37 Ways to Cut Your Cancer Risk, According to Science
Cancer is the number two killer in America, second only to heart disease. What can you do to reduce your chances of getting this deadly condition? You have more control than you might imagine.
Get a colonoscopy
One surefire way for preventing cancer: Stay up to date with recommended screenings. Although rates of colon cancer deaths have been dropping due to improved screening programs, it’s estimated that one in three adults over 50 aren’t being tested as they should. “Screening for colorectal cancer is the most important way to lessen one’s cancer risk,” says Ashwin Ashok, MD, a gastroenterologist at PIH Health in Whittier, California. Although there are other tests like X-rays, CT scans, or testing on stool, the colonoscopy remains the “gold standard,” Dr. Ashok says. “The benefit of a colonoscopy is that it can actually prevent colon cancer,” he says. “During a colonoscopy, pre-cancerous lesions called polyps can be identified and removed.” Colonoscopies aren’t fun—they’re done under sedation and you have to empty your bowels completely ahead of time—but they can reduce your cancer risk. Find out the silent symptoms of colon cancer you might be ignoring.
See your dentist
You probably don’t associate the dentist with preventing cancer, but regular checkups can help spot anything unusual going on in your mouth or throat. “Unfortunately, there are no good screening techniques for cancer of the throat and mouth,” says Robert D. Burk, MD, a specialist in head and neck cancers at Albert Einstein College of Medicine. “Nevertheless, dentists and other health-care providers can exam the oral cavity for masses and lesions.” In addition, studies have shown that poor oral hygiene is a risk factor for head and neck cancer, so brush and floss daily. The National Cancer Institute recommends checking in with your dentist or doctor if you have a mouth sore that won’t heal, a sore throat or hoarseness that doesn’t go away, or difficulty swallowing.
Stay out of the sun at midday
You’ve probably been given the advice to wear sunscreen and avoid tanning beds, but your best bet might be to avoid the sun altogether when it’s at its strongest—especially in summer. “Refrain from going to the beach when the sun is high in the sky,” Geoffrey Kabat, PhD, a senior epidemiologist at Albert Einstein College of Medicine/Montefiore Health System. “Depending on how fair your skin is, this might be from 10 a.m. until 4 p.m.” If you do venture outside, consider the color of your clothing: Bright colors like red and yellow as well as dark ones absorb more UV rays, which protects your skin. Also, wear tightly woven fabrics to prevent the sun from shining through.
Take a daily aspirin
Dr. Ashok says that taking a daily aspirin could reduce your cancer risk, and many studies support the advice. Recent research from the Yale Cancer Center found that using aspirin was associated with a 46 percent decreased risk of pancreatic cancer. And a U.K. review of studies found that among people who had cancer, taking aspirin reduced their risk of death. “Our review, based on the available evidence, suggests that low-dose aspirin taken by patients with bowel, breast, or prostate cancer, in addition to other treatments, is associated with a reduction in deaths of about 15 to 20 percent, together with a reduction in the spread of the cancer,” study author Professor Peter Elwood, an epidemiologist at Cardiff University, said. Doctors aren’t quite sure why aspirin works to prevent cancer—it could be because of its anti-inflammatory effects, although recent research suggests it may also block the interaction of platelets and cancer cells, hindering abnormal growth. Talk with your doctor to see if an aspirin regimen is right for you. Make sure to avoid these foods that are directly tied to cancer.
Ironically, even though good oral health is one way how to prevent cancer, using mouthwash daily has been linked to it in some studies. “Alcohol is a risk factor for oral cancer, so mouthwash that is high in alcohol content might be considered a risk factor,” says Dr. Burk. Although the link is not well understood, it still might be best to play it safe and choose a mouthwash without alcohol—or better yet, skip the mouthwash all together and stick to brushing and flossing.
Drink more coffee
A recent study from the University of Southern California found that drinking even modest amounts of coffee—regular or decaf—reduced the risk of colorectal cancer by 26 percent. According to the American Cancer Society, it could be the antioxidant properties of coffee beans that helps with preventing cancer. And it’s not just colorectal cancer—prostate, liver, endometrial, and others have also been associated with a reduced risk of cancer from drinking coffee. But be careful—adding cream and sugar could contribute to weight gain that might increase your risk. Plus, “coffee later in the afternoon may disrupt sleep/wake cycles,” says Lanie Francis, MD, an oncologist at the University of Pittsburg Medical Center (UPMC) and the director of the UPMC CancerCenter Wellness and Integrative Oncology Program. This is what cancer doctors do to prevent cancer.
