A study unveiled at the American Society of Clinical Oncology (ASCO) Annual Meeting last month revealed that obesity is linked to an increased risk of death from the most common type of early-stage breast cancer. The finding, derived from a review of 70 clinical drug trials enrolling 80,000 women, showed that obesity increases the risk of death in women with estrogen-receptor-positive breast cancer, which accounts for approximately 75 percent of breast cancer cases.
The research supports growing data that suggest worse overall outcomes for breast cancer in women who are overweight or obese compared with women who maintain a healthy weight — a point that ASCO President and Memorial Sloan Kettering Breast Cancer Medicine Chief Clifford Hudis emphasized in his Presidential Address, describing obesity as “the new tobacco for our generation.”
We spoke with clinical nutritionist Cara Anselmo of our nutrition service about the risks associated with obesity and how women can maintain a healthy weight when they are coping with breast cancer.
Extra fat tissue can increase the risk of developing breast cancer. Why is that?
It’s not entirely clear, but the likely answer is that multiple factors are involved. We know that fat cells, or adipocytes, help make and store hormones including estrogen. Therefore, excess fat tissue may increase breast cancer risk by increasing the body’s exposure to circulating estrogen. Research suggests this is more of a concern in postmenopausal women — while their ovaries cease estrogen production, excess fat tissue remains a source of exposure over time. We also know that carrying excess fat, particularly around the abdomen [called visceral fat], is associated with metabolic and hormonal disorders including insulin resistance, which may be related to cancer development. Chronic inflammation, which is linked with obesity, may also promote tumor growth.
What are some nutrition tips you can offer to help women with breast cancer who want to avoid excess weight gain or lose weight?
Start with a balanced, mostly plant-based diet that includes a variety of whole vegetables, fruits, grains, and legumes, and plenty of water. Limit refined carbohydrates and added sugars — they’re a big source of added calories, make our bodies metabolically lazy, and don’t provide much satiety [the feeling of being full]. Perhaps most important, eat less overall. In some cases, women aren’t eating foods that are unhealthy per se; they are just eating portions that are too big.
Some patients find that they gain weight due to stress and less physical activity during cancer treatment. What advice can you give them?
Keep a handwritten food diary where you record everything you eat and drink with as much detail as possible. Include time of day, who you were with, if anyone, and how you were feeling. This is a self-monitoring tool. It isn’t meant to shame or judge, but foster individual accountability and identify possible patterns and triggers for less-than-ideal food choices. For instance, you might find that late evenings are when you usually overeat, simply due to fatigue, or that when you don’t have a morning meal, your mood is worse by mid-afternoon and then you crave comfort foods. Or every time you go for a slice of pizza, you want soda, when normally you’d drink water. Once you see these habits, it is easier to make practical behavior changes.
Let your friends and family know very specifically how they can help. If you don’t want them to bring you cookies, say so! Ask them to be a walking buddy, or buy you a new hat or scarf, or send you interesting podcasts instead of food that isn’t part of your eating plan.
Find and keep visible reminders of simple activities that help you feel less stressed and don’t involve food. These might include taking your dog for a walk, doing a crossword puzzle, taking a cool shower, reading a novel, or calling a friend.
As for exercise, some is better than none, and the benefits are twofold. Movement expends calories to help with weight management. But exercise also improves your mood and your awareness of natural appetite and satiety signals, increases mindfulness, and boosts energy — all of which help you to eat smart.
And remember, this is a process. Just because you gained two pounds after a treatment doesn’t mean you should throw in the towel and give yourself mental permission to keep gaining. Just because you overeat on one occasion doesn’t mean you’re doomed to always overeat. You can hit the restart button as many times as you need to.
Can you tell us more about your work as a nutritionist with patients at Memorial Sloan Kettering? How does the process generally work and how do you tend to collaborate with a patient’s team of doctors?
I see breast cancer patients at all stages of treatment, from when they are first diagnosed to many years afterward. Physicians, nurses, social workers, or any other provider can refer a patient to me, or a patient can “self-refer” for a nutrition consult. Some patients I see only once or twice for basic nutrition education; others I see regularly for ongoing nutrition counseling and support. I’m here to do what best serves the individual patient and to help the entire team offer the best possible care.
Learn how to make an appointment with Memorial Sloan Kettering’s nutrition team.