Wu X, Beecher GR, Holden JM, Haytowitz DB, Gebhardt SE, Prior RL., Thu, 12/23/2004
Energy for cellular processes is produced in the mitochondria. During the process, free radicals are produced. This is a molecule of oxygen with only one electron, not with two electrons that are bonded together which is the normal form of oxygen. This means it can go scavenge for other molecules to bond with. Normally this isn't a problem because nearby antioxidants will bond with the free radicals and render them harmless. When there are too many free radicals and not enough antioxidants, they can do a lot of damage. This process is called oxidative stress.
As we age, our energy metabolism gets less efficient; free radicals go scavenging and can destroy cellular compounds and damage proteins, lipids, and DNA, and lead to cell death - especially in the brain which generates more oxidative by products than other organs of the body. Diet, always important, becomes even more so.
Oxidative stress also occurs in all of the neurodegenerative disorders -- not just Huntington's Disease but Alzheimer's, Parkinson's, the ataxias, ALS and in stroke. Antioxidants have been found to delay onset and progression in mouse models of various neurodegenerative disorders.
A diet rich in antioxidants looks like a good bet for being proactive.
In addition to confirming the well-publicized high antioxidant ranking of such foods as cranberries and blueberries, the researchers found that Russet potatoes, pecans and even cinnamon are all excellent, although lesser-known, sources of antioxidants, which are thought to fight cancer, heart disease and Alzheimer's. The study appears in the June 9 print edition of the Journal of Agricultural and Food Chemistry, a peer-reviewed publication of the American Chemical Society, the world's largest scientific society.
"The bottom line is the same: eat more fruits and veggies," says Ronald L. Prior, Ph.D., a chemist and nutritionist with the USDA's Arkansas Children's Nutrition Center in Little Rock, Ark., and lead author of the study. "This study confirms that those foods are full of benefits, particularly those with higher levels of antioxidants. Nuts and spices are also good sources."
The new study is more complete and accurate (thanks to updated technology) than previous USDA antioxidant data and includes more foods than the previous study, the researchers say. They analyzed antioxidant levels in over 100 different foods, including fruits and vegetables. In addition, the new study includes data on spices and nuts for the first time.
Among the fruits, vegetables and nuts analyzed, each food was measured for antioxidant concentration as well as antioxidant capacity per serving size. Cranberries, blueberries, and blackberries ranked highest among the fruits studied. Beans, artichokes and Russet potatoes were tops among the vegetables. Pecans, walnuts and hazelnuts ranked highest in the nut category.
Although spices are generally consumed in small amounts, many are high in antioxidants. On the basis of antioxidant concentration, ground cloves, ground cinnamon and oregano were the highest among the spices studied.
Prior says that the data should prove useful for consumers seeking to include more antioxidants in their diet. But he cautions that total antioxidant capacity of the foods does not necessarily reflect their potential health benefit, which depends on how they are absorbed and utilized in the body. Researchers are still trying to better understand this process, he adds.
Currently, there are no government guidelines for consumers on how many antioxidants to consume and what kind of antioxidants to consume in their daily diet, as is the case with vitamins and minerals. A major barrier to such guidelines is a lack of consensus among nutrition researchers on uniform antioxidant measurements. Scientists will soon attempt to develop such a consensus at the First International Congress on Antioxidant Methods, held June 16-18 at the Caribe Royale Hotel and Conference Center in Orlando, Fla., with the ultimate goal of developing better nutritional data for consumers. ACS is the principal sponsor of the meeting.
For now, USDA officials continue to encourage consumers to eat a variety of fruits and vegetables for better health.
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| Rank | Food | Serving Size | Total Antioxidant Capacity per serving size |
|---|---|---|---|
| 1 | Small Red Bean | 1/2 cup dried beans | 13727 |
| 2 | Wild blueberry | 1 cup | 13427 |
| 3 | Red kidney bean | 1/2 cup dried beans | 13259 |
| 4 | Pinto bean | 1/2 cup | 11864 |
| 5 | Blueberry | 1 cup cult- ivated berries | 9019 |
| 6 | Cranberry | 1 cup whole berries | 8983 |
| 7 | Artichoke hearts | 1 cup cooked | 7904 |
| 8 | Blackberry | 1 cup | 7701 |
| 9 | Prune | 1/2 cup | 7291 |
| 10 | Raspberry | 1 cup | 6058 |
| 11 | Strawberry | 1 cup | 5938 |
| 12 | Red Delicious apple | 1 | 5900 |
| 13 | Granny Smith | 1 | 5381 |
| 14 | Pecan | 1 ounce | 5095 |
| 15 | Sweet cherry | 1 cup | 4873 |
| 16 | Black plum | 1 | 4844 |
| 17 | Russet potato | 1 cooked | 4649 |
| 18 | Black bean | 1/2 cup dried beans | 4181 |
| 19 | Plum | 1 | 4118 |
| 20 | Gala apple | 1 | 3903 |