The link between alcohol and cancer is well-established—in fact, in its Report on Carcinogens, the U.S. Department of Health and Human Services lists consumption of alcoholic beverages as a known carcinogen. “Excessive and prolonged alcohol use can weaken the immune system, which is important for preventing and controlling cancer,” says Robert L. Ferris, MD, PhD, chief of the Division of Head and Neck Oncologic Surgery at UPMC. Dr. Kabat notes that the risk is much worse if you smoke in addition to drinking heavily. According to the National Cancer Institute, there are other links between alcohol and cancer: The ethanol in alcohol breaks down to a toxic chemical that can damage DNA; alcohol may prevent the body from absorbing nutrients that may decrease cancer risk; and it increases estrogen, which is linked to breast cancer. Cancer-causing chemicals could also enter alcoholic beverages during the fermentation process. However, “moderate alcohol, particularly red wine, may have anti-inflammatory properties that contribute to a larger preventative goal,” Dr. Francis says. “Personally, I enjoy moderate alcohol as part of a lifestyle that promotes gratitude and social engagement.”
Ignore your sweet tooth
Unfortunately, the yumminess that sugar brings your taste buds has many downsides—one of which is an increase in cancer risk. A study from Spain showed how high sugar levels can lead to abnormal cell growth. “The larger theory is that factors related to insulin resistance and the general inflammation from certain types of processed foods may increase growth factors associated with cancer risk,” Dr. Francis says. “Working toward your ideal body weight through a diet that limits white sugar” is best, she advises. Find out what type of cancer is hitting millennials hard.
Cool it with hot dogs
Along with sugar, look to cut other processed foods, specifically processed meat, which is classified by the International Agency for Research on Cancer (IARC) as a carcinogen. This means hot dogs, ham, bacon, sausage, and some deli meats. Also, avoid any meats that have been smoked or cured, which can lead to the production of cancer-causing chemicals. The occasional meaty treat is OK—it’s really eating the stuff daily, which can increase the risk of colorectal cancer by 18 percent. “Studies have shown that the higher the intake of processed meat, the higher the risk of colorectal cancers and other chronic diseases,” Kana Wu, MD, PhD, a senior research scientist at Harvard T.H. Chan School of Public Health, said on the school’s website.
Eat less red meat
Unfortunately, red meat has also gotten a bad rap when it comes to a diet for preventing cancer. IARC classifies it as a “possible carcinogen,” and the American Cancer Society recommends a diet low in red meat. “Ideally, we should be thinking of red meat as we do lobster, having it for a special occasion if we like it,” Dr. Wu says. “This is how red meat is consumed in many traditional eating cultures, such as the Mediterranean diet.” The American Institute for Cancer Research suggests limiting red meat to 18 ounces per week.
Get away from grilling
If you do eat meat, rethink how you cook it: A recent study from the University of North Carolina showed that eating grilled and barbecued meat increased the risk of death among breast cancer survivors. “Dangerous chemicals called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) can be produced when cooking muscle meat like beef, pork, poultry, and lamb at high temperatures over open flame or hot coals,” says Shayna Komar, a licensed and registered dietitian at Piedmont Healthcare in Georgia. “These chemical reactions cause compounds in the meat to change into potentially cancer-causing agents.”
Consider the Mediterranean diet
As Dr. Wu suggests, the “Mediterranean diet,” which is high in vegetables, fruits, whole grains, legumes, nuts, olive oil, fish, and poultry, could have cancer-preventing benefits. A recent study from the Netherlands found that a specific type of breast cancer was 40 percent less prevalent among women who followed a Mediterranean diet. But, “rather than thinking about foods that are ‘magic bullets’ and about a diet that protects against cancer, one should think about a diet that is good for health generally,” Dr. Kabat says. “In this sense, a diet that contains lots of fruits and vegetables, as well as beans, nuts, seeds, and that is low on simple carbohydrates—sugars and starch—with small amounts of poultry, fish, and meat, is probably the best diet for overall health.” These surprising things can raise your risk of cancer.
