What does an ORAC score really mean?
ORAC scores are commonly used on food and supplement labels as a way to advertise health benefits, but I’d guess most people don’t know what it really measures. It’s just one of those things people take as a cue as to whether something’s healthy or not.
If you’re using ORAC scores to help you make purchasing decisions you deserve to know what it is, what it isn’t, how it changes, and how it can be manipulated.
ORAC Score: A Measure of a Food’s Antioxidant Capacity
The intent of an ORAC score is to measure how powerful of an antioxidant a food is.
ORAC stands for Oxygen Radical Absorbance Capacity. It’s an assay done in a test tube that measures how much a particular substance (like acai extract or cinnamon) stops free radicals from degenerating fluorescent molecules. It’s units are called TE’s which can range anywhere from 50 to 15,000. The higher the score the more powerful the antioxidant.
What’s good about an ORAC score?
- It’s an easy way to compare the inherent antioxidant capacity of different foods
- It measures antioxidant capacity regardless of how long it takes for the oxidation to take place
- The test is more or less standard and pretty accurate for what it measures
But that raises the question: what exactly does it measure?
It might not be what you think.
How An ORAC Score Might Be Misleading
The huge knock on the ORAC score is that it’s done in a test tube, and sometimes what happens in a test tube has no correlation to what happens in your body. None.
This is likely true for the ORAC test.
- The free radicals used in an ORAC test don’t occur in the body
- There are about 1,234,845.6 different types of oxidizing reactions that can take place in your body, and an ORAC score measures exactly 1 of them.
- ORAC scores can actually differ for the same food depending on the particular method used.
- ORAC scores can lower by as much as 90% when foods are cooked or processed
- Different antioxidant molecules behave very differently in an ORAC test
- The biological significance of the ORAC test has actually not been determined
- ORAC scores can be easily manipulated.
At best it means ORAC scores can be a general approximation of the antioxidant potential of a food. At worst it means an ORAC score can be completely useless and a tool for manipulation.
Let’s talk about that.
How an ORAC Score Can Be Manipulated
The measuring units of the ORAC score can change with the density of the food. So a grape can actually have a lower antioxidant score than a raisin which comes from the exact same food source.
This means the antioxidizing capabilities of natural foods which are high in water can be underestimated while highly processed foods which have had the water and insides sucked out of them can be overestimated using an ORAC score. The ORAC score also hasn’t been officially validated by federal agencies and companies get in trouble all the time for attaching false health claims to ORAC scores.
It’s also important to understand that the value of antioxidants is dependent on the bulk quantity consumed. So even though turmeric or wolfeberry or whatever might be an extremely powerful antioxidant it still won’t mean much if you only add a teaspoon to your recipes every week. The overall effect is nil.
Which Foods Have the Highest ORAC Scores?
Despite their limitations, ORAC scores are still generally useful. Sort of. And a lot of people like to know which foods have how much of them.
Raw cocoa usually tests as having the highest ORAC score. Especially compared to “everyday” foods. Exotic fruits like Acai, wolfberry, noni, goji, etc are all reported to have very high ORAC values, but the truth is there’s no golden standard for comparing them.
The USDA offers this chart of ORAC scores from their website:
So what are the take home points?
- ORAC scores are not the holy grail of health….or even antioxidant capacity
- Be skeptical of foods that frame their value solely on their ORAC score
- Cooking significantly reduces an ORAC score
- If you do cook food, steaming food reduces ORAC scores the least
- Eat fresh, unprocessed foods and you should be fine