ADIT: Effect of Fruit and Vegetable Consumption on Immune Function in the Elderly

Sponsor

Queen's University, Belfast (Other)

Overall Status

Completed

CT.gov ID

NCT00858728

Collaborator

(none)

Enrollment

Location

Arms

Duration (Months)

2.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The immune system undergoes a range of changes as individuals become elderly. These may manifest as an increasing susceptibility to infection or a tendency to develop autoimmune or malignant disease. Multiple underlying factors contribute to this phenomenon of immunological aging, and in this study the investigators will examine the possibility that inadequate diet may be one such contributing factor. Fruit and vegetable intake, which can be low in the elderly, is associated with reduced chronic disease risk. This proposal will test the hypothesis that increased fruit and vegetable intake may positively affect clinically relevant measures of immune function. One hundred healthy volunteers aged 65-85 years following a low fruit and vegetable diet (<=2 portions/d) will be recruited and randomised to continue following their normal diet, or to consume at least 5 portions of fruit and vegetables daily for 16 weeks. Immune function and biochemical markers of nutritional status will be assessed before and after the intervention period.

Condition or Disease	Intervention/Treatment	Phase
Immune Function	Behavioral: 5 portions Behavioral: 2 portions	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

83 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Outcomes Assessor)

Primary Purpose:

Prevention

Official Title:

Effect of Fruit and Vegetable Consumption on Immune Function in the Elderly: a Randomised Controlled Trial

Study Start Date :

Oct 1, 2006

Actual Primary Completion Date :

Dec 1, 2008

Actual Study Completion Date :

Sep 1, 2009

Arms and Interventions

Arm	Intervention/Treatment
Experimental: 1 5 portions fruit and vegetables/day	Behavioral: 5 portions Subjects randomised to the intervention group will be provided with a selection of fruit and vegetables once a week (from a local supermarket) and will be asked to consume 5 portions of fruit and vegetables per day. For the purposes of this study, a portion will be as defined by the Food Standards Agency, i.e. an 80 g serving (one apple, orange or banana, or 3 heaped tablespoons of vegetables).
Other: 2 2 portions fruit and vegetables/day	Behavioral: 2 portions Subjects randomised to the control group will be provided with a selection of fruit and vegetables once a week (from a local supermarket) and will be asked to consume 2 portions of fruit and vegetables per day. For the purposes of this study, a portion will be as defined by the Food Standards Agency, i.e. an 80 g serving (one apple, orange or banana, or 3 heaped tablespoons of vegetables).

Arm

Intervention/Treatment

Experimental: 1

5 portions fruit and vegetables/day

Behavioral: 5 portions

Subjects randomised to the intervention group will be provided with a selection of fruit and vegetables once a week (from a local supermarket) and will be asked to consume 5 portions of fruit and vegetables per day. For the purposes of this study, a portion will be as defined by the Food Standards Agency, i.e. an 80 g serving (one apple, orange or banana, or 3 heaped tablespoons of vegetables).

Other: 2

2 portions fruit and vegetables/day

Behavioral: 2 portions

Subjects randomised to the control group will be provided with a selection of fruit and vegetables once a week (from a local supermarket) and will be asked to consume 2 portions of fruit and vegetables per day. For the purposes of this study, a portion will be as defined by the Food Standards Agency, i.e. an 80 g serving (one apple, orange or banana, or 3 heaped tablespoons of vegetables).

Outcome Measures

Primary Outcome Measures

Change in natural killer cell cytotoxicity and antibody response to Tetanus toxoid and Pneumovax II vaccination [16 weeks]

Secondary Outcome Measures

Change in other markers of immune function [16 weeks]

Eligibility Criteria

Criteria

Ages Eligible for Study:

65 Years to 85 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Age 65-85 years
Habitual consumption of fruit and vegetables <= 2 portions daily

Exclusion Criteria:

Those on special diets, taking nutritional supplements or medications known to affect immune function or absorption of nutrients
Excessive alcohol consumption (>28 U/week men or >21 U/week women)
BMI>35 kg/m2
History of diabetes or dementia
Pneumovax II vaccination within previous 2 years
Inability to provide informed consent
Any other problem which would prevent adherence to a high fruit and vegetable diet
Recent infection (<3 weeks since completion of any antibiotic course or symptoms of viral illness)