Samsung Galaxy Watch 8 tracks fruit and vegetable intake via Antioxidant Index

Samsung has expanded the health capabilities of its latest wearables by introducing an "Antioxidant Index" feature in the Galaxy Watch 8 series. The tool provides users with a non-invasive way to monitor dietary habits and healthy aging by estimating the levels of carotenoids in the skin.

Available on the Galaxy Watch 8, Watch 8 Classic, and Galaxy Watch Ultra—but notably absent from the Galaxy Watch 7—the feature utilizes the device's BioActive sensor. To obtain a reading, users press their thumb against the sensor for five seconds. The watch then generates a score from 0 to 100, which serves as a proxy for the user's intake of colorful fruits and vegetables. Samsung notes that pressing firmly on the sensor is critical because it clears blood from the area, minimizing noise and producing a more accurate read.

The Science of Skin Scanning

The technology relies on multi-wavelength absorption spectroscopy, employing a combination of yellow, blue, purple, and green LEDs. Carotenoids, the antioxidants found in various produce, absorb specific wavelengths of light, with blue light being particularly important for detection. By analyzing how this light is absorbed and reflected, the sensor can estimate carotenoid concentration.

To ensure accuracy, Samsung designed the process to minimize biological interference. Pressing the thumb against the sensor not only restricts blood flow to reduce hemoglobin interference but also helps mitigate the impact of melanin. Samsung validated the sensor's performance by comparing its results against Raman spectroscopy—a precise laboratory technique—as well as blood tests and food logs from several hundred participants.

A Shift Toward Nutritional Monitoring

While consumer wearables have traditionally focused on biometric data like heart rate, sleep patterns, and physical activity, nutrition has remained a difficult metric to track without manual diaries or invasive blood work. By quantifying carotenoids, which are among the few antioxidants measurable through the skin, Samsung is moving toward a model of "nutritional monitoring."

This shift transforms the smartwatch from a fitness tracker into a holistic wellness hub. By providing a tangible, numerical incentive to increase produce consumption, the feature targets long-term health outcomes. Increasing daily fruit and vegetable intake, even by a single serving, can lead to substantial decreases in chronic conditions over time.

What to Watch

As Samsung integrates more biochemical markers into its hardware, the industry may see a broader trend of wearables attempting to replace manual food logging with biological sensors. While the Antioxidant Index provides a baseline trend for nutrition, users will likely look for further integration with dietary apps to turn these scores into actionable meal plans. It remains to be seen if this technology will trickle down to future budget-friendly models or remain a premium feature for the Ultra and Classic lines.