If you’re following a typical western diet, there's a good chance that you’re not eating enough phytochemical-rich plant foods. According to research, the biggest phytochemical gap is in the blue/purple fruit and vegetable category. Does this sound like you?

Phytochemicals are chemical compounds that occur naturally in plants and which may protect us from disease. They are in fact antioxidants that can stop the reactions of dangerous free radicals in the body.

Free radicals are formed during normal metabolism, and whenever the body is exposed to stresses such as pollutants in the air, cigarette smoke, trans fatty acids in food, heavy metals in water and even excessive exercise.

Left unchecked, these free radicals cause extensive damage to the cells of the body and are believed to play a role in the development of degenerative diseases such as heart disease, type 2 diabetes and cancer. Free radicals can also cause premature ageing.

By eating plant foods rich in phytochemicals, you can help your body to counteract the damage that can be caused by free radicals. As a result, antioxidants may slow or possibly prevent the development of the diseases mentioned above.

Not enough phytochemicals in our diets

As different phytochemicals occur in the different colour pigments of plant foods, it's a good idea to eat a variety of plant foods every day.

Interestingly, research shows that the colour of fruits and vegetables eaten daily can be as important as the quantity, and that most of us probably aren't including enough phytochemicals in our diets.

According to the US Phytonutrient Report (2009), Americans have a phytochemical gap in every colour category. Findings showed:

    • The biggest phytochemical gap is in the blue/purple fruit and vegetable category, where 88% of participants fell short.

    • Study participants did a little better on getting phytochemicals found in green fruits and vegetables – but 69% still fell short.

    • Seventy-eight percent of the participants fell short in in terms of red plant foods, 86% in terms of white plant foods and 79% in terms of eating enough orange/yellow plant foods.

Although these figures relate to the American population, it's safe to say that Australians who follow a typical western diet, junk food and all, probably don't eat enough phytochemical-rich plant foods either.

Where to find the phytochemicals

    • Green fruits and vegetables like spinach and broccoli contain phytochemicals such as isothiocyanate, lutein, zeaxanthin and isoflavones. Isothicyanate, for instance, may protect against chemically-induced cancers such as lung and liver cancer.

    • Red fruit and vegetables such as tomatoes and pomegranates contain phytochemicals such as lycopene and ellagic acid. New research shows that the ellagic acid in pomegranates might cut the risk for oestrogen-responsive breast cancer, but more tests need to be done. There’s also some evidence that lycopene could protect against cancer and heart disease.

    • White fruit and vegetables such as garlic and apples contain allicin and quercetin. Several preliminary studies have indicated that garlic may help protect against cancer, while quercetin has been shown to help alleviate prostate pain and inflammation.

    • Purple/blue fruit and vegetables such as cabbage, beetroot and black grapes contain resveratrol. This phytochemical has been widely studied and it looks like it may indeed have anti-tumour properties.

    • Yellow/orange fruit and vegetables such as pumpkin and carrots contain alpha-carotene, beta-carotene, hesperitin and beta-cryptoxanthin. Beta carotene, for one, is being widely studied for the prevention of certain types of cancer.

Strive for five

While the jury is still out on the exact mechanisms of many of these antioxidants and whether they really do prevent certain diseases, it certainly doesn’t hurt to “strive for five”.

Experts agree that we should all eat at least five servings of fruit and vegetables every day. Have a mid-morning and mid-afternoon snack in the form of a fruit every day, and get three portions of vegetables during lunch and dinner. The phytochemicals in different foods quite possibly work together to give you a health kick, so remember to make your plate of food as colourful as possible.

Also keep in mind that it’s better to get your fruit and vegetables in whole fruit form. Although juice is a source of antioxidants, the sugar is highly concentrated.

(Sources:  US National Cancer Institute (2004). Antioxidant and Cancer Prevention: Fact Sheet, http://www.cancer.gov/cancertopics/factsheet/prevention/antioxidants; Nutrilite Health Institute (2009). America’s Phytonutrient Report: Quantifying the Gap, http://www.pwrnewmedia.com/2009/nutrilite90921nmr/downloads/AmerciasPhytonutrientReport.pdf)

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