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 precise carotenoid levels – the industry’s first measurable nutrition index. By miniaturizing lab-grade sensor technology with exceptional accuracy, 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[1] 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 proven 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 health insights for everyone.
1. The first prototype of the spectroscopy-based antioxidant sensor.
2. A clinical-ready version of the sensor.
3. 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.
After seven years of rigorous testing and optimizing since the first prototype, the team developed the miniaturized sensor, a groundbreaking tech that combines multi-wavelength LEDs with a custom photodetector array to provide accurate 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’s 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,[2] the watch estimates carotenoid levels with impressive accuracy. The advanced algorithms that continuously calibrate in real-time also support precision while delivering personalized insights to each user.
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, making the results more accurate.
Extensive trials conducted at Samsung Medical Center[3] 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 clear 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 health. Paired with other Galaxy Watch8 features like sleep coaching, activity tracking and Vascular Load monitoring, the Antioxidant Index offers a holistic view of your well-being, empowering smarter decisions for healthier aging.
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 Health, 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. "Over time, this simple practice can help prevent some cancers and other age-related diseases, making it a very effective way to support long-term health."
Antioxidants are an emerging area of focus, but research has been limited due to the challenges of accurate measurement. Galaxy Watch8’s Antioxidant Index goes beyond current industry developments and delivers meaningful innovation.
Samsung’s ability to measure antioxidant levels with precision, acknowledged by experts as a benchmark for future research, represents a breakthrough in health monitoring. By helping users identify risks early and take proactive steps towards better health, Samsung is paving the way for a smarter, more proactive approach to wellness and redefining the role of wearables in preventative healthcare.
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