Acute Effects of Watermelon on Vascular Function and Serum Lycopene
Condition: Vascular Health of Postmenopausal Women
Study type: Observational

Summary: 
      This study aimed to examine the effects of a one-time dose of 100% watermelon juice on
      circulating lycopene levels and measures of vascular health among a cohort of postmenopausal
      women.
    

Detailed description: 
      Purpose and Objectives Arterial stiffness and endothelial dysfunction are early independent
      predictors of cardiovascular disease (CVD), the leading cause of death for women ages 60 and
      older in the United States. It is well-known that age-related decreases in vascular function
      are partially due to increases in oxidative stress and inflammation. In attempts to combat
      CVD, previous studies have investigated provision of isolated food compounds in supplement
      form. For example, purified lycopene has been shown to decrease oxidative stress, and our
      previous work supports the supplemental use of glutamine and arginine powders for improving
      vascular endothelial function of older adults. Watermelon is among the greatest plant sources
      of arginine and glutamine, and it is one of the richest sources of lycopene. However,
      clinical studies evaluating the whole food have not been done.

      According to the Healthy Eating Index, only 27% of women ages 60 and older meet the daily
      dietary recommendations for 2.5 fruit servings. Likewise, although no Recommended Dietary
      Allowance for lycopene exists, this age group consumes less lycopene daily than is provided
      in one serving of watermelon. While reasons for poor fruit intake among older adults are
      multifactorial, difficulty chewing and inability to prepare fresh foods in the home
      environment have been noted as significant barriers to fresh fruit and vegetable intake. Of
      note, a previous systematic review suggests that 100% fruit and vegetable juices may be
      practical vehicles for improving intake of antioxidant nutrients among older adults. The
      provision of 100% watermelon juice to older adult women represents a practical, innovative
      approach to increase consumption of a food containing multiple components that may act in
      synergy to improve vascular function. Therefore, the purpose of this study is to investigate
      the effects of a one-time serving of 100% watermelon juice on blood vessel function and serum
      lycopene.

      Specific Aims

      The specific aims of this study are to:

        1. To determine whether consumption of a 12-ounce serving of 100% watermelon juice by
           non-obese women ages 60-75 will result in increased levels of serum lycopene.

           Hypotheses: Acute supplementation with 100% watermelon juice will result in increased
           serum lycopene.

        2. To determine whether consumption of a 12-ounce serving of 100% watermelon juice by
           non-obese women ages 60-75 will result in improved vascular endothelial function as
           assessed by flow-mediated dilation (FMD) and decreased arterial stiffness as assessed by
           pulse wave analysis (PWA).

      Hypotheses: Acute supplementation with 100% watermelon juice will result in improved vascular
      endothelial function and decreased arterial stiffness.
    

Intervention name(s): 100% watermelon juice
Intervention type(s): Other
Intervention description(s): Participants consumed a one-time dose of 100% watermelon juice. Blood was sampled before and 2 hours after ingestion. Blood pressure and brachial artery flow-mediated dilation were measured before and 2 hours after ingestion.
Observational model: Other
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Community-dwelling postmenopausal women
      
Biospecimen description: 
      Banked serum will be stored at -80 degrees C.