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 University¹ 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.

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.

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.

▲ Galaxy Watch8’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 photodiodes², 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 prototype testbed at the back of Galaxy Watch8.

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 Center³ 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.

¹Seoul National University is a leading academic institution in South Korea.
²Photodiodes are semiconductor devices that convert light into electrical signals.
³Samsung Medical Center in Seoul, South Korea, is a leading medical institution known for its patient-centered care, advanced medical technologies, and specialized centers such as the Comprehensive Cancer and Proton Therapy Centers.

▲ Photo copyright: Regents of the University of Michigan. Eric Bronson/Michigan Photography.

Samsung Electronics, together with the University of Michigan, today announced that the University of Michigan Human Performance & Sport Science Center (HPSSC) — renowned for its integrated and comprehensive sport, exercise, and human performance-related research and education — has validated the high accuracy of Samsung Galaxy Watch’s fitness tracking features.

HPSSC’s Michigan Performance Research Laboratory (MiPR) found a significant correlation between Galaxy Watch and the clinical and sport science reference devices’ measurement of heart rate, sweat loss, VO₂ max and body fat percentage measurements, validating the reliability of Galaxy Watch’s monitoring capabilities. This partnership demonstrates how the collaboration between the two organizations makes advanced and precise fitness solutions to more people.

The MiPR studies verified the accuracy of Galaxy Watch’s fitness tracking features by monitoring key metrics from elite runners, including:

• Heart rate: As the most commonly checked health metric during workouts, heart rate measures how hard the heart works during physical activity. Findings show an excellent 90% correlation with electrocardiogram equipment while running, the gold standard in heart rate measurement.
• Sweat loss: Sweat loss estimates the amount of fluid lost during physical activity and helps guide proper hydration after workouts. The study found a 95% correlation for Galaxy Watch in assessing sweat loss over varying distances ranging from 2.5 km to 20 km.
• VO₂ max: Understanding how much oxygen the body absorbs during a workout helps individuals assess their fitness levels and set optimal goals and limits. The study demonstrated an 82% correlation, indicating acceptable alignment between Galaxy Watch and clinical-grade diagnostic equipment.
• Body fat percentage: Measuring a person’s body fat percentage allows for a better understanding of physical health and fitness than tracking body weight alone. Galaxy Watch readings showed a 95% correlation with dual-energy X-ray absorptiometry (DEXA) results, the standard diagnostic test for body composition using low-dose X-rays.

“We’re proud to be recognized by the renowned Michigan Performance Research Laboratory — their skilled researchers and expertise in wearable technology give us confidence in the accuracy of the Galaxy Watch’s fitness tracking capabilities,” said Dr. Hon Pak, Senior Vice President and Head of Digital Health Team, Mobile eXperience Business at Samsung Electronics. “We are committed to delivering precise and insightful fitness tracking experiences through strategic partnerships and advanced research.”

“Our partnership with Samsung exemplifies the power of combining industry-leading expertise with pioneering independent research at the academic level,” said Co-PIs Adam Lepley, MiPR director and associate director of HPSSC research. “Together, we can advance scientific discovery and provide information back to consumers that will enhance the use of Samsung’s technology. This synergy underscores the power of uniting academic excellence with industrial innovation, and we are grateful for this collaboration.”

“We are excited to continue our partnership with Samsung to ensure that innovations in wearable technology are accessible and accurate across all segments of the population,” said Kenneth Kozloff, HPSSC co-director. “HPSSC and MiPR are eager to unveil these outstanding outcomes that solidify our commitment to enhancing heart rate and health monitoring and are look forward to future collaborations.”

The following tips can enhance your fitness journey with the Galaxy Watch series, from setting personal goals to post-workout recovery:

• Body composition¹: Get a comprehensive snapshot of your body, including body fat percentage, body water content and skeletal muscle mass. Set personalized goals based on your current body status and track your progress.
• Personalized heart rate zone: Creating a personalized heart rate zone tailored to your activities allows you to align your health and wellness objectives, and train at optimal intensity levels according to your physical capabilities.
• VO₂ max²: Gain deeper insight into your fitness levels by analyzing how much oxygen your body uses during physical activity. VO₂ max is widely regarded as the best indicator of cardiovascular endurance.
• Sweat loss: After a run, measure your sweat loss and re-hydrate appropriately after each workout based on data​ for improved recovery.

About HPSSC and MiPR.

The Human Performance & Sport Science Center supports and grows integrated and comprehensive sport, exercise, and human performance-related research and education across the University of Michigan. Through innovative and cross-disciplinary projects, HPSSC seeks to translate sport and exercise research discoveries into communities of all types, ages, and abilities. HPSSC’s Michigan Performance Research Laboratory (MiPR) helps elite athletes and everyday exercisers achieve their personal best. The MiPR team investigates the biomechanics and physiology of human movement to optimize function, enhance injury resiliency, and ensure lifelong health. Learn more at hpssc.umich.edu and hpssc.umich.edu/performance-lab.

