In a study of how beta-carotene affects the brain, researchers from Brigham and Women’s Hospital and Harvard Medical School in Boston, Massachusetts, examined two groups of healthy men.
The first group of 4,052 men took 50 mg of beta-carotene every other day or a low-dose aspirin placebo for an average of 18 years. The second group of 1,904 men took beta-carotene or a placebo for less than 10 years.
After age 65, doctors tested how accurately and quickly the men recognized, remembered and verbalized, and found no significant differences compared to placebo in the 10-year group. But those who had taken beta-carotene for an average of 18 years had significantly better memory, recognition and verbal skills than placebo.
Doctors noted that even small differences in how well the brain works, especially verbal memory, predict large differences in risk for dementias such as Alzheimer’s later on in life, and that supplementing long-term with beta-carotene may substantially improve public health.
In a study of carotenoids and the brain on 1,300 healthy French men and women in their 70s, doctors discovered that those who had low levels of lycopene and zeaxanthin tended to perform mental tasks poorly.
Researchers tested how quickly and accurately participants recognized, remembered, verbalized, visualized and made coordinated hand movements. Study authors don’t know which came first, the low carotenoid levels or the brain problems, but said that the results suggest that carotenoids do help keep the brain healthy and working well.
Many previous studies show that zeaxanthin protects eyesight, but this is the first study to link zeaxanthin with the brain.