Radical absorbent capacity values for fruits and vegetables - South Asia Mail

Radical absorbent capacity values for fruits and vegetables - South Asia Mail

Dr. David Williams

Several years ago, U.S. Department of Agriculture tested a wide variety of foods for what they call their ORAC (Oxygen Radical Absorbance Capacity) values. This is simply a test which measures the ability of foods and other compounds to subdue oxygen free radicals.

As I’m sure you’re aware, long-term free radical damage is now recognized as the greatest contributor to age-related health problems. By limiting the activity of oxygen free radicals, antioxidants protect cells and their components from this damage—thereby lessening the risk of cancer, heart disease, vision problems, and other diseases. The higher the ORAC value of a food, the more beneficial it is to your health.

The following is a list of the fruits and vegetables with the highest ORAC values:

ORAC Values of Fruits and Vegetables

(per 100 grams, or 3.5 ounces)

VEGETABLES FRUITS

Kale 1,770 Prunes 5,770

Spinach, raw 1,260 Raisins 2,830

Brussels sprouts 980 Blueberries 2,400

Alfalfa sprouts 930 Blackberries 2,036

Spinach, steamed 909 Cranberries 1,750

Broccoli florets 890 Strawberries 1,540

Beets 841 Raspberries 1,220

Red bell pepper 713 Plums 949

Onion 450 Oranges 750

Corn 400 Grapes, red 739

Eggplant 390 Cherries 670

Cauliflower 377 Kiwifruit 602

Peas, frozen 364 Grapes, white 446

White potatoes 313 Cantaloupe 252

Sweet potatoes 301 Banana 221

Carrots 207 Apple 218

String beans 201 Apricots 164

Tomato 189 Peach 158

Zucchini 176 Pear 134

Yellow Squash 150 Watermelon 104

The researchers didn’t just stop at analyzing the different fruits and vegetables for their ORAC values. They also started testing what effects could be obtained by eating these high-ORAC foods. The results were amazing to say the least.

First, eight women were given various test meals containing either high-ORAC foods, red wine or vitamin C. (Red wine also has a high-ORAC value.) They discovered that 10 ounces of fresh spinach produced the greatest increase in the women’s blood antioxidant levels—even more than 1,250 milligrams of vitamin C. Researchers found that simply eating these high-ORAC foods could raise the antioxidant capacity of the blood in humans anywhere from 10 to 25 percent.

Next, they set up tests with mice to determine just what effects increasing the antioxidant capacity of the blood by these amounts might have on overall health. When the antioxidant levels in mice were increased to these levels using extracts of these same foods, many of the most common problems and diseases associated with aging were prevented by including these foods in the diet.

Researchers documented health benefits observed in mice fed high-ORAC food extracts, and the results are astounding. (For simplicity’s sake, I’ll refer to the mice fed the high-ORAC foods as the ORAC mice.)

Older and middle-aged ORAC mice exhibited significantly better long-term memory and retained more of their learning ability as they aged than mice fed normal diets. Also, brain cells of the ORAC mice maintained the ability to respond to chemical stimulus, counter to the brains of normally aging that became less responsive.

The ORAC mice also had the highest scores in tests designed to measure the brain’s ability to maintain balance and coordination. Additionally, the small blood vessels (capillaries) of the ORAC mice were much stronger than normal and exhibited less damage and resisted leakage.

Eat Whole Foods…

In each and every one of these situations, there’s no reason to believe that the same or very similar effects couldn’t be achieved in humans. There are two factors you should keep in mind in terms of applying this research in your own life: there’s no substitute for whole foods and food-based supplements, and consistency is the key.

Consuming whole foods is critical to achieving the benefits seen in the ORAC mice—and the benefits seen in decades of human clinical research on antioxidants. This is because antioxidants do not have their beneficial effects when isolated. For example, a couple studies published some years ago appeared to associate beta-carotene with increased risk of certain diseases. However, this wasn’t consistent with numerous other studies which showed that the nutrient offered significant protection against these diseases.

There are between 400 and 500 different carotenes, yet many studies only use beta-carotene. While we know that beta-carotene can increase life expectancy on its own, the most consistent benefits are seen when it is naturally combined with these other carotenes.

Studies in the past few years have shown that the carotene lutein protects the macula and retina from light radiation, and the carotene lycopene offers significant protection against prostate cancer (and, according to some very early research data, against breast cancer, as well).

To get a complete mix of carotenes in your diet, include spinach and other green leafy vegetables, yams, sweet potatoes and carrots. Supplements like the algae spirulina are also a good source of carotenes.

The researchers informed me that to achieve results like those exhibited in the animals above, a human would need to consume between 3,000 and 5,000 ORAC units every day. You can achieve this by eating a hefty serving of a high-ORAC fruit or vegetables, or moderate portions of two or more.

…on a Consistent Basis to Maximize Antioxidant Benefits

The second thing to keep in mind about these studies is the fact that the daily antioxidant capacity of these animals’ blood was kept very consistent over time. I don’t think the importance of consistency can be over-stressed. As you go through the different phases of life, periods of increased stress, illnesses and injuries, and the unpredictable demands of everyday living, your body’s needs for antioxidants and other nutrients change. The only way to ensure that you’re meeting these needs is to be consistent with your diet and supplement program. Your body cannot stockpile antioxidants, and there’s no way to predict when you’ll need them.