Like the song says: Try to look on the bright side of life. It just might help keep your brain healthy into old age.

Studies have previously shown depression and anxiety in mid-life and old age might bring a heightened risk of dementia. But researchers have now shown that even repetitive negative thinking could pave a path to the same sort of brain decline.

A paper published in the journal Alzheimer’s and Dementia found that this persistent negativity over a long period of time might contribute to a higher risk of dementia.

The research notes prolonged negativity appears to be associated with the accumulation of harmful brain proteins that are linked to Alzheimer’s disease.

The study included nearly 300 participants over the age of 55 who were tracked for several years. They were quizzed during this time about how they think about negative experiences, how they ruminated about the past and worried about the future. The volunteers, among other things, underwent brain scans to measure proteins that cause the most-common types of dementia.

The paper’s findings could point to the need of interventions to increase positive thoughts among those people who consistently view the glass as half empty. Scientists say one possible safety valve to dissipate some of those negative thoughts might be meditation.

Keeping thoughts positive can certainly be challenging during tumultuous times, but researchers note their work examined the consequences of long-term negativity. Pessimism over the short-term is not thought to pose a risk.

You have choices in life. Not every day is going to be rosy, but whenever possible, choose to look on the bright side.