Summer is berry season, and berries come with a familiar marketing halo. Juices, powders, and “superfruit” capsules advertise antioxidant power in big numbers: “15,000 ORAC units per serving,” “more antioxidants than 10 servings of blueberries,” “the highest ORAC score on Earth.” The implication is that a bigger number means more protection for your cells.
That number is real, but it measures the wrong thing. Here’s what ORAC is, why it doesn’t translate to your body, and what to focus on instead.
What ORAC Measures
ORAC stands for oxygen radical absorbance capacity. It’s a laboratory test. Researchers generate free radicals in a test tube alongside a fluorescent molecule that the radicals damage. Then they add a food extract and measure how long it protects the fluorescent molecule. More protection means a higher ORAC value.
As a chemistry tool, it’s useful for comparing samples under controlled conditions. The problem starts when the test-tube result gets used as a stand-in for “how healthy this is for you.”
Why the Test Tube Doesn’t Match Your Body
Most of it doesn’t get absorbed intact
Many of the compounds that drive high ORAC scores are polyphenols, such as anthocyanins in berries, catechins in tea, and procyanidins in cocoa and grape seed. Many polyphenols are poorly absorbed in the small intestine. What does get absorbed is quickly modified by the liver into different molecules, and much of the rest travels to the colon, where gut bacteria break it down into smaller compounds. Blood levels of the original polyphenols tend to be low and short-lived.
So the molecule tested in the tube is often not the molecule circulating in your body, and it’s present at much lower concentrations.
The body runs its own antioxidant system
Your cells don’t rely mainly on dietary antioxidants to neutralize free radicals. They use internal systems: enzymes like superoxide dismutase, catalase, and glutathione peroxidase, along with glutathione itself. These are regulated, ramped up and down as needed. Our guide on glutathione covers how this system works.
A current idea in nutrition research is that many plant compounds help less by directly mopping up radicals and more by acting as mild signals that nudge the body’s own defense and repair pathways. If that’s right, a higher test-tube score isn’t the relevant measure at all.
Free radicals aren’t purely bad
Free radicals and related reactive molecules also serve as signals. They’re part of how muscles adapt to exercise and how immune cells fight microbes. That’s one reason “more antioxidants” isn’t automatically better. Several trials found that high-dose vitamin C and E supplements taken around training blunted some of the adaptations exercise normally produces. Our antioxidants guide goes deeper on this balance.
Different tests give different answers
ORAC is one of several antioxidant assays. Others measure different chemical reactions, and they don’t always rank foods in the same order. A food can look outstanding on one test and ordinary on another. That inconsistency is a sign these numbers describe chemistry, not biology.
The USDA Pulled Its ORAC Database
The USDA once published a database of ORAC values for hundreds of foods. In 2012, it withdrew the database, explaining that ORAC values had no demonstrated relevance to the effects of specific bioactive compounds in the body, and that the numbers were being misused to market foods and supplements.
ORAC claims still appear on labels and websites, but the main public reference behind them was retired by the agency that created it.
What the Evidence Shows About Antioxidant Pills
If antioxidant power in a test tube predicted health, high-dose antioxidant supplements should have done well in human trials. Overall, they haven’t.
- Large trials of vitamin E, vitamin C, and beta-carotene supplements generally failed to show broad benefits for major health outcomes in well-nourished people.
- Some results were concerning. Trials in smokers found higher rates of lung cancer among those taking high-dose beta-carotene. High-dose vitamin E has been linked to an increased bleeding tendency, especially alongside blood thinners.
- Concentrated green tea extracts have been associated with rare cases of liver injury, particularly at high doses or on an empty stomach.
None of this means antioxidant nutrients are useless. Vitamin C and vitamin E are essential, and deficiency causes real problems. It means that megadoses chasing an “antioxidant” effect haven’t delivered what the marketing implies.
Why Berries Are Still Worth Eating
Debunking ORAC doesn’t make berries, tea, or cocoa less worthwhile. Diets rich in fruits and vegetables are consistently associated with better health in population studies. The reasons are likely many: fiber, potassium, folate, vitamin C, a wide range of polyphenols, and less room on the plate for ultra-processed food. Some controlled trials on berries and cocoa flavanols have reported modest effects on markers like blood pressure or blood vessel function, though results vary.
The benefits seem to come from the whole food eaten regularly, not from a concentrated number on a label. Our polyphenols guide covers the main families and where they come from.
Practical Takeaways
- Ignore ORAC claims when choosing products. Treat them as marketing, not evidence.
- Eat a variety of produce. Aim for 5 or more servings of fruits and vegetables a day. Mixing colors gives you a broader range of compounds.
- Use summer. Fresh berries, cherries, tomatoes, and leafy greens are at their best now. Frozen berries are a good option the rest of the year.
- Meet nutrient needs, don’t megadose. Adults need about 75 mg/day of vitamin C (women) or 90 mg/day (men), with an upper limit of 2,000 mg/day. Vitamin E needs are about 15 mg/day, with a supplemental upper limit of 1,000 mg/day. Most people meet these through diet.
- Be choosy with concentrated extracts. If you take one, such as green tea extract or grape seed extract, follow label doses, take it with food, and choose third-party tested brands.
Safety Notes
- Blood thinners: high-dose vitamin E, grape seed extract, and some other polyphenol extracts may add to bleeding risk. Talk to your clinician before combining.
- Smokers and former smokers should avoid high-dose beta-carotene supplements.
- Liver concerns: stop green tea extract and seek care if you notice dark urine, yellowing skin or eyes, or abdominal pain.
- Cancer treatment: some antioxidant supplements may interfere with chemotherapy or radiation. Discuss any supplement with your oncology team first.
- Pregnancy and nursing: food sources are fine, but high-dose antioxidant or herbal extracts haven’t been well studied. Check with your provider.
Bottom Line
ORAC is a test-tube measurement that doesn’t predict what happens in your body, and the USDA retired its ORAC database because the numbers were being misused. High-dose antioxidant supplements have mostly disappointed in human trials, and some have caused harm. The approach with the best evidence is plain: eat a variety of fruits and vegetables, meet your vitamin needs, and don’t pay extra for a big antioxidant number on a label.
This article is for educational purposes only and is not medical advice. Consult a healthcare provider before starting any supplement, especially if you are pregnant, nursing, taking medication, or managing a health condition.