Breast cancer is probably the disease women fear above all others. It's the most commonly diagnosed invasive cancer and the leading cause of cancer death among women worldwide.1
Much is made of genetics and family history when it comes to breast cancer, but there's plenty you can do to slash your chances of getting the disease, even if your risk is high.
Just in time for breast cancer awareness month, we've rounded up nine simple lifestyle strategies you can employ-whatever your age-to help reduce your risk.
1 Watch your weight
Excess body weight is associated with breast cancer. According to a University of Manchester review, every 5 kg/m2 increase in your body mass index (BMI) increases the risk of postmenopausal breast cancer by 12 per cent.2 Losing weight, on the other hand, can dramatically slash your chances of developing the disease. Among postmenopausal women who had never used postmenopausal hormones, those who lost 10 kg (22 lb) or more and kept it off cut their breast cancer risk by more than half compared with women whose weight stayed more or less the same after menopause.3
2 Keep moving
Whatever your age, regular exercise can cut your risk of breast cancer. In fact, it's thought that becoming physically active could prevent an estimated 10 per cent of breast cancers worldwide.4 Vigorous exercise provides the greatest risk reduction, but even just brisk walking is beneficial. In one study, postmenopausal women who did the equivalent of about an hour a day of walking were 15 per cent less likely to get breast cancer than those with the lowest levels of physical activity.5
3 Ditch the drink
A few glasses of wine a week may help protect against heart disease, but when it comes to breast cancer, even low levels of alcohol can raise your risk. The Nurses' Health Study-one of the largest and longest-running investigations of factors that influence women's health-found that women who drank three to six alcoholic beverages on average per week were 15 per cent more likely than teetotallers to be diagnosed with breast cancer. Heavy drinkers-those who had at least two drinks per day-were 51 per cent more likely than never-drinkers to develop breast cancer.6 So, if you do like a drink, try to make it an occasional treat.
4 Eat organic
Besides aiming to eat a healthy, balanced whole-food diet that includes plenty of fresh fruit and vegetables, try eating organic whenever possible. Pesticides, which contaminate nearly half the food we consume in the UK,7 are known hormone disruptors and have been linked to breast cancer in several studies.8
Although a recent study reported that eating organic does not reduce the risk of breast cancer, it had several limitations and may be missing the full picture. Only a small percentage of the participants reported eating organic usually or always, for example, and as these women were also more likely to have attended breast cancer screenings, they were more likely to be diagnosed. Plus, the study lasted only nine years which, when it comes to cancer, is probably too short a time to show any significant differences between the observed groups.9
Another recent study, a review of more than 300 published papers, found that, compared with conventional produce, organic food contains significantly higher levels of antioxidants-potent cancer-fighting compounds-and lower levels of cadmium, a toxic metal associated with breast cancer10-two more reasons to go organic.
5 Don't skip the tomatoes
Make sure tomatoes (organic ones) are on your shopping list. They're packed with a powerful anticancer antioxidant called lycopene, found to inhibit the growth of breast cancer cells and induce apoptosis (cell death) in the lab.11 In one study from Brazil, regular tomato eaters had a significantly lower risk of breast cancer, while watermelon, another fruit high in lycopene, also had protective effects.12
6 Be a natural beauty
Most cosmetics and personal-care products are brimming with hazardous chemicals, many of which can disrupt the body's delicate hormone system. Parabens-used to stop bacteria and other microbes from growing in your favourite lipstick or lotion-are among the worst offenders. They have oestrogenic activity and have been found in 99 per cent of human breast cancer tissue samples. They can also stimulate human breast cancer cell growth at concentrations measurable in the breast.13
Diethyl phthalate and some synthetic musk chemicals-common ingredients in perfumes-have also been linked to breast cancer.14
You can avoid these and other chemical nasties by switching to natural, non-toxic products whenever possible. Check out our Healthy Shopping section each month (pages 71-77) for our pick of the beauty brands that are better for you.
7 Use greener cleaners
The products we use to clean our homes are another source of hormone-disrupting chemicals, and the evidence suggests they are a possible cause of breast cancer. Researchers from the Silent Spring Institute in Massachusetts quizzed more than 1,500 women about their cleaning-product use and found that those who used more air fresheners and products for mould and mildew control had a higher incidence of breast cancer. Overall, the women who reported the highest total use of cleaning products had twice the risk of breast cancer of those with the lowest self-reported use.15
As with personal-care products, go for alternative brands using non-toxic formulas like Bentley Organic (www.bentleyorganic.com) and Indee's (www.indeesproducts.com).
8 Get enough D
A lack of the sunshine vitamin has been implicated in a wide range of conditions, including breast cancer. In one study, women with the highest levels of vitamin D-from sun exposure and diet-were significantly less likely to have the disease.16 Another study reported a reduced breast cancer risk among women getting at least an hour of sun every day.17
Sunshine is the best source of the vitamin, but you need to go without sunscreen to synthesize it, so be careful not to burn, and cover up or seek shade when your skin starts to go red. You can also get a decent dose of D through diet, as fatty fish (like salmon and tuna), egg yolks and liver are good sources.
Supplements are another option for upping your intake of vitamin D, especially if you don't get much sun, although a large, randomized controlled trial found no difference in breast cancer risk between women taking a daily 400 IU vitamin D supplement and those taking a placebo. But this dose is lower than what many believe is needed for cancer prevention. Another trial is now underway (see www.vitalstudy.org) to look at the effect of taking 2,000 IU on the risk of breast cancer and other diseases.
9 Avoid extra hormones
It's wise to avoid exposing your body to hormones like oestrogen and progestin from birth-control pills and hormone replacement therapy (HRT). The evidence suggests that both the Pill and HRT may be responsible for a substantial number of breast cancer cases. 18,19 In fact, a Canadian study reported a 9.6 per cent drop in breast cancer incidence between 2002 and 2004, which coincided with a sharp decline in the use of HRT, following concerns raised by the Women's Health Initiative trial.19 "The results support the hypothesized link between the use of hormone replacement therapy and invasive breast cancer incidence," the authors said.
Instead, consider non-hormonal solutions for contraception (see WDDTY April 2014) and menopausal symptoms (see WDDTY November 2013).
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2 Lancet, 2008; 371: 569-78
3 JAMA, 2006; 296: 193-201
4 Lancet, 2012; 380: 219-29
5 Arch Intern Med, 2010; 170: 1758-64
6 CA Cancer J Clin, 2014; 64: 186-94
8 Gynecol Obstet Fertil, 2008; 36: 969-77
9 Br J Cancer, 2014; 110: 2321-6
10 Br J Nutr, 2014; 112: 794-811; Breast Cancer Res Treat, 2013; 138: 235-9
11 Cancer Sci, 2014; 105: 252-7
12 Nutr Hosp, 2007; 22: 565-72
13 J Appl Toxicol, 2014; 34: 925-38; J Appl Toxicol, 2012; 32: 219-32
14 Environ Health Perspect, 2010; 118: 539-44; Arch Environ Contam Toxicol, 2002; 43: 257-64
15 Environ Health, 2010; 9: 40
16 Am J Epidemiol, 2008; 168: 915-24
17 Environ Health Perspect, 2014; 122: 165-71
18 Cancer Epidemiol Biomarkers Prev, 2013; 22: 1931-43
19 J Natl Cancer Inst, 2010; 102: 1489-95