Antioxidant-rich Foods

Antioxidants work throughout our bodies: different ones in different

spaces protect different tissues. Some are water-soluble, so they are

found in the blood, cerebro-spinal fluid and connective tissues. If you

consume more than you need of these, they are excreted in your urine.

Others are fat-soluble, working to protect your cell membranes and

other fatty tissues, including your brain! These can be stored and

accumulate in the body, so it is important not to take too much of

these.

We need the whole spectrum of antioxidants for good health: they

work in concert. And they can recycle each other, so if one is being

used up, for example due to dealing with a chemical in a polluted

environment, the others can help out!

Vitamin C is a water-soluble vitamin. It is found in its highest

concentration in the fluid that your brain swims in, probably because

there’s a lot of action going on there!  It supports immune function,

skin health, and helps the body absorb iron. Vitamin C is essential for

synthesis of collagen and neurotransmitters. In addition to being an

antioxidant, it also helps prevent the formation of plaque in the

arteries, has anti-cancer properties, and is an immunomodulator.

Food sources are many, including citrus fruits, strawberries, bell

peppers, broccoli, Brussels sprouts, green vegetables, and tomatoes.

Vitamin C content declines after picking, is lower in fruits and

vegetables that are picked before they are fully ripe, and some will be

lost by cooking.

Nobel Prize winner Linus Pauling, who studied vitamin C extensively,

used to take many grams every day. Be aware that very high doses can

trigger loose stools in some people.

Vitamin E (tocopherol) is fat-soluble, and helps protect our fats (lipids)

from lipid peroxidation, safeguarding our cell membranes from free

radical damage. It is best taken as a complex of mixed tocopherols,

the way it exists in nature.

Foods high in vitamin E include natural vegetable oils, wheat germ oil,

whole grains, nuts, sunflower seeds, avocados, spinach, eggs, poultry,

and meat. Vitamin E will degrade if food is poorly stored, like nuts that

are rancid, and some vitamin E is lost in cooking.

Supplemental doses of over 400IU daily are considered to be of questionable benefit.

Beta-carotene is a fat-soluble member of the carotenoid family, can be converted to active vitamin A in the liver, and is a strong free

radical quencher.

Beta-carotene is essential for vision: it’s true that carrots are good for

the eyes! It is also important for immune and skin health. 

Beta-carotene is present in many fruits, grains and vegetables (carrots,

green plants, squash, spinach). All deeply coloured fruits and

vegetables are good sources of beta-carotene. Although it is fat-soluble,

it doesn’t have the toxicity that vitamin A does: it just makes your skin

turn orange if you take much too much, and the palms of your hands

will show it first! 

Lycopene, a carotenoid, possesses antioxidant and anticancer

properties. It is very protective, particularly against prostate cancer.

The major dietary source of lycopene is tomatoes. The lycopene in

cooked tomatoes, tomato juice and tomato sauce is more bioavailable

than in raw tomatoes. It is also better absorbed if it is consumed with

some fat, such as olive oil. Watermelon, pink grapefruit, and papaya are

other dietary sources.

Selenium is a trace mineral found in soil, water, and many foods, if they

are grown on soil containing sufficient selenium.

It is part of several antioxidant enzymes, supports thyroid function,

strengthens the immune system, and may help prevent certain cancers.

Selenium-rich foods include garlic, onion, grains, Brazil nuts, soybeans,

sea foods, eggs, meat, liver and yeasts.

It is important not to exceed supplemental intake of 400 μg selenium per day, because high levels can be toxic.

Polyphenols include broad classes of plant compounds that have

antioxidant and anti-inflammatory properties. They include flavonoids,

anthocyanidins and curcumin. Polyphenols are found in plant foods of

all kinds, and often give the food its characteristic colour, scent and

flavour. Some well-known and often consumed polyphenol-rich foods

are green tea, dark chocolate, blueberries, raspberries, red wine,

and apples.

Flavonoids are the most abundant source of polyphenols in the diet.

Over 4000 flavonoids have been identified. They may prevent or delay a

number of chronic and degenerative ailments such as cancer,

cardiovascular diseases, arthritis, cataracts, memory loss, stroke,

Alzheimer’s disease, inflammation, and infection.

Every plant contains a unique combination of flavonoids, which is why

different herbs, all rich in these substances, have very different effects

on the body. Some natural sources of flavonoids include green tea,

grapes (red wine), apple, cocoa (chocolate), ginkgo biloba, soybeans,

berries, onions and broccoli.

Curcumin is a well-known flavonoid compound. It comes from turmeric

root, often used in curries. It has broad anti-inflammatory

properties, and may help manage arthritis and support brain health.

Anthocyanidins are another category of flavonoids. They are found in

blueberries, blackberries, cherries and pomegranates, and may protect

against heart disease, support cognitive function, and reduce

inflammation.

If you choose to supplement antioxidants, look for a mixture of several. Some companies make capsules of vitamins A, C and E with a bit of zinc

or selenium. That’s a nice mix for most of us, especially for the times

our diets may not be at their best.

For more on this topic:

Is scurvy making a come-back?

Why eat the rainbow?

Polyphenol-rich foods chart

Antioxidants Explained