Study pits fruit juice vs sugar drinks for insulin resistance
per cent fruit juice instead of sugary drinks have a reduced risk
of insulin resistance, providing more argument for long-term
studies using direct measures.
Sugary drinks have previously been implicated in rising obesity rates and other lifestyle diseases such as type II diabetes. In view of the overwhelming shift towards healthier eating, beverage makers are offering more and more healthyproducts alongside their sweet offerings - and these can include fruit juices. The study involved 2,500 healthy adults who were enrolled in the Framingham Offspring Study. The subjects self-reported usual dietary intake of sugar-sweetened soft drinks, diet soft drinks, and fruit juice over the past year, and these data were then used to determine average consumption. The researchers then took blood samples from the subjects after an eight-hour fast, and measured insulin and glucose levels. Both high fasting insulin and high fasting glucose levels are precursors to type 2 diabetes. Fasting glucose levels were not seen to be significantly different between those who drank sugary drinks and those who did not - but fasting insulin levels were significantly affected. By contrast, participants who reported drinking two or more servings of 100 per cent fruit juice per day had "modestly lower" fasting glucose levels than those who did not consume fruit juices. Although at face value the results could be taken as an exhortation to consume more juice, corresponding author Nicola McKeown, PhD, of the USDA's Epidemiology Program, urged caution. "While 100 per cent fruit juice can be a healthful beverage, too much fruit juice can add excess calories and sugar to the diet," she said. Rather, she said, whole fruit is often a better choice. Amongst the limitations to the study is the fact that the researchers were relying on self-reporting. Paul Jacques, director of the Epidemiology Program and a professor at Tufts University, said that although the lack of impact seen on glucose and insulin in the juice consumers could be a result of nutrients and phytochemicals, the observation could also be down to these people having a healthier overall diet. Jacque and McKeown cautioned against using their results to claim a cause and effect link between sugary drinks and insulin resistance. While they said that consumption of these drinks could be an important determinant for insulin resistance, more long-term studies, using direct measures of insulin-resistance, are needed. Global drinks consumption rose by 2.5 per cent during 2005, according to the globaldrinks.com, Zenith International's online database. The total volume consumed was 1.47 million million (trillion) litres, equivalent to 227 litres per person. The rise in beverage sales was driven mainly by soft drinks, whose worldwide consumption increased by 3.9 per cent to 499 billion litres, equal to 77 litres per person. But in the context of growing concern about obesity levels and greater public interest in health, it is interesting to note that the advance of soft drinks was led by better for you categories such as bottled water, fruit drinks and functional drinks. Source: The Journal of Nutrition September 2007, 137: 2121-2127 "Surrogate markers of insulin resistance are associated with consumption of sugar-sweetened drinks and fruit juice in midlle and older-aged adults." Authors: Yoshida M, McKeown NM, Rogers G, Meigs JB, Saltzman E, D'Agostino R, Jacques PF.