Do Plant-Based Diets Reduce Risk of Certain Breast Cancers?

Plant based diets can be a great choice for many different reasons. Many choose to switch to a plant based diet for health reasons rather than humanitarian and sustainability reasons.

I partially chose to adopt a vegan diet to help regulate my hormone levels.  Many meat and cheese products contain high hormone levels which can affect women’s health and estrogen levels. Many studies show that high estrogen levels correlate with a higher risk of breast cancer, does this mean a vegan or plant based diet can prevent breast cancer?

Can a Vegan Diet Prevent Breast Cancer?

According to the Maurer Foundation 80% of all breast cancers grow according to estrogen supply.  These cancers are called hormone-receptor-positive cancers, many of these cancers are effectively treated by restricting estrogen in the body. Do high levels of estrogen actually cause cancer though? In a study conducted by the Women’s Health Initiative 8,506 women took hormone therapy with estrogen and progesterone and after 5.2 years they were not found to have an increased risk of breast cancer, however after a longer term of therapy the women taking the therapy were found to be 26% more likely to develop breast cancer than those taking the placebo and the study was stopped. After being off hormone therapy the women’s risk was significantly reduced.

Does mean increase estrogen levels

Based off the studies I found it seems that there is evidence to support that higher estrogen levels can increase women’s risk of breast cancer. Next I looked to see if there is research to support that eating meat really does increase estrogen levels. A study by Cambridge University found that estrogen red meat did not have a significant correlation with breast cancer in young women, it did increase the likelihood of breast cancer by 22% in post-menopausal women. This would indicate that there is some relationship between breast cancers and red meat, but their affects are not typically seen in young women. This correlates with the average age that breast cancers are seen to develop, between 55-64 in healthy women. Another study by the European Journal of Cancer found in a study of 262,195 women that breast cancer risk was not increased by red meat, but instead increased by a high consumption of processed meat. Looking a processed foods in general studies show that a diet including processed food in general, not just processed meat increases the risk of breast cancer in women. Vegan diets are often, but not always lower in processed foods because a vegan diet cuts out all processed meats and dairy. However, it is possible to eat a plethora of processed foods as a vegan, which will still increase the risks of certain cancers.

Are Vegans less likely to get breast cancer

Looking at a study specifically done to determine the risks of breast cancer between vegans, vegetarians, and non-vegetarians there was minimal difference in risk between vegetarians and non-vegetarians but a notably lower risk with a vegan diet (see table below)

Table 1

Non-cases Cases P
Dietary pattern (age-standardised to full cohort)
    Vegetarian 51·9% 53·1% <0·0001
        Vegan 7·5% 5·5% <0·0001
        Lacto-ovo-vegetarian 28·4% 31·3% <0·0001
        Pescetarian 10·3% 10·2% 0·23
        Semi-vegetarian 5·8% 6·1% 0·0009
    Non-vegetarian 48·1% 46·9% <0·0001
    All subjects 49 512 892 NA
Covariates (age-standardised to full cohort)
    Age at censoring (years) (mean) 64·77 61·82 <0·0001
    Age at menarche (years) (mean) 12·54 12·35 0·0003
    Age at first birth (years) (mean) 24·04 24·44 0·051
    Age at natural menopause (years) (mean) 47·85 48·67 0·0008
    BMI (kg/m2) (mean) 27·38 27·58 0·37
    Height (inches) (mean) 64·24 64·39 0·16
    Menopause (%) 69·0% 69·0% 0·60
    Hormone replacement therapy (% among menopausal women) 37·7% 43·6% <0·0001
    Oral birth control (%) 60·0% 61·5% <0·0001
    Family history of breast cancer (%) 11·7% 22·1% <0·0001
    Family history of ovarian cancer (%) 4·1% 4·0% 0·51
    Family history of breast or ovarian cancer (%) 15·0% 25·2% <0·0001
    Parity (% at baseline) 84·3% 84·1% 0·051
    Breastfeeding (total months) (mean) 12·26 11·55 0·16
    Number of children 2·71 2·60 0·018
    Some college or higher 78·3% 78·1% 0·25
    Screening (% of mammography last 2 years) 71·8% 77·1% <0·0001
    Physical activity (min/week) 74·43 75·75 0·71
    Smoking (% ever) 16·2% 14·1% <0·0001
    Alcohol (within 2 years of enrolment) 10·9% 12·6% <0·0001

(source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4907539/)

In this study those following a vegan diet were also found to have a lower overall BMI and a higher level of physical activity, and had a tendency to have a lower incidence rates of female cancers in general.

A vegan diet is not a cure-all that will 100% prevent people from getting breast cancer. However, there does seem to be some notable correlation between higher intake of processed meats and processed foods and an increased risk of cancer. While a plant-based diet isn’t going to make people immune to all cancer, it can decrease some risks if done properly. People with a higher intake of fruits and vegetables often are healthier and have a lower risk of cancers than people with little to no intake. Following a vegan diet can be a great lifestyle change that can help many people increase their fruit and vegetable intake and promote healthier living. Vegans, in general tend to be more conscious of the ingredients in food as a result of following a plant based diet. While there isn’t evidence that it is actually the lack of meat is what causes lower cancer rates in vegans, a high intake of processed foods and meats definitely does play a factor in a woman’s risk for breast cancer.

While I am not a scientist or a researcher I found this a really interesting subject to research, what are your thoughts on reducing the risk of cancers with a Vegan diet? Do you think there is a direct correlation between a vegan diet and a lower cancer risk or are their other factors at play? If you liked this topic make sure to follow me on social media for more vegan lifestyle posts and follow my blog below for more vegan and health related posts!

Sources

Brechon, Sarah. “Estrogen And Breast Cancer.” Maurer Foundation, 6 Sept. 2013, www.maurerfoundation.org/estrogen-and-breast-cancer/.

Figueiredo, Marta. “Breast Cancer Risk Linked to Consumption of Processed Meat: Study.” Breast Cancer News, 8 Jan. 2018, breastcancer-news.com/2018/01/08/breast-cancer-risk-increases-post-menopausal-women-increased-processed-meat-consumption-uk-study-finds/.

Alexander, Dominik D., et al. “A Review and Meta-Analysis of Red and Processed Meat Consumption and Breast Cancer | Nutrition Research Reviews.” Cambridge Core, Cambridge University Press, 26 Nov. 2010, www.cambridge.org/core/journals/nutrition-research-reviews/article/review-and-metaanalysis-of-red-and-processed-meat-consumption-and-breast-cancer/198C311287441E51D01B5CB7A2AB572A.

“Figure 2f from: Irimia R, Gottschling M (2016) Taxonomic Revision of Rochefortia Sw. (Ehretiaceae, Boraginales). Biodiversity Data Journal 4: e7720. Https://Doi.org/10.3897/BDJ.4.e7720.” doi:10.3897/bdj.4.e7720.figure2f.

“Breast Cancer Mortality Rates: Recent Figures and Trends – Moose and Doc.” Breast Cancer – Moose and Doc, 7 Sept. 2018, breast-cancer.ca/diag-chnces/.

Reinberg, Steven. “Highly Processed Foods Tied to Higher Cancer Risk.” WebMD, WebMD, 14 Feb. 2018, www.webmd.com/cancer/news/20180214/highly-processed-foods-tied-to-higher-cancer-risk#1.

Penniecook-Sawyers, Jason A., et al. Advances in Pediatrics., U.S. National Library of Medicine, May 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC4907539/.

 

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