Top Five Food Sources of Antioxidants

USDA's ORAC System Ranks Antioxidant Values in Foods

Foods with antioxidants are important to help decrease oxidative stress in the body. Knowing which foods contain high levels of antioxidants helps dietary planning.



Free radicals are oxygen molecules in the body with an extra electron. They're used normally to mark foreign material such as viruses or bacteria in the body for destruction. Too many free radicals can lead to destruction of normal structures like DNA in cells. Some theorists believe free radical damage contributes to many problems in the body such as:

•cancer
•Alzheimer's disease
•Parkinson's disease
•heart disease
•aging
Antioxidant Foods Remove Free Radicals
Antioxidants help to remove free radicals from the body, minimizing damage to the system. Vitamin C, vitamin E and selenium are considered to be antioxidants. Many foods are considered to be good sources of antioxidants and often contain other healthy phytochemicals as well.

Oxygen Radical Absorbance Capacity (ORAC) of Foods
The U.S. Department of Agriculture has developed a database of food antioxidant levels measured by the ORAC system. ORAC includes measurements of the antioxidant capacity of 59 different foods. Higher ORAC values indicate an increased ability of the food to absorb oxygen free radicals from the body. These levels can help people choose appropriate antioxidant food sources to add to their diet.

Spices are Antioxidant-Rich
Many spices contain very high levels of antioxidants. Some, like sumac, have levels in the hundreds of thousands. Others with increased antioxidants include:

•turmeric
•cinnamon
•cloves
•chili powder
•ginger

High Antioxidant Levels in Grains
Grains like sorghum and rice bran also have very high levels of antioxidants as well as fiber. Processing of the grain makes a difference with more highly-processed grains containing much lower levels of antioxidants. The bran portion of most grains contains the most antioxidants with some ORAC levels well into the hundreds of thousands.


Herbs with High Antioxidant Capacities
Many herbs also have high levels of antioxidants. These include:

•parsley
•oregano
•peppermint
•thyme
ORAC values are measured per 100 g portions. It takes a large volume of herbs to reach this level of antioxidants.

Dark Chocolate is a Good Source of Antioxidants
Dark chocolate, baking chocolate and cocoa all have very high ORAC values, ranging from 15,000 to 40,000. Milk chocolate contains much lower levels due to the amount of processing. Many gourmet chocolates contain high levels of dark chocolate, as much as 80% or more in some specialty chocolate bars.

Some Nuts are High in Antioxidants
Some nuts like pecans and walnuts are rich in antioxidants based on the ORAC system, while other nuts such as peanuts contain much lower levels. Nuts are high in fat which must be balanced along with other fats in the diet.

Top Ten Overall Immune System Booster Foods

Proper Nutrition is Critical to Improve Immune Response

Perhaps the single most important aspect of boosting immune system health is also one of the simplest - including plenty of immune system booster foods in your diet.



When researching foods to improve immune system function, certain foods crop up over and over again.

Garlic
This simple plant is at the top of every immune system enhancing list. According to the National Geographic Desk Reference to Nature's Medicine, by Steven Foster and Rebecca L. Johnson, "when garlic is cut or crushed, alliin comes into contact with the enzyme alliinase, which quickly transforms alliin into allicin. Allicin [is] largely responsible for garlic's beneficial actions in the body. They exhibit notable antibiotic, antiviral, and antifungal properties." Garlic also has pronounced general immune system boosting qualities, as well as anti-tumor and antioxidant features. Because of the volatile nature of most of the beneficial compounds, it should be used fresh or only added at the very end of cooking.

Yogurt
According to abcnews.com, yogurt "packs a healthy dose of good bacteria that can protect the body against harmful bacteria and infections." Although they may not have a direct impact on the immune system, these probiotics are very important to keep digestion working properly, so that you can absorb the nutrients from other foods that are essential for immune system health.

Red Bell Peppers
Surprisingly, red bell peppers contain more vitamin C, ounce for ounce, than almost any other food – including oranges. A half cup contains almost twice the daily amount of vitamin C recommended by the FDA. In addition, they have a wide range of phytochemicals and beta carotene.

Tuna
This fish contains a number of important nutrients for immune system health, including selenium and omega-3 fatty acids, and some amount of zinc, while being very low in 'bad' fats.

Broccoli The bane of many children, this is among the top foods for proper immune system function. It contains significant levels of vitamin A, vitamin C, vitamin E, and beta carotene; most of the top immune system nutrients. In addition, it has glucosinolates, another potent immune system booster; and sulforaphanes, strong anti-cancer nutrients. Other cruciferous vegetables, including cauliflower, kale, Brussels sprouts, bok choy, cabbage, turnip (roots and greens), rutabaga, mustard (seeds and greens), radishes, and horseradishes (including wasabi), are almost equally important.

Yellow or Orange Squashes
Including yellow squash, acorn squash and pumpkin, these vegetables are packed with beta carotene. The brighter the better, as the color is usually indicative of the beta carotene concentration.

Leafy Greens
Leafy greens include spinach, kale, mustard greens, collard greens, and turnip greens. Again, these are valued for their content of beta carotene, but also for vitamin E, which can be difficult to find in sufficient quantities in the diet.

Lean Beef
Along with other lean red meat, beef is surprisingly important for immune system health. Unfortunately for vegetarians, it is very difficult – almost impossible, in fact – to find all the amino acids and proteins the body needs to remain healthy in plants alone. In addition, beef is one of the top sources of zinc in the diet, which is absolutely necessary for full immune system health.

Mushrooms Particularly shiitake mushrooms, these are consistently listed among the top immune system boosters, although few places seem to have any idea what components in particular are so helpful for the immune system.

Green TeaAlso white and black tea, there are few better sources for important antioxidants. In addition to generally boosting the immune system, there is strong evidence that some of the compounds in tea, such as epigallocatechin gallate, or EGCG, are offensive as well as defensive — that is, they act directly on invading microbes like cold or flu viruses, in addition to helping to build immune system health.


Sources:
The Herbal Drugstore, by Linda B. White, MD, and Steven Foster (Rodale Inc., 2000)
Prescription for Herbal Healing, by Phyllis A. Balch (Avery, 2002)
National Geographic Desk Reference to Nature's Medicine, by Steven Foster and Rebecca L. Johnson (National Geographic Society, 2006)