It started with a simple question: What if you could measure your nutrition in real-time, right from your wrist?
Samsung’s Antioxidant Index on Galaxy Watch8 transforms what once seemed like science fiction into everyday technology. In five seconds, a thumb scan returns carotenoid levels – the industry’s first measurable nutrition index[1].
By miniaturizing lab-grade sensor technology, it turns your diet into an actionable metric for healthier aging. Establishing this new benchmark in wearable health tracking required years of intensive R&D, countless prototypes, and unwavering grit.
Breaking New Ground in Nutrition Tracking
Back in 2018, Samsung saw a critical gap in wearables: we could count every step and calorie, yet there was no simple way to measure how our diet impacted our health. Deeper nutritional insights were locked behind expensive and time-consuming lab tests, out of reach for many people.
As people live longer, the focus is shifting from simply increasing lifespan to improving the quality of those additional years.
“In this context, antioxidation naturally gains attention as a method to slow down aging,” explains Dr. Hyojee Joung, a Seoul National University public health nutrition expert who guided parts of the tech’s development. “If antioxidant management is neglected, Reactive Oxygen Species (ROS) accumulate in the body, increasing the risk of chronic diseases such as cardiovascular disease, diabetes, and cancer.”
This realization made antioxidants the cornerstone of Samsung’s mission. Engineers and scientists focused on carotenoids – key antioxidants and indicators of fruit and vegetable intake – to create a device small enough to sit on your wrist, yet powerful enough to turn complex antioxidant data into simple, actionable insights for everyone.
The first prototype of the spectroscopy-based antioxidant sensor
A clinical-ready version of the sensor
A prototype designed for use in skincare products
Challenge #1: How to Shrink the Lab-Grade Sensor Technology
From day one, the dream of a nutrition-tracking wearable hit an immediate snag: traditional methods for measuring carotenoid levels like Raman spectroscopy are laser-based, non-invasive and precise, but rely on bulky machines that are far from wearable. So the team’s first mission was to shrink the lab-grade tech into a coin-sized sensor.
The first prototype of the spectroscopy-based antioxidant sensor
A clinical-ready version of the sensor
A prototype designed for use in skincare products
After seven years of rigorous testing and optimizing since the first prototype, the team developed the BioActive sensor, a groundbreaking tech that combines multi-wavelength LEDs with a custom photodetector array to provide – carotenoid readings in a compact design.
“Our breakthrough was integrating reflectance spectroscopy with LEDs, which allowed us to miniaturize the technology while maintaining a high level of accuracy,” explains Jinyoung Park, a developer from Digital Health team at Samsung Electronics.
Antioxidant sensor LED-PD sensor modules
Unlike lasers, which emit a sharp, narrow wavelength, LEDs emit a broader wavelength range. By analyzing how much light is absorbed by the skin at multiple wavelengths through photodiodes, the watch estimates carotenoid levels. The advanced algorithms that continuously calibrate in real-time also support precision while delivering personalized insights to each user.[2]
The LED-PD Watch prototype testbed
Challenge #2: How to Ensure the Tech Reaches Everyone
Creating a coin-sized carotenoid sensor was a major milestone, but the next challenge was ensuring it could work accurately and reliably across diverse skin types, making it truly accessible to everyone.
To overcome challenges like melanin interference in darker skin tones, Samsung’s engineers opted to use the fingertip for measurements since it has the least melanin across all ethnic groups. They also added simple tweaks, like light fingertip pressure during scans, which helps temporarily reduce blood flow and hemoglobin interference.
Extensive trials conducted at Samsung Medical Center, included hundreds of participants, validating the sensor’s performance. This paved the way for a feature that seamlessly transitioned from the lab to users worldwide, offering an inclusive solution designed for everyday life.
How it Works:
Carotenoids are the natural red, yellow, and green pigments found in fruits and vegetables. Since our bodies can’t produce carotenoids on their own, the levels stored in the body offer a snapshot of how much fruit and vegetables someone has been eating.
This is where your Antioxidant Index score comes in, reflecting your carotenoid levels based on these categories:
Very low: Less than 50% of the daily WHO recommendation of 400g per day.
Low: Between 50%–100%.
Optimal: 100% or more.
“Skin carotenoids metabolize and accumulate in tissues gradually, so short-term changes in fruit and vegetable intake won’t immediately appear in the score,” explains Dr. Hyojee Joung. “Our research shows that increased carotenoid intake leads to a meaningful rise in skin carotenoid levels after about one to two weeks, making the Index a valuable tool for tracking consistent, long-term dietary habits.”
Lifestyle factors like sleep quality, stress levels, and physical activity also influence the Index, making it a well-rounded indicator of overall wellness. Paired with other Galaxy Watch8 features like sleep coaching[3], activity tracking and Vascular Load monitoring[4], the Antioxidant Index offers a holistic view of your wellness, empowering smarter decisions.
The Antioxidant index feature measures carotenoid levels in seconds with the sensor on the back of the Galaxy Watch8 and provides additional nutritional insights on paired Galaxy smartphones.
Your Wellness, Reimagined
“New wearable sensors can play a role in helping people build healthy eating habits by tracking and encouraging sufficient daily intake of fruits and vegetables,” says Professor Yoonho Choi from Samsung Medical Center.
Antioxidants are an emerging area of focus, and research has been limited due to the challenges of accurate measurement. But Galaxy Watch8’s Antioxidant Index goes beyond current industry developments and delivers meaningful innovation.
Samsung’s ability to measure antioxidant levels is a game-changer in health monitoring. By helping users identify risks early and take proactive steps towards improving their wellness, Samsung is paving the way for a smarter, more proactive approach and reimagining what role wearables can play.
[1] To measure, place the center of your finger on the sensor at the back of the Watch and hold it for 5 seconds. While Anti-oxidant index can be measured using any finger, the thumb is recommended for most accurate result. Repeat measurement if there is uneven placement of finger. Requires Samsung Account login and Samsung Health app 6.27 or later. Available on devices with Android OS 10 (Q OS) or later. AGEs is supported in Samsung Galaxy Watch7 and later released Samsung Galaxy Watch models only. Not intended for use in detection, diagnosis, treatment of any medical condition. Anti-oxidant monitoring is for your personal reference only. Please consult a medical professional for advice.
[2] Not intended for use in detection, diagnosis, treatment of any medical condition or diseases. The measurements are for your personal reference only. Please consult a medical professional for advice. Accuracy of results is not guaranteed.
[3] Sleep tracking features are intended for general wellness and fitness purposes only. Not intended for use in detection, diagnosis, treatment of any medical condition or sleep disorder. The measurements are for your personal reference only. Please consult a medical professional for advice. Sleep Coaching requires sleep data of at least 7 days, including 2 days off. Requires the latest version of the Samsung Health app (version 6.27 or later).
[4] Vascular Load is available on Android phones (Android 10 or above) and requires the Samsung Health app (V6.30 or above). Samsung account login is required. To measure vascular load, it is required to wear Galaxy Watch (Galaxy Watch Ultra, Watch8 and later release Galaxy Watch series) when sleeping for at least 3 days out of recent 14 days. Vascular load monitoring is for fitness and wellness only. If you have been diagnosed with cardiovascular disease or are recovering from surgery, be sure to follow your doctor’s treatment plan. Not intended for use in detection, diagnosis, treatment of any medical condition or diseases. This is a Labs feature that you can preview before its official launch. If you don’t want to use this feature, you can turn if off in Samsung Health settings.