Impact of Pulse-enriched Foods on Cognitive Function and Cardiometabolic Health in Obese Adults

University of Manitoba150 enrolled

Overview

The Canadian population, as is the case in most developed countries, is ageing and becoming increasingly overweight and/or obese. Both ageing and obesity are associated with reduced cognitive performance which can impact adversely on the ability to undertake daily activities and increases the risk of loss of independent living and reduced quality of life. The investigators predict that consumption of ½ cup of pulses per day for 12 weeks will improve cognitive function in older overweight/obese adults and thus decrease the rate of cognitive decline that occurs in this at-risk population.

This is a multi-site, randomized, controlled, parallel, dietary intervention food study designed to examine the impact of pulse-enriched foods on cognitive function and cardiometabolic health in obese adults. Recruitment will consist of approximately 160 participants (n= 80 participants per site) at 2 sites located in Winnipeg and South Australia. Participants will be randomly allocated to one of 2 groups; a pulse group or a control group. The pulse group will consume pulse-enriched foods designed to deliver ½ cup of pulses per day for 12 weeks. The control group will consume comparator foods for 12 weeks. The pulse and comparator food items will be provided to participants and they will be asked to incorporate these into their usual diet. Participants will be requested not to change their diet or physical activity habits during the study period, other than as required to comply with the study requirements. Five-day weighed food records will be completed during the week prior to baseline and during the final week of the study to monitor dietary intake, in particular intake of pulses. This will determine whether participants are incorporating the study foods as required, and will be used to evaluate associated changes in dietary intake and body weight, if they occur.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Masking

NONE

Enrollment

150

Eligibility

Sex: ALLMin age: 50 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Male or females, between 50-80 years of age * Body Mass Index (BMI) of \>25 kg/m2 * Must be on a stable regime for the past 6 months if taking medications or supplements for elevated lipids, blood pressure, glucose management, mood, pain, or insomnia * Consume 1 or less servings of pulses per week * Able to read and understand English * Willing to comply with the protocol requirements * Willing to provide informed consent. Exclusion Criteria: * Body weight ≥135 kg (since this exceeds the capability for Dual Energy X-ray Absorptiometry, i.e, DEXA scanning to assess body composition) * Established cardiovascular, liver, or kidney disease * Uncontrolled diabetes (hemoglobin HbA1c \>8) * A score of ≤23 on the Mini Mental State Examination * Use of appetite suppressants or Orlistat (Xenical) * Inability to consume pulse-enriched foods (i.e., beans, peas, chickpeas, and lentils) due to allergies or severe gastrointestinal reactions * Pregnancy * Smoking or only recently quit smoking (smoked any cigarettes within the last 12 months) * Weight loss of ≥3kg of body weight within the 6 months prior to enrolling in the study * Adherence to a weight loss diet or physical activity program designed to facilitate weight loss * Acute or terminal illness.

Outcomes

Primary Outcomes

Vascular Function

Vascular function will be assessed non-invasively (at baseline, Week 6, and Week 12) with measurement of arterial compliance (elasticity) by pulse wave analysis and pulse wave velocity. Measurement of arterial vasodilation will be done non-invasively to evaluate endothelial cells which line the blood vessels that regulate blood flow. Blood samples will be taken to assess markers of vascular function.

Time frame: 12 weeks

Cerebral Blood Flow Velocity (Australian Site only)

Cerebral blood flow velocity will be assessed (baseline , Week 6, Week 12) by transcranial Doppler ultrasonography. This will serve as an index of arterial vasodilator responsiveness in the cerebral circulation. This will be performed by the Australian site only.

Time frame: 12 Weeks

Secondary Outcomes

Cognitive Function

A selection of cognitive tests will be administered (baseline, Week 6, and Week 12) by a qualified member of the study team to assess varying aspects of the participant's level of functioning cognition.