Cannabis Is No Longer Just About Legalization and Money. Science Is Shifting the Conversation

Entering 2026, cannabis is no longer just a legalization story. The narrative increasingly includes public health and aging, as use rises among seniors and researchers try to pin down what that means for the brain.

According to a large UK study of adults aged 60 and over, cannabis use is not uniformly associated with worse cognition in older adults. About 17% of participants reported lifetime cannabis use, and as a group they performed slightly better on average across several tested cognitive domains — including attention, executive function, processing speed, and visual and working memory — in the paper, “History of cannabis use and cognitive function in older adults: findings from the UK Biobank.”

“Past use was linked to better performance and slower decline in some cognitive domains,” the researchers concluded in the study, published in November 2025 in Age and Ageing. “However, specific usage patterns, such as longer duration, were associated with poorer outcomes in other domains.” The authors emphasized that the findings are observational and do not establish cause and effect.

These mixed results echo emerging research — including early studies exploring cannabinoids in the treatment of neurodegenerative diseases like Alzheimer’s — and underscore ongoing debate over cannabis’s potential role and risks in cognitive aging.

In another line of inquiry, a small Brazilian study published in October 2025 in the International Journal of Alzheimer’s Disease reported that very low-dose cannabis extract was associated with improvements in patients with dementia related to Alzheimer’s disease, without producing an intoxicating “high.” The research, led by Professor Francisney Nascimento and colleagues at the Federal University of Latin American Integration (UNILA), recruited 24 patients ages 60 to 80 diagnosed with mild Alzheimer’s who used cannabis oil with equal parts THC and CBD at very low daily doses (0.3 mg each). Researchers described the work as exploratory, noting that larger controlled trials are needed to confirm the findings and assess safety.

With cannabis use among older Americans climbing sharply in recent years, the expanding research focus on aging populations is hardly unexpected. A nearly 46% relative increase in self-reported past-year cannabis use among U.S. adults aged 65 and older between 2021 and 2023, reported in JAMA Internal Medicine last year, helps explain why more studies are now honing in on seniors — and why the public-health questions around cannabis are shifting from legalization to long-term aging outcomes.