to be attributed to treatment advances and earlier detection through screening.

Breast cancer incidence rates in the US decreased in 2000, after increasing for the last 20 years. The incidence rates fell by 7% from 2002 to 2003 alone. This decrease might be due to the reduced use of hormone replacement therapy (HRT) by women after the Women’s Health Initiative published results in 2002. The results suggested a correlation between HRT and heightened breast cancer risk. However, incidence rates increased slightly by 0.3% annually in recent years.

Low-Fat Diet and Reduced Risk of Dying From Breast Cancer

Breast cancer treatments have advanced in recent decades but understanding how to stop tumors from forming has been a challenge, reported Alice Park of Time, an American weekly news magazine. A study led by Dr. Rowan Chelbowski and his fellow researchers focused on analyzing nearly 49,000 women who were randomly tasked to follow either a low-fat diet or a control diet for 8.5 years.

The former group was asked to reduce their fat intake to 20% of their total daily calorie intake and increase fruit, vegetable, and grains consumption. None of the participants in the research had breast cancer. The rates of new breast cancers were about the same in the low-fat diet and control diet groups after the study concluded. However, participants who were diagnosed with breast cancer had a 35% lower risk of dying unlike those in the control diet group.  

Even after 20 years, the women who followed a low-fat diet continued to have a 15% lower mortality risk. In the follow-up data, their risk of dying from breast cancer was 21% lower than their peers who didn’t introduce dietary changes. Medical oncologist at Memorial Sloan Kettering Cancer Center Dr. Neil Iyengar said proponents who support incorporating diet and exercise in the cancer treatment plan are excited by the study’s findings.

Dr. Iyengar, who was not part of the study, added that it is the first research to show that health professionals can improve and prevent deaths from cancer through dietary changes. Chlebowski explained, “It’s about taking smaller pieces of meat, and adding vegetables to the plate to balance things out.”

Mediterranean Diet and Reduced Breast Cancer Risk

Tiffany M. Newman, Mara Z. Vitolins, and Katherine L. Cook noted in their research “From the Table to the Tumor: The Role of Mediterranean and Western Dietary Patterns in Shifting Microbial-Mediated Signaling to Impact Breast Cancer Risk” that the Mediterranean diet is touted as one of the healthiest of all dietary patterns. The Mediterranean diet pattern (MeD) protects a person against cancer, cardiovascular disease, and diabetes.

Published in open-access journal Nutrients and life sciences journal archive Europe PMC, the Western dietary pattern (WeD) is consumed by many in the US and is known to contain high amounts of refined starches, sugar, red and processed red meats, saturated fats, and trans fats, The WeD contains low amounts of fruits, vegetables, and whole grains. Newman and colleagues cited a cross-sectional study of 3,584 women who participated in a breast cancer screening program from October 2007 to July 2008 to tackle the association between WeD and MeD and mammographic density.

Mammographic density was categorized into that less than 10%, 10-25%, 25-50%, and greater than 50%. It was found that women who had higher adherence to the WeD (242 women, 27%) were more likely to have high mammographic density compared to women who had lower adherence to the said dietary pattern (169 women, 19%) with a fully adjusted odds ratio of 1.25. However, there was no association between MeD and mammographic density. In fact, the latter is associated with heightened breast cancer risk.

Another study cited by Newman and colleagues involved evaluating the association between dietary patterns and risk of breast cancer in Spanish women, consisting of 1,017 participants with incident breast cancer and 1,017 matched healthy controls of similar age with no history of breast cancer.

Utilizing the Alternate Heathy Eating Index and the Alternate Mediterranean Diet score to gauge diet adherence, the researchers found that adherence to the WeD was correlated with increased risk. Low adherence and adherence to MeD were linked with a lower risk of breast cancer. Newman and her team concluded that epidemiological data supports the impact of dietary pattern on breast cancer risk. Based on the studies cited by the authors, adherence to WeD increased breast cancer risk while MeD reduces such risk.  

There are other treatment options for breast cancer such as chemotherapy or radiation therapy depending on the stage of the person’s breast cancer. However, the risks can be reduced by either adhering to a low-fat or a Mediterranean diet. Individuals may choose to visit a health professional if they think they need to change their diet to reduce the risk of having breast cancer. Doctors can also do their part by orienting patients about the importance of adhering to a healthy diet.