Primary Prevention and Breast Health

Primary prevention consists of a variety of approaches that help prevent/protect an individual from developing breast cancer. A growing body of evidence shows the link between healthy lifestyle choices and a lower risk of developing breast cancer.

According to these studies, excess body weight and physical inactivity deserve special attention, since they account for about one-third of all breast cancer cases.As a result, being active, eating a well-balanced diet and maintaining a normal body weight are three simple but crucial lifestyle choices.

Physical Activity​

Avoiding Obesity
Nutrition
Other risk factors

Physical Activity

Growing evidence demonstrates that there is a protective association between physical activity and breast cancer, preferably over a lifetime, but probably beneficial even if begun after menopause.

Regular physical activity at all ages reduces the risk of breast cancer. Being physically active for more than 30 minutes a day could reduce breast cancer risk by 20%.


Not being active enough may increase the risk of breast cancer. Prolonged sedentary behaviour is associated with an increased risk of breast cancer, according to meta-analyses. The risk increases slightly with increased sedentary time, particularly with watching television. Being sedentary at work is linked to a more than 15% increase in the risk of breast cancer.

To reduce their risk of breast cancer women should:

  • Stay healthy and active
  • Engage in moderate exercise for at least 30-60 minutes every day
  • Keep in mind that physical activity is not only sport, but also walking, gardening, occupational, housework, dancing, etc.

Avoiding Obesity and Being Overweight

Women should pursue a healthy lifestyle that will reduce the known breast cancer risk factors as much as possible, including avoiding obesity and being overweight, increasing physical activity and adopting healthy habits. Recent studies indicate that women who avoid being overweight reduce their risk of postmenopausal breast cancer.

Weight and risk of breast cancer differ by menopausal status. Women who are lean before menopause have an increased risk of breast cancer, whereas obesity in menopause (body mass index [BMI] of 30 or higher) and gaining weight in adulthood are associated with an increased risk. 

Nonetheless, maintaining a healthy weight throughout life could reduce the risk of postmenopausal breast cancer by 50%. Postmenopausal women who are overweight or obese and achieve a healthy weight may decrease their risk of breast cancer by 50%


How to Calculate Your Body Mass Index (BMI)

BMI = weight in kilograms divided by height in metres2

Nutrition

While studies have not linked specific diets to breast cancer risk, nutrition is still important. Eating a well-balanced diet is recommended. It should include fresh fruit and vegetables in daily food choices, while limiting consumption of red meat and avoid processed foods. Eating the right amount to maintain a healthy weight is advised.

High-level research shows that a Mediterranean-style diet, with a high intake of fruits, vegetables, legumes, olive oil, nuts, plant protein, and whole grains, fish, and minimal wine, is protective against breast cancer. It could be used as primary prevention measure, especially in post-menopausal women. Foods such as vegetables, soy and carotenoids seem to be protective, while a higher intake of total meat, or red or processed meats, or of foods with a high sugar content, or eggs would seem to be associated with a higher risk of breast cancer.


A large study in France found that compared with women with less than 12% of energy intake from ultra-processed foods, those with more than 25% of energy intake from ultra-processed foods had a 38% higher risk of postmenopausal breast cancer.


Eating foods high in industrial trans fatty acids (0.54-0.97 g/day) is associated with a 10% increased breast cancer risk compared with consuming less than 0.54 g/day. The risk rises with increasing amounts consumed, and especially with elaidic acid. Industrial trans fatty acids are created when fats and oils are partially hydrogenated during industrial processing. They are found in fast foods, industrially produced products and snacks, deep fried and ultra-processed foods, and baked goods.


Limiting Alcohol Consumption


There is a link between alcohol consumption and risk of breast cancer. This risk increases with increasing alcohol intake, although any amount of alcohol has an associated risk. This is true for all types of alcoholic beverages, including beer, wine and spirits. In the WHO European region in 2018, 25% of new cases of breast cancer were attributed to drinking a maximum of 2 drinks (20 g pure alcohol) per day, and 46% were attributed to 3 to 6 drinks (60 g pure alcohol) per day. Although only 8% of deaths due to breast cancer were linked to alcohol intake, this represented 12,100 women in Europe in 2018.


Among a sample of women in the United States who drank 4 or more drinks a week, reducing intake to no alcohol or less than 1 serving a day was estimated to reduce their risk of breast cancer by 35%.

Other Risk Factors

Reproductive and Biological Factors


Having children at a younger age (under 30 years) and having several children reduces breast cancer risk particularly oestrogen-receptor (ER)-positive breast cancer. Breast-feeding for long periods of time (eg, 2 years per child) and breastfeeding multiple children is protective against breast cancer. Breastfeeding has been associated with decreased risk of hormone-receptor-negative breast cancer.


Menstrual factors

such as early age of first menstruation (ie, 12 years or younger) and increasing age at menopause (ie, 53 years or older) increase the probability of developing breast cancer.


High breast density

on mammography is associated with 4 to 6 times increased risk for breast cancer compared with women with low breast density.


Menopausal Therapy and Contraceptive Use


Recent use of menopausal hormone therapy (MHT) (particularly oestrogen plus progestin) and recent use of oral contraceptives are both associated with increases in overall breast cancer risk.


A large prospective study on the use of MHT published in 2019 by the Collaborative Group on Hormonal Factors in Breast Cancer showed that all types of MHT, except vaginal oestrogens, were associated with an increased risk of breast cancer, which increased with duration of use. Risks were larger for combined oestrogen-progestogen therapy than for oestrogen-only therapy. Based on the data, it was estimated that MHT use in western countries has caused about 1 million breast cancers, out of a total of about 20 million since 1990.


Women without a history of breast cancer are advised to discuss the risks and benefits of taking MHT with their doctor in order to make an informed decision as to whether this therapy is right for them. If they opt for MRT, it is recommended that they take the lowest effective dose for the shortest amount of time needed to treat menopausal symptoms. For women with a history of breast cancer, MRT is generally not recommended as high-level indicates that it may increase the risk of breast cancer recurrence.  Any decision to take HRT should be discussed in detail with their physician.


Oral contraceptive use

is associated with increased risk of breast cancer. Findings from 36 years of follow-up from the Nurses’ Health Study indicate that while use of oral contraceptives at any time ever in one’s life was not associated with risk of dying from breast cancer, using them for 5 years did have an association. The risk declined 10 years after stopping using these therapies. While these data are based on use of combined oestrogen-progestogen oral contraceptives with higher doses of oestrogen, evidence is emerging that contemporary hormonal contraceptives have an associated risk for breast cancer. A study in Denmark with 19.6 million person-years of follow-up found a 19% increased risk of breast cancer among current and recent users of combined contraceptives. A progestogen-only contraceptive had a slight increase in risk of breast cancer.


Avoiding Smoking

Findings on breast cancer risk associated with tobacco smoking suggest that young women should avoid smoking. A long duration of smoking before a first pregnancy is associated with an 18% increased risk of breast cancer (mainly oestrogen-receptor-positive) compared with women who did not smoke.

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