I have been looking forward to writing this column since hearing Dr. Elizabeth Johnson speak at the Florida Academy of Nutrition and Dietetics annual meeting. Her information is critically important for maintaining eyes and brains while getting older. Having had five surgeries on my right eye, you can be sure I was in the front row for this presentation.
The topic was lutein, the antioxidant carotenoid found in dark green and orange vegetables as well as eggs and avocados. Lutein concentrates in the macula, the area in the retina with the greatest visual acuity. The amount of lutein in the macula determines macular pigment density, and dense is better for eye health.
Now here is where it gets interesting. Lutein from food crosses the blood brain barrier and takes the same path to the retina and the brain. Therefore increased macular pigment density is indicative of a high lutein content in the brain as well as the eye.
At her Tuft's research lab, Johnson has demonstrated that increased macular pigment density, which is easily measured, is related to improved cognitive function in the elderly. Areas of improvement were verbal fluency and recall. Understandable since lutein is the major carotenoid in brain tissue. Her research has also shown that dietary changes can increase macular pigment density.
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I hope you're sold on lutein. In one study using lutein + DHA supplements, the subjects receiving supplements scored higher on cognitive functions tests than those receiving placebo. And the study showed that eggs and avocados increased macular density more than a supplement. Food is a complex delivery system that is hard to duplicate. A supplement can add on but does not replace food.
Other lutein-rich foods are kale, spinach, corn, orange peppers and most other green and orange foods. Adding a healthy fat, like olive oil, will increase lutein absorption in naturally fat-free vegetables. I see a spinach omelet in my future.
Sheah Rarback is a registered dietitian on the faculty of the University of Miami Leonard M. Miller School of Medicine. Follow her on Twitter @sheahrarback.