Why Diet Matters on Aromatase Inhibitors
Aromatase inhibitors (AIs), such as anastrozole (Arimidex) and letrozole (Femara), are a standard treatment for postmenopausal women with hormone receptor-positive breast cancer. These medications work by blocking the aromatase enzyme, which prevents the production of estrogen in fat tissue. By lowering estrogen levels, they help slow or stop the growth of estrogen-sensitive cancer cells. However, this reduction in estrogen can lead to side effects like bone thinning, joint pain, hot flashes, and weight gain. Strategic dietary choices can help manage these symptoms and ensure the medication works optimally.
Foods and Supplements to Avoid or Limit
High-Concentration Phytoestrogen Supplements
Phytoestrogens are plant-based compounds that can mimic estrogen in the body. In high, concentrated doses found in supplements, they could potentially counteract the effects of aromatase inhibitors. While the impact of phytoestrogens from whole foods like soy is debated and often considered safe in moderation, it's best to avoid supplements with high concentrations of these compounds.
- Herbal Supplements: High-dose supplements containing black cohosh, red clover, licorice root, ginseng, and flaxseed extracts are typically recommended for avoidance.
- Soy Supplements: Soy protein powders and other concentrated soy supplements contain isoflavones, which are potent phytoestrogens. While moderate consumption of whole food soy (like tofu) is generally deemed safe by many experts, supplements should be discussed with a doctor.
- Whey Protein: Some research suggests whey protein may have phytoestrogenic properties and could alter drug effectiveness, so it is best to check with your doctor.
Alcohol
Alcohol can have multiple negative effects while on AI therapy. It can worsen common side effects, such as hot flashes and nausea. Furthermore, alcohol consumption may increase estrogen levels, which could interfere with the treatment's efficacy. Excessive alcohol can also increase the risk of liver problems, a potential side effect of some AIs.
Grapefruit and Seville Oranges
Grapefruit and related citrus like Seville oranges contain compounds that can interfere with liver enzymes responsible for metabolizing certain drugs. While the interaction with some AIs like anastrozole is not firmly established, it is a risk, particularly with exemestane. It is safest to avoid grapefruit and grapefruit juice unless your doctor explicitly says it is safe.
Processed and High-Fat Foods
Foods high in saturated fats and excessive sodium, often found in processed and fast foods, can contribute to weight gain and heart health issues. Since AIs can sometimes raise cholesterol levels, reducing saturated fat intake is beneficial for promoting heart health. Processed meats may also contain nitrates and hormones that should be limited.
Sugary and Salty Foods
Diets high in added sugars can fuel insulin resistance and inflammation, both of which are linked to breast cancer progression. Furthermore, excessive salt and sugar intake is correlated with reduced bone density, which is a significant concern for patients on AIs. Limiting salty, sugary snacks, and sweetened drinks is a smart move for overall health.
Comparison of Dietary Considerations on Aromatase Inhibitors
| Type | Foods to Limit/Avoid | Reasons for Limitation | Foods to Consider for Support | Reasons for Support |
|---|---|---|---|---|
| Hormonal Balance | High-dose phytoestrogen supplements (soy, flaxseed, red clover), whey protein supplements | May mimic estrogen or interfere with drug metabolism | Cruciferous vegetables (broccoli, cauliflower), mushrooms, pomegranates | Contains compounds that support healthy estrogen metabolism |
| Side Effects (Hot Flashes, Nausea) | Alcohol, spicy foods, caffeine, fried and greasy foods | Can trigger or worsen hot flashes, nausea, and general digestive discomfort | Water, herbal tea, ginger, clear broth, small frequent meals | Can help soothe digestive issues and aid hydration |
| Bone Health | High salt foods, high sugar foods, alcohol | Can contribute to bone density loss over time | Calcium-rich foods (low-fat dairy, fortified foods), vitamin D sources (fatty fish, fortified cereals) | Supports bone density and helps the body absorb calcium |
| Heart Health | Saturated fats (fatty meats), processed foods, added sugars | Can negatively impact cholesterol levels, a potential side effect of AIs | Monounsaturated fats (avocados, olive oil), whole grains, lean proteins, nuts, seeds | Promotes heart health and can help manage cholesterol levels |
Important Considerations and Conclusion
Maintaining a healthy diet during aromatase inhibitor therapy is not about eliminating all enjoyable foods but about making smart substitutions and being mindful of portion sizes and the quality of what you eat. A whole-food, plant-based diet rich in fiber, fruits, and vegetables can provide essential nutrients and help manage side effects. Regular exercise is also beneficial for maintaining a healthy weight and combating side effects like bone density loss and joint pain.
Always consult with your oncologist or a registered dietitian before making significant dietary changes. They can provide personalized recommendations based on your specific health profile and treatment plan. For more information on managing breast cancer treatment side effects, refer to a reliable source like the Breastcancer.org nutrition section. By being proactive about your nutrition, you can take an active role in supporting your overall health during and after treatment.
