What is Breast Cancer?
Breast cancer is one of the most common of all cancers and is the leading cause of cancer deaths in women across the world. In India, it is the second most common type of cancer to affect women, and the incidence of breast cancer has been rising rapidly, affecting more women in urban areas.
In 2002, the number of women in the country affected by breast cancer was 80,000. In a decade (2012), the figure doubled to 144,937. The incidence of breast cancer can be significantly reduced with increased awareness of these risk factors; one of these risk factors is dietary.
Red Meat and Breast Cancer
The association between red meat and cancer is something that we have often heard about, but it is something that most of us have never taken seriously, as most studies so far had been inconclusive because of methodology. In recent years, however, there has been significant progress in research and a peer-reviewed study that was published in BMJ in 2014 clearly demonstrated this link.
The study was conducted to investigate the association between dietary protein sources in early adulthood and risk of breast cancer.
As stated by lead researcher Maryam S Farvid, a lot of the ambiguity from previous studies can be attributed to the time period during which exposure is measured. Farvid said that this particular study focused specifically on adolescence and early adulthood because this is the period when the mammary glands are most susceptible to carcinogen exposure.
Another problem with many previous studies is that they did not take into account age groups or changes in consumption patterns. This basically means that many of the women in the studies were past the age of 40 and although they consumed significant amounts of red meat during adolescence and early adulthood, these dietary patterns changed towards middle age.
Reported dietary patterns at the present, therefore, had no bearing on current health outcomes that may have been driven by past eating habits.
If you love eating those pork chops and salivate at the very mention of a beefsteak, you will be predisposed to being dismissive of such studies that force you to question your world view, or your taste buds! But these findings are noteworthy because the study took into account the limitations and flaws in previous models and made every effort to address them.
The study did not exclude women above 40, but it took into account the age of participants and this was factored into the results. The study which began in 1991, continued until 2011, with the eating habits of each participant being monitored during the 20-year period. The findings of the study were revealing, to say the least, but there are practical solutions even for those with a craving for red meat.
The studies conducted by Farvid present us with some clear facts that should help women make better dietary decisions taking into account breast cancer risk assessment. Here are some pertinent facts that are worth noting:
- From the data collected, it becomes apparent that the risk of breast cancer from red meat consumption is very real although the reasons are not clear. The risk in fact increased by as high as 22 percent in women who consumed red meat 1.5 times a day, as opposed to amongst women who simply consumed red meat once a week.
- Findings reveal that each additional serving of red meat increased the risk of breast cancer by 13 percent. This makes it a significant and controllable dietary risk.
- The risk assessment in this scenario was independent of other known risk factors such as smoking, alcohol consumption, obesity, oral contraceptive use and age.
- Young women on the pill should be most worried and cautious with their red meat intake, as the strongest connection between the intake of red meat and increased breast cancer risk is in this demographic. Young women on the pill experience an increased risk of breast cancer, with each additional red meat serving to increase the risk by 54 percent.
- Based on observations made from the Hiroshima and Nagasaki atomic bombings, it is clear that the risk of breast cancer increased on account of exposure. This exposure raised the risk significantly for younger women, while those past 40 were unaffected in the sense that there was no increased risk. Farvidís follow-up study confirmed this suspicion and it appears that the mammary glands are more susceptible to carcinogens upon exposure during the periods of growth and development.
- The findings also make it clear that high red meat intake during adolescence and early adulthood increases the risk of premenopausal breast cancer but it does not have any known effect on postmenopausal breast cancer.
Although red meat consumption is associated with an increased risk of breast cancer, this depends on various factors such as the quality of red meat, your age, the frequency of consumption and quantity consumed. Experts do not recommend abstaining from red meat altogether, so you donít need to fret. What they do advise however, is that you cut down on your intake of red meat drastically, especially if you have been in the habit of consuming red meat on a daily basis.
While certain risk factors like genetics cannot be controlled, women at high risk for breast cancer should be especially careful about other factors that can be controlled such as diet and lifestyle choices.
It should be pointed out that it is not clear why red meat contributes to cancer development but the researchers point to two hypotheses which have also been supported by other studies.
- Cooking meat at high temperatures results in certain carcinogenic by-products, which means that the method of preparation is one contributing factor.
- Industrial livestock practices involve administering growth hormones to cattle and hormone residues in the meat are another possible cause of cancer.
It is also worth noting that the authors of the study found that there was a reduction in post-menopausal breast cancer risk among women who consumed poultry regularly before they reached menopause. They recommend substituting servings of red meat with poultry, nuts, legumes and fish to lower the risk while limiting red meat consumption to once a week or less.
- Farvid MS, Cho E, Chen WY, Eliassen AH, Willett WC. Dietary protein sources in early adulthood and breast cancer incidence: prospective cohort study. BMJ. 2014 Jun 10;348:g3437. doi: 10.1136/bmj.g3437. PubMed PMID: 24916719; PubMed Central PMCID: PMC4051890.
- Why does eating red meat elevate breast cancer risk, especially for young women on the pill?† - (http://blogs.plos.org/publichealth/2014/11/05/red-meat/)
- Harvard School of Public Health. News: Red meat consumption and breast cancer risk. - (http://www.hsph.harvard.edu/news/features/red-meat-consumption-and-breast-cancer-risk/ (accessed 14 July 2015)
Latest Publications and Research on Consumption of Red Meat Increases Breast Cancer Risk
- Diagnostic yield of a custom-designed multi-gene cancer panel in Irish patients with breast cancer. - Published by PubMed
- Breast cancer patients' experiences of adherence and persistence to oral endocrine therapy: A qualitative evidence synthesis. - Published by PubMed
- Current immunoassay methods and their applications to clinically used biomarkers of breast cancer. - Published by PubMed
- Association Between Polymorphisms in DNA Damage Repair Genes and Radiation Therapy-Induced Early Adverse Skin Reactions in a Breast Cancer Population: A Polygenic Risk Score Approach. - Published by PubMed
- [Comparing outcomes of Immediate Breast reconstruction with and without use of radiotherapy]. - Published by PubMed