Samsung Galaxy Watch 8 Gauges Antioxidants in 5 Seconds With 0-100 Thumb Scan
Updated
Updated · Engadget · Aug 15
Samsung Galaxy Watch 8 Gauges Antioxidants in 5 Seconds With 0-100 Thumb Scan
1 articles · Updated · Engadget · Aug 15
Summary
A five-second thumb scan on Samsung's Galaxy Watch 8 now produces a 0-100 Antioxidant Index, estimating skin carotenoids rather than measuring all antioxidants in the body.
Samsung says the watch uses multi-wavelength absorption spectroscopy—yellow, blue, purple and green LEDs plus photodiodes—to read reflected light from the thumb, where lower melanin and temporarily reduced blood flow limit interference.
Several hundred participants were used to validate the sensor against Raman spectroscopy, blood tests, food logs and clinical data, but Samsung has not published a consumer-facing accuracy rate or margin of error.
The company says the feature is not for diagnosing or treating medical conditions, and carotenoid levels typically take two to three weeks to build up in skin, making the score more useful for tracking longer-term diet trends.
Engadget's review found only small day-to-day moves—56 to 60 after a deliberate diet change—underscoring that the metric is a slow-moving wellness indicator rather than a blood-test substitute.