Algal Lutein Against Decline of Intellectual Nimbleness

Lutein is a xanthophyll pigment found in photosynthesizing organisms. Its beneficial effects on health, including brain function and visual performance, have been recognized for many years. However, to date, only a limited number of well-designed human intervention studies have been published regarding the effects of incorporating lutein into the daily diet (as humans are unable to synthesize lutein endogenously). Unfortunately, within the Western dietary pattern, the average daily intake of lutein is approximately 1.7 mg, whereas achieving health benefits- such as reducing the risk of age-related macular degeneration and cataract, as well as neurodegenerative diseases- requires an intake of 6 to 14 mg per day.

In light of the above, it is therefore justified to enrich the daily diet with products that are sources of lutein. Unfortunately, the consumption of dark green vegetables- the richest dietary source of lutein-remains insufficient. Lutein preparations currently available on the market are extracted from marigold or calendula flowers. However, lutein production from these raw materials requires greater water consumption and land use, which is not aligned with the principles of sustainable development. An alternative approach involves the production of lutein preparations from microalgae (from species approved as food by the European Food Safety Authority, EFSA), as the rate of lutein production from microalgae is three to six times higher than that from marigold flowers.

Taking the above into account, the primary objective of this project is to evaluate the dose-response relationship in establishing the anti-aging mechanism of action of lutein derived from microalgae.

As part of the project, a six-month randomized, placebo-controlled trial is planned. The study will include 300 polish women (aged 48-60 years), after natural menopause, with visceral obesity (waist circumference ≥ 88 cm). In order to enable the inclusion of such a large study population, the research team will conduct intensified recruitment efforts for several months prior to the initiation of the dietary intervention.

Participants who meet the inclusion criteria will be randomly assigned to one of three groups: lutein supplementation at a dose of 6 mg (n = 100), lutein supplementation at a dose of 14 mg (n = 100), or placebo (n = 100). The volunteers will be instructed to take the prescribed preparation daily for 180 days. All preparations will be identical in appearance, taste, and smell.

All volunteers expressing willingness to participate in the experiment will be asked to provide written informed consent prior to enrollment in the study.

The study will be conducted in accordance with the previously calculated sample size (n = 300 postmenopausal women with visceral obesity). In order to obtain a homogeneous study population, appropriate inclusion and exclusion criteria will be applied.

Conducting the research in such a large and homogeneous group will enable the generation of high-quality scientific evidence identifying the dose of microalgae-derived lutein that allows for the determination of its anti-aging mechanism of action. It will also be possible to elucidate the potential role of short-chain fatty acids (SCFAs) in feces in this process, which may represent a significant novelty in this field of research.

The study will contribute to the development of new knowledge regarding the anti-aging properties of lutein derived from microalgae in populations vulnerable to cognitive impairment (postmenopausal women). However, microalgae-derived lutein may be used as a dietary supplement not only in the studied group but also in the general population.

The specific objectives are as follows:

* To assess the effect of lutein derived from microalgae (at doses of 6 mg and 14 mg) on the concentration of brain-derived neurotrophic factor (BDNF), inflammatory markers, cardiometabolic parameters, fecal short-chain fatty acid (SCFA) concentrations, and cognitive function in postmenopausal women with visceral obesity. * To evaluate adherence to lutein supplementation recommendations (by assessing macular pigment optical density). * To determine whether supplementation with microalgal lutein increases fecal SCFA concentrations and whether SCFAs may act as mediators in improving inflammatory markers and cognitive function in postmenopausal women with visceral obesity. * To determine whether supplementation with microalgal lutein (at doses of 6 mg and 14 mg) affects changes in selected gut bacterial populations and β-glucuronidase enzymatic activity in postmenopausal women with visceral obesity. * To analyse the association between polymorphisms in genes related to lutein metabolism and transport in the body and the effectiveness of supplementation with this compound. * To identify dietary behaviour patterns associated with high exposure to bisphenol A (BPA) and the presence of inflammation in postmenopausal women with visceral obesity.