A diet with carotenoid-rich foods such as carrots, spinach and corn could make a significant contribution to the prevention of Alzheimer’s. Because the concentration of carotenoids such as lutein, zeaxanthin, lycopene and vitamin E in the brain seems to be directly related to the risk of Alzheimer’s.
A research team led by Professor Dr. In a recent study, C. Kathleen Dorey from the Virginia Tech Carilion School of Medicine examined the connection between Alzheimer’s and the concentrations of carotenoids in the brain. The results are published in the Journal of Alzheimer’s Disease.
Carotenoids strengthen the brain
Among other things, carotenoids function as antioxidants that protect the brain from damage caused by oxidative stress. Previous studies have shown that carotenoid-rich foods such as carrots and the like strengthen our brain.
The research team led by Prof. Dorey was also able to prove for the first time in 2004 that the brain selectively accumulates carotenoids such as lutein, zeaxanthin and beta-cryptoxanthin, and since then various research projects have provided further evidence of a connection between cognitive performance or the risk of dementia and carotenoids .
Carotenoids analyzed in the brain
However, it has so far remained unclear whether the concentration of carotenoids in the brain is directly related to the risk of developing Alzheimer’s disease. Using samples from the brains of people with Alzheimer’s and healthy people, Prof. Dorey’s research team has now been able to demonstrate this connection.
In brains with Alzheimer’s neuropathology, significantly lower concentrations of lutein, zeaxanthin, lycopene and tocopherols were found, some of which were only half as high as in brains of the same age without Alzheimer’s pathology, the team reports.
Carotenoids reduce Alzheimer’s risk
“This study shows for the first time deficiencies in important antioxidants in Alzheimer’s brains,” emphasizes Prof. Dorey. The results are consistent with large population studies that found that people who eat a diet rich in carotenoids or who have high levels of lutein and zeaxanthin in their blood have a significantly lower risk of developing Alzheimer’s.
In the Rush University Memory and Aging Project, for example, the diet including the intake of carotenoids and the cognitive functions of more than 1,000 people were analyzed over a period of more than a decade. Those who ate the most carotenoids or lutein/zeaxanthin over a 10-year period showed a 50 percent lower risk of developing Alzheimer’s disease.
The new finding of selective carotenoid and tocopherol deficiencies in the brains of people with Alzheimer’s reinforces the evidence that higher dietary carotenoid intake can slow cognitive decline before – and possibly also after – an Alzheimer’s diagnosis, the team said .
Measurement via the retina possible?
Research has also shown that the retina selectively absorbs dietary lutein and zeaxanthin, forming a visible yellow macular pigment that improves vision and protects photoreceptors. This allows the concentration of lutein and zeaxanthin in the brain to be determined using non-invasive measurements of the optical density of the macular pigment.
Diet rich in carotenoids for the brain
Overall, study author Prof. Dorey believes that a carotenoid-rich diet can help keep the brain in top shape at any age, and she would be happy if the new data “motivate people to keep their brains healthy through a colorful diet high in carotenoids (…) to be kept in optimal condition.”
For example, lutein is particularly high in kale and spinach, and zeaxanthin is found in higher amounts in corn and orange bell peppers. But other foods can also make a significant contribution to the absorption of the various carotenoids. (fp)
