Obesity

Obesity is associated with higher risk of multiple cancers, but especially breast cancer.  This seems to be even more so in the postmenopausal women. 
Women who are obese and have had a breast cancer are also at 30% higher risk of recurrence and a 50% higher risk of dying from breast cancer. 
The relationship of increased risk and recurrence of breast cancer is linked to higher levels of oestrogens and other hormones (insulin). It has been shown that weight loss and weightloss plus exercise decrease oestrogen levels in the body.

Smoking

Smoking does not increase the risk of developing breast cancer, but it does increase the risk of breast cancer recurrence, breast cancer mortality and mortality overall.  Women who have had or do smoke were 25% more likely to die of breast cancer.  Women who stop smoking can decrease their risk of dying from breast cancer by a third then those women who continue to smoke. 

Exercise

Moderate exercise has been shown to decrease the risk of breast cancer by up to 20%.  Moderate exercise should be performed for 30 min each day for 5 days in a week.  30 min may be in one session or multiple sessions.  Level of moderate exercise is different for different, but is best monitored with heart rate.  Any exercise that increases your heart rate to moderate levels is defined as moderate exercise. For moderate-intensity physical activity, a person's target should be 50 to 70 per cent of their maximum heart rate. The maximum rate is based on a person's age. An estimate of a person's maximum heart rate can be calculated as 220 beats per minute (bpm) minus your age.

Diet

Diet is thought to be partly responsible for about 30% to 40% of all cancers. Breast cancer is less common in countries where the typical diet is plant-based and low in total fat (polyunsaturated fat and saturated fat).

  • High fat diet - a European study suggests that a diet high in fat, particularly saturated fat, is linked to a greater risk of hormone-receptor-positive breast cancer, as well as breast cancer that is HER2-negative.

  • Alcohol - Research consistently shows that drinking alcoholic beverages -- beer, wine, and liquor -- increases a woman's risk of hormone-receptor-positive breast cancer. Alcohol can increase levels of estrogen and other hormones associated with hormone-receptor-positive breast cancer. Among women, light drinkers have a 4% increase in breast cancer risk. Moderate drinkers have a 23% percent increase in risk. Heavy drinkers who consume more than eight drinks per day have a 63% increase in risk.

  • Diet high in Vegetables, fruit and whole grains – decreases rates of cancers.

  • Decrease amount of animal protein and mix it with vegetable protein (quinoa, beans, lentils etc) and eggs.

 Sleep

Adequate sleep is necessary for well-being, for most people this is 7-9 hours per day.  Research on sleep duration and breast cancer risk isn’t conclusive, but we know that getting less than 6 hours per night can lead to trouble. Much of the repair of the everyday wear and tear of living happens during the night. Sleep deprivation can cause low grade inflammation, which is linked to almost all types of cancer and heart disease. Too much light at night has been linked to higher breast cancer risk — which may be due to lower melatonin levels. Melatonin is the sleep hormone that comes out in darkness. It appears to have an important role in regulating normal cell growth.

Meditation

Meditation seems to help breast cancer patients better manage symptoms of fatigue, anxiety, fear of recurrence and hot flushes.  It just makes you feel a bit better in many aspects of your life.  Meditation can be guided or non-guided.  It can be done in groups or alone.  Some people use smartphone/tablet apps like headspace or Calm.