Antioxidants are present in foods as vitamins, minerals, carotenoids, and polyphenols, among others.
Many antioxidants are often identified in food by their distinctive colors: the deep red of cherries and of tomatoes; the orange of carrots; the yellow of corn, mangos, and saffron; and the blue-purple of blueberries, blackberries, and grapes. The most well-known components of food with antioxidant activities are vitamins A, C, and E; alpha carotene and the mineral selenium.
While antioxidants such as alpha-carotene are recommended by health specialists to prevent premature aging, some of the antioxidants used as food preservatives may be unhealthy. Contained in nearly every processed food on the market, antioxidants prevent fatty foods from spoiling when exposed to oxygen.
Antioxidants are substances or nutrients in our foods which can prevent or slow the oxidative damage to our body. When our body cells use oxygen, they naturally produce by-products which can cause damage. Antioxidants act as by product scavengers and hence prevent and repair damage done by these free radicals. 
Health problems such as heart disease, mascular degeneration, diabetes, cancer etc are all contributed by oxidative damage. Indeed, a recent study conducted by researchers from London found that five servings of fruits and vegetables reduce the risk of stroke by 25 percent.
Antioxidants may also enhance immune defence and, therefore, lower the risk of cancer and infection. It is important to eat the right fruits and vegetables for your blood type. Refer to your blood type list.
Commonly known antioxidants include:
Vitamin A foods like: Carrots, squash, broccoli, sweet potatoes, tomatoes, kale, collards, cantaloupe, peaches and apricots (bright-coloured fruits and vegetables!)
Vitamin C foods like: Citrus fruits like oranges and lime etc, green peppers, broccoli, green leafy vegetables, strawberries and tomatoes.
Vitamin E foods like: nuts and seeds, whole grains, green leafy vegetables, vegetable oil and liver oil.
Food containing selenium like: Fish & shellfish, red meat, grains, eggs, chicken and garlic. Soya, red wine, purple grapes, cranberries, grapefruit, watermelon,  dark green vegetables such as kale, broccoli, kiwi, Brussels sprout and spinach, flaxseed, oatmeal, barley and rye.

BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole) are two of the food additives that are used as a preservative to keep food from spoilage.  BHA and BHT can be found in butter, meats, chewing gum, snack foods, dehydrated potatoes, and even beer.  These additives are approved by the FDA as safe for human consumption.  Some people have difficulty metabolising these chemicals, which is thought to result in health and behavioral problems and hypersensitivity. They cause allergic reactions, may also contribute to the development of tumors and cancer, as well as be toxic to the nervous system and the liver.

Colouring
Food colouring is any substance that is added to food or drink to change its colour. Food colouring is used both in commercial food production and in domestic cooking. Due to its safety and general availability, food coloring is also used in a variety of non-food applications, for example in home craft projects and educational settings
People associate certain colors with certain flavors, and the colour of food can influence the perceived flavour in anything from candy to wine. For this reason, food manufacturers add dyes to their products. Sometimes the aim is to simulate a colour that is perceived by the consumer as natural, such as adding red coloring to glace cherries (which would otherwise be beige).
While most consumers are aware that food with bright or unnatural colours are likely to contain food coloring, far fewer people know that seemingly ‘natural’ foods such as oranges and salmon are sometimes also dyed to mask natural variations in colour.