Use rubber gloves when cleaning
Environmental toxins don’t just come from pollution outside—they could be coming from inside your home. Household cleaning products contain toxic chemicals that could cause cancer, including phthalates, petroleum solvents, and formaldehyde. One study found that women who reported the highest cleaning product use had double the risk of breast cancer compared to those with the lowest use—although, this could be because women who had breast cancer were hyper-aware of anything they may have done to “cause” their cancer. Even so, given the toxic chemicals in household cleaners, it’s best to use caution. “Don’t use strong solvents, drain-cleaners, or cleaning agents that could get absorbed through the skin without using rubber gloves,” Dr. Kabat says. Or better yet, clean with non-toxic products like baking soda and vinegar.
If household cleaners can cause cancer, so can not cleaning. A review of studies found that many toxic chemicals, including phthalates, fluorinated chemicals, and flame retardants, are present in dust, so dusting is something you should do to help with preventing cancer. “We identified 45 chemicals from five chemical classes that have been measured in U.S. indoor dust,” study author Veena Singla, PhD, wrote on the Natural Resources Defense Council’s website. “These commonly measured chemicals in the home are associated with health hazards such as cancer” and other problems, she says. The chemicals come from everything in our home, from building materials, flooring, furniture, electronics, carpets, clothes, and more. To reduce your risk of exposure, dust, mop, and vacuum frequently.
Don’t burn certain candles
Think that citrus candle smells refreshing? You might be inhaling cancer-causing chemicals. In a small study in the U.K., researchers found that when the fragrance limonene, which gives candles, air fresheners, and cleaning products their lemon-y fresh scent, is released, it reacts with ozone in the air to create the cancer-causing chemical formaldehyde. You can open the window to allow the limonene to disperse through the air, but it might be even better to avoid using products with limonene or the vague “fragrance” ingredient that might contain it.
House some houseplants
Although the link isn’t definitive, houseplants have been shown to remove toxins from the air—and this could include some cancer-causing chemicals, which help with preventing cancer. In the limonene study, adding houseplants reduced the levels of formaldehyde indoors. Especially effective were English ivy, ferns, geraniums, and lavender (which has the added benefits of smelling nice naturally and reducing stress). Previous studies, including one from the American Society for Horticultural Science, have also shown indoor plants to reduce formaldehyde and other chemicals. “It is evident from our results that certain species have the potential to improve interior environments and, in so doing, the health and well-being of the inhabitants,” study author Kwang Jin Kim said. Many people think these things cause cancer, but they actually don’t.
Go for the greens
Whatever type of diet you choose to go with, focusing on vegetables is always a healthy option—and it might prevent cancer as well. “Stick to plant-based foods and make sure you are eating foods with a lot of color—this usually means more nutrients, vitamins, and antioxidants,” Komar says. “You should aim to have three cups of greens—things like kale, spinach, and collards—per week.” Although the National Cancer Institute says studies haven’t actually proved greens prevent cancer, some research has shown a positive association. “When you eat more plant-based foods, you are filling your body with phytochemicals and antioxidants that fight cancer cells,” Komar says. “It’s like putting your ‘armor’ on each day to protect your body.”
Lose some weight
Being overweight or obese is never good for your health, and that includes your risk for cancer. “Keeping your body lean and maintaining a healthy body mass index lowers your overall risk of cancer,” says Jennifer Hopper, MS, director of employee wellness, worklife, and fitness at Piedmont Healthcare. According to the American Cancer Society, excess body weight contributes to as much as one in five cancer-related deaths. “Putting on excess weight as one ages increases one’s risk of cancer, particularly for postmenopausal breast cancer, endometrial cancer, and kidney cancer,” says Dr. Kabat. Although researchers aren’t sure of the exact connection between weight and cancer, it could have something to do with levels of hormones, factors that regulate cell growth, and immune system function. “Obesity may contribute to cancer risk by promoting inflammation,” Dr. Ferris says. A recent study from Sweden found that the risk of getting liver cancer later on is increased in adolescent men who have a high BMI (body mass index)—so the importance of maintaining a healthy weight from a young age is paramount. “Weight control can play a role to prevent certain kinds of cancer and certain cancer recurrences,” Dr. Francis says. “Taking the time to take care of yourself through diet and exercise is the first step.”
Get your z’s
Here’s a good reason to get your seven to eight hours of shut-eye a night: Chronic lack of sleep and poor sleep habits have been linked to cancer. Many studies have shown this association with different types, from prostate to colorectal to breast cancer. According to the Cancer Treatment Centers of America, the link could be because poor sleep leads to inflammation and disrupts immune function, which may promote cancer growth. Also, the sleep hormone melatonin might act as an antioxidant, so if you aren’t getting enough sleep, you aren’t getting that benefit. Plus, “sound sleep is important for overall health,” Dr. Kabat says. These groundbreaking cancer discoveries could save your life.
