The Impact of a Natural Olive-Derived Phytocomplex (OliPhenolia®) on Exercise-Induced Oxidative Stress in Healthy Adults

Abstract

The role of natural polyphenols in reducing oxidative stress and/or supporting antioxidant mechanisms, particularly relating to exercise, is of high interest. The aim of this study was to investigate OliPhenolia® (OliP), a biodynamic and organic olive fruit water phytocomplex, rich in hydroxytyrosol (HT), for the first time within an exercise domain. HT bioavailability from OliP was assessed in fifteen healthy volunteers in a randomized, double-blind, placebo controlled cross-over design (age: 30 ± 2 yrs; body mass: 76.7 ± 3.9 kg; height: 1.77 ± 0.02 m), followed by a separate randomized, double-blinded, cohort trial investigating the short-term impact of OliP consumption (2 × 28 mL∙d−1 of OliP or placebo (PL) for 16-days) on markers of oxidative stress in twenty-nine recreationally active participants (42 ± 2 yrs; 71.1 ± 2.1 kg; 1.76 ± 0.02 m). In response to a single 28 mL OliP bolus, plasma HT peaked at 1 h (38.31 ± 4.76 ng∙mL−1), remaining significantly elevated (p < 0.001) until 4 h. Plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and HT were assessed at rest and immediately following exercise (50 min at ~75% V˙O2max then 10 min intermittent efforts) and at 1 and 24 h post-exercise, before and after the 16-day supplementation protocol. Plasma HT under resting conditions was not detected pre-intervention, but increased to 6.3 ± 1.6 ng·mL−1 following OliP only (p < 0.001). OliP demonstrated modest antioxidant effects based on reduced SOD activity post-exercise (p = 0.016) and at 24 h (p ≤ 0.046), and increased GSH immediately post-exercise (p = 0.009) compared with PL. No differences were reported for MDA and CAT activity in response to the exercise protocol between conditions. The phenolic compounds within OliP, including HT, may have specific antioxidant benefits supporting acute exercise recovery. Further research is warranted to explore the impact of OliP following longer-term exercise training, and clinical domains pertinent to reduced oxidative stress.

Keywords: OliPhenolia®; antioxidants; exercise; nutrition; oxidative stress; polyphenols.

Figure 1

Plasma hydroxytyrosol (HT) responses following consumption of single serve of either Oliphenolia (OliP) or placebo (PL). (A) Instrument peak area ratio; (B) Converted HT concentration. ** denotes significant difference between conditions at timepoint (p ≤ 0.009). # denotes significant difference within OliP compared to baseline (p < 0.001).

Figure 2

Plasma malondialdehyde (MDA) responses expressed in mean absolute (pmoL·mL⁻¹) and fold change terms in participants that were supplemented with OliPhenolia^® (OliP) for 16 consecutive days or with a matched placebo (PL). (A,C) Pre-intervention, before supplementation; (B,D) Post 16-day supplement intervention. * denotes difference within OliP compared with resting levels (p ≤ 0.038); ** denotes difference within OliP compared to rest (p ≤ 0.008); a indicates difference within trial compared with PostEX (p = 0.05); # all significantly different to comparative timepoint pre-intervention within both PL and OliP (p ≤ 0.014).

Figure 3

Plasma superoxide dismutase (SOD) activity expressed in mean absolute (U·mL⁻¹) and fold change terms in participants that were supplemented with OliPhenolia^® (OliP) for 16 consecutive days or with a matched placebo (PL). (A,C) Pre-intervention, before supplementation; (B,D) Post 16-day supplement intervention. * denotes significant difference compared to rest within condition (p ≤ 0.038); # difference between conditions at timepoint (p ≤ 0.046).

Figure 4

Plasma catalase (CAT) activity expressed in mean absolute (nmoL·min⁻¹·mL⁻¹) and fold change terms in participants that were supplemented with OliPhenolia^® (OliP) for 16 consecutive days or with a matched placebo (PL). (A,C) Pre-intervention, before supplementation; (B,D) Post 16-day supplement intervention. * denotes difference PostEx to all other timepoints within both OliP and PL pre-intervention, but only OliP post-intervention (p ≤ 0.04); a denotes difference compared with PostEx within PL only (p = 0.044); ** denotes difference within trial compared with rest (p ≤ 0.006), and all timepoints within OliP post-intervention (p ≤ 0.003); b denotes difference to PostEx within PL only (p ≤ 0.032); # all significantly different to comparative timepoint pre-intervention within both PL and OliP (p ≤ 0.024).

Figure 5

Plasma reduced glutathione (GSH) responses expressed in mean absolute (µM) and fold change terms in participants that were supplemented with OliPhenolia^® (OliP) for 16 consecutive days or with a matched placebo (PL). (A,C) Pre-intervention, before supplementation; (B,D) Post 16-day supplement intervention. * denotes significant difference compared to rest within trial (p = 0.05). # difference between trials at comparative timepoint for OliP only (p = 0.009).

Figure 6

Plasma hydroxytyrosol (HT) responses expressed as instrument peak area ratio (A,C) and mean concentration (ng·mL⁻¹; B,D) in participants that were supplemented with OliPhenolia^® (OliP) for 16 consecutive days or with a matched placebo (PL). (A,B) Resting data pre-intervention (open symbols) compared with post-intervention (filled symbols); (C,D) Responses post 16-day supplement intervention. Within (A,B) * indicates difference between comparative points (p = 0.029), whereas ** indicates highly significant difference between comparative points (p ≤ 0.003). Within (C,D) * indicates difference between conditions at timepoint (p ≤ 0.029), ** indicates stronger significance between conditions at timepoint (p ≤ 0.004).