Investigating a Natural Antioxidant Food Product on Oxidative Stress in Recreationally Active Participants
Condition: Oxidative Stress; Exercise Recovery
Study type: Interventional

Summary: 
      The aim of this study is to investigate the short term use of olive extract polyphenols on
      markers of oxidative stress in response to acute endurance exercise in recreationally active,
      healthy volunteers.The study will be conducted under laboratory conditions following a 16 day
      supplemental period. Participants will be required to attend the laboratory for a
      pre-screening/familiarisation trial followed by assessments PRE (baseline, days 1,2) and POST
      intervention (days 18,19). Across the intervention, participants will maintain habitual
      dietary intake/ exercise training.

      Additionally participants will be randomised in a double-blinded manner to either a placebo
      or antioxidant-rich supplementation (olive extract water).

      It is hypothesised that the polyphenols (antioxidants) found within olive extract drink will
      enhance markers of recovery to an endurance exercise bout compared with the placebo drink.
    

Detailed description: 
      There is current scientific interest in the use of fruit and plant-based polyphenol
      supplementation for exercise recovery. Current inference highlights that acute
      supplementation (~3d) with >1000mg polyphenols per day may enhance recovery from intensive
      exercise, with most focus on pomegranate, cocoa, green tea extracts, Montmorency cherry
      concentrate and blackcurrant food products. However, further research is needed to access
      impact of natural polyphenols at lower or similar doses for longer time periods (>7d) on
      endurance based activities and subsequent recovery.

      There has also been significant clinical research interest in the properties of waste water
      produced when cold pressing olives, which has been shown to contain high concentrations of
      natural polyphenols. Fattoria La Vialla is an Italian-based organic farm producing various
      products including cold-pressed olive oil. In doing so, they also produce olive extract which
      is commercially available as 'Oliphenolia'. Whilst several clinical studies have been
      undertaken using this product, to date there have been no studies investigating the
      polyphenol potential of olive extract on exercise recovery and subsequent performance.

      As such, this study proposes to investigate the short term use of olive extract polyphenols
      on markers of oxidative stress in response to acute endurance exercise in recreationally
      active, healthy volunteers. Following a study briefing and provision of written, informed
      consent, participants will be required to attend the Human Physiology Laboratory at Anglia
      Ruskin University on 5 occasions as follows:

      Session 1 - assessment of metabolic responses to incremental exercise intensity and
      individual maximal oxygen uptake (VO2max) using a standardised treadmill-based ramp protocol.
      Measurement of VO2max will be required for assessment of exercise intensity for sessions 2
      and 4 (see below). The treadmill protocol to be used is similar to that previously published,
      involving two graded exercise tests (GXT1 and GXT2). Following a 10min resting period and
      assessment of baseline measures (e.g. blood pressure, body composition) and a 5min warm up
      period, GXT1 will involve participants completing ~6 x 4min stages (3mins running, 1 minute
      passive recovery in which capillary blood sampling for glucose/lactate will be carried out).
      Starting speeds will be between ~6-10km/h (1 % gradient) with each stage involving speed
      increments of 1 km/h. Exercise will continue until blood lactate concentration exceeds 4
      mMol/L. Following a 10 min rest, GXT 2 will begin at a speed 2 km·h-1 below the previous GXT
      1 final speed, with gradient increasing by 1 % each min and continuing until volitional
      exhaustion. Throughout the test, breath-to-breath analysis (using a Metalyser 3B respiratory
      analyser) will be undertaken.

      Session 2 - Having overnight fasted, and following resting measures (blood pressure, body
      composition via bioelectrical impedance analysis, 3x4ml blood sample), participants will
      complete an endurance training session (~75% VO2max for 60mins) on a treadmill. Additional
      wholeblood samples (3x4ml) will be collected immediately and 1hr post exercise.

      Session 3 - Participants will return the next morning (overnight fasted) for a resting blood
      sample (3x4ml, 24 hours post exercise) and complete the same GXT1 and GXT2 tests carried out
      in session 1. This will be used to quantify metabolic and recovery indices.

      Session 4 and 5 - following a 16 day nutrition product supplementation period, participants
      will return and complete exercise testing as per sessions 2 and 3.

      Nutritional supplementation - all products will be supplied/certified independently via
      Fattoria La Vialla, Italy. Participants will be randomly assigned in a double-blinded manner
      to either: i) Experimental condition: 2x25ml olive extract drinks
      (https://www.oliphenolia.it/uk/) per day for 16 days, taken one mid-morning, one
      mid-afternoon between meals or ii) matched placebo (2x25ml of prune juice water).

      Blood samples - wholeblood samples will be immediately centrifuged with serum allocated into
      separate cryovials for the analysis of: i) the main polyphenol compound- hydroxytyrosol; ii)
      a marker of oxidative stress (malondialdehyde, MDA) and iii) key antioxidant enzymes
      (catalase, superoxide dismutase) and redox status (reduced glutathione (GSH) to oxidized
      glutathione (GSSG) ratio).

      Over the 16 day study period, there will be no dietary restrictions in place (other than
      following a low polyphenol diet 24 hours prior to each testing session), however participants
      will need to follow the allocated supplementation and maintain their training program (~3-4
      run training sessions per week).
    

Intervention name(s): Antioxidant supplement; Placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Short term (16d) supplementation of either the antioxidant supplement (Oliphenolia) or placebo. Participants required to consume 2x25ml drinks, one mid-morning, one mid-afternoon between meals.; Placebo
Other intervention name(s): Oliphenolia
Intervention MeSH terms: Antioxidants
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants randomly assigned to either placebo or antioxidant-rich olive extract in a parallel, double blind manner
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: Antioxidants; Exercise Metabolism; Exercise Nutrition