Eating fresh fruits and vegetables every day is important for health. But how do you actually know whether you are eating healthily? This can be done with the antioxidant index1 the Samsung Galaxy Watch8 series is very easy. The function measures the level of antioxidants in the skin and shows how diet and lifestyle affect it. Jinyoung Park, Health H/W R&D Group, Mobile eXperience (MX) Business at Samsung Electronics reports on how Samsung developed the sensor for the Galaxy Watch8 series.
Jinyoung Park, Health H/W R&D Group, Mobile eXperience (MX) Business bei Samsung Electronics
Scan for 5 seconds instead of keeping a food diary
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Detailed food diaries or blood tests are often used to find out how well you eat and how your body absorbs nutrients. The Galaxy Watch8 series offers a simple and quick way to get an assessment: press your thumb on the sensor on the back of the device for 5 seconds, the watch measures the carotenoid content in the skin and displays it as an antioxidant index.
The heart of this method is the BioActive Sensor from Samsung. “The sensor uses multi-wavelength absorption spectroscopy, in which light of different wavelengths hits the skin and the absorption and reflection patterns are analyzed,” explained Jinyoung Park. “The Samsung Galaxy Watch8 series is the first wearable to measure organic compounds in the body using skin absorption spectra.”
Carotenoids are electron-rich compounds made up of 40 carbon atoms that strongly absorb blue light. The smartwatch takes advantage of this: The sensor emits yellow, blue, violet and green LED light. Some wavelengths are absorbed by carotenoids, but others are reflected. The Samsung Galaxy Watch8 series analyzes the reflected light and can thus measure the concentration of carotenoids. “Those who regularly eat fruit and vegetables have more carotenoids in their skin. This increases the index measured by the Galaxy Watch8.” Melanin and hemoglobin in the skin can influence the measurement. “To minimize these effects, we chose the finger as the measuring point to have low melanin interference. Gently pressing the finger temporarily restricts blood flow and reduces the influence of hemoglobin,” she explained.
Small, smaller, precise
Samsung began researching sensors for the antioxidant index in 2018. The challenge: To develop a sensor that is small enough to fit in a watch, but precise enough to compete with large laboratory devices. “Even the slightest change in the arrangement of the LEDs and photodiodes could have affected the results,” recalls Jinyoung Park. “After countless tests, we finally found the right configuration.”
Sensor prototypes developed before integration into the Samsung Galaxy Watch8 series
In order to be able to measure accurately, the team sent the sensor into comparison tests with Raman spectroscopy, a laser-based technique that is often used in research and clinical practice. It determines the enriched amount of carotenoids in the skin using molecular vibrations. “Raman spectroscopy requires large, complex equipment, which makes it not practical for everyday use,” she explains. “In the Samsung Galaxy Watch8 series, we applied an LED-PD based skin reflection method to be able to use a small sensor. To ensure that it measures precisely despite its small size, we compared the results with those of Raman spectroscopy.”
The team also conducted comparative studies using blood tests and clinical trials. “We checked the accuracy of the non-invasive measurements by comparing carotenoid levels in the blood with the sensor values,” she said. “The clinical participants photographed and recorded every meal for a week so that we could compare how much fruit and vegetables they ate with the sensor data. We scientifically tested the performance of the sensor using a statistically significant sample of several hundred participants.”
Collaboration with various partners was the key to successful development. “In addition to our long-standing collaboration with Professor Hyojee Joung of Seoul National University, we have conducted clinical research with Samsung Medical Center and partnered with the University of Connecticut to collect data from various ethnic groups,” she added. “This network of experts from the fields of nutrition, medicine and consumer analysis made the development of the sensor possible.”
Make the most of the antioxidant index
How often should you measure your antioxidant index? “It typically takes 2 to 3 weeks for dietary carotenoids to be detectable in the skin,” Park explained. “We recommend eating a consistently healthy diet for at least 2 weeks and measuring once or twice a day, always at the same time.” The Samsung Health app2 gives nutritional tips based on the antioxidant index and records changes. Users can view daily, weekly, monthly and annual data to continuously monitor their well-being and lifestyle.
Beyond diet, the antioxidant index can also show changes in exercise and lifestyle. “Carotenoids decrease when excessive free radicals are formed in the body. This also happens after an unusually high level of physical exertion. Then the antioxidant index also drops. Another plus: there are tips from Google Gemini3. The AI is available for the first time on the Samsung Galaxy Watch8 series. “I once asked Gemini to suggest nearby restaurants with antioxidant-rich foods and it gave me good options,” says Jinyoung Park. “Combining the antioxidant index with personalized AI could further expand tailored care.”
A health interpreter on your finger
Park sees the antioxidant index as a kind of interpreter that makes the effects of diet and lifestyle habits understandable. “We are often not aware of how we eat or how much stress we have. I hope that the antioxidant index will help people better understand their well-being. Disease prevention also starts with healthy eating and lifestyle habits. Given the sharp increase in chronic diseases among younger generations, the antioxidant index can be a useful guide for healthier lifestyle habits.” However, the antioxidant index only shows part of the picture: “The Samsung Galaxy Watch8 series and Samsung Health offer valuable functions such as sleep value and energy value. With these functions, users receive extensive insight and a wide range of information about their well-being.”
Actively promote well-being and influence the aging process – Professor Hyojee Joung explains how this can be easily done on the wrist with the Samsung Galaxy Watch8 series in the article Aging healthily: Measuring and controlling the antioxidant content in the body.
1 Antioxidant Index is available on Android smartphones (Android 10 or later) and requires the Samsung Health app version 6.30 or later. Samsung account login required. To measure, place your finger on the sensor on the back of the Galaxy Watch and hold for 5 seconds. For an accurate result, the thumb is recommended. Repeated measurement due to uneven skin texture may produce inaccurate results. The Antioxidant Index is for fitness and wellness purposes only. This is a Labs feature that users can test before the official launch. Not intended to be used to detect, diagnose or treat medical conditions and is intended for personal information only. For medical advice, please consult a healthcare professional.
2 These features are intended for general wellness and fitness purposes only. They are not intended to detect, diagnose or treat any disease or condition. Availability of these features may vary by market or device. Requires a smartphone running Android 10.0 or later and the latest version of the Samsung Health app (version 6.28 or later).
3 Requires an internet connection, a Samsung account and a Google account login. Google and Gemini are trademarks of Google LLC. Google Gemini Live is available for ages 18+ and is only compatible with certain features/accounts. Availability or range of functions depends on individual settings, installed programs, country, language, operating system/One UI version, device model and mobile phone provider. Service availability may vary by language or region. A language pack download and/or separate setup may be required. No guarantee is given as to the accuracy, completeness or reliability of the AI results.
