Q: Can fitness trackers, like Fitbit, cause cancer or other health problems?
A: There’s no conclusive evidence that wearable technology devices, which emit low-powered, non-ionizing radio frequency (RF) energy, are either safe or risky. Typically worn all day and sometimes at night, the devices use low-powered Bluetooth technology, Wi-Fi, or a 3G/4G connection to send data (such as the number of steps you take) to your smart phone, computer, or cloud storage. The Federal Communications Commission (FCC) sets limits for how much RF energy the devices can emit.
Proponents of the devices maintain that the level of RF energy emitted is too low to be of concern. But some experts, including Joel Moskowitz, Ph.D., at the UC Berkeley School of Public Health, believe that biological effects could occur even at low RF levels because of interference with the normal electrical fields generated by processes within body cells, particularly those involving proteins and genes.
Dr. Moskowitz cites animal studies showing that low-intensity exposures can generate free radicals, damage DNA, and disrupt the blood-brain barrier (which normally prevents pathogens and toxins from reaching the brain), among other potential adverse effects.
Moreover, though these devices emit even less RF energy than cell phones, the exposure is more continuous. According to Dr. Moskowitz, “We don’t know the long-term effects because there hasn’t been any published research that has examined the long- or short-term health consequences of wearing activity trackers around the clock.”
What to do: More studies are needed to settle the safety debate. If you want to be ultra-cautious and minimize RF exposure from these devices, turn off the all-day sync setting (sync it only when the device is off your body). Or use a device that you can plug into your computer to sync the data, rather than having it transmit the information wirelessly. If you do keep the wireless sync setting on, you might want to avoid wearing the device near your head, abdomen, breasts, or reproductive organs, especially if you’re pregnant (keep it in your bag, not in your pocket or clipped to your bra, for instance).