For people with diabetes, fructose is perhaps the most controversial of the three main forms of dietary sugar (the others are glucose and galactose, which joins with glucose to form lactose in milk products). While the risks of glucose are clear — it raises blood glucose levels — and lactose seems to be fine unless a person is lactose-intolerant, there has often been conflicting evidence regarding the health effects of fructose. On the one hand, it tends to have only a modest effect on blood glucose levels because it must be broken down gradually by an enzyme in the liver, which converts it to glucose that the body can use for energy. On the other hand, fructose has been implicated in raising triglyceride levels in the blood as well as blood pressure. Is there any way to weigh its risks and benefits?
That is what scientists recently tried to do in an analysis of 18 clinical trials that studied fructose consumption, published in the journal Diabetes Care. These trials were selected on the basis that their participants had Type 1 or Type 2 diabetes, they lasted at least seven days, and they measured the effects of dietary fructose on fasting blood glucose and insulin levels as well as HbA1c. These were all randomized controlled trials in which a standard meal plan was compared with one containing more fructose but the same number of calories.
According to an ANI (India) article on the analysis, the researchers found that fructose had an overall beneficial effect on blood glucose control, as measured by HbA1c. This effect was accomplished without any detected adverse effects on body weight, blood pressure, or blood cholesterol, and no change in insulin levels. Meanwhile, the average reduction in HbA1c from fructose substitution was 0.53%, representing a major impact on blood glucose control.
Of course, the studies included in the analysis could have been too short to detect negative health effects associated with fructose — and for this reason, the researchers recommended long-term clinical studies to find out more. At the same time, the lack of any measurable negative effects suggests that in the real world, the root of many problems associated with fructose may be overconsumption. Since it tends not to spike blood glucose levels, some people with diabetes may consume it at unhealthy levels rather than using it as a substitute for moderate levels of other forms of sugar. Fructose is available in pure granulated form — often called crystalline fructose — and it is also the main sugar found in agave syrup, which many people use as a beverage sweetener and honey substitute.
Do you use fructose regularly as a sweetener? Why or why not — are you concerned that it might raise your blood pressure or triglyceride level? Do you find zero-calorie sweeteners more or less appealing? If you have concerns about fructose, do they apply only to refined forms of it, or also to naturally occurring fructose in fruit? Does this analysis make you want to add agave nectar to your coffee? Leave a comment below!