Samsung Galaxy Watch 8 Debuts Antioxidant Index Sensor
AI-generated image · US National Wire
The new wearable feature estimates carotenoid levels in the skin to track fruit and vegetable intake, though Samsung stops short of providing a consumer-facing accuracy margin.
Samsung has introduced an "Antioxidant Index" in the Galaxy Watch 8, Watch 8 Classic, Galaxy Watch Ultra, Watch 9, and Ultra2, as Engadget first reported. The feature provides a score from 0 to 100 based on a five-second thumb scan using a BioActive Sensor.
Rather than measuring all bodily antioxidants, the sensor estimates the concentration of carotenoids—pigments found in green, orange, and yellow produce—that accumulate in the skin. Samsung reports that the sensor utilizes multi-wavelength absorption spectroscopy, employing green, purple, blue, and yellow LED lights. Photodiodes then detect reflected light to calculate the index. Samsung notes that the thumb is used to minimize interference from hemoglobin and melanin.
Samsung claims the sensor was validated using blood tests, food logs, and Raman spectroscopy, a laboratory technique. A 2023 randomized controlled trial with Samsung researchers showed that reflection spectroscopy and Raman spectroscopy correlate strongly when measuring skin carotenoids.
However, Engadget notes that Samsung has not released a specific margin of error or accuracy percentage for consumers. The company further states that the Antioxidant Index is not intended to treat or diagnose medical conditions and that factors such as stress, alcohol, and UV exposure can influence the score. Additionally, Samsung indicates it typically takes two to three weeks for dietary carotenoids to reach detectable levels in the skin. In a review by Engadget, writer Amy Skorheim found the metric to be stubborn, noting her score only fluctuated between 56 and 60 over several days, even after a deliberate one-day dietary change.