October is Breast Cancer Awareness month and we wanted to shed some light on ways you can reduce your risk of developing the second most deadly cancer for women in the U.S. In 2021, breast cancer became the most common cancer globally, accounting for 12% of all new cancer diagnoses. As of January of 2022, there are more than 3.8 million women living in the U.S. that have a history of breast cancer. In our country it was estimated that this year, 30% of all new cancer diagnoses would be breast cancer cases and it is the most commonly diagnosed cancer for American women.
Weight is a Risk Factor
Besides genetic factors increasing a women’s risk of developing breast cancer, being overweight or obese causes risk to become higher. In a group of 100 women who are at a healthy weight, 9 of them are likely to develop breast cancer. Contrastingly, in a group of 100 women who are either overweight or obese, 11-12 of them are likely to receive a breast cancer diagnosis. That is a risk increase of 2-3% with weight being the only difference between the two groups of women. The amount of weight a woman gains over her lifetime and how long she carries that weight plays a significant role in breast cancer diagnosis. A meta-analysis found that for every 11 pounds a woman gained after the age of 18, her risk for breast cancer rose by 7%. The longer she is at an unhealthy weight, the more her risk grows. Unfortunately, being overweight/obese also increases the risk of the cancer coming back after a woman initially goes into remission. More than ever it is important for you as a woman to pay attention to your health and your weight!
Body Composition Matters
Overall weight matters for a cancer diagnosis, but body composition (the ratio of fat to muscle) also can increase a woman’s risk of breast cancer. Specifically, risk increases when there is an excess of fat. If two women have the same BMI score, you would think that they would be at equal risk for developing breast cancer. But say one of the women has a high amount of muscle mass and a normal amount of body fat and the other woman has a high amount of body fat and a low amount of muscle mass. The first woman would have a superior body composition even though the two are the same height and weight. Having an ideal body composition and an adequate amount of muscle and a healthy amount of fat can lower a woman’s risk of breast cancer. Studies show that it’s not just how much fat a woman has that increases her risk of breast cancer, it is also where that fat is located that makes a difference. Researchers found that fat gained around the abdomen and visceral fat (fat surrounding the organs) is more dangerous and increases risk of breast cancer more than subcutaneous fat found in other areas of the body.
Hormones and Increased Risk
For the general population, hormones aren’t commonly thought of as something that can increase risk for breast cancer. In fact, the association between excess body fat, estrogen, and breast cancer has only recently been advertised in the past few years. The link to increased risk can be broken down into a few steps. Fat cells secrete estrogen, a natural process. When a woman has excess body fat, she has more free flowing estrogen than a normal weight woman. Increased estrogen levels have the potential to make hormone-receptor-positive breast cancer cells grow and spread and thereby increase her risk of developing cancer compared to a woman who has normal amounts of body fat. Estrogen isn’t the only hormone that has been linked to increased risk of a cancer diagnosis. In a large study, high insulin levels have been associated with higher risks of breast cancer especially in postmenopausal women. Conditions that increase blood insulin levels include Type II Diabetes, pre-diabetes, and insulin resistance. Also, women who are overweight or obese tend to have higher insulin levels than normal weight women do.
Risk Increases if You Gain Weight After Menopause
We’ve looked into the increased risk of breast cancer due to weight gain but now we’re going to expand on weight gain and age as it relates to risk. Postmenopausal women are more vulnerable to cancer risk compared to premenopausal women. In one study, overweight and obese women (BMI>25) have a higher risk of being diagnosed with breast cancer than normal weight women, especially after menopause. Researchers found that women who are overweight/obese have a 20-60% higher risk of developing breast cancer after menopause than lean women. Lastly, a different study found that for every 20 pounds a post menopausal women gained, her risk rose by 18% compared to women who gained little to no weight after menopause. In later stages of life it is crucially important to keep weight in check and prevent unnecessary weight gain!
What can you do?
The best way to prevent cancer is to reduce your risk! Being at a healthy weight and having a healthy body composition with adequate muscle mass and minimal excess body fat affect several risk factors. Having stable estrogen and insulin levels as a result of being at a normal weight will also help to lower your risk of breast cancer, especially if you’re postmenopausal. Making sure to portion food so as not to overeat, eating nutritious foods and minimizing processed foods, exercising, and getting adequate sleep can all help to keep your weight in control which in turn will lower your risk. If you’re not sure where to start, we here at 30/10 are here to help! We believe losing weight can be the most powerful and effective way to improve your health and reduce risk for cancers. Just remember it only takes the first brave step to get started!
“One day at a time, one step at a time. Do what you can, do your best.”