Targeting the eye-brain connection with lutein

Natural solutions that support cognitive function and performance continue to grow. This expansion is being fuelled by both ageing consumers who are concerned about preserving cognition and a younger population that’s determined to maximise their performance, improve alertness and reduce stress, reports Brian Appell, Marketing Manager, OmniActive Health Technologies

Protection against cognitive decline should start earlier than most people think. It takes time to build up appropriate amounts of nutrients that feed the brain and ensure that it continues to function optimally.

In other words, it is already too late for most people to try to reverse obvious cognitive deficits once they start to occur. In this regard, educating consumers about the strong link between diet and exercise and brain health should in reality start long before the age of 50.

From a performance standpoint, many consumers, especially younger demographics, are looking to gain an edge. Millennials want their brains to work better and perform longer without burning out. Using this as an entry point makes talking about a seemingly mundane topic such as brain health relatable to this crowd.

Currently, there is no defined requirement for the major dietary carotenoids — such as lutein and zeaxanthin — as they do not fulfil the criteria of essential nutrients such as vitamins and minerals.

However, there is enough data to suggest that lutein and the zeaxanthin isomers may be considered to be “conditionally essential” — nutrients that are usually synthesised or present in adequate amounts endogenously but, under certain circumstances, may require additional supplementation.

Until this is universally recognised, however, there continues to be a gap between consumer understanding and scientific consensus, especially among younger demographics, which is reflected in the poor dietary intake of foods that are rich in macular carotenoids.1

Cognitive carotenoids

Lutein and zeaxanthin are frequently referenced for their eye health benefits. But, researchers now have evidence that they are also a very powerful pair in terms of brain function. In fact, they are the only two dietary carotenoids known to cross the blood-brain barrier.

Among the carotenoids, lutein preferentially accumulates in the infant and adult brain, leading researchers to believe there is a tight relationship between lutein status and visual and cognitive function in younger and older adults, as well as preadolescent children.2,3

“Based on lutein intakes being related to a decreased risk of AMD (age-related macular degeneration), which has similar risk factors to age-related cognitive decline, average lutein intakes are low for adults. The elderly may be a particularly vulnerable group owing to poor nutrition for reasons including economics, medication use and decreased sense of taste and smell,” researchers said in a July 2019 review of lutein’s role across the lifespan.4

“More recent observational evidence indicates that lutein is also likely to be important for brain development and cognition in early life,” researchers continued. “Breast milk is the optimal source of lutein for infants; however, lutein content in breast milk is dependent on maternal intake. Lutein-supplemented formulas may be used as an alternative source of lutein in infants.”

In full-term human infants, lutein accounts for approximately 60% of total carotenoids in the brain despite survey data indicating that lutein accounts for only about 12% of total carotenoids consumed in the diet in the first year of life.4

The preferential accumulation of lutein in the brain is also observed at the opposite end of the lifespan, when lutein accounts for approximately 35% of total carotenoids in the centenarian brain, despite making up only 20% of the carotenoids in matched serum

That being the case, researchers ponder whether measuring macular pigment optical density (MPOD) would be a reasonable way to also establish one’s lutein status in the brain. In other words, could this be a reasonable biomarker that corresponds to both eye and brain health?

In a 2013 study of almost 4500 subjects aged 50 and older, a lower MPOD was significantly associated with poorer performance on the mini-mental state examination and on the Montreal cognitive assessment.5

Individuals with a lower MPOD also had significantly poorer prospective memory, took significantly longer time to complete a trail-making task and had significantly slower and more variable reaction times on a choice reaction time task.

The researchers in this study concluded: “Overall, the findings support the theory that xanthophyll carotenoids impact cognitive function, underscoring the need for exploration of novel, non-invasive biomarkers for cognitive vulnerability and preventive strategies.”

The latest research

Lutemax 2020 is a naturally derived marigold extract providing all three macular carotenoids — lutein and enhanced levels of both zeaxanthin isomers (RR-and RS [meso]-zeaxanthin) — at the same 5:1 ratio as found naturally in the diet.

A study on Lutemax 2020 published in September 2019 shows that it positively affects cognitive performance by interrupting inflammatory pathways that can lead to a decrease in brain derived neurotropic factor (BDNF).6

BDNF is a compound found in the brain that plays a role in supporting the survival of neurons, encouraging the growth and differentiation of new neurons and synapses in the brain. It is vital to learning, memory and higher thinking.

The six-month randomised, double-blind, placebo-controlled study involved 59 young, healthy male and female subjects between 18 and 25 years of age. Supplementation with Lutemax 2020 showed significant relationships between the changes in serum/retinal levels of lutein and zeaxanthin isomers, BDNF and reduced inflammation, which led to improvements in cognitive performance.

This research further strengthens the notion that the eyes and brain are connected, and that supplementing with a combination of lutein, zeaxanthin and meso-zeaxanthin (the carotenoid combination found in Lutemax 2020) can positively influence visual-neural processing and outcomes associated with vision, cognition and stress.

Commenting on the findings, the author of the study, James Stringham, PhD, said: “Compelling results such as these lend credence to the idea that macular carotenoids play a vital role in both the eyes and the brain by interrupting inflammatory pathways that can lead to a reduction in BDNF, which plays a role in learning and memory.”

References

  1. https://epi.grants.cancer.gov/diet/usualintakes/pop/2007-10.
  2. https://www.ncbi.nlm.nih.gov/pubmed/24691400.
  3. https://www.ncbi.nlm.nih.gov/pubmed/23840953.
  4. https://academic.oup.com/cdn/article/3/7/nzz066/5511268.
  5. https://www.ncbi.nlm.nih.gov/pubmed/23769396.
  6. https://doi.org/10.1016/j.physbeh.2019.112650.

Companies