Whole Grain Polyphenol Bioavailability and Effects on Health

Overweight Clinical Trial

Official title:

Whole Grain Polyphenol Bioavailability and Effects on Inflammatory, Oxidative and Hormonal Status

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01293175
• Other study ID #: DSA-FF-002
• Status: Completed
• Phase: N/A
• First received: February 9, 2011
• Last updated: July 11, 2013
• Start date: February 2011
• Est. completion date: August 2012

Study information

• Verified date: July 2013
• Source: Federico II University
• Contact: n/a
• Is FDA regulated: No
• Health authority: Italy: Ethics Committee
• Study type: Interventional

Clinical Trial Summary

Whole grains (WG) contain numerous physiologically bioactive compounds, a key group being polyphenolic compounds such as ferulic acid (FA). These whole grain polyphenolic compounds have been shown to have potent antioxidant activity. This study will evaluate bioavailability of WG bioactive compounds and their physiological impact on health outcomes, mainly related to inflammatory, oxidative and hormonal status, in overweight subjects.

Description:

Epidemiological evidence indicates that consumption of whole grains (WG) is associated with improved health and decreased risk for common chronic diseases. However there is paucity of intervention data regarding the beneficial effects of WG in vascular health and associated metabolic disorders.

From 2007 up to now five main intervention studies using WG were published. The results from these studies consistently showed no efficacy of WG to modify biochemical parameters in free-living subjects including WG in their habitual diet. Anyway some drawbacks could be found and mainly regarding subject compliance to the treatment and the type of WG-rich foods supplied.

Our working hypothesis is based on WG physiologically bioactive compounds mainly polyphenolic compounds such as ferulic acid (FA). FA is covalently bound to arabinoxylans constituting WG dietary fiber. This structure represents a natural way to carry polyphenol compounds, into the lower gut. A previous work indicated that intestinal microflora particularly Bifidobacteria and Lactobacilli is able to ferment WG polysaccharide moiety (prebiotic effect) and at the same time microbial esterases can release free phenolic acids. The free acids are adsorbed through the colon barrier into the blood. The slow and continuous release of phenolic acids, particularly FA, determines an increase of baseline level of FA in the blood of WG consumers. However no study correlated FA plasma concentration with health parameters such as biomarkers of inflammation, glucose metabolism and oxidative status which may be in turn associated to the CVD risk.

In this framework a controlled, parallel, two arm intervention study will be performed using a WG-rich product that will be selected from those commercially available for having a high content of FA (>500 mg/kg). The aim of this study is to evaluate the bioavailability of FA over a two month-treatment in overweight subjects and to correlate variation of FA plasma concentrations with biomarkers of oxidative (plasma antioxidant capacity, MDA) and inflammatory (CRP, anti- and pro-inflammatory cytokines) status, with nutritional status and with gastro-intestinal hormones related to appetite and glucose metabolism (ghrelin, PYY, PP, insulin, GLP-1, GIP and leptin). Eighty subjects will be selected in the respect of strict inclusion and exclusion criteria and will be randomized to include WG in opportunely revised individual habitual diet, or to continue with their habitual diet. At baseline, after 1 month and after 2 months from starting the protocol, blood drawings will be performed and urine and feces will be collected from fasting subjects. Gastro-intestinal hormone response and glucose metabolism following a standard meal will be also evaluated at baseline and at 2 months.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 80
• Est. completion date: August 2012
• Est. primary completion date: February 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• 18 - 60 years old, male and female

• Healthy by medical assessment

• Overweight: BMI > 25 and < 32 kg/m2

• Habitual diet characterized by i) absence of WG (all dietary carbohydrates derived from refined cereals); ii) absence of pro-biotics; iii) intake of dietary fibre = 10 g/d; iv) intake of fruit and vegetables = 2 portions/die; v)habit to have breakfast

• Sign of a written informed consent

Exclusion Criteria:

• Age < 18 and > 60 years old

• Pregnancy or breastfeeding

• Fasting plasma triglycerides = 200 mg/dl and cholesterol > 200 mg/dl

• Cardiovascular events (AMI and/or stroke) in the last 6 months

• Regular intensive physical activity

• Hypertension

• Intestinal or metabolic diseases/disorders such as diabetic, renal, hepatic, pancreatic or ulcer

• Previous abdominal/gastrointestinal surgery

• Regular consumption of medication

• Antibiotic therapy within 2 months previous the study

• Food allergies and intolerances (celiac disease, lactose intolerance,)

• Concurrent participation or having participated in another clinical trial during the last 3 weeks

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Prevention

Related Conditions & MeSH terms

• Overweight

Intervention

Dietary Supplement:
• Whole grains
Subjects will consume whole grains at dose of 80 g/die, for two months

Locations

Country	Name	City	State
Italy	Department of Food Science	Portici

Sponsors (1)

Lead Sponsor	Collaborator
Federico II University

Country where clinical trial is conducted

Italy, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Variation of serum polyphenol concentration	Measure of serum polyphenol concentration (nmol/L)	1 year	No
Primary	Variation of plasma lipids	Measure of plasma concentrations (mg/dL) of Total-, LDL-, and HDL-Cholesterol, as well as Triglycerides	1 year	No
Secondary	Variation of serum antioxidant capacity	Measure of plasma FRAP (µmol/L) and MDA (µmol/L) concentrations.	1 year	No
Secondary	Variation of body weight	Measure of body weight (kg)	1 year	No
Secondary	Variation of serum inflammatory marker concentration	Measure of serum CRP, IL-6, TNF-a, PAI-1, Visfatin, Resistin concentration (pg/mL)	1 year	No
Secondary	Variation of fecal microbiota composition	By FISH (colony-forming unit, CFU/g)	1 year	No
Secondary	Variation of serum gastro-intestinal hormone concentration	It will be evaluated following a standard meal test. In particular plasma response (pg/mL) of Ghrelin, PYY, Leptin, GIP, GLP-1, PP and insulin will be assessed	1 year	No
Secondary	Variation of blood pressure	Measure of blood pressure (mmHg)	1 year	No
Secondary	Variation of body circumferences	Measure of waist and hip circumferences (mm)	1 year	No
Secondary	Variation of body composition	Measure of body composition (% of lean and fat mass, % water)	1 year	No