Lutein is one of the main carotenoids in the human macula and retina. It is selectively incorporated into the macula as well as the brain, and has been associated with healthy cognition. Astaxanthin, a powerful carotenoid from the microalgae haematococcus pluvialis, has a very unique structure which gives it its strong antioxidant properties.
Previous research has demonstrated the benefits of lutein and astaxanthin on eye health and some research is emerging on their benefits on cognition; however, previous randomized controlled trials have shown inconsistent results. In a review published two weeks ago in Nutrients, researchers investigated the effects of lutein and astaxanthin on the improvement of cognitive function.
This review included five studies with lutein and two studies with astaxanthin. The inclusion criteria included randomized controlled trials using oral carotenoid supplementation in healthy individuals in which cognitive functions were assessed. These seven studies took place between 2008 and 2018 and included 429 participants with a sample size ranging from 44 to 91 individuals. Four of the studies were conducted for 1 year, one study was 4 months in duration, another study took place over 12 weeks, and the final study was conducted over 8 weeks. Overall, 80 cognitive test outcomes were used in these studies divided among seven domains. Four of the studies measured macular pigment density and serum lutein. Macular pigment volume increased after supplementation as seen in previous studies. In addition, serum lutein was statically improved compared to the placebo group, and there was a trend of increasing serum lutein in middle-aged and senior participants compared to younger individuals. As a result, 10 mg of lutein over a 12-month period demonstrated selective improvement of visual episodic memory in young and middle-aged adults. One of the two studies with astaxanthin showed a significant improvement of verbal episodic memory performance in middle-aged adults. This was only seen in the higher doses of astaxanthin at 8 mg to 12 mg per day.
Lutein has impressive antioxidant properties and has also been shown to support a healthy inflammatory response. Recent research has shown it increasing total antioxidant capacity and brain-derived neurotrophic factor (BDNF) in young adults. In addition to supplementation, avocados are a great source of lutein, containing approximately 0.5 mg of this carotenoid. Previous research demonstrated that avocado consumption helps increase macular pigment density.
Other brain-supportive nutrients to consider are GPC, CDP-choline, Ginkgo biloba, phosphatidylserine, and fish oil. GPC and CDP-choline are water soluble forms of choline that supports brain health. These help make more acetylcholine and neurotransmitters, as well as phosphatidylcholine in the cell membranes. In addition, phosphatidylserine is an essential nutrient for brain function and is not found in the diet.
Source: Nouchi R, Suiko T, et al. Effects of Lutein and Astaxanthin Intake on the Improvements of Cognitive Functions among Healthy Adults: A Systemic Review of Randomized Controlled Trials. Nutrients. 2020 February 27; 12(3).