Research conducted in 2022 studied the effect of an olive fruit extract rich in hydroxytyrosol in Caenorhabditis elegans models expressing proteins related to Alzheimer's Disease (AD). The extract was found to prevent oxidative stress and delay Aβ-induced paralysis by reducing Aβ aggregation. It also mitigated tau protein-related toxicity. The protective effects were linked to the activation of the transcription factor SKN-1/NRF2 and increased expression of heat shock proteins, which play roles in cellular stress responses.

A 2021 review examining the neuroprotective potential of hydroxytyrosol, exploring mechanisms by which this olive-derived biophenol may protect neural tissue from oxidative and inflammatory damage associated with neurodegenerative conditions.

This 2020 study indicated that hydroxytyrosol could improve mitochondrial function in cellular models of Alzheimer's Disease. By enhancing mitochondrial activity, hydroxytyrosol may help counteract the energy deficits commonly observed in neurons affected by AD.

In this 2018 study, researchers supplemented the diets of TgCRND8 mice — an AD model — with hydroxytyrosol. Results demonstrated significant improvements in cognitive functions and a notable reduction in beta-amyloid (Aβ) plaque formation in the cortex and hippocampus. These benefits were associated with lower expression of tumour necrosis factor alpha (TNF-α) and reduced astrocyte activation, suggesting that the neuroprotective effects of hydroxytyrosol may be mediated through anti-inflammatory pathways and autophagy induction.

A 2023 study investigating the protective mechanisms of hydroxytyrosol against alpha-synuclein toxicity — a key hallmark of Parkinson's Disease — exploring how this olive-derived polyphenol may offer neuroprotective benefits in the context of dopaminergic neuron degeneration.

This 2021 study presents evidence for hydroxytyrosol acting as an anti-inflammatory agent in the context of Parkinson's Disease, detailing the specific molecular mechanisms through which it modulates neuroinflammatory pathways relevant to disease progression.

Research published in 2024 demonstrated that hydroxytyrosol possesses significant antidepressant properties. The study showed that hydroxytyrosol treatment improved behavioural outcomes and corrected neurotransmitter imbalances in mice subjected to chronic stress. Notably, levels of key neurotransmitters such as serotonin, dopamine and norepinephrine in the hippocampus increased significantly following hydroxytyrosol administration. Furthermore, hydroxytyrosol improved hippocampal neuropathology, indicating its neuroprotective effects.

Published in 2021, researchers studied the effects of hydroxytyrosol in mice subjected to unpredictable chronic mild stress — a model commonly used to simulate depression. Results revealed that hydroxytyrosol administration significantly improved depressive-like behaviours. The compound exerted its effects by reducing oxidative stress and neuroinflammation in the hippocampus. Specifically, hydroxytyrosol increased superoxide dismutase activity (an antioxidant enzyme), reduced reactive oxygen species levels and decreased pro-inflammatory cytokines. Additionally, hydroxytyrosol increased expression of brain-derived neurotrophic factor (BDNF) and related signalling proteins, which are crucial for neuronal health and plasticity.

Hydroxytyrosol is recognised for its exceptional antioxidant capacity — superior to that of vitamins C and E. This potent antioxidant activity helps neutralise free radicals, thereby protecting skin cells from oxidative damage and potentially reducing signs of ageing. Studies have also demonstrated that hydroxytyrosol possesses anti-inflammatory effects, which may be beneficial in treating skin conditions characterised by inflammation. By modulating inflammatory responses, it may help alleviate symptoms associated with various dermatological disorders.

Research with human dermal fibroblasts has demonstrated that hydroxytyrosol can promote cell proliferation and migration — processes essential to wound healing and skin regeneration. These findings suggest its potential role in supporting skin repair mechanisms, including protection and repair of skin from UVA radiation damage.

Clinical evaluations have indicated that formulations containing hydroxytyrosol are safe and effective for skin application. Their incorporation into skin care products has been associated with improvements in skin health, further supporting their use in cosmetic applications.

Recent research suggests that hydroxytyrosol may inhibit epithelial-mesenchymal transition (EMT) — a process involved in wound healing and fibrosis. By modulating EMT, hydroxytyrosol may contribute to more effective wound healing and reduce the risk of excessive scarring.