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

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

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.

Study Overview

• Status: Completed
• Conditions: Immune Function
• Intervention / Treatment: Behavioral: 5 portions; Behavioral: 2 portions

• Study Type: Interventional
• Enrollment (Actual): 83
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Co Antrim
    • Belfast, Co Antrim, United Kingdom, BT12 6BJ
      • Queen's University Belfast

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years to 85 years (Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / 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).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in natural killer cell cytotoxicity and antibody response to Tetanus toxoid and Pneumovax II vaccination	16 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in other markers of immune function	16 weeks

Collaborators and Investigators

• Sponsor: Queen's University, Belfast

Publications and helpful links

General Publications

• Neville CE, McKinley MC, Draffin CR, Gallagher NE, Appleton KM, Young IS, Edgar JD, Woodside JV. Participating in a fruit and vegetable intervention trial improves longer term fruit and vegetable consumption and barriers to fruit and vegetable consumption: a follow-up of the ADIT study. Int J Behav Nutr Phys Act. 2015 Dec 18;12:158. doi: 10.1186/s12966-015-0311-4.
• Neville CE, Young IS, Gilchrist SE, McKinley MC, Gibson A, Edgar JD, Woodside JV. Effect of increased fruit and vegetable consumption on physical function and muscle strength in older adults. Age (Dordr). 2013 Dec;35(6):2409-22. doi: 10.1007/s11357-013-9530-2. Epub 2013 Apr 2.
• Gibson A, Edgar JD, Neville CE, Gilchrist SE, McKinley MC, Patterson CC, Young IS, Woodside JV. Effect of fruit and vegetable consumption on immune function in older people: a randomized controlled trial. Am J Clin Nutr. 2012 Dec;96(6):1429-36. doi: 10.3945/ajcn.112.039057. Epub 2012 Nov 7.

Study record dates

Study Major Dates

• Study Start: October 1, 2006
• Primary Completion (Actual): December 1, 2008
• Study Completion (Actual): September 1, 2009

Study Registration Dates

• First Submitted: March 9, 2009
• First Submitted That Met QC Criteria: March 9, 2009
• First Posted (Estimate): March 10, 2009

Study Record Updates

• Last Update Posted (Actual): December 16, 2021
• Last Update Submitted That Met QC Criteria: December 1, 2021
• Last Verified: December 1, 2021

More Information

Terms related to this study

• Keywords: Antibody response; Natural killer cell cytotoxicity; Tetanus toxoid vaccination; Pneumovax II vaccination; Total serum immunoglobulins; IgG subclasses
• Other Study ID Numbers: 06/NIR03/64