Breasts: An Owner’s Manual: Every Woman’s Guide to Reducing Cancer Risk, Making Treatment Choices and Optimising Outcomes. Kristi Funk

like to take a moment to slam them down.

      First up, wake up to coffee. A lot of the women I meet believe that coffee causes breast cancer, but absolutely no link exists between your sacred cup of joe and breast cancer.⁷ In fact, mounting evidence suggests that coffee might actually have a preventive effect.⁸ That being said, the caffeine in coffee isn’t always a plus for your breasts, as it can increase breast pain and breast cysts, particularly in young women with fibrocystic breast changes—but that’s not cancer. So if your breasts don’t hurt, it doesn’t hurt your breasts to love a latte.

      And speaking of lattes, the idea that dairy causes breast cancer is unproven. Evidence from more than forty case-control studies and twelve cohort studies does not support an association between dairy product consumption and breast cancer risk.⁹ It sounds intuitive to say that the presence of hormones, growth factors, fat, antibiotics, and chemical contaminants often found in dairy would lead to a proliferation of cancer cells, especially hormonally sensitive breast cancer cells, but the evidence contradicts our intuition. That being said, dairy is a major source of saturated fat, so you must be mindful of how fat influences your risk, which we discuss in chapter 4.

      At first blush, the evidence seems to point toward the fact that no causative link exists between the consumption of red meat, white meat, total meat, or fish and breast cancer.¹⁰ Hit the brakes and screech to a skidding stop! Ladies, it took my writing this book to live inside the hundred-plus confusing and contradictory breast/meat studies and really figure it out. Meat is so toxic to your breasts that even the slightest consumption of it nullifies a measurable difference between “high” and “low” meat consumers. Only when you compare zero/zippo meat consumption to any meat consumption might you arrive at the truth. Minimize meat. See you in chapter 4 to understand why.

      Finally, I hear from a lot of my most nutrition-savvy patients that acidic foods alter the body’s pH balance to the extent that it could cause breast cancer. But here’s the thing: your body tightly regulates your blood pH to be 7.35 to 7.45 no matter what you eat, and even minor changes to this range would cause severe symptoms and life-threatening illness. According to the American Institute for Cancer Research, this myth clashes with everything science teaches about the chemistry of the human body. There isn’t much wiggle room, since a pH outside of 6.8 to 7.8 equals certain death. And don’t be fooled by test kits said to rate your body’s acidity through urine. If you check the pH of your urine, and it’s not a perfect 7.35, that’s because your body constantly fine tunes excess acid or base to maintain proper blood pH balance, and it does so by excreting the excess in your urine.

      That said, it’s true that cancer cells flourish in acidic microenvironments.¹¹ However, it’s the cancer itself that creates the acid it bathes in, so consuming low pH foods doesn’t provide a happy place for cancer; cancer doesn’t even need you for that.¹² Besides, stomach juices are pure acid at pH 1.5 to 3.5. Your alkaline water slides down the esophagus and splashes right into an acidic bath; it will not change your body’s pH, and it will not neutralize a cancer cell’s acidic little world. I will say that the foods (nuts and veggies) you would consume in a (futile) effort to change your pH to more alkaline actually pack a massive punch to cancer cells via high antioxidant levels, DNA–damage control, and immune system support, but it’s not from making you alkaline.

      BOGUS LIFESTYLE BELIEFS

      We’ll dive into the lifestyle changes that matter most in chapter 5, but I’d like to first clear the decks on certain popular myths so you don’t think I’m skipping these.

      Let’s talk bras. They don’t start or stimulate breast cancer, thankfully, because we need their unwavering support. Underwire bras, tight bras, sleeping in a bra, or wearing a bra more than twelve hours a day has no connection to risk. I’ve heard the claims, and initially they seem so plausible that one might believe they have a basis in fact. I repeatedly hear two schools of thought. One involves stating that tight bras compress the lymphatic system of the breast, which leads to toxins building up within the breast tissue itself, deleteriously altering the cells. This has no grounding in breast anatomy or physiology. We treat breast lymphedema (a blockage of lymphatic fluids within the breast that infrequently occurs after cancer surgery and radiation) with, among other strategies, breast compression.¹³ The other smart-sounding hypothesis proposes that the underwire itself conducts environmental electromagnetic fields (EMFs). As you will read in a minute, even if this antenna theory were true, EMFs don’t cause breast cancer.

      A 2014 study compared bra-wearing habits between postmenopausal women with and without invasive breast cancer. Researchers found that details such as cup size, underwire presence, age first beginning to wear bras, and average hours worn were not associated with an increased risk of breast cancer.¹⁴ So, ladies, whatever you feel is appropriate in terms of chest support, I support you.

      Next up: antiperspirants and deodorant. You can officially slow your search for the ultimate natural substitute because no scientific evidence backs the claim that antiperspirants or deodorants cause breast cancer due to toxin buildup or aluminum exposure or parabens.¹⁵ As a reminder, antiperspirants block the pores with astringents such as aluminum chlorohydrate so that they can’t release sweat, thereby preventing bacterial buildup and odor. On the other hand, deodorants don’t prevent sweating but rather neutralize the smell of excess bacteria by combining fragrances that mask odor with propylene glycol that creates an environment where bacteria can’t grow.

      One cancer-linking theory purports that pore-plugging aluminum compounds absorbed near the breast contain estrogen-like activity.¹⁶ As we will review later, estrogens feed and fuel the majority of breast cancer cells. Therefore, the presence of estrogen-behaving compounds might increase the division of cancer cells. A second study suggests that aluminum itself directly negatively affects breast tissue cells.¹⁷ But a 2014 systematic review of peer-reviewed literature regarding these two potential health risks posed by aluminum concluded that no such relationships exist.¹⁸

      Maybe it’s not the aluminum? One publication found traces of a preservative called parabens inside a tiny sample of twenty breast cancer tumors.¹⁹ As “endocrine disrupters,” parabens demonstrate weak estrogen-like properties, but the study in question made no cause-and-effect connection between parabens and breast cancer, nor did it conclusively identify how they got there in the first place. Parabens have even been found inside tumors when women don’t use underarm products at all.²⁰ Besides, the dose of parabens required to initiate a mutation in a human breast would be much higher than that absorbed through the application of a stick or spray. Additionally, most brands no longer use parabens, but if you’re still worried about this, choose a product that specifically says paraben-free on the packaging.

      Another widely circulating rumor claims that antiperspirant prevents you from sweating out toxins, which can then accumulate in the lymph nodes and cause breast cancer. To draw conclusions that wipe the sweat off our concerned brows (and pits), we need epidemiologic studies that compare two groups of people who are alike except for one deodorant factor. Luckily we have a few. In 2002, researchers at the Fred Hutchinson Cancer Research Center in Seattle conducted an epidemiologic study to address the sweat issue and other antiperspirant-related toxicity theories. They compared 1,600 women with and without breast cancer and found no link between breast cancer and antiperspirants, with or without shaving.²¹ A similar but smaller Iraqi study of 104 women with and without breast cancer also showed no link.²²

      The only published epidemiologic study with a competing point of view observed 437 Chicago-area breast cancer survivors and divided them according to underarm habits.²³ The author found that women who used antiperspirant/deodorant earlier in life and more frequently and with underarm shaving were statistically more likely to develop breast cancer at an earlier age. He theorized that aluminum salt substances found in these products entered the lymphatic system through nicks in the skin caused by shaving. However, this study did not demonstrate a conclusive link between underarm hygiene habits