Gillian McKeith's Food Bible (60 page)

Usefulness right through old age.

Why do we age and what is the process?

The definition of ageing is hardly uplifting—“the ever-increasing susceptibility to disease and death that accompanies advancing age.” But what, exactly, causes ageing and why do some people manage to look younger than their years? One of the most compelling, and scientifically accepted, theories is that it’s due to oxidative stress. Stick with me and it will all make sense: although oxygen is essential to life, it is also a highly reactive chemical in the body, and it causes oxidation—a bit like rusting—in your cells. Compounds called “free oxidizing radicals” (or just “free radicals”) attack the DNA of the cell, causing damage and affecting how your cells multiply. This cellular damage is a major contributor to the visible signs of premature ageing as well as the chronic disease that often comes with age, such as cancer, heart disease, Alzheimer’s disease, cataracts, respiratory tract infections, and many other conditions.

So, the fewer free radicals we have roaming about our bodies, the better. Unfortunately, you can no more avoid free radicals than you can revisit your youth. I wish I could promise you otherwise! What I can do is help you to arm yourself with the armor required to halt the action of these damaging chemicals.
You’ve probably already heard of them, but may not be quite sure what they are. They’re called antioxidants and they literally deactivate free radicals. And your best source of antioxidants…surprise, surprise, is food.

Antioxidant vitamins, minerals, and enzymes

Vitamin A (and its precursor, beta-carotene)
is especially protective against diseases of the respiratory system, one of the major causes of death in the elderly.

Vitamin C
is one of the most important water-soluble antioxidants in cells and plays a protective role in just about every part of the body. It is essential for the formation of collagen, the intracellular “glue” that holds cells together and keeps skin elastic and wrinkle-free. Highly concentrated in the eye, vitamin C protects against light damage and helps to prevent the development of cataracts. Not only is it a powerful antioxidant in itself, known to strengthen the immune system and prevent the growth of tumors, but it also enhances the action of vitamin E, which in turn enhances the action of the antioxidant enzyme glutathione, an important liver protector.

Vitamin E
protects fats from oxidizing (the brain is about 60 percent fat so its protective role is vital) and is often found in healthy fatty foods, such as nuts. Like vitamin C, it plays an important role in guarding the eyes from age-related damage and is also involved in preventing free-radical damage to the cardiovascular system.

Selenium
is linked to the prevention of cancer, especially breast and prostate, and decreased levels are also linked to cataract formation and age-related macular degeneration of the eye. This mineral is also vital for heart health, yet it is known that levels of selenium in the soil are widely deficient on a global scale. As well as being an antioxidant in itself, selenium is also necessary to make antioxidant enzymes in the body, such as glutathione.

What are the best sources of these wonderful nutrients that work to protect our health and delay the ravages of time? They tend to be found in the same foods, namely fruits, vegetables, nuts, seeds, legumes, and just about any other plant food you can think of. The best sources of vitamin C are berry fruits (blueberries, strawberries, raspberries, and so on), kiwis, and citrus fruits. Potatoes are also a good source. Vitamin A is found only in animal foods, such as liver, oily fish, and dairy foods, but its plant-based precursor, beta-carotene, is widely found in fruits and vegetables with a yellow, red, or orange pigment, such as carrots, peppers, apricots, and oranges. Vitamin E—together with selenium—is found in nuts and seeds, particularly pumpkin seeds, walnuts, cashews, and Brazil nuts. Nuts are also rich in the antioxidant enzyme glutathione. Another good source of selenium is garlic. Many raw foods contain food antioxidant enzymes, which help you to break down and digest your food.

Antioxidant phytonutrients

The wide range of phytonutrients so far discovered is broadly categorized into two families: carotenoids and polyphenols. The most famous carotenoid is beta-carotene, the plant-based precursor to vitamin A, and most people associate carrots with this carotenoid. There are plenty of other good sources, however, such as sweet potatoes, which also contain good levels of both vitamin C and vitamin E, red and yellow peppers, and pumpkins. Other carotenoids, including lycopene, lutein, and zeanxanthin, are just as important.

Tomatoes are particularly rich in the carotenoid lycopene, a high intake of which is associated with lowered risk of prostate cancer. Men are susceptible to developing benign prostatic hyperplasia—enlarged prostate—from the age of 50 onward, so would do well to make sure they eat plenty of lycopene-containing foods. Lycopene is thought to contain the greatest amount of
antioxidant activity of all the carotenoids, and has been studied widely for its anticancer effects. Dark leafy greens are also rich in a variety of carotenoids—these include spinach, broccoli, brussels sprouts, watercress, and kale.

The retina of the eye contains particularly high levels of zeaxanthin and lutein. Eyesight is at particular risk of degeneration in later life because eyes are constantly exposed to light and free radicals. Carotenoids, together with vitamin C, have been shown to help to prevent the development of cataracts.

It’s not only eyesight that light—especially sunlight—can cause to deteriorate prematurely. Nothing ages skin quite like prolonged exposure to the effects of the sun’s rays. As well as looking like a wrinkled-up prune, sun overexposure is also firmly established as a major cause of skin cancer. Yet life would not exist without the sun, and all energy ultimately comes from it. The focus of preventative care has been heavily on either avoiding exposure—which means risking vitamin D deficiency—or slathering ourselves in sunscreen. Yet carotenoids have been shown to protect against the harmful effects of the sun’s rays, both in terms of premature ageing and skin cancer, by blocking or inhibiting the effects of UV-induced free radicals. This makes sense when you consider that plants contain these compounds for their own protection: without carotenoids, all plant life on the planet would turn into a burnt mass shortly after sunrise.

Polyphenols

There are numerous types of polyphenols exerting powerful antioxidant effects, and more and more are being discovered. The best known are the flavanoids, which are powerfully antioxidant and can block the formation of cancer cells. One excellent flavanoid is quercetin, found in red onions and apples. Quercetin is anti-inflammatory and is used therapeutically to ease age-related inflammatory conditions such as arthritis.
Flavanoids are associated with a lower risk of developing coronary heart disease by helping to keep arteries clear of plaque.

You can spot a flavanoid-rich food by its color—look for deep reds, purples, and blues. Berries are particularly flavanoid-rich. What’s more, they are especially rich in vitamin C. Blueberries are known to help protect against sun damage to the eye as well as cataract formation. Blackberries help to prevent the buildup of plaque on artery walls and blueberries and strawberries are believed to have anticancer properties. Goji berries are also flavanoid packed and make an easy snack.

Another potent antioxidant polyphenol is ellagic acid, found in grapes, strawberries, blueberries, and cherries. Other polyphenol-rich sources to look out for are green tea, herbs (especially rosemary and thyme), turmeric, and mushrooms—in particular shiitake, maitake, and reishi. You should also aim to eat plenty of foods from the cruciferous family—kale, cabbage, and broccoli are rich in glucosinolates, which can help prevent certain cancers, including those of the breast, stomach, and colon.

There are a few other antioxidants that deserve special mention, namely alpha-lipoic acid (ALA), pycnogenol (extract of French maritime pine bark), and coenzyme Q10. Alpha-lipoic acid is known as the “universal antioxidant” because it has the extraordinary ability to regenerate other antioxidants, such as vitamins C and E, making them active again. The body makes ALA in small quantities but it is also available in supplement form. Pycnogenol is believed to help to prevent that most dreaded of age-related disorders, varicose veins, while coenzyme Q10 is believed to help to strengthen the cardiovascular system and prevent gum disease.