By Emily Reich, RD
From smartwatches that track your heart rhythm to continuous glucose monitors (CGMs) that show real-time blood sugar data, these up and coming devices promise unprecedented insight into your body. But what does the evidence actually tell us about their benefits and limitations? At Princeton Longevity Center, we believe in evidence-based approaches to health optimization. In this article, we’ll break down what wearable technology can and cannot do for you, and how to use these tools wisely.
Activity Trackers
Fitness trackers and smartwatches are everywhere, and the evidence supporting their effectiveness is encouraging. Research has shown that activity trackers can help increase physical activity by approximately 1,800 extra steps per day, add about 40 minutes of additional walking time daily, and reductions of approximately 1 kg in bodyweight. [1,2].
For step counting, devices like the Fitbit, Apple Watch, and Garmin have demonstrated to be relatively accurate and reliable. However, accuracy was shown to vary depending on what is being measured. Step count and heart rate tended to be accurate, but energy expenditure had poor accuracy [3].
Heart Rhythm Detection
One of the most promising applications of wearable technology is detecting atrial fibrillation (AFib), a heart rhythm disorder that significantly increases stroke risk and heart disease. Research has shown that smartwatches have shown excellent diagnostic accuracy for AFib detection, with sensitivity of approximately 95% and specificity of 97% [4].
There was a large study done that specifically took a closer look at apple smartwatches in relation to AFib, and this study enrolled over 419,000 participants. It found that among those who received an irregular pulse notification from their watch, they ended up having an 84% positive predictive value for AFib [5]. This has significant implications for stroke and heart disease prevention, as AFib is often silent or minimally symptomatic. Approximately 700,000 people in the United States may have undiagnosed AFib, and these wearable devices can be a great step in the right direction for assistance with this [6].
Continuous Glucose Monitors
Continuous glucose monitors were created for people with diabetes to track their blood sugar 24/7. For people with diabetes, CGMs have demonstrated clear benefits: improvements in hemoglobin A1c, reductions in hypoglycemia, and better time spent within the target glucose ranges [7]. CGMs also show promise for prediabetes, supporting dietary changes, reducing weight gain, and improving A1c levels [8].
Recently, there has been growing interest in using CGMs for prediabetes management and general wellness and disease prevention [9]. This is for the purported use of improving mental or physical performance and promoting motivated healthy behavioral changes.
One of the most compelling findings is that people respond very differently to the same foods. A study continuously monitoring glucose levels found high variability amongst different people in responses to identical meals [10]. This suggests that universal dietary recommendations may have limited utility, and personalized approaches could be more effective. Using CGMs could be a great way to replicate this research to identify someone’s unique dietary needs.
CGMs may also help detect early abnormal glucose regulation before it shows up on standard blood tests. Learning how different foods and physical activity affect your glucose response can provide valuable insights for optimizing health [11].
Important Considerations
While wearable technology offers many benefits, there are important caveats to consider before using them. Wearable use can lead to obsessive tendencies, rumination, and anxiety for some individuals. The constant availability of data may trigger unhealthy fixations around diet, exercise, and health metrics [12]. In addition to unhealthy fixations, the abundance of data from wearables can be overwhelming for some, so understanding what the numbers mean, and what is actually normal for you, often requires professional guidance for patients [13].
With that being said, these devices should be interpreted by a medical provider for proper assessment. Lastly, certain devices have been found to generate false positives at times, potentially causing unnecessary anxiety. Research has shown that false atrial fibrillation alerts from smartwatches can negatively impact perceived physical well-being and confidence [14].
Our Recommendations
Wearable health technology can be a valuable tool when used appropriately. Here’s how to get the most benefit:
- Focus on actionable data. Step counts, activity trends, and sleep patterns are generally reliable and can motivate positive behavior change. Energy expenditure and calorie burn calculations are less accurate and should be interpreted cautiously.
- Consider your risk factors. If you have a family history of diabetes, have had gestational diabetes, or have other risk factors for heart disease, wearables may provide meaningful early detection benefits. If you’re generally healthy with no risk factors, the utility is less clear.
- Work with your healthcare team. The data from wearables is most useful when interpreted by a physician, registered dietitian, or other healthcare professional who can put the numbers in context.
- Monitor your relationship with the technology. If tracking becomes anxiety-provoking rather than empowering, take a step back. Consider reducing notification frequency or taking breaks from monitoring.
- Don’t ignore health assessments. Wearables complement, but don’t replace comprehensive health evaluations. A full assessment from your physician provides a more complete picture of your health than any wearable device alone. Contact us today for a comprehensive health assessment at Princeton Longevity Center.
Summary
Wearable health technology is an exciting new aspect of preventive medicine, being used to help individuals make healthier choices and lifestyle changes. However, these tools work best as part of a comprehensive health strategy guided by medical professionals, not as a replacement for expert care. If you’re considering using wearable technology as part of your health plan, we encourage you to discuss it with your healthcare team to determine if it’s the right fit for your individual needs and goals.
References:
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