Cannabis has long been considered a risk to the brain. A new study now shows a different picture for older people.
Feb 9, 2026, 2:07 p.mFeb 9, 2026, 3:01 p.m
Melanie Rannow / t-online
To date, research has primarily examined how cannabis affects the brain in young people. Scientists at the University of Colorado Anschutz (USA) now focused their attention on middle-aged and older people. To do this, they evaluated data from the British Biobank, one of the largest medical databases in the world.
Cannabis: Moderate use is associated with better thinking, according to study.image: getty
Over 26,000 participants between 40 and 77 years old
The study is based on data from 26,362 adults aged 40 to 77. The average age was 55 years. The researchers divided the participants into three groups:
- people without cannabis consumption,
- People with moderate consumption and
- People with high consumption over their lifetime.
They then used tests and scans to compare the brain structure and cognitive performance of the subjects. Experts understand cognitive performance as mental abilities such as memory, attention, learning and processing speed.
Why individual brain regions are crucial
In contrast to previous work, the team did not just look at the total volume of the brain. The researchers specifically analyzed individual areas of the brain. The focus was on regions with a high density of cannabinoid receptors of the CB1 type. These receptors serve as docking sites for active ingredients from cannabis. Particularly important was the hippocampus, an area of the brain that plays a central role in memory and shows early changes in old age and dementia.
The evaluation showed a clear connection: higher cannabis consumption over a lifetime was associated with larger volumes in several brain regions. At the same time, these people achieved better results in cognitive tests. The effects were most noticeable with moderate consumption. This group performed particularly well in learning, remembering and attention.
Important to know
A larger brain volume does not automatically mean better performance. However, as we age, the brain often shrinks due to atrophy, i.e. the breakdown of nerve cells. This process is often accompanied by mental decline and an increased risk of dementia. Larger volumes can therefore indicate better preserved brain structures and more stable mental abilities.
But not all results were positive. A different connection was found in one area of the brain: the posterior cingulate cortex (PCC) was smaller on average with heavier cannabis consumption. This area is part of the limbic system and is involved in memory, learning and emotions. Previous studies suggest that lower volume in this area may be associated with better working memory. The exact significance of this finding remains open.
The study shows that in people between the ages of 40 and 77, cannabis consumption is associated with larger brain volumes and better cognitive performance, especially with moderate use. At the same time, individual findings make it clear how complex the effect of cannabis on the aging brain is. However, according to the research team, the results do not provide a license for cannabis consumption. Further research into the benefits and risks in old age is also important.