Data published in Clinical Nutrition indicated that 15 milligrams per day of hydroxytyrosol significantly reduced markers of oxidative stress, including oxidized LDL levels, protein carbonyls and 8-OHdG (8-hydroxy-2′-deoxyguanosine, a marker for oxidative stress and DNA damage).
The olive polyphenol was also associated with decreases in levels of interleukin-6 (IL-6), a key pro-inflammatory cytokine, reported the study, led by scientists from the Spanish National Research Council, CSIC.
“These findings highlight the potential of hydroxytyrosol, when consumed as a dietary supplement, to protect lipids from oxidative damage, thus expanding previously reported effects for this compound when found outside of EVOO [extra virgin olive oil] matrix,” they wrote. “Moreover, the study demonstrates that these effects are also relevant in populations at increased risk for NCDs [non-communicable diseases], thereby underscoring its promise in early preventive strategies.”
The benefits of hydroxytyrosol
In a 2018 review published in Molecules, scientists from the University of Murcia in Spain reported that hydroxytyrosol offers several health benefits, including protecting against oxidative stress, potential anti-inflammatory effects and cardiovascular support via its impact on LDL cholesterol, as well as improvement in both skin and eye health.
Another review, published in 2019 in Pharmacological Research, reported that the anti-inflammatory potential of hydroxytyrosol also has implications for supporting the immune system and protecting against age-related conditions, particularly cognitive declines.
“This research expands the scientific evidence supporting the role of hydroxytyrosol in reducing oxidative, inflammatory and metabolic stress, positioning it as a key natural ingredient for cardiovascular health and healthy aging,” stated Alvinesa Natural Ingredients in a press release. The company funded the new study.
“With this new publication, Alvinesa reinforces its commitment to scientific research, sustainability and innovation, developing functional ingredients through a circular economy and upcycling model, using co-products from the wine and olive oil industries.”
Study details
The researchers recruited 52 overweight prediabetics between the ages of 40 and 70 to participate in their randomized, double-blind, placebo-controlled trial. Participants were randomly assigned to receive either 15 mg of hydroxytyrosol (Hytolive, Alvinesa Natural Ingredients) or placebo every day for 16 weeks.
Results showed that, for the 49 people who completed the study,hydroxytyrosol (HT) supplementation led to statistically significant improvements in seven key biomarkers of oxidative stress and inflammation.
“We demonstrated that HT supplementation led to a reduction in oxLDL levels, a well-established biomarker of atherogenesis risk,” the researchers wrote. “This finding aligns with the EFSA health claim, which recognizes the role of olive oil phenolic compounds within EVOO in reducing LDL oxidation.
“However, evidence on the effects of HT in isolation remains inconsistent, likely due to differences in study design, duration and formulation […] In this complex landscape, our study provides novel insights by demonstrating that HT alone, administered as a dietary supplement, can reach a similar effect against lipoprotein oxidation as that achieved by olive phenols within EVOO.”
Significant reductions were also recorded for other markers of oxidative stress, including protein carbonyls and 8-OHdG, while increases were recorded for the total antioxidant capacity and the activity of glutathione peroxidase (GPX), antioxidant enzymes that protect cells from oxidative damage.
Although the hydroxytyrosol group experienced significant reductions in pro-inflammatory IL-6 in , no differences between the groups were recorded for other markers of inflammation, such as C-reactive protein and TNF-alpha.
“Chronic supplementation with 15 mg/day of HT for 16 weeks significantly improved antioxidant and anti-inflammatory status in individuals with overweight and prediabetes, suggesting a potential preventive role against aging-related diseases,” the researchers concluded.
Source: Clinical Nutrition, 2025, 52:17-26. doi: 10.1016/j.clnu.2025.07.006. “Hydroxytyrosol supplementation improves antioxidant and anti-inflammatory status in individuals with overweight and prediabetes: a randomized, double-blind, placebo-controlled parallel trial”. Authors: I. Moratilla-Rivera, et al.
