While a diet rich in foods such as allium vegetables (garlic and leek), dietary fiber, soy, legumes, fish, nuts, whole grains such as brown rice, indole-3-carbinol and fruits such as apples, bananas, grapes and oranges may help in breast cancer prevention and to stay away from the signs and symptoms of breast cancer, following a unhealthy dietary pattern with wrong foods may increase the risk of breast cancer, and may ultimately make it difficult to fight the cancer or even support the treatment. Hence avoid high intake of heme iron, ultra-processed foods, sugary drinks, foods causing obesity such as red meat and processed meat and alcohol to reduce the risk of breast cancer. Following a healthy lifestyle by eating the right foods, limiting alcohol, doing regular exercises and staying physically active are some of the steps that we can take for breast cancer prevention.
Breast Cancer Incidence
Breast cancer is the one of the most commonly diagnosed cancers and the leading cause of cancer-related deaths in women across the world. In 2018, there were over 2 million new breast cancer cases diagnosed. About 1 in 8 women are diagnosed with breast cancer during their lifetime.
However, if breast cancer is diagnosed at an early stage, there is a good chance of recovery.
Breast Cancer Treatments
The treatment for breast cancer is decided based on the stage (extent of cancer spread) of the cancer, molecular characteristics of the cancer, and general health of the patient.
Today, there are many treatments available for breast cancer which includes:
- Hormonal therapy
- Targeted therapy
Either, one of these treatments, or a combination of these are used for the treatment of breast cancer.
Hormone positive breast cancer patients mostly receive endocrine/hormone treatment.
Signs and Symptoms of Breast Cancer
Following are some of the common signs and symptoms of breast cancer.
- a new lump or thickened tissue in either breast
- a discharge of fluid from nipple
- a rash on or around the nipple
- a lump or swelling in the armpits
- a change in the size or shape of the breast
- dimpling on the skin of the breasts
- a change in the appearance of the nipple- becoming sunken into the breast
One should consult a doctor if we notice any of the above signs or symptoms of breast cancer.
Foods/Diet that may Reduce Breast Cancer Risk and Support its Prevention
Having a healthy and balanced diet which includes the right set of foods can reduce the risk and support the prevention of breast cancers· Based on different meta-analyses and observational studies, here are some examples of foods that can help with breast cancer prevention.
Soy Food Intake may Reduce Breast Cancer Risk in Chinese women
In a large-scale prospective cohort study called the China Kadoorie Biobank (CKB) cohort study involving over 300,000 women aged between 30 and 79 years, enrolled between 2004 and 2008, from 10 geographically and economically diverse regions in China, with a follow-up of approximately 10 years and 2289 women breast cancers reported, it was found that for every 10 mg/day increase in soy intake, there was a 3% reduction in breast cancer risk. (Wei Y et al, Eur J Epidemiol. 2019)
Dietary Fiber Intake May Reduce Breast Cancer Risk
Researchers from Hangzhou Cancer Hospital, Zhejiang in China analyzed data from 24 studies found through literature search in the PubMed, Embase, Web of Science, and Cochrane Library databases and found a 12% decrease in breast cancer risk in women with high dietary fiber intake. The dose-response analysis also found that for every 10 g/day increment in dietary fiber intake, there was a 4% reduced risk of breast cancer. (Sumei Chen et al, Oncotarget., 2016)
Allium Vegetable Intake may Reduce Breast Cancer Risk
Researchers of Tabriz University of Medical Sciences, Iran evaluated data from 285 breast cancer women in Tabriz, aged between 25 and 65 years old and age- and regional-matched hospital based-controls and found that a high consumption of garlic and leek may reduce the risk of breast cancer, whereas, a high consumption of cooked onion may increase the risk. (Ali Pourzand et al, J Breast Cancer., 2016)
Legume Intake may Reduce Breast Cancer Risk
