Examining the Effects of Juice Fasting
Condition: Epigenetics; Microbiome
Study type: Interventional

Summary: 
      This study tests the effectiveness of dietary interventions that have the possibility to
      improve markers of gut health and improve general well-being. This study will allow
      healthcare professionals to learn how dietary interventions involving fasting can affect
      health. Food is increasingly recognized as a core component of preventive and ameliorative
      health care. Juice fasting has quickly become one of the most popular self-prescribed dietary
      interventions in the United States. A wide variety of juice fasts are available in the
      popular market; a popular variation is the three-day juice fast. The purpose of this study is
      to assess the effects of a three-day juice fast on certain markers of age-related disease and
      bio-markers of longevity. In particular, this study will assess certain epigenetic markers,
      which measure how the environment (including diet) can change the way that genes are
      expressed without changing the genes themselves. The study will also assess the microbiome,
      and inflammatory and glycemic markers.
    

Detailed description: 
      Up to 30 participants will be enrolled in the study and will be randomized into one of the
      three arms: the "juice fasting" arm, the "juice plus ad hoc" arm, and the "caloric
      restriction" arm. Participants will come into the lab for an initial visit, during which they
      will complete questionnaires on their usual diet and demographics and will be informed about
      their assignment to one of the three arms.

      In all three arms, the three-day diet intervention will be preceded and followed by three
      days of self-conducted elimination diet. The pre-intervention diet will encourage
      participants to eat a healthy, light diet for three days (basic instructions: eat only fresh
      raw or cooked fruits and vegetables (preferably organic), whole grains and eggs; drink 8
      glasses of water a day; avoid or eliminate alcohol, caffeine, sugar, processed foods, dairy,
      red meat, and gluten). The post- intervention diet will instruct participants to gradually
      return to eating solid foods, and limit strenuous exercise (basic instructions: follow a diet
      similar to the pre-intervention elimination diet; day 1 after the intervention: eat fruits &
      green vegetables, and drink 8 glasses of water; day 2 add in: nuts, gluten-free grains like
      whole oats, quinoa, or brown rice; day 3 add in: organic meats, fish, & gluten-containing
      grains).

      Biological samples and self-reported outcomes will be collected at four time points: baseline
      (prior to the first elimination diet period), pre-intervention (after the elimination diet
      and before the three-day intervention), post-intervention (after the intervention), and
      14-day post- intervention. At each time point, participants will complete questionnaire on
      quality of life (PROMIS - Global Health Scale, which is an NIH measure on an individual's'
      overall physical and psychological well-being; see appendix) and collect their stool samples.
      Participants will be provided self-administered tool kits and be taught how to collect the
      stool sample at their first lab visit. At each of the four time points, the research
      assistant will coordinate the collection of cheek swabs, saliva samples, and blood spot
      samples. Biometrics will also be collected at each time point (weight, waist circumference,
      and blood pressure).

      Over the course of the study, participants will be instructed to keep a diet diary days one
      through nine to record their daily dietary intake. During the intervention period, the
      research team will also contact the participants for daily check-ins. Participants will not
      need to record diet data for the remaining 11 days of the post-intervention period.

      At the conclusion of the study, participants will bring back the final biological samples
      (stool wipe and saliva), provide the set of samples, and be debriefed about the purposes of
      the study.

      The biological samples collected will then be processed and assayed for microbiome,
      methylation, inflammatory markers, and glycemic markers.
    

Intervention name(s): Juice; Caloric restriction via Plant-based meals; Plant-based meal
Intervention type(s): Dietary Supplement; Behavioral; Dietary Supplement
Intervention description(s): Participants will be drinking 800-900 kcal/day in cold-pressed juices.; Participants' caloric intake will be limited to 800-900 kcal/day.; Participants will be eating ~900 kcal/day in pre-prepared plant-based meals.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Juice fasting; methylation; microbiome; caloric restriction