The objectives of this proposal are to address the gaps in knowledge regarding the metabolic effects of consuming orange juice, the most frequently consumed fruit juice in this country, compared to sugar-sweetened beverage.
The Effects of Orange Juice Compared With Sugar-sweetened Beverage on Risk Factors and Metabolic Processes Associated With the Development of Cardiovascular Disease and Type 2 Diabetes
Specific Aims: There is considerable epidemiological evidence that demonstrates associations between added sugar/sugar-sweetened beverage consumption and increased risk for or prevalence of chronic diseases such as cardiovascular disease (CVD), type 2 diabetes (T2D), metabolic syndrome, and gout. Especially concerning is recent evidence from National Health and Nutrition Examination Survey III that demonstrates that there is increased risk of CVD mortality with increased intake of added sugar across quintiles (Yang, 2014). Even the US mean added sugar intake, 15% of daily calories, was associated with an 18% increase in risk of CVD mortality over 15 years. The results from the investigator's recently completed study (1R01 HL09133) corroborate these findings (Stanhope, 2015). They demonstrate that supplementing the ad libitum diets of young adults with beverages containing 0, 10, 17.5 or 25% of daily energy requirement (Ereq) as high fructose corn syrup (HFCS) affects lipid/lipoprotein risk factors for CVD in a dose response manner. Specifically, levels of nonHDL-cholesterol(C), LDL-C, apolipoprotein B (apoB), and postprandial triglycerides (TG) increased linearly over a 2-week period with increasing doses of HFCS. Furthermore, even the participants consuming the 10% Ereq dose exhibited increased levels of these risk factors compared to baseline.
These and similar results have helped to lead to reductions in soda consumption in this country, and new dietary guidelines and FDA food labeling requirements to promote reductions in added sugar consumption. However, there are gaps in knowledge about other sugar-containing foods that lead to public confusion concerning healthier options for soda, and impede further progress in implementing public health policies that will promote further reductions in soda consumption. One such food is naturally-sweetened fruit juice. The amount of sugar in fruit juice is comparable to the amount in soda. Because of this, a consumer seeking answers on the internet will find many articles in which experts state or suggest that the effects of consuming fruit juice are as detrimental as or even worse than those of soda. However, in contrast to soda, fruit juice contains micronutrients and bioactives that may promote health. Therefore the consumer can also find numerous articles on the internet where the health benefits of fruit juice and these bioactives are extolled. There are a limited number of clinical dietary intervention studies that have directly compared the metabolic effects of consuming fruit juice and sugar-sweetened beverage, and their results are not conclusive. Thus we will pursue the following Specific Aims:
- Specific Aim 1: To compare the weight-independent effects of consuming 25%Ereq as orange juice or sugar-sweetened beverages for 4 weeks on risk factors for CVD and other chronic disease in normal weight and overweight men and women.
- Specific Aim 2: To mechanistically compare the weight-independent effects of consuming 25%Ereq as orange juice or sugar-sweetened beverages on metabolic processes associated with the development of CVD and T2D in normal weight and overweight men and women.
- Specific Aim 3: To relate the changes assessed under Specific Aims 1 and 2 to the changes in the urinary levels of metabolites and catabolites of the main flavanones in orange juice, hesperetin and naringenin.