Researchers from Tehran University of Medical Sciences and Isfahan University of Medical Sciences in Iran evaluated data obtained from a population-based case-control study which included 350 breast cancer patients and 700 controls and found that among postmenopausal women and normal-weight participants, groups with a high legume intake had a 46% reduced risk of breast cancer compared with those with low legume intake. (Yaser Sharif et al, Nutr Cancer., 2020)
Brown Rice Consumption may Reduce Breast Cancer Risk in Premenopausal Women
Analysis of data from Nurses’ Health Study II which included 90,516 premenopausal women aged between 27 and 44 years, found that refined grain food intake may not be associated with the risk of breast cancer. However, the study found that a diet including brown rice consumption may be associated with a lower risk of overall and premenopausal breast cancer. (Maryam S Farvid et al, Breast Cancer Res Treat., 2016)
Fish Intake may Reduce Breast Cancer Risk
Analysis of data from the Reykjavik Study, a population-based cohort study, which was initiated by the Icelandic Heart Association, involving 9,340 women born between 1908 to 1935, as well as diet information for different periods of life from a subgroup of the 2882 women who entered the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study found that a very high intake of fish during early adulthood to midlife may be associated with a reduced risk of breast cancer. (Alfheidur Haraldsdottir et al, Cancer Epidemiol Biomarkers Prev., 2017)
A Diet Rich in Nuts may Reduce Breast Cancer Risk
Analysis of data from 97 breast cancer women between 2012–2013 recruited from a single public hospital center, Instituto Estatal de Cancerología de Colima, Mexico and 104 women with normal mammograms with no prior history/signs/symptoms of breast cancer, found that a high intake of nuts as part of the diet significantly reduced the risk of breast cancer by two to three times. (Alejandro D. Soriano-Hernandez et al,Gynecol Obstet Invest., 2015)
Green Tea Intake May Reduce The Risk of Breast Cancer Recurrence
A study done by the researchers from the University of Perugia in Italy based on 13 studies including 8 cohort studies and 5 case-controlled studies involving 163,810 people, found that green tea consumption reduced the risk of breast cancer recurrence by 15%. However, analysis didn’t find any evidence that green tea is able to reduce the risk of breast cancer incidence. (Gianfredi V et al, Nutrients., 2018)
Whole Grain Consumption May Reduce Breast Cancer Risk
Researchers from China and U.S. analyzed data obtained through literature search in databases such as PubMed, Embase, Cochrane library databases, and Google Scholar till April 2017 which included 11 studies with 4 cohort and 7 case-control studies involving 1,31,151 participants and 11,589 breast cancer cases, and found that a high intake of whole grains may reduce the risk of breast cancer. (Yunjun Xiao et al, Nutr J., 2018)
Intake of Apples, Bananas, Grapes, Oranges and Kale may Reduce the Risk of ER -ve Breast Cancer
In a study published by the researchers from Harvard T.H. Chan School of Public Health in Boston, US and the coauthors, based on data from 90476 premenopausal women participants aged between 27-44 from the Nurses’ Health Study II, it was found that a high consumption of apple, banana, and grapes during adolescence, and oranges and kale during early adulthood significantly reduced the risk of Estrogen Receptor (ER) -ve breast cancers. (Maryam S Farvid et al, BMJ., 2016)
Indole-3-Carbinol (I3C) use may Help in Breast Cancer Prevention
Researchers from the Strang Cancer Prevention Center in New York, United States included data from 60 women who were at an increased risk for breast cancer when enrolled in a placebo-controlled trial out of which, 57 women with a mean age of 47 years completed the study. The study found that indole-3-carbinol (I3C), found in cruciferous vegetables, at a minimum effective dose of 300 mg per day may be a promising agent for breast cancer prevention.(G Y Won et al, J Cell Biochem Suppl., 1997)
Foods/Diet that may Increase Breast Cancer Risk
While a diet with the right foods can influence reducing the risk of developing breast cancer, following an unhealthy eating pattern by taking the wrong foods can increase the risk of this cancer, ultimately make it difficult to fight the cancer.