Although stress hasn’t exactly been proven to cause cancer, some studies point in that direction—and a review of research by the UTMD Anderson Cancer Center and the University of Iowa found that stress has been shown to help cancer grow. “Studies over the last 30 years have identified psychosocial factors including stress, chronic depression, and lack of social support as risk factors for cancer progression,” the authors wrote. Another study from Ohio State University may have found the reason why: Turning on a “stress gene” may promote the growth of cancer cells. Practicing mindfulness and physical activity can help lower your stress levels while working on preventing cancer. “For me, I practice yoga along with running and barre class, and this is a stress release, a chance to socialize with my community,” as well as good exercise, Dr. Francis says.
Binge on broccoli
This veggie may hold specific powers for preventing cancer. One recent study from Oregon State University found that sulforaphane, a dietary compound present in high amounts in broccoli, can help prevent cells from becoming malignant. “Recent data from a study at the University of Pittsburgh regarding cancer prevention suggests that sulforophane may prevent certain types of cancers,” says Dr. Ferris. “Potent doses of broccoli sprout extract activate a ‘detoxification’ gene and may help prevent cancer recurrence in survivors of head and neck cancer.” A clinical trial at the University of Pittsburg Cancer Institute is now underway to see if broccoli sprout extract (a pill called Avmacol, available online) can prevent oral cancers in high-risk patients, Dr. Ferris says.
Trim the fat
Along with cutting down on red meat, a diet free from high-fat foods may have benefits for preventing cancer. A recent study in mice showed how a fatty diet can lead to cancer growth—and in humans, a study from the University of North Carolina found that prostate cancer was more aggressive in men who ate a lot of saturated fat. Because people who eat fatty foods are less likely to be healthy in general, it’s hard to tease out the direct effects of fat on cancer, but in any case it’s not good for you. “I tell patients to limit their intake of high-fat meats—there are other great sources of protein you can try including fish, eggs, soups with beans, quinoa pasta, and veggie wraps,” Komar says. “When you do eat high-sugar or high-fat foods, they are taking up valuable space in your diet, in turn making your immune system work overtime, which leads to cancer-causing inflammation.” She recommends eating 80 percent whole foods like fruits, veggies, nuts, and legumes, and 20 percent animal products like dairy, meat, and eggs in order to limit the fat in your diet.
Don’t store food in plastic
Phthalates are chemicals that are used to make plastics flexible, and although the link to cancer has not been definitively established, certain phthalates are listed as “reasonably anticipated to be a human carcinogen,” according to the National Institutes of Health. To be on the safe side, Harvard Medical School suggests to not microwave foods in plastic containers (that aren’t marked microwave-safe) and don’t let plastic wrap touch food when microwaving—instead, try covering your food with wax or parchment paper, or a paper towel. Also, throw out old or scratched plastic containers, and consider replacing them with glass instead. “The push toward storage and containing food products in glass is a strategy that I recommend to patients,” Dr. Francis says. (Phthalates are also used in cosmetics and personal care products, but the doctors we talked to said these are trace amounts that aren’t of concern.) Make sure you don’t believe these health myths that make doctors cringe.
Be careful with cans
There is strong evidence to show that BPA causes cancer in mice, but studies on humans have been ethically difficult. Still, it’s reasonable to try to avoid the chemical when possible. Plastics are also worrisome for containing BPA, although many are now labeled BPA-free. Another unlikely source, though, is the lining of cans. In a recent study from Stanford, researchers found people who ate one canned food item in the past day had a 24 percent higher concentration of BPA in their urine than people who didn’t. Eating two or more canned food items led to a 54 percent higher concentration. Miriam Rotkin-Ellman, MPH, a senior scientist with the Natural Resources Defense Council (NRDC), advises avoiding canned products, especially those with a high acidity, like tomato products.
