Study highlights ‘unique roles lutein & zeaxanthin may play during pregnancy’
The rate of transfer from maternal to fetal blood for lutein and zeaxanthin was also the highest of all carotenoids, according to data published in Nutrients.
The new study, led by scientists from Nebraska Medical Center, is said to be the first to analyze lutein and zeaxanthin levels in the placenta, although previous studies have examined levels in maternal and umbilical cord blood.
“[Lutein and zeaxanthin] consisted of 49.1% of placental carotenoids, highlighting the unique roles [lutein and zeaxanthin] may play during pregnancy,” wrote the researchers.
Importance for development
The data adds to an ever-growing body of science supporting the potential benefits of lutein and zeaxanthin in the fetal and infant development. While most associated with eye health, there is also accumulating evidence to support the importance of lutein in brain health, which is unsurprising given that the eyes and the brain are connected.
Indeed, a 2014 paper reported 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 is a preference for lutein in the brain (Vishwanathan et al. J Pediatr Gastroenterol Nutr. 2014).
Lutein for eyes and brains
The link between lutein and eye health was first reported in 1994 by Dr Johanna Seddon and her co-workers at Harvard University, who found a link between the intake of carotenoid-rich food, particularly dark green leafy vegetables like spinach, and a significant reduction in age-related macular degeneration (AMD) (JAMA, Vol. 272, pp. 1413-1420).
A 2017 study by scientists from Queens University Belfast and the Macular Pigment Research Group at the Waterford Institute of Technology found that higher blood levels of lutein and zeaxanthin may be associated with better cognition, memory, and executive function (Journal of Gerontology, Series A)
Placenta, maternal serum, and umbilical cord blood samples were analyzed from 82 mother-infant pairs, and the moms also completed a food frequency questionnaire and demographic/birth outcome data.
The results showed that the median level of lutein and zeaxanthin (L + Z) in the placenta was 0.105 micrograms/gram (mcg/g) and these were significantly correlated with levels in the maternal serum and the umbilical cord blood. On the other hand, there was no correlation between placental or umbilical cord blood levels with dietary intake.
“These results only contribute to our current knowledge base of nutrient transfer from food to mother to infant. While placenta and umbilical cord blood L + Z levels rely significantly on maternal blood levels, maternal serum levels remain the most sensitive to modifiable maternal lifestyle factors like dietary intake. This correlated chain of carotenoid transfer highlights how heavily dependent infants are on their mothers for receiving nutrients,” explained the researchers.
When compared to the other carotenoids (alpha-carotene, beta-carotene, lycopene, and beta-cryptoxanthin), lutein and zeaxanthin were the most prevalent in the placenta (49%) and the umbilical cord blood (37%). However, they were not the most prevalent in the maternal serum (19% vs 50% for lycopene) or dietary intake (19%, vs 39% for lycopene and 37% for beta-carotene).
The researchers noted that lutein and zeaxanthin may be found in higher levels in the placenta because of their structural properties and how they align themselves in the cell membranes. But there may also be selective uptake by the placenta because these carotenoids improve the functioning of the placenta.
“Poor functioning [of the placenta] likely leads to multiple disruptions, but with main alterations being in nutrient transfer and oxygen exchange. Later consequences to the offspring include increased risk of developmental delay or autism and fetal programming that may result in chronic disease such a hypertension, coronary artery disease, or Type 2 diabetes,” they wrote.
“If these adverse outcomes can be prevented or diminished by improved placental composition, uptake of lutein and zeaxanthin may be a mechanism of biological adaptation.”
2019; 11(1): 134. doi: 10.3390/nu11010134
“Quantification of Lutein + Zeaxanthin Presence in Human Placenta and Correlations with Blood Levels and Maternal Dietary Intake”
Authors: M. Thoene, et al.