None listed
Conditions
Brief summary
Fruit, including kiwifruit, are a valuable component of the human diet because of the wide range of vitamins, minerals and other bioactives that they supply. They are also generally rich in sugars, in particular fruit sugar (fructose) and glucose. Now that glucose intolerance and diabetes are becoming global megatrends there is a growing challenge of how to include fruit in the diets of glucose-intolerant consumers, especially in Asian markets for kiwifruit, in which the incidence of diabetes is expected to reach >400 million by 2030. Glucose may increase exposure to glycaemia and risk of long-term medical complications typical of diabetes. On the other hand, fructose, although less glycaemic, may raise blood triglycerides. Therefore, a concern is that reduced exposure to glycaemia as a result of ingesting fruit in place of more glycaemic foods may be counteracted by unfavourable changes in blood lipids. The challenge is, therefore, multifaceted: • How to increase fruit intake without adversely increasing exposure to glucose-induced postprandial glycaemia (HbA1c). • How to do so without unfavourably altering plasma lipids due to an increase in fructose intake, • How to use whole kiwifruit to gain the protective benefits of fruit bioactives against processes leading to diabetic complications. The associated research questions are: 1. Can kiwifruit be included in the diet without exacerbating exposure to postprandial glycaemia? 2. Can the fructose-rich sugars in kiwifruit be regularly consumed without plasma lipid changes associated with increased disease risk? 3. Can it be shown that regular consumption of kiwifruit in fact counteracts the systemic biochemical processes through which glycaemia leads to medical complications typical of long-term diabetes, which are believed to be mediated by glycation, inflammation and oxidative stress, and counteracted by fruit bioactives such as phenolics and vitamin C?
Interventions
Intervention:
Participants will be assigned randomly to two groups of 20 subjects each. Both the groups will be asked to continue with their customary diet for fifteen weeks (3 weeks lead in, 12 weeks trial period), but not to consume vitamin supplements. During the lead in period of 3 weeks, all the participants will be asked not to consume any kiwifruit to ensure that the 12 weeks kiwifruit intervention period is a discrete kiwifruit consumption period. The control group will then continue to
Intervention: Participants will be assigned randomly to two groups of 20 subjects each. Both the groups will be asked to continue with their customary diet for fifteen weeks (3 weeks lead in, 12 weeks trial period), but not to consume vitamin supplements. During the lead in period of 3 weeks, all the participants will be asked not to consume any kiwifruit to ensure that the 12 weeks kiwifruit intervention period is a discrete kiwifruit consumption period. The control group will then continue to not consume any kiwifruit for twelve weeks but will be asked to drink 250 mL of provided water 30minutes before their breakfast every day. The kiwifruit intervention group will be asked to consume two kiwifruit per day for 12 weeks, PREFERABLY 30 MINUTES BEFORE BREAKFAST. All participants will be asked to attend the Plant & Food Research clinic in the mornings twice, (1) at the beginning of the trial, (2) at the end of the twelve weeks.. The participants will be asked to fast overnight (10-12 hours) and allow 30 mL of venous blood to be withdrawn from their arm by a trained phlebotomist. Finger prick blood will also be taken for fasting blood glucose measurement. Anthropometric measurement including height, weight, blood pressure (automatic sphygmomanometer), waist and hip circumference will be taken during each visit and questions regarding their general wellbeing will be asked. The participants will therefore be expected to attend the clinic two times during the trial and once for screening before the start of the trial. Participants will also be asked to fill out a seven day food diary two times, covering the seven days leading up to each visit to the clinic. Blood sampling and analytes: On the two visits to the clinic during the intervention period, the participants will be asked to provide fasting venous blood samples which will be taken by a trained phlebotomist. Subjects will be seated and once relaxed and comfortable venous blood will be withdrawn from the anterior cubital fossa into Vacutainer™ tubes. Total blood volume collected at each clinic visit will be 30m. The blood samples will be used to measure the following: 1. HbA1c, insulin, uric acid, creatinine 2. Serum lipids 3. Biomarkers of oxidative stress and inflammation 4. Plasma vitamin C Capillary finger prick blood sample will be taken for fasting blood glucose measurement. SunGold kiwifruit will be supplied by the study team.
Sponsors
New Zealand Institute for Plant and Food Research Limited
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
All participants have pre-diabetes and may or may not be taking medication
Exclusion criteria
Intolerance of kiwifruit. Allergic to kiwifruit Planned change in diet or medication within the trial period Any illness or gastrointestinal disorder within the 3 weeks prior to the trial.
Outcome results
None listed