Lutein levels linked to better memory in adults: Study

Data published in the journal Nutrients​​ indicated that higher serum levels of lutein were associated with accuracy in object binding and inversely related to misplacement error.

“Our results revealed that serum lutein was significantly related to two metrics of relational memory performance even after adjusting for significant covariates. While this study was correlational, it lays the groundwork for subsequent research in this area,”​ wrote the scientists, led by Naiman Khan, PhD, RD.

Lutein and brain health​

Lutein is most commonly associated with eye health, but numerous studies with data from primates, children, middle-aged people, and the elderly now support the importance of lutein in brain health. 

Data from pediatric brain tissue studies have shown that about 60% of the total carotenoids in the pediatric brain tissue is lutein, and yet NHANES data show that lutein is only about 12% of the carotenoids in the diets, so there appears to be a preference for lutein in the brain (Vishwanathan et al. J Pediatr Gastroenterol Nutr.​ 2014).

A 2017 study in rhesus macaques found that enriching infant formula with lutein led to selectively increased levels of the carotenoid in the infant brain, with the highest amounts in the visual processing center, the occipital cortex (Jeon et al., Nutrients​​).

The new study assessed dietary carotenoid intakes and serum carotenoid levels from 94 adults aged between 25 and 45. The participants also underwent relational memory tests.

After adjusting the results to factor in age, sex, and BMI, only serum lutein was associated with specific types of memory performance, said the researchers.

How?​

Commenting on the potential mechanism(s) of action, the researchers noted that this may be linked to lutein’s anti-oxidant and anti-inflammatory activity.

“Participants with overweight or obesity are more susceptible to oxidative and inflammatory stress due to the higher levels of chronic inflammation associated with excess adipose tissue,” ​they wrote. “Inflammation and oxidative stress can be mitigated by fruit and vegetable intake, foods that are often rich in carotenoids. Inflammation is detrimental to hippocampal function, specifically by inhibiting long term potentiation, the molecular mechanism for memory formation. In the retina, lutein is protective against age-related macular degeneration by reducing oxidative stress. Thus, we hypothesize that lutein may play a similar role in the hippocampus.”​

Dr Khan and his co-workers called for that future intervention studies to assess carotenoids in the macula and serum in order to better understand this relationship, particularly in overweight or obese people.

Source: Nutrients​​
2019, 11​(4), 768; doi: 10.3390/nu11040768​
“Serum Lutein is related to Relational Memory Performance”​
Authors: C.N. Cannavale et al.