Updated 19 June 2015

Phytochemicals: powerful protectors

If you follow a typical western diet, you are probably not eating enough phytochemical-rich foods. The biggest phytochemical gap is in the blue/purple fruit and vegetable category.


Phytochemicals are chemical compounds that occur naturally in plants and may protect us from diseases. 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, cancer and arthritis. Free radicals can also cause premature ageing.

By eating plant foods that are rich in phytochemicals, you can help your body to counteract the destruction that can be caused by free radicals.

Too little 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), Amercians 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.
  • 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 the red, 86% in white and 79% in orange/yellow.

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

Where to find which phytochemicals

  • Green fruits and vegetables like spinach and broccoli contain phytochemicals such as isothiocyanate, lutein, zeaxanthin and isoflavones.
  • Red fruit and vegetables such as tomatoes and pomegranates contain phytochemicals such as lycopene and ellagic acid.
  • White fruit and vegetables such as garlic and apples contain allicin and quercetin.
  • Purple/blue fruit and vegetables such as cabbage, beetroot and black grapes contain resveratrol.
  • Yellow/orange fruit and vegetables such as pumpkin and carrots contain alpha-carotene, beta-carotene, hesperitin and beta-cryptoxanthin.

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. And remember to make your plate of food as colourful as possible.

Read more:

Free radicals and chronic disease
Top 10 sources of antioxidants
Fruit and veggies: super foods


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