Daily Consumption of Well-Cooked Broccoli May Affect Glucosinolate Metabolites and Inflammatory Biomarkers
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Investigator, Outcomes Assessor
Primary Purpose: Prevention
- The change in glucosinolate metabolites will be measured in blood plasma and urine [ Time Frame: At end of diet period 1 (week 3) and at the end of diet period 2 (week 12) ]To track the change of endogenous broccoli isothiocyanates in this crossover study, glucosinolate metabolites will be measured in both blood plasma and urine
- Body composition will be determined by dual energy x-ray absorptiometry (DEXA) [ Time Frame: Day 0, just prior to beginning the controlled diet ]Determine fat, lean, and bone mineral mass, and visceral fat deposition in our subjects
- The ability of fecal microbiota to metabolize glucosinolates will be determined [ Time Frame: once per week during diet periods 1 and 2 (weeks 1, 2, 3, 10, 11, and 12) ]Fecal samples will be presented with glucoraphanin to determine the ability of fecal microbes to metabolize it
- Fecal microbiota will be analyzed for microbial DNA [ Time Frame: once at the beginning and end of diet periods 1 and 2 (weeks 1, 3, 10, and 12) ]Fecal microbial communities will be determined using DNA extracted from fecal samples
- Markers of gut health will be analyzed in blood [ Time Frame: once in the third week of diet periods 1 and 2 (weeks 3 and 12) ]Zonulin in blood serum will be measured by ELISA
- Markers of inflammation will be measured in blood [ Time Frame: at end of diet period 1 (week 3) and at end of diet period 2 (week 12) ]Cytokines and acute phase proteins will be measured in blood
|Actual Study Start Date:||February 27, 2017|
|Estimated Study Completion Date:||May 19, 2017|
|Estimated Primary Completion Date:||May 19, 2017 (Final data collection date for primary outcome measure)|
Participants will receive a controlled diet (base diet), typical of an American diet, with 0 g/day of broccoli (control).
Other: Control Diet
Participants will receive a controlled diet with 0 g/d of broccoli. Meals will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet.
Other Name: Base Diet
Active Comparator: Brassica Diet
Participants will receive a controlled diet with 100 g of broccoli at both breakfast and dinner daily.
Other: Base Diet with Broccoli
Participants will receive a controlled diet with 100 g of broccoli at both breakfast and dinner daily. Meals will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet.
Consumption of Brassica vegetables is inversely associated with incidence of several cancers, including cancer of the lung, stomach, liver, colon, rectum, breast, endometrium, and ovaries. Brassica vegetables are a good source of many nutrients, but the unique characteristic of Brassicas (Broccoli in particular) is their rich content of glucosinolates. Glucosinolates are sulfur-containing compounds that are converted to isothiocyanates (ITC) by an enzyme in the plant called myrosinase, which is released when the vesicles containing myrosinase are ruptured by chewing or cutting. The isothiocyanates are considered to be the active agent for cancer prevention. Some of the mechanisms by which isothiocyanates likely inhibit cancer include modulation of cytochrome P450 enzymes, induction of phase II enzymes, and apoptosis.
The aim of this study is to investigate how daily consumption of broccoli with myrosinase inactivated by cooking influences glucosinolate metabolism and absorption, and consequent regulation of inflammatory markers.
Please refer to this study by its ClinicalTrials.gov identifier: NCT03013465
|United States, Maryland|
|USDA-ARS, Beltsville Human Nutrition Research Center|
|Beltsville, Maryland, United States, 20705|