In the news: Olive Oil Linked to Lower AMD Risk; Can Lutein / Zeaxanthin Reduce Stress?

Regular Olive Oil Intake May Lower AMD Risk

Following the Mediterranean diet has been linked to better health, including a reduced risk of heart disease, slower cognitive decline, and a lower risk of age-related macular degeneration (AMD). The health benefits of this diet have been attributed, in part, to one of its key components, olive oil.

The Alienor Study is a study on eye diseases in a French population of older individuals. Researchers recently looked at the associations between olive oil use and AMD prevalence in 654 Alienor Study participants (1).

They measured how frequently the participants consumed various dietary fats and oils and categorized them by ‘no use’ and ‘regular use’. Using retinal photographs, participants were divided into three groups: no AMD, early AMD, and late AMD.

After adjusting for other factors that could affect AMD risk, they report that regular use of olive oil was significantly associated with a decreased risk of late AMD. Regular users were 56% less likely to have late stage AMD. No associations were found with olive use and early AMD.

The Alienor findings are similar to those of an earlier Australian study (2) of over 6,700 people, where olive oil intake was also linked to lower late AMD prevalence.

Besides its mono-unsaturated fatty acids (MUFAs), olive oil is a rich source of polyphenols with antioxidant and anti-inflammatory actions – compounds with tongue-twisting names like oleuropein (o-lura-pene), and oleocanthal (oleo-canthal).

Since a number of studies have reported seeing no association of MUFAs with AMD risk, the researchers suspect that the apparent protective effect of olive oil consumption they observed may be due to olive oil’s polyphenols.

Can Lutein & Zeaxanthin Reduce Stress?

If you’ve eaten some green leafy vegetables today, such as kale and spinach, you’ve consumed a good daily dose of the eye-healthy carotenoid lutein. Lutein is especially concentrated in the macular region of the eye’s retina, where it is believed to protect against harmful blue light, oxidative damage, and AMD.

It has recently become clear that the human brain also preferentially accumulates lutein, and that the concentration of lutein and zeaxanthin in the macula (measured by MPOD) appears to reflect the content of these carotenoids in the brain. MPOD may, in fact, be linked to cognitive function. For example, low MPOD has been associated with lower cognitive performance in older individuals.

A new report suggests that supplemental lutein and zeaxanthin isomers may reduce psychological stress and improve measures of emotional health (3). In the 12-month long double-blind trial, 59 young healthy adults were assigned to receive either placebo, high dose lutein with zeaxanthin, or about half the dose of these carotenoids.

At the study’s start, MPOD correlated with measures of stress – Beck’s anxiety scores, serum cortisol, and psychological stress scores. Supplementation with lutein and zeaxanthin isomers significantly reduced stress, serum cortisol levels, and improved symptoms of suboptimal emotional and physical health at the trial’s conclusion.

There was no difference in results between the low dose group (a little over 10 mg of lutein and 2 mg zeaxanthin isomers) and the high dose group (about double the dose). The increase in MPOD over the study was virtually identical in both groups. More research is needed to confirm these preliminary findings.

References

1. Cougnard-Grégoire A, et al. Olive oil consumption and age-related macular degeneration: The Alienor Study. PLoS ONE. 11(7): e0160240, 2016.
2. Chong EW, et al. Fat consumption and its association with age-related macular degeneration. Arch Ophthalmol. 2009; 127:674–80, 2009.
3. Stringham NT, et al. Supplemention with macular carotenoids reduces psychological stress, serum cortisol, and sub-optimal symptoms of physical and emotional health in young adults. Nutr Neurosci. Epub  Feb. 15, 2017.