Comparing the Effect of Whey and Soy Protein on the Absorption of Pomegranate Polyphenols in the Human Body
Condition: Healthy
Study type: Interventional

Summary: 
      This study is comparing the quantity of active metabolites from consuming pomegranate juice
      in three different preparations. People who participate in this study will come in to the
      Center for a screening visit, which includes a blood test and medical history. If you qualify
      based on the screening visit, you will then come in to the Center while fasting in the
      morning on three different days. You will eat a standardized breakfast and drink one of three
      juices, and then remain for metabolic testing at the Center for a period of time after
      eating. You will also be provided a standardized lunch and water during this period. Each of
      those visits will last about 7 hours. During this time, and for the rest of the 24 hours
      following drinking the juice, you will collect all of your urine. Following all three of
      these 7-hour visits, you will return to the Center again the next day for a fasting blood
      draw, drop off your urine sample, and pick up a new container to collect another 24 hour
      urine sample. The following day, you will return to the Center to drop off your second urine
      sample collection.
    

Detailed description: 
      Pomegranate (Punica granatum L.) fruits are widely consumed as pomegranate juice (PJ), and
      their health benefits have been studied extensively in animals and humans (1-6). The
      pomegranate fruit is a rich source of polyphenols, most of which are ellagitannins (ETs).
      Pomegranate extracts,which incorporate these major polyphenols from the pomegranate fruit,
      have been developed in dry and liquid forms to provide alternative convenient sources for
      obtaining the bioactive polyphenols found in PJ. We have previously reported on the
      pharmacokinetics and metabolism of pomegranate polyphenols, after the consumption of PJ in
      normal healthy human volunteers (7). In humans, ETs are converted to ellagic acid (EA) in the
      small intestines and absorbed with a maximum plasma concentration observed at approximately 1
      hour. EA disappears from plasma 6 hours after administration of PJ. Ellagitannins and ellagic
      acid remaining in the intestine and are then further converted by gut microflora to
      urolithin-A, absorbed and derivatives, which are metabolized by phase II enzymes and excreted
      in human urine for up to 48 hours after consumption of PJ(7).

      Polyphenols are dietary constituents of plants associated with health-promoting effects. In
      the human diet, polyphenols are generally consumed in foods along with macronutrients.
      Because the health benefits of polyphenols are critically determined by their
      bioavailability, the effect of interactions between plant phenols and food macronutrients is
      a very important topic. The protein-polyphenol complexes can significantly change the plasma
      kinetics profile. (8) Protein-polyphenol binding is mediated by a combination of hydrogen and
      hydrophobic bonding depending on chemical (polarity) and structural (size/shape) properties
      of interacting molecules. Covalent interactions between purified glycinin, a soybean storage
      protein, and selected flavonoids and phenolic acids have also been reported. Recently it is
      reported that protein-rich defatted soybean flour protects anthocyanins during transit
      through upper digestive tract for subsequent colonic delivery/metabolism (9).
    

Intervention name(s): Pomegranate Juice; Soybean Flour Protein; Soy Isolate Protein
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): Pomegranate Juice alone; Soybean Flour Protein combined with Pomegranate Juice; Soy Isolate Protein combined with Pomegranate Juice
Other intervention name(s): Nutrasorb; Solae
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Basic Science
Keywords: Pomegranate polyphenols; Soy Protein; Ellagitannins