Handling fruit before blood sugar testing may throw off results

While eating more fruit can help diabetics minimize their risk of heart disease, it may lead to elevated blood sugar test results. However, this is not necessarily because their blood sugar is higher after eating a piece of fruit. Researchers from Juntendo University Graduate School of Medicine in Tokyo have found that tiny scraps of fruit can stay on the fingers of diabetics, which can throw off test results.

Most diabetics have to regularly test their blood sugar levels throughout the day. This is an important part of making sure their condition is not worsening. If these results are not accurate, it could pose a significant risk to their health.

For the study, which was published in the journal Diabetes Care, the researchers asked a group of healthy participants who had normal glucose tolerance to test their blood sugar after peeling an orange, some grapes or a kiwifruit. Some of the participants were asked to either wash their hands or clean their fingers with an alcohol swab prior to submitting to the blood sugar test.

Regardless of whether individuals cleaned with alcohol, the researchers found that participants' blood sugar readings came back alarmingly high. Only hand washing was shown to mitigate the effects of handling fruits before testing.

Given the fact that the participants were free of any metabolic dysfunction, the researchers concluded that the elevated test results could only have been caused by interference from peeling the fruit.

"To avoid overestimation of blood glucose using portable monitors, the hands should be washed before monitoring capillary blood glucose, especially after fruit has been handled," the researchers wrote in their report.