High Heme Iron intake may Increase the Risk of Breast Cancer
Researchers from the University of Toronto and Cancer Care Ontario, Canada analyzed data from 23 studies obtained through literature search in MEDLINE, EMBASE, CINAHL, and Scopus databases till December 2018 and found that when compared to those with lowest heme iron intake, there was a 12% increased risk of breast cancer in women with highest heme iron intake. However, there was no significant association between dietary, supplemental or total iron intake and breast cancer risk. (Vicky C Chang et al, BMC Cancer., 2019)
Intake of Ultra-processed Foods may Increase Breast Cancer Risk
Researchers from France and Brazil analyzed data from the NutriNet-Santé cohort Study, a population based study, which included 1,04980 participants aged at least 18 years and a mean age of 42.8 years and found that every 10% increase in consumption of ultra-processed foods was associated with a 11% increased risk of breast cancer. (Thibault Fiolet et al, BMJ., 2018)
Consumption of Sugary Drinks may Increase Breast Cancer Risk
Analysis of results from the French NutriNet-Santé cohort Study which included 1,01,257 participants aged 18 and over found that those who had an increased consumption of sugary drinks were 22% more likely to develop breast cancer compared to those who did not or seldom consumed sugary drinks. (Chazelas E et al, BMJ., 2019)
Obesity may Increase the Risk of Breast Cancer
Analysis of results from a nationwide cohort study involving 11,227,948 adult Korean women selected from the National Health Insurance Corporation database merged with national health examination data from 2009 to 2015, found that increased BMI and waist circumference were associated with an increased risk for postmenopausal breast cancer, but not with premenopausal breast cancer. The study also mentioned that in premenopausal women, increased waist circumference may indicate increased breast cancer risk only when BMI was considered. (Kyu Rae Lee et al, Int J Cancer., 2018)
Diet high in Red Meat and Potatoes was associated with an Increased Risk of Breast Cancer in Postmenopausal Women
Researchers of different Universities in New York, Canada and Australia evaluated data from 1097 breast cancer cases and an age-matched group of 3320 women from 39,532 female participants in the Canadian Study of Diet, Lifestyle and Health (CSDLH) and confirmed the findings of their analysis in 49,410 participants in the National Breast Screening Study (NBSS) in which 3659 cases of breast cancer incidence were reported. They highlighted that while a “healthy” dietary pattern which consisted of vegetable and legume food groups was associated with a reduced risk of breast cancer, the “meat and potatoes” dietary pattern which included red meat groups and potatoes was associated with an increased risk of breast cancer in postmenopausal women. (Chelsea Catsburg et al, Am J Clin Nutr., 2015)
Alcohol Consumption may Increase Breast Cancer Risk
Researchers from the Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston evaluated data from a prospective observational study of 105,986 women enrolled in the Nurses’ Health Study followed up from 1980 until 2008 with an early adult alcohol assessment and 8 updated alcohol assessments, and 7690 cases of invasive breast cancer reported during the follow-up period. The study found that alcohol intake both earlier and later in adult life, as well as, increasing alcohol consumption by 3 to 6 drinks per week can significantly increase the risk of breast cancer. The study also found that binge drinking, but not frequency of drinking, was significantly associated with breast cancer risk. (Wendy Y Chen et al, JAMA., 2011)
Different observational studies and meta-analyses suggest that while a diet rich in foods such as allium vegetables (garlic and leek), dietary fiber, soy, legumes (peas and beans), fish, nuts (almonds, walnuts and peanuts), whole grains such as brown rice, indole-3-carbinol (found in cruciferous vegetables such as broccoli, kale, spinach etc) and fruits such as apples, bananas, grapes and oranges may help in breast cancer prevention and to stay away from the signs and symptoms of breast cancer, following a unhealthy dietary pattern with wrong foods may increase the risk of breast cancer and can even make it difficult to fight the cancer. Hence, one should avoid high consumption of heme iron, ultra-processed foods, sugary beverages, foods causing obesity such as red meat and processed meat and alcohol to reduce the risk of breast cancer. Staying away from these foods may even help to fight breast cancer by not harming the ongoing treatments.
Taking the right foods as part of the diet, limiting alcohol, doing regular exercises & staying active can aid in breast cancer prevention, fight cancer & support treatment.
While on breast cancer treatment, a personalized nutrition including the right foods that can support your treatment and reduce the signs and symptoms and avoiding those foods and supplements that can harm the treatment becomes important. Have a look at our previous blog to know more about personalized nutrition and foods to include as part of metastatic breast cancer patients’ diet to fight cancer while on treatment.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer.Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.