Samsung’s latest Galaxy Watch 8 introduces a five-second thumb scan that estimates carotenoid levels to provide a new Antioxidant Index, offering users a rapid lifestyle health indicator.
Samsung has added a new nutrition-related reading to the Galaxy Watch 8 line, using a five-second thumb scan to estimate carotenoid levels in the skin and turn them into an Antioxidant Index score from 0 to 100. According to Samsung’s product pages and launch material, the feature is designed to help users gauge whether their diet may be affecting their health, alongside other tools such as the AGEs Index and Food Tracker. The company presents it as a wellness measure rather than a medical test.
The system works through the watch’s BioActive sensor, which shines multiple wavelengths of light on the thumb and analyses how the skin absorbs and reflects them. Samsung says the feature relies on multi-wavelength absorption spectroscopy and was validated against laboratory methods, including Raman spectroscopy. The thumb is used rather than the wrist because skin pigmentation and blood flow can make optical readings less reliable, while pressing the fingertip against the sensor briefly reduces interference from haemoglobin.
The measurement is not a general antioxidant test. Reports from TugaTech and Cybernews note that it focuses specifically on carotenoids, the plant pigments found in brightly coloured fruit and vegetables, rather than on all antioxidants in the body. Samsung also acknowledges that factors such as alcohol, stress and ultraviolet exposure can influence the result, which makes the score a broad indicator of lifestyle trends rather than a complete biochemical profile.
In practice, the score may change slowly. An Android Central tester said their reading improved after dietary changes, but only gradually, and TugaTech reported that even a major shift in eating habits produced only a small immediate fall before the number stabilised. That fits the biology of carotenoid storage, which can take weeks to show up in the skin. Samsung’s compatibility information currently places the feature on the Galaxy Watch 8, Watch 8 Classic and Galaxy Watch Ultra, but not the Watch 7.
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