¹ Body Composition is only supported in Samsung Galaxy Watch4 series and later released Galaxy Watch models. Body Composition should not be used if you have an implanted pacemaker or other implanted medical devices, or if you are pregnant. Any health-related information accessed through the device and application should not be treated as medical advice. Measurement results may not be accurate if you are under 20 years old. The measurements are for your personal reference only. Please consult a medical professional for advice.
² Accurate VO2 max reading requires running outdoors for at least 20 minutes with GPS on; consult user manual before use.

Today, more than ever, people are defining their own wellness goals. From looking to stay fit or gaining more muscle mass, achieving better sleep, or caring for personal or family physical and mental health issues, everyone’s goals for better health look different. But one thing is common, the daily management and path towards these goals can be complicated and challenging, and most importantly, it is defined by you.

That’s why at Samsung, we’re working to empower more people to manage their health — and those they care for — their way, with a comprehensive, yet simplified approach to everyday wellness. Our vision is to improve the health of billions through connected care centered around the home by connecting devices, services and people — like only Samsung can.

Simplifying Wellness by Uniting Scattered Health Data

One of the biggest challenges the healthcare industry is facing today is fragmented data and how to bring it all together. Samsung is uniquely positioned to undertake this with one of the largest, most diverse connected device ecosystems. Now with Samsung Health, we’re connecting different devices and partner solutions within one cohesive platform, making it simpler to track health conditions on a Galaxy wearable.

By collecting data through advanced sensor technology, you’ll receive a deeper, more holistic understanding of your health with improved insights and integrated third party health data. And as always, your personal data on the Galaxy devices remains secure thanks to the Samsung Knox security platform.

Turning Data Into Meaningful Insights With the Transformative Power of AI

Like any good data model, how you leverage the information is key. In this new mobile era of AI, Samsung is focused on remaining at the forefront of maximizing information. With the intelligence of AI, the most transformative technology of the century, users will receive more personalized insights and tailored health experiences through Samsung Health’s extensive global dataset from 64M monthly active users. And while every user’s wellness journey is unique, we believe they all start in the same way — by gaining a deeper understanding of their health through more comprehensive insights, spanning the longest time possible.

This is why we’ve continued to build a portfolio of tools that help track their health conveniently, continuously and accurately. This approach comes to life in our wearables portfolio with upcoming features like My Vitality Score¹ and Booster Card,² combining more data with new intelligent analysis to deliver even more personalized and actionable guidance day and night.

Bringing It All to Life Starting With a Good Night’s Sleep

With more data and greater intelligence, users will receive even more insights for preventative wellness end-to-end solutions, starting with sleep. We’ve developed a variety of features that offer users a deeper understanding of their sleep quality and other aspects of their health during sleep. For example, the sleep apnea feature, which recently received De Novo clearance from US FDA, will detect signs of moderate to severe obstructive sleep apnea — and often undiagnosed and untreated — chronic medical condition, so they can address it with their healthcare provider.

This is just the beginning. We’re working with partners to connect these capabilities to real world solutions and services that expand access to healthcare in the home. For instance, you can create a more optimal sleep environment with a smart mattress that can fine-tune the ideal sleep temperatures for rest.

The Future of Wellness Is at Your Fingers

Samsung recognizes that gaining a deep understanding of one’s personal health can result in significant long-term wellness benefits for our users. As we look to deliver on our vision of providing users with a comprehensive yet simplified approach to everyday wellness, we realize choice is a big factor. Obtaining accurate, detailed and advanced information on personal health conditions is the foundation of helping better track and action change.

Mobile devices will become the primary access point for AI, and through Samsung Galaxy — with our broad and comprehensive product portfolio, heritage of innovation and philosophy of open collaboration — we’re well positioned to accelerate its global expansion. That’s why we’re thrilled to be introducing Samsung Galaxy Ring later this year — bringing Samsung’s accumulated innovations to the smallest form for comfortable 24/7 wear. As a new addition to our wearables portfolio, Galaxy Ring will offer users an all-new way to simplify everyday wellness, empowering them with greater insights and more ways to understand themselves day and night. With Galaxy Ring, users can embrace an unrivalled experience during every step of their wellness journey, all while being delivered in lockstep with Samsung’s broader vision for a more connected, integrated and seamless digital wellness platform.

Samsung will continue to enrich and expand Galaxy AI experiences across our product categories and collaborations to bring forward mobile experiences that defy imagination. The launch of Galaxy Ring is just one of Samsung’s many initiatives that exemplifies this and delivers on our vision of improving the health and wellness of billions, starting at home, with you. Through the power of intelligence, partnerships and advanced technology, we’re helping more people better understand themselves and make the small changes that have a big impact, every day. With this, the power of Galaxy AI and many more exciting health and wellness solutions and updates on the horizon, we can’t wait for you to see what we have in store.

¹ My Vitality Score will be made available on Samsung Health within 2024. Availability may vary by market, carrier, or wearable device. Features are intended for general wellness and fitness purposes only. The measurements are for your personal reference only. Please consult a medical professional for advice.
² Booster Card will be made available on Samsung Health within 2024. Availability may vary by market, carrier or wearable device.