Understanding Antioxidants

An antioxidant is a substance that counters the negative effect of oxygen.

In foods anti-oxidants prevent the oxidation of different food components. Oxidation of foods results for example in an undesirable brown colour and/or off-odours and off-flavours known as rancidity. Antioxidants are substances that react with oxygen and thus counteract the negative effects. Examples are vitamin C, vitamin E, Zinc, Alpha Lipoic Acid, Grape Seed Extract etc.

In the body antioxidants protect key cell components by neutralizing the damaging effects of "free radicals," natural byproducts of cell metabolism. Free radicals form when oxygen is metabolized, or burned by the body. They travel through cells, disrupting the structure of other molecules, causing cellular damage. Such cell damage is believed to contribute to aging and various health problems. Example of anti-oxidants which are active in the body are the vitamins A, C and E, and polyphenols (a group of plant chemicals, present in for example tea and fruits).

Scientists at the U.S. Department of Agriculture (USDA) are using modern technology to rank foods based on which has the highest concentrations of antioxidants, compounds that fight free radical damage and thereby block disease. Small red beans head their new Top 20 list in the June issue of the Journal of Agricultural and Food Chemistry

1. Small red beans (dried)
2. Wild blueberries.
3. Red Kidney beans.
4. Pinto beans.
5. Blueberries (cultivated).
6. Cranberries.
7. Artichokes (cooked).
8. Blackberries.
9. Prunes.
10. Raspberries.
11. Strawberries.
12. Red Delicious apples.
13. Granny Smith apples.
14. Pecans.
15. Sweet cherries.
16. Black plums.
17. Russet potatoes (cooked).
18. Black beans (dried).
19. Plums.
20. Gala apples.

Researchers note that color often characterizes antioxidant-rich foods. They also warn that just because a food tests high in nutrients in the lab, does not guarantee that it will be well-absorbed by the body. The processing of a food also affects its antioxidant potency. For instance, blueberries are best fresh; whereas, gentle cooking enhances the antioxidant properties of tomatoes.

The Journal of Agricultural and Food Chemistry reported a new research study focusing on the antioxidant capacities of over 100 foods. This study is the largest, most comprehensive analysis to date of the antioxidant content of commonly consumed foods.

Total Antioxidant Capacity (TAC) of the top 50 Foods

Rank	Food Item	Serving Size	TAC
1	small red bean	1/2 cup 92 g	13,727
2	blueberry, wild	1 cup 144 g	13,427
3	red kidney bean	1/2 cup 92 g	13,259
4	pinto bean	1/2 cup 96 g	11,864
5	blueberry, cultivated	1 cup 144 g	9,019
6	cranberry	1 cup whole 95 g	8,983
7	artichoke	1 cup hearts 84 g	7,904
8	blackberry	1 cup 144 g	7,701
9	raisin	1/2 cup 85 g	7,291
10	raspberry	1 cup 123 g	6,058
11	strawberry	1 cup 166 g	5,938
12	apple, Red Delicious	1 fruit 138 g	5,900
13	apple, Granny Smith	1 fruit 138 g	5,381
14	pecan	28.4 g (1 oz)	5,095
15	potato, russet raw	1 potato 369 g	4,882
16	cherry, sweet	1 cup 145 g	4,873
17	plum, black	1 fruit 66 g	4,844
18	potato, russet cooked	1 potato 299 g	4,649
19	black bean	1/2 cup 52 g	4,181
20	plum, red	1 fuit 66 g	4,118
21	apple, Gala	1 fruit 138 g	3,903
22	apple, Red Delicious peeled	1 fruit 128 g	3,758
23	apple, Gold Delicious	1 fruit 138 g	3,685
25	apple, Fuji	1 fruit 138 g	3,578
26	date, Medjool	1/2 cup 89 g	3,467
27	avocado, Haas	1 fruit 173 g	3,344
28	pear, green	1 fruit 166 g	3,172
29	pear, Red Anjou	1 fruit 166 g	2,943
30	apple, Gold Delicious peeled	1 fruit 128 g	2,829
31	macadamia	28.4 g (1 oz)	2,739
32	broccoli raab raw	1/5 bunch 85 g	2,621
33	navy bean	1/2 cup 104 g	2,573
34	orange, navel	1 fruit 140 g	2,540
35	prune	1/2 cup 75 g	2,537
36	cabbage, red cooked	1/2 cup 75 g	2,359
37	potato, red raw	1 potato 213 g	2,339
38	potato, red cooked	1 potato 173 g	2,294
39	walnut	28.4 g (1 oz)	2,267
40	pea, blackeye	1/2 cup 52 g	2,258
41	potato, white raw	1 potato 213 g	2,257
42	fig	1/2 cup 89 g	2,124
43	asparagus, raw	1/2 cup 67 g	2,021
44	grape, red	1 cup 160 g	2,016
45	pepper, yellow raw	1 pepper 186 g	1,905
46	grapefruit, red	half 123 g	1,904
47	beet	1/2 cup 68 g	1,886
48	potato, white cooked	1 potato 173 g	1,870
49	pepper, orange sweet raw	1 pepper 186 g	1,830
50	peach, fresh	1 fruit 98 g	1,826