Neuroprotective Olive Polyphenols Improve Lifelong Cognitive Health
Let food be thy medicine and medicine thy food (Hippocrates, 400 b.c.). In this context, all parts of the olive tree have been successfully used for centuries to treat all kind of ailments. Associated with the Mediterranean diet and its famed health impact, (extra) virgin olive oil has been extensively studied for its health benefits. The cold pressing process of extra virgin olive oil, unlike heat-treated olive oil, preserves the olive polyphenols. These are also present in other parts of the olive tree such as the leaves.
The manifold beneficial effects of olive derivatives
Olive compounds, especially the olive polyphenols, have been shown to have positive effects on many physiological parameters. Scientific studies have demonstrated i.a. anti-oxidative, anti-carcinogenic, blood pressure-lowering, anti-inflammatory, neuroprotective and antimicrobial properties of olive polyphenols. Olive polyphenols and their derivatives are therefore suitable for use in nutritional anti-ageing strategies, as natural health-promoting ingredients in the food and animal feed industry, for natural preservation or in cosmetics as natural UV protection. (Galanakis et al. 2018; Haloui et al. 2011). In recent years this impact of olive-derived ingredients on healthspan, particularly concerning neuroprotection and cognitive health, has garnered significant attention (Angeloni et al., 2017; Gonçalves et al., 2024; Romero-Márquez et al. 2023). Healthspan stands for healthy lifespan; longevity research increasingly focuses on ways to live a healthy life for longer and reduce functional decline from aging-associated disease, rather than extending the lifespan. One such intervention may come from olive polyphenols’ effects on cognitive health.
Cognitive function enhancement and neuroprotection
A key research focus lies on the olive polyphenols, such as ligstroside, hydroxytyrosol and oleuropein, three major polyphenols found in olives, olive oil and olive leaves, which have been shown to induce neuroprotective effects and enhance cognitive functions. Gunter Eckert from the University of Giessen has contributed to this field by exploring the biochemical pathways through which these compounds are effective, particularly in relation to oxidative stress and neurodegenerative diseases like Alzheimer’s disease.
Research indicates that long-term consumption of olive polyphenols can positively influence cognitive health. For instance, a study involving aged NMRI mice demonstrated that a blend of highly purified olive secoiridoids improved cognitive function and increased brain ATP levels, suggesting enhanced energy metabolism in the brain mitochondria (Reutzel et al., 2018). A subsequent study was able to confirm an improvement in cognition and mitochondrial function after feeding old mice with isolated, highly purified olive polyphenols (Grewal et al., 2020).
Sharing about these advancements in the field, Professor Eckert stated: „In a recent investigation (Grewal et al., 2020) focusing on highly purified olive polyphenols, a substance known as ligstroside was found to be of particular interest. This natural compound has been observed to demonstrate significant biological activity, even at minimal concentrations. The findings of the study suggest that ligstroside enhances cognitive function and significantly prolongs the lifespan of aged mice.”
This aligns with findings that the olive polyphenol hydroxytyrosol exhibits antioxidant properties that help mitigate oxidative damage, a key factor in cognitive decline (Yoon et al., 2023; Calahorra et al., 2019). Furthermore, the neuroprotective effects of olive polyphenol oleuropein have been highlighted, showing its ability to reduce amyloid beta aggregation, a hallmark of Alzheimer's disease, thereby potentially alleviating cognitive deficits (Alkhalifa et al., 2024; Casamenti and Stefani, 2017; Saul et al., 2021). Extra virgin olive oil consumption was also found to decrease neuroinflammation in mice models of Alzheimer’s disease, indicating multiple pathways in which olive derivatives combat age-related cognitive decline (Li et al., 2024).
Indirect Impacts on Cognitive Function: Cardiovascular, Anti-inflammatory and Glucose Metabolism Effects
The Mediterranean diet, which is rich in olive oil, has been associated with lower incidences of neurodegenerative diseases. The polyphenols in olive oil not only contribute to cardiovascular health but also play a crucial role in maintaining cognitive function. A systematic review indicated that high-polyphenol extra virgin olive oil positively affects cardiovascular risk factors, which are closely linked to cognitive health (George et al., 2018). Additionally, studies have shown that these polyphenols can enhance endothelial function and reduce inflammation, further supporting brain health (Moreno‐Luna et al., 2012; Storniolo et al., 2014). The consumption of olive oil has been linked to improved insulin sensitivity and glucose metabolism, which are essential for cognitive function. Moreover, research has indicated that olive leaf extracts can normalise glucose levels and improve insulin sensitivity, thereby reducing the risk of cognitive impairment associated with diabetes (Peršurić et al., 2019; Wainstein et al., 2012). This is particularly relevant given the increasing prevalence of metabolic disorders that contribute to cognitive decline in aging populations. For good reason, olive oil polyphenols have been approved for carrying an official European Health Claim confirming their beneficial activity for the protection of blood lipids from oxidative damage.
Olives and Longevity: Into the Future
In summary, the ingredients derived from olives, particularly their polyphenolic compounds, have a significant impact on cognitive health and healthspan. The work of researchers like Gunter Eckert underscores the importance of these compounds in combating oxidative stress and promoting cognitive resilience. As the body of evidence grows, it becomes increasingly clear that incorporating olive products into the diet may serve as a strategic approach to enhance cognitive health and longevity.
References:
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