Healthy Volunteers
Conditions
Brief summary
The primary objective of this study is to determine how daily consumption of kale changes the activity of human xenobiotic metabolizing enzymes. Secondary objectives are to measure absorption and metabolism of kale phytonutrients, and to determine how kale consumption affects gene expression related to metabolism and lipid measures associated with cardiovascular health.
Detailed description
Consumption of Brassica vegetables (which include broccoli, cabbage, and kale) is inversely associated with the incidence of several cancers, including cancers 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 is their rich content of glucosinolates. Glucosinolates are sulfur-containing compounds that are converted to bioactive metabolites by a plant enzyme called myrosinase, which is released when the vesicles containing myrosinase are ruptured by chewing or cutting. These bioactive compounds are considered to be the active agent for cancer prevention. Their ability to reduce risk of cancer may derive in part from their ability to modulate foreign-substance metabolizing enzymes, which include enzymes called Phase I cytochrome P450s and Phase II enzymes. The primary aim of this study is to investigate how daily consumption of kale influences foreign-substance metabolizing enzymes, which in turn may reduce cancer risk. Secondary aims of this study include measuring metabolism of kale nutrients, effect of kale consumption on fecal microbiota, and how kale consumption influences risk factors for cardiovascular disease.
Interventions
OTHERBase Diet
Base Diet
OTHERKale Treatment
Base Diet plus Kale
Sponsors
USDA Beltsville Human Nutrition Research Center
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
21 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* 5 years cancer free * Not a tobacco product user * Blood glucose less than 126 mg/dL * Able to voluntarily agree to participate and sign an informed consent document
Exclusion criteria
* Brassica vegetable allergy or intolerance * use of oral contraceptives * Women who have given birth in the previous 12 months * Type 2 diabetes requiring the use of diabetes pills, insulin, or non-insulin shots * Use of blood-thinning medications such as Coumadin (warfarin), Dicumarol, or Miradon (anisindione) * History of bariatric surgery or nutrient malabsorption disease * Pregnant, lactating, or intending to become pregnant during the study period * Crohn's disease or diverticulitis * Suspected or known strictures, fistulas or physiological/mechanical GI obstruction * Self-report of alcohol or substance abuse within the past 12 months and/or current acute treatment or rehabilitation program for these problems (long-term participation in Alcoholics Anonymous is not an exclusion)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| CYP1A2 activity will be analyzed | Day 7 | Plasma will be analyzed for caffeine metabolite ratios |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Metabolites of Kale | On days 35 and 36 | Metabolites of Kale will be measured in plasma and urine. |
| Fecal microbiota will be analyzed for microbial DNA | Days 0, 14, 35, and 49 | Fecal microbial communities will be determined using DNA extracted from fecal samples. |
| UGT1A1 activity will be analyzed | On days 7, 14, 42, and 49 | Serum will be analyzed for bilirubin concentration to assess UGT1A1 activity |
| Glutathione S-transferase alpha concentration | On days 7, 14, 42, and 49 | Glutathione S-transferase alpha concentration will be measured in serum |
| Total cholesterol | On days 0, 7, 14, 35, 42, and 49 | Total cholesterol will be measured in serum |
| LDL cholesterol | On days 0, 7, 14, 35, 42, and 49 | LDL cholesterol will be measured in serum |
| The ability of fecal microbiota to metabolize glucosinolates will be determined | Days 14 and 49. | Fecal samples will be presented with glucosinolates to determine the change in the ability of fecal microbes to metabolize the glucosinolates. |
| Triacylglycerides | On days 0, 7, 14, 35, 42, and 49 | Triacylglycerides will be measured in serum |
| Apolipoprotein A1 | On days 0, 7, 14, 35, 42, and 49 | Apolipoprotein A1 will be measured in serum |
| Apolipoprotein A2 | On days 0, 7, 14, 35, 42, and 49 | Apolipoprotein A2 will be measured in serum |
| Apolipoprotein B | On days 0, 7, 14, 35, 42, and 49 | Apolipoprotein B will be measured in serum |
| Changes in gene expression | On days 0, 14, 35, and 49 | messenger RNA concentrations in whole blood will be measured |
| HDL cholesterol | On days 0, 7, 14, 35, 42, and 49 | HDL cholesterol will be measured in serum |
Countries
United States
Outcome results
None listed