With few exceptions, whole fruit is a good source of vitamins (e.g., A, B and C), minerals (e.g., magnesium and potassium), antioxidants (e.g., flavonoids and phenolic acids) and dietary fibre (e.g., cellulose and pectins), and has a relatively low energy density. It is therefore probably not a surprise to read that regular fruit consumption has been associated with a reduced risk of several chronic diseases as well as improved glycemic control in people with type 2 diabetes (see this month’s DIABETES CARE).
Sugar-sweetened beverages (SSBs), on the other hand, are generally high in added sugars (e.g., glucose, fructose and/or sucrose), and generally don’t contain any dietary fibre, vitamins or minerals, unless they have been fortified. As most people know, consumption of large amounts (more than 1 – 2 Cups (250 – 500 mL) a day) of SSBs is associated with weight gain and the risk of associated chronic diseases like type 2 diabetes, heart disease and stroke.
As well as elevated blood glucose levels, high levels of blood insulin, blood fats (cholesterol and triglycerides), blood pressure and blood uric acid are considered to be cardiometabolic risk factors, increasing the risk of having a heart attack, stroke and gout, amongst other things.
With all this in mind, Lisa Te Morenga and colleagues recently hypothesized that due to its more favourable nutritional properties, fruit would have a more favourable effect on cardiometabolic risk factors than sugar-sweetened beverages. They randomly provided 41 overweight (average BMI 32 kg/m2) but otherwise healthy men (21) and women (20) with either 6 items of fresh (bananas and apples) and dried (raisins) fruit per day or 955 mL of sugar-sweetened soft drink per day, in addition to their usual (ad libitum) diet, for 4 weeks. The interventions were matched for both energy (fruit: 1,800 kilojoules/day; soft drink: 1,767 kilojoules /day) and fructose content (fruit: 51.8 grams/day; soft drink: 51.7 grams /day). The soft drink intervention provided 101 grams of total sugars, which was all added sugar and the fruit intervention provided 97 grams of total sugars, which were all natural sugars.
Much to the researcher’s surprise, there were no changes in body weight, blood pressure or other cardiometabolic risk factors (fasting blood glucose, insulin, cholesterol or triglycerides), except for uric acid (men only), in either of the groups, suggesting that participants sub-consciously moderated their overall food intake to compensate for the extra energy from sugars. The rise in uric acid may increase the risk of men developing gout, who are more prone to the condition than women.
The authors concluded “… that public health approaches to reducing population obesity focusing only on reducing sugary drink intake may not be particularly effective and should focus on improving the quality of population diets as a whole.”
- Te Morenga and colleagues. No Effect of Added Sugars in Soft Drink Compared With Sugars in Fruit on Cardiometabolic Risk Factors. Front Nutr. 2021
Dr Alan Barclay, PhD, is a consultant dietitian and chef with a particular interest in carbohydrates and diabetes. He is author of Reversing Diabetes (Murdoch Books), and co-author of 30-plus scientific publications, The Good Carbs Cookbook (Murdoch Books), Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment Publishing).