Food as Medicine - Natural Antioxidants

Studies at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston suggest that consuming fruits and vegetables with a high-ORAC value may help slow the aging process in both body and brain. ORAC--short for Oxygen Radical Absorbance Capacity--measures the ability of foods, blood plasma, and just about any substance to subdue oxygen free radicals in the test tube.

Early evidence indicates that this antioxidant activity translates to animals, protecting cells and their components from oxidative damage. Getting plenty of the foods with a high-ORAC activity, such as spinach, strawberries, and blueberries, has so far:

• raised the antioxidant power of human blood,
• prevented some loss of long-term memory and learning ability in middle-aged rats,
• maintained the ability of brain cells in middle-aged rats to respond to a chemical stimulus,
• protected rats' tiny blood vessels—capillaries—against oxygen damage.
  

These results have prompted Ronald L. Prior to suggest that "the ORAC measure may help define the dietary conditions needed to prevent tissue damage."

Science has long held that damage by oxygen free radicals is behind many of the illnesses that come with aging, including cardiovascular disease and cancer. There's firm evidence that a high intake of fruits and vegetables reduces risk of cancer and that a low intake raises risk. And recent evidence suggests that diminished brain function associated with aging and disorders such as Alzheimer's and Parkinson's diseases may be due to increased vulnerability to free radicals.

Such evidence has spurred skyrocketing sales of antioxidant vitamin supplements in recent years. But several large trials testing individual antioxidant vitamins have had mixed results. "It may be that combinations of nutrients found in foods have greater protective effects than each nutrient taken alone," says Cao from the USDA. For example, foods contain more than 4,000 flavonoids. These constitute a major class of dietary antioxidants and appear to be responsible for a large part of the protective power of fruits and vegetables. Combinations of nutrients found in foods may have greater protective benefits than each nutrient on its own. Many people obtain a number of their daily nutrients from supplements in pill or powder form, but in order to receive the best form of nutrients, it is essential to receive them from plant chemicals rather than just from supplements. There are certain types of plants that have a better antioxidant level than others, and the ORAC score can measure these.

Different types of fruit and vegetables have different ORAC scores. The recommended “5-a-day” fruit and vegetable servings will give you an ORAC score of 1,750 units. You could pick seven fruits with a low ORAC level and achieve only 1,300 ORAC units, or you could pick seven with high values and receive around 6,000 ORAC units or more. A large handful of blueberries would give you an ORAC score of around 6,000.

Studies have shown that eating foods with a high ORAC score will raise the antioxidant levels in the blood by around 10 to 25%. The ORAC figure suggested by experts is around 5,000 units per day to have a significant effect on plasma and tissue antioxidant levels. Eating eight to ten servings of brightly colored fruits and vegetables or dark greens will help achieve this level, but only a handful of cranberries could satisfy this requirement.

Selected ORAC Values of Foods

Dried Apples 6680
Fuji apples 1236

Red Delicious Apples 4235

Red Wine 5034

Dried Apricots 3234

Red Kidney Beans 8459

Black beans 8040

Bananas 879

Blueberries 6552

Cranberries 9584

Carrots 666

Cooked Broccoli 2386

Corn 728

Oats 2169

Extra virgin olive oil 1150

Peanut Oil 106

Cocoa 80933

Almonds 4288

Green tea 1253

Chili powder 23636

Turmeric 159277

Cinnamon 267536

Oregano 200129

Ginger 28811

Source: USDA, ORAC of Selected Foods, 2007

Some surprises to me:

Beans (kidney, black) are loaded with antioxidants

Oats have a decent amount of antioxidants, but we only really consider them for fiber.

Not all oils are created equal: olive oil has 10X AOX compared to peanut oil.

Spices can really boost the antioxidants in your meals - use them profusely.

Berries are one of the richest sources of fruits - blueberries, cranberries, blackberries, strawberries.

Nuts contain a decent amount of antioxidants. Pecans and almonds are great.

Cocoa - so glad to see it on the list of rich AOX foods. Not milk chocolate, but the pure stuff.