None listed
Conditions
Brief summary
Both dietary fibre and unsaturated fats are known for their health benefits on cardiovascular health, however, there are a lack of studies evaluating the effects of dietary fibre from whole foods on endothelial function. The purpose of the study is to assess the impact of a high fibre diet compared to a lower carbohydrate, high unsaturated fat diet on endothelial function, as an early indicator of cardiovascular disease risk. Males over 45 years old and females post menopause with a low dietary fibre intake of less than 15 g/day will be randomised to one of two groups: high fibre diet (40 g/day from whole foods - wholegrains, legumes, fruits, vegetables, nuts and seeds), or high unsaturated fat diet (approx. 40% energy intake from fat from whole foods). Participants will be provided with dietetic counselling to adhere to their allocated diet during the first 3 months of the study, with a follow up at 6 months from commencement. A subset of participants will be assessed in the postprandial phase (as a more sensitive marker or metabolic health), where they will be provided with a high fat, high sugar meal and have their endothelial function tested every 2 hours for up to 6 hours at baseline and 3 months. This study may help with the development of clinical practice guidelines for dietitians to provide dietary advice to patients for vascular health. We hypothesise that both diets will improve endothelial function.
Interventions
Dietary advice to increase dietary fibre intake to 40 g per day using a whole of diet approach for 3 months, with a follow up at 6 months from commencement. This group will focus on consuming fibre from a variety of fibre rich foods (whole grains, legumes, vegetables, fruit, nuts and seeds), by slowly increasing fibre intake over the first 4 weeks to increase to 40 g fibre per day. Participants will see the study dietitian in person at baseline (~1 hour), and via telephone or Zoom at weeks 2, 4,
Dietary advice to increase dietary fibre intake to 40 g per day using a whole of diet approach for 3 months, with a follow up at 6 months from commencement. This group will focus on consuming fibre from a variety of fibre rich foods (whole grains, legumes, vegetables, fruit, nuts and seeds), by slowly increasing fibre intake over the first 4 weeks to increase to 40 g fibre per day. Participants will see the study dietitian in person at baseline (~1 hour), and via telephone or Zoom at weeks 2, 4, and 8 (~30 minutes each). To monitor dietary adherence, participants will provide a food diary prior to each study day visit (baseline, 3 months and 6 months), prior to dietitian appointments (weeks 2, 4, and 8), and at 4 months and 5 months after commencement. At study visits (baseline and 3 months only), participants can self nominate to opt in to a postprandial meal challenge (rather than fasting only). After fasting measures have been taken, participants will be provided with a high fat, high refined sugar meal to consume within 15 minutes, and flow mediated dilation will be tested at 2 hours, 4 hours and 6 hours post meal consumption. The first 10 participants in each group to opt in will be chosen for the postprandial meal challenge.
Sponsors
Monash University
Study design
Allocation
Randomised controlled trial
Primary purpose
Prevention
Eligibility
Sex/Gender
All
Age
45 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Male aged 45 years and above, or female post menopause Fibre intake less than 15 g/day
Exclusion criteria
Currently smoking or vaping History of irritable bowel syndrome (IBS) (moderate to severe) or inflammatory bowel disease (IBD) Gastrointestinal surgery the past 12 months Major cardiovascular surgery (i.e., surgery that involves the heart or blood vessels) Cardiovascular events the past 12 months (e.g., heart attack, stroke) Implanted cardiac pace maker Planning to start a new exercise program during the study Using fibre or omega-3 supplements the past 1 month Changes to medication use the past 6 weeks (e.g., if you have been on the same statin dose the past 6 weeks or long, you are eligible)
Outcome results
None listed