Get off the couch
Physical activity is huge for cancer prevention—a recent, large review of research on over 1.4 million people found that exercise reduced the risk of 13 different cancers by as much as 30 percent. People who are physically active tend to have less body fat, which also reduces risk, but there may be other ways exercise lessons your chances of cancer, according to the National Cancer Institute. “Regular exercise may help reduce inflammation, improve immune system function, and lower the levels of some hormones that are associated with cancer,” Hopper says. Physical activity also helps things move along the digestive tract, reducing exposure to possible carcinogens. “Try to work in four to six hours of moderate exercise per week to reduce your overall risk,” Hopper says. “That can seem daunting at first, but this can be achieved by breaking it down into smaller segments—take three brisk walks per day for approximately 20 minutes and you easily will accomplish your weekly goal.”
Although research has been mixed, there is evidence to support that drinking a lot of fluids reduces the risk of bladder cancer—and drinking a lot is recommended by the American Cancer Society. But, because of concerns with incidents of well water linked to cancer, it’s best to filter your water before drinking. In fact, the NRDC says that bottled water isn’t any safer than tap. “Filtering your water if there are concerns about your water source is reasonable,” Dr. Francis says. “I drink as much water as I can and bring a large glass bottle to work every day that sits on my desk so I am reminded to drink it throughout the day.” Cancer docs try to never eat these foods.
Avoid fast food—but not for the reason you think
Greasy fast food is bad enough in itself—we already know that a high-fat diet is linked to cancer. But there could be another cause for concern when you hit up your local fast food joint: the wrappers the food comes in. A recent study from the University of Notre Dame found perfluorinated chemicals (PFCs) in fast food wrappers from chains like McDonald’s, Burger King, Chipotle, Starbucks, Panera, and others. The chemicals, which have been linked to kidney and testicular cancer, may also be found in pizza boxes, microwave popcorn bags, and Chinese food containers.
A recent report by the International Agency for Research on Cancer (IARC) found that the widely used herbicide glyphosate is “probably carcinogenic to humans.” Although the study was criticized for cherry-picking data, IARC stood by their research, and made a good case for for those who worry about pesticides. Until the issue becomes clearer, if you’re concerned about pesticides, choose organic fruits and vegetables. “When possible, buy organic for the ‘Dirty Dozen,’ which includes apples, celery, cherry tomatoes, and cucumbers,” Komar says. “Depending on your budget, buy the ‘Clean Fifteen’ [which have the least amount of pesticide residue], non-organic or organic. Clean Fifteen produce includes asparagus, avocados, cabbage, and cantaloupe.” But, the cancer-preventing benefits of eating fruits and vegetables probably outweighs any danger from pesticides, so if you can’t buy organic, just wash your produce well. Now that’s a fact!
Get (a little) sun
Although you want to protect yourself against skin cancer, there are also benefits to getting small amounts of sunlight (10 or 15 minutes) per day. In a recent study from the University of California, women with high levels of vitamin D in their blood had a 67 percent lower risk of cancer than those with low levels. “There is good evidence that vitamin D levels, at an optimal serum level, may reduce the risk of certain cancer recurrences,” Dr. Francis says. Vitamin D can also be obtained in food such as fatty fish and fortified cereals, as well as in supplements.
Don’t take a million supplements
You may think you’re being healthy by popping a lot of vitamin pills a day (and didn’t we just say to take your vitamin D?). Some other vitamins, like vitamin C, have been shown to ward off cancer as well. But the issue of supplements is complicated, and too much of a good thing (even among cancer-fighting antioxidants) may actually cause cancer. “There is no evidence that taking vitamin supplements reduces one’s risk of cancer,” Dr. Kabat says. “There is some evidence that vitamin supplements may actually increase the risk of some cancers.” The best advice? Get your nutrients from food, not supplements. “If you eat a balanced diet, you should get the majority of vitamins and minerals necessary,” Dr. Francis says. You need to stop believing these rampant cancer myths.
The jury is still out on whether radiofrequency energy from cell phone use is linked to cancer. According to the National Cancer Institute, most large studies have not shown a link, but some smaller studies have. Because of this, IARC lists cell phones as “possibly carcinogenic to humans.” Until the picture becomes clearer, the American Cancer Society says people can reduce their exposure by talking on speaker, or using an earpiece like Bluetooth or ear buds—basically anything that keeps the phone further from your head helps with preventing cancer.
Don’t assume vaping is better than smoking
It’s not news that smoking causes cancer—but you might not know that e-cigarettes do, too. A recent study from Portland State University found significant levels of benzene, a cancer-causing chemical, in e-cigarette vapors. Other research has found formaldehyde as well. Dr. Francis says that vaping can be a bridge to quitting smoking—but, the trend of young people heading straight to vaping is worrisome. “The act of vaping is so similar to smoking, and the nicotine so addictive that the act of smoking is being renormalized,” Stanley Marks, MD, the chair of UPMC’s Cancer Center, wrote on the university’s website.
