Unraveling the Mystery: Brain Blood Flow and Cognition
Can improving blood flow to the brain enhance cognitive skills? A recent study has shed light on this intriguing question, and the findings might surprise you.
The American Heart Association's International Stroke Conference 2026 presented a preliminary study that challenges conventional wisdom. Researchers found that procedures to improve blood flow to the brain, such as removing plaque from a narrowed carotid artery or using stents to prop it open, did not lead to better cognitive function compared to medications and lifestyle changes.
But here's where it gets controversial...
The study, a substudy of the CREST-2 trial, involved over 2,000 adults with carotid stenosis, a condition where the carotid arteries in the neck become narrowed due to plaque buildup. Standard treatment options include intensive medical management, such as aspirin and medication for blood pressure and cholesterol, along with lifestyle changes. In severe cases, carotid endarterectomy or stenting may be recommended.
The CREST-2 trial compared stroke rates among participants randomly assigned to receive either intensive medical management alone, combined with carotid endarterectomy, or with stenting. The trial also included a unique "cognitive core" component, assessing cognitive performance before treatment and annually for up to four years.
And this is the part most people miss...
Despite the association between carotid stenosis and lower cognitive function scores in previous research, the CREST-2 substudy found no significant difference in thinking or memory skills between participants who underwent procedures to restore blood flow and those treated solely with intensive medical therapy. This was true even for participants with the lowest initial cognitive function, who were expected to benefit the most from these treatments.
The study's lead author, Ronald M. Lazar, Ph.D., FAHA, emphasized that health care professionals can no longer assert that treating carotid stenosis will improve cognition. However, he also highlighted that worsening cognition over time may indicate the need for a re-evaluation and potential adjustment of treatment.
So, what does this mean for patients and healthcare professionals?
These findings suggest that while improving blood flow through large vessels is beneficial for reducing stroke risk, it may not be sufficient to address cognitive decline associated with aging. Other factors, such as inflammation, neurodegeneration, and small vessel disease, might play a more significant role. More research is needed to understand how to mitigate cognitive decline and reduce dementia risk, which is why organizations like the American Heart Association continue to support studies in these crucial areas.
The study's limitations include the use of phone-based cognitive tests, which limited the assessment of visuo-spatial skills and executive functions, and the inclusion of only English-speaking participants, potentially limiting the generalizability of the results.
What are your thoughts on these findings? Do they align with your expectations? Feel free to share your insights and opinions in the comments below!
