BRCA and Nutrigenomics (Blog Post)

Can the Mediterranean diet keep breast cancer away?

Author Credit: Annika Chambers, MSc

While nutrition can’t change BRCA mutation status, research shows that what you eat may still influence a mutation carrier's overall health, well-being and cancer risk.

Everyone has a unique genetic makeup. Our individual genomes determine the colour of our hair and our eyes, but can also influence how we metabolize different foods and the health benefits or risks we derive from them. Nutrigenomics studies the interaction between nutrition and our genes (Braicu et al., 2017, Fenech et al., 2011).  Nutrigenomic research on breast cancer patients and BRCA mutation carriers has identified several different dietary options and foods that may benefit overall well-being and potential disease prevention.  

It is often cited that alcohol can lead to increased breast cancer risk, as alcohol can increase both breast density and circulating estrogen levels in the blood (Bagnardi et al., 2015). This risk occurs on a molecular level whereby alcohol interacts with your DNA. Seeing that alcohol can increase your general risk of breast cancer, there are also foods which have been shown to decrease your risk using similar pathways. People at elevated risk of breast cancer may want to carefully consider their alcohol intake in their overall personal risk management strategy.

Controversially, soy and soy products were once labelled as potentially carcinogenic but may now be considered a risk-reducing food. Soy may work to reduce breast cancer risk by decreasing the conversion of healthy cells to carcinogenic cells (cancer-causing) and helping regulate the BRCA gene that is responsible for tumour development (Sellami & Bragazzi, 2020).

Diets under study include the Mediterranean diet, which consists of the consumption of vegetables, olive oil, nuts, fruit, whole grain cereals, fish, and small amounts of wine. (Bruno et al., 2017). This diet is often promoted as a preventative wellness diet with cancer-reducing properties for the general population.  However, it may include more benefits for those with BRCA mutations.

Researchers have hypothesized that insulin resistance may influence the relationship between BRCA mutations and cancer risk (Bruno et al., 2017). A study by Pasanisi et al. (2018) examined the Mediterranean diet to determine its effectiveness in reducing insulin resistance in BRCA mutation carriers and measures of metabolic syndrome. Results revealed that compared to controls that did not alter their diet, those eating the Mediterranean diet had reduced markers of insulin resistance, but only when the diet was eaten in combination with moderately reduced protein intake (Pasanisi et al., 2018). At this time, the extent to which this reduction in insulin resistance affects the causal relationship between BRCA mutations and cancer risk needs to be more fully explored. However, the Mediterranean diet may hold some benefit in reducing breast cancer risk in BRCA+ individuals, when combined with reduced protein intake.

What BRCA carriers may want to consider 

While this field of research is emerging, it is also important to consider your personal preferences. This research is in no way intended to promote a specific diet to BRCA carriers, but rather identify foods and, more especially, nutrients which may benefit one's own wellness given their genetic makeup. The BRCAinBC virtual support group education session features nutrigenomics expert Dr Ahmed El-Sohemy - if you would like to learn more, please watch the recording of the session. 

Directions for future research

It is important to note that this field of research on optimized nutrition for your genetic composition is still evolving, and as such, recommended guidelines may change over time. Currently, there is a gap in evidence to definitively support the relationship between certain foods and cancer prevention. However, longitudinal studies that track populations with BRCA mutations and their diets over time may lead to new and exciting discoveries in the future.

References

Bagnardi, V., Rota, M., Botteri, E., Tramacere, I., Islami, F., Fedirko, V., Scotti, L., Jenab, M., Turati, F., Pasquali, E., Pelucchi, C., Galeone, C., Bellocco, R., Negri, E., Corrao, G., Boffetta, P., & La Vecchia, C. (2015). Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis. British journal of cancer, 112(3), 580–593. https://doi.org/10.1038/bjc.2014.579

Braicu, C., Mehterov, N., Vladimirov, B., Sarafian, V., Nabavi, S. M., Atanasov, A. G., & Berindan-Neagoe, I. (2017). Nutrigenomics in cancer: Revisiting the effects of natural compounds. Seminars in Cancer Biology, 46, 84-106. https://doi.org/10.1016/j.semcancer.2017.06.011

Bruno, E., Manoukian, S., Venturelli, E., Oliverio, A., Rovera, F., Iula, G., Morelli, D., Peissel, B., Azzolini, J., Roveda, E., & Pasanisi, P. (2017). Adherence to mediterranean diet and metabolic syndrome in BRCA mutation carriers. Integrative Cancer Therapies, 17(1), 153-160. https://doi.org/10.1177/1534735417721015

Fenech M, El-Sohemy A, Cahill L, Ferguson LR, French TA, Tai ES, Milner J, Koh WP, Xie L, Zucker M, Buckley M, Cosgrove L, Lockett T, Fung KY, Head R. Nutrigenetics and nutrigenomics: viewpoints on the current status and applications in nutrition research and practice. J Nutrigenet Nutrigenomics. 2011;4(2):69-89. doi: 10.1159/000327772. Epub 2011 May 28. PMID: 21625170; PMCID: PMC3121546.

Pasanisi, P., Bruno, E., Venturelli, E., Morelli, D., Oliverio, A., Baldassari, I., Rovera, F., Iula, G., Taborelli, M., Peissel, B., Azzollini, J., & Manoukian, S. (2018). A dietary intervention to lower serum levels of igf-i in BRCA mutation carriers. Cancers, 10(9), 309. https://doi.org/10.3390/cancers10090309

Sellami, M., & Bragazzi, N. L. (2020). Nutrigenomics and breast cancer: State-of-Art, future perspectives and insights for prevention. Nutrients, 12(2), 512. https://doi.org/10.3390/nu12020512