The Effects of Orange Juice on Plasma Lipids
- Conditions
- ObesityDyslipidemiaInsulin Resistance
- Interventions
- Dietary Supplement: Orange Juice
- Registration Number
- NCT01350843
- Lead Sponsor
- University of Nottingham
- Brief Summary
The aim of this study is primarily to investigate the ability of antioxidants found in orange juice (OJ) to improve the serum lipid profile. Overweight or mildly obese men, who are otherwise healthy, but with elevated serum total cholesterol concentration will be recruited. The time commitment for subjects is \~14wks. Subjects will attend the laboratory on 5 occasions after fasting from midnight. The 1st is a medical screening. Laboratory visits 2 \& 5 will take \~90min and will be separated by 3 months, during which time subjects will consume 250ml of an orange drink (either OJ or an orange flavoured control drink) once a day. During visits 2 \& 5, subjects will have a scan to assess their %body fat using a low-dose x-ray machine, a 20ml blood sample taken and a small sample of fat tissue (about the size of a haricot bean)taken from underneath the skin of the belly. Subjects will record their food intake for 3-days in weeks 3, 7 and 11 of consuming the drink, and come to the lab for visits 3\&4 during weeks 4\&8. Laboratory visits 3\&4 repeat measurements taken in the 1st (screening) visit.
- Detailed Description
Background:
Overweight and mild obesity are associated with insulin resistance and mild elevations in lipid risk factors which are not usually sufficiently abnormal to merit treatment. Such people are encouraged to lose weight to reduce their risk of progressing to type 2 diabetes and coronary heart disease, but there is clearly a potential role for dietary modifications to maximize any potential benefit of this weight loss. Flavonoids are known to have vascular effects which might enhance substrate delivery to metabolically active tissues, and thus improve insulin sensitivity. Moreover, there is much interest in the potentially beneficial effect of flavonoids on serum lipid profile.
There are many different dietary sources of flavonoids, with fruits such as apples, berries and citrus being rich sources. However, some researchers have expressed concern that a high dietary intake of 100% juice may contribute to the development of insulin resistance, obesity and the Metabolic Syndrome (Bazzano, Li et al. 2008), although this is not universally accepted (Fujioka, Greenway et al. 2006; O'Neil and Nicklas 2008). To date, there have been no studies investigating the effects of citrus fruits on indices of cardio-metabolic health in people who are presently healthy but are at risk of developing some features of the Metabolic Syndrome.
Aims:
To investigate the effects of orange juice (OJ) intake on appetite hormones, blood pressure and plasma lipids. In addition we aim to investigate any gene expression changes associated with OJ consumption, in particular in adipose tissue.
Experimental protocol and methods:
Overweight or obese men (BMI 27-35), who are otherwise healthy, will be recruited onto the study. They will attend the 'David Greenfield Human Physiology' laboratories on 5 convenient mornings, following an overnight fast. The 1st visit is a medical screening and will involve signing a consent form, completing medical screening, food frequency and activity questionnaires, having height, weight, and hip/waist circumference measurements taken and a sample of blood taken for CBC, urea, electrolytes, LFT, TFT, glucose and insulin analysis. Subjects will then be asked to complete a 3-day diet diary for macronutrient assessment. The 2nd visit will involve having a DEXA body composition scan, an adipose tissue biopsy and a blood sample taken for white blood cell harvest, serum lipids, glucose, insulin, cytokines, appetite hormones and catecholamine analysis. Starting on the following morning, subjects will then consume an orange drink (either OJ or a carbohydrate matched orange flavoured drink) once a day for 12 wks. A 3-day diet diary for macronutrient assessment will be recorded during wks 3,7and 11 of taking the drink, and measurements made at screening will be repeated on visits 3 and 4 which will take place in weeks 4 and 8. The final laboratory (5th) visit will be identical to visit 2.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 36
- BMI 27-35
- waist circumference >96cm.
- Serum Total Cholesterol >5mmol/l
- Any clinically significant metabolic or endocrine abnormalities
- screening blood results (other than lipids) outside of the normal range
- fasting total cholesterol >7.0mmol/l
- taking routine medication
- herbal supplement use
- food allergies or sensitivities related to the investigational product Regular citrus consumers (whole fruit or juice) daily consumption of sucrose or high fructose corn syrup containing soft-drinks
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Orange Drink Orange Juice Sugars matched, low flavonoids orange drink Orange Juice Orange Juice Juice high in flavonoids
- Primary Outcome Measures
Name Time Method Total Serum Cholesterol concentration after 3 months' intervention Fasting Serum total cholesterol concentration (mmol/l)
- Secondary Outcome Measures
Name Time Method GLP-1 After 3 months intervention Fasting Plasma GLP-1 concentration
insulin After 3 months intervention Fasting serum Insulin concentration
Low density cholesterol after 3 months' intervention Fasting Serum LDL concentration
High Density Cholesterol (HDL) after 3 months' intervention Fasting Serum HDL concentration
leptin after 3 month intervention fasting Serum Leptin concentration
IL-1 afetr 3 month intervention Serum IL-1 concentration
Ghrelin After 3 months intervention Fasting Plasma Ghrelin concentration
IL-6 After 3 months intervention Serum IL-6 concentration
Gene expression in adipose tissue after 3 months' intervention Expression of genes related to lipid metabolism in adipose tissue
Blood Pressure after 3months intervention Resting blood pressure, measured semi-supine
TNF alpha After 3 months intervention Serum TNF-Alpha concentration
Trial Locations
- Locations (1)
David Greenfield Human Physiology Unit, University of Nottingham
🇬🇧Nottingham, Notts, United Kingdom