Breast cancer survivors may have a lower risk of developing dementia than the general population, according to a large-scale study. Dementia refers to a group of conditions that affect memory, thinking, and social abilities severely enough to interfere with daily life.

For the study, researchers analyzed data from the UK Clinical Practice Research Datalink, following individuals aged 60 and older over a 30-year period. Among the more than 3 million people followed, 412,903 had some type of cancer diagnosis, and 230,558 later developed dementia. After adjusting for factors like age, smoking status, and other health conditions, they found that cancer survivors had a 25 percent lower risk of dementia compared to people who have not had cancer​.

When researchers looked at the data by cancer type, they found that breast cancer survivors specifically had a 20 percent lower risk of developing dementia. This link remained significant even after accounting for additional health factors.

The researchers explored several possible explanations for this unexpected link, including:

• Biological changes — Cancer itself may cause increased cell repair and immune system activation that helps protect the brain against gradual loss or damage of brain cells.
• Genetic factors — Some cancer-related genes may lower Alzheimer’s disease risk.
• Cancer treatments — Some breast cancer treatments may have effects that shield brain cells from damage.

More research is needed to understand how breast cancer, its treatments, or genes associated with cancer risk might influence brain health.

Focus on Brain Health

For breast cancer survivors, these findings are encouraging. However, while the study points to a possible link between cancer and reduced dementia risk, the reasons behind this association remain unclear. More research is needed to better understand how cancer or its treatments may influence cognitive health over time.

Regardless, it’s important to stay aware of changes in memory or thinking. If you notice symptoms like confusion or forgetfulness, talk with your doctor. Early detection of cognitive changes can help you get better support and care.

While this study looked at long-term brain health, it’s also common to experience short-term memory and cognitive issues during treatment, often called “chemo brain.” Learn how to better manage chemo brain during breast cancer treatment.

Find Your Team

On MyBCTeam, the social network for people living with breast cancer, members come together to ask questions, give advice, and share experiences with others who understand. Have you noticed any changes in your memory or thinking after breast cancer treatment? Share your thoughts in the comments below, start a conversation on your Activities page, or connect with like-minded members in Groups.