Effect of Plant and Animal Proteins on Biomarkers of Colorectal Cancer and Type 2 Diabetes in Healthy Adults (ScenoProt)
Condition: Colorectal Cancer; Type2 Diabetes
MeSH terms: Colorectal Neoplasms; Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Interventional

Summary: 
      The aim of this study is to investigate the effects of dietary plant and animal proteins on
      gut metabolism and markers for colorectal cancer as well as blood protein metabolites and
      markers for type 2 diabetes in healthy adults. The study participants will be stratified into
      three groups with different protein composition in diets: 1) animal 70%/plant 30%; 2) animal
      50%/plant 50% and 3) animal 30%/plant 70%. The participants will get part of their diet as
      ready foods or raw material to promote their compliance. The participants will also get
      personal advice for their diets. Blood, stool and urine samples will be collected in the
      beginning and in the end of the 12 week intervention, as well as phenotype measures like BMI,
      blood pressure and body composition. The participants will also fill food diary before and in
      the end of the intervention.
    

Detailed description: 
      A human intervention study with healthy volunteers will be carried out to compare the effects
      of animal and plant-based protein sources on gut metabolism and markers for colorectal cancer
      as well as blood protein metabolites and markers for type 2 diabetes.

      The study will be done in parallel-design, randomized fashion, with healthy human volunteers
      aged 20 - 69 years. Exclusion criteria will be as follows: strict vegan, regular user of fish
      oil or other food supplements, extreme sports, inflammatory bowel disease, colon irritable,
      celiac disease, continuous antibiotics or less than three months of the latest antibiotics
      use, type 2 diabetes and hormonal, liver or kidney disease. Duration of the intervention will
      be 12 weeks.

      Intervention groups will be as follows (n=50/group):

      Group 1: Dietary proteins from animal sources 70% and from plant sources 30%, representing an
      average Finnish diet consumed at the moment.

      Group 2: Dietary proteins from animal sources 50% and from plant sources 50%, containing at
      most 500 g red meat/week (according to the current Finnish Nutrition Recommendations).

      Group 3: Dietary proteins from animal sources 30% and from plant sources 70%.

      The intake of total protein will be kept at similar level compared to habitual, but intakes
      of fat and carbohydrates may vary as composing a diet with plant-based protein sources
      inevitably causes changes for example in dietary fibre intake. We will aim at controlling
      other potential dietary confounders to the extent that is possible in a whole-diet approach.
      This will ensure the feasibility of the diets and facilitate future applications in dietary
      practices at the population level.

      Before starting the intervention, the persons will get dietary advice how to fulfill their
      diets. They will get part of foods free to help to implement the diets and to enhance
      compliance.

      Blood, urine and fecal samples will be collected at the baseline (at the beginning of the
      intervention) and at the end of the intervention. Dietary intake and food consumption during
      the intervention will be followed by 3-day food records in the beginning and at the end of
      the intervention period. Nutrient intakes will be calculated using AIVO program.

      The following data collection and analyses will be carried out at the beginning and at the
      end of intervention:

        -  height, weight, waist circumference

        -  body composition by bioelectrical impedance analysis

        -  resting blood pressure, hemoglobin

        -  fasting lipid profile in the blood (total cholesterol, LDL and HDL, triglycerides)

        -  fasting glucose and insulin, HbA1c in the blood

        -  markers for low-grade inflammation in the blood: hs-CRP, cytokines such as IL-1beta,
           IL-6, IL-10

        -  protein metabolomics in the blood

        -  markers of nutritional status in the bood: vit. D25-OH, carotenoids, vitamin C and B12,
           alkyl resorcinols

        -  urea/nitrogen in the urine

        -  measures of gut metabolism and risk markers for colorectal cancer: total N-nitroso
           compounds in the feces, plant-derived polyphenol metabolites in the feces, concentration
           of bile acids, cytotoxicity and genotoxicity assays of fecal water samples in 2D and 3D
           colon cancer cell cultures and gut microbiota analyses.
    

Intervention name(s): 70% animal, 30% plant proteins in diet; 50% animal, 50% plant proteins in diet; 30% animal, 70% plant proteins in diet
Intervention type(s): Other; Other; Other
Intervention description(s): Diet contains 70% of proteins from animal sources (beef, pork, chicken, dairy products, fish) and 30% from plant sources (bread and cereals).; Diet contains 50% of proteins from animal sources (beef, pork, chicken, dairy products, fish) and 50% from plant sources (bread and cereals, legumes, nuts, seeds, soy products).; Diet contains 30% of proteins from animal sources (beef, pork, chicken, dairy products, fish) and 70% from plant sources (bread and cereals, legumes, nuts, seeds, soy products).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: colorectal cancer; type 2 diabetes; diet; plant protein; animal protein