Color your hair safely
An analysis from Finland found a 23 percent increase in the risk of breast cancer among women who dyed their hair, suggesting chemicals in hair dye could be unsafe. “Some hair dyes, especially the semi-permanent and permanent ones, do penetrate into the hair follicle,” says Dr. Concepcion Diaz-Arrastia, an associate professor of gynecologic oncology at McGovern Medical School at UTHealth and Memorial Hermann. “Some of the hair dyes use chemicals classified as aromatic amines, which are carcinogenic in lab animals. Plant-based hair dyes may be a better option.”
Get the HPV vaccine
Although there’s been much debate about the safety of the HPV vaccine, the scientific evidence shows it’s safe and effective against cervical cancer. “The new 9v Gardasil HPV vaccine will decrease the risk of cervical cancer by an extraordinary 90 percent,” Dr. Diaz-Arrastia says. “This means that if we implement comprehensive vaccination for boys and girls aged 11 to 14, the 10,000 annual cases of cervical cancer in U.S. would decrease to 1,000 women annually. Globally, over 200,000 lives of women would be saved.” Women should still be screened with a Pap and HPV test as well, she says, but these only need to be done every three to five years, depending on your age. In addition, “the HPV vaccines include HPV16, which is responsible for more than 90 percent of all HPV-associated head and neck cancers,” Dr. Burk says. Although the vaccine is generally recommended only until age 26, Dr. Burk says people above that age can still get it. “Receipt of the vaccine after 26 still has efficacy,” he says. “So individuals over 26 might still benefit from the vaccine if they are at risk for exposure to HPV—although they would likely have to pay out of pocket.” Here’s what doctors wish you knew about cervical cancer.
Every woman has to make the best individual choice for how to feed her baby, but one advantage to breastfeeding does appear to be a reduced risk for breast cancer later on. “Breastfeeding for one and a half to two years slightly lowers the risk of breast cancer,” Dr. Diaz-Arrastia says. “The mechanism is unclear, but it is felt that it is because it decreases the number of lifetime menstrual cycles or ovulations a woman experiences.” Less cycles means fewer hormones produced that could lead to cancer. Research also shows that breastfeeding alters cells in the breast, possibly making them less receptive to cancer.
Mammograms are no fun, and because some organizations have different recommendations for how often to get them, it can be easy to put them off. But Dr. Diaz-Arrastia says to get them yearly starting at age 40 for preventing cancer. “Breast cancer screening with mammography saves lives by catching breast cancer at a very early stage, before it becomes evident by feel or palpation,” she says. “The earlier the cancer diagnosis, the lower the risk of metastasis, the better the prognosis, and the more tolerable and less disfiguring the treatments.” If someone in your family has breast cancer, your doctor may recommend you start getting mammograms even earlier. In addition, the American Cancer Society recommends a yearly MRI for women with risk factors and dense breast tissue, which can make it hard to see cancer on a mammogram. Talk to your OB-GYN about the best timeline for your mammograms.
Think carefully about hormones
Because hormones including estrogen and progesterone can impact your cancer risk, it’s important to consider the pros and cons before starting the birth control pill, a hormonal IUD, or hormone replacement therapy (HRT). “Women taking birth control pills have a slightly increased risk of breast cancer, but this increased risk goes back to normal risk after a woman stops taking it,” Dr. Diaz-Arrastia says. But, studies have shown that the pill could also reduce the risk of endometrial and ovarian cancer. If you choose a hormonal IUD like Mirena, it could increase your risk of breast cancer, according to recent research. “Some IUDs have progestin [the man-made form of progesterone] in it,” Dr. Diaz-Arrastia says. “A very small amount of the progestin does leave the uterus, circulates throughout the body, and reaches the breast tissue.” As for hormone therapy after menopause, the situation is also a bit murky: HRT seems to increase the risk of some cancers but lower the risk of others. “Different hormone therapies—estrogen alone or estrogen plus progestin—have different potential effects on breast cancer or on endometrial cancer,” Dr. Kabat says. “We have learned that shorter term use immediately after onset of menopause for one to five years carries a modest risk.” Talk to your doctor about which hormone options are right for you. Now, make sure to avoid these everyday things that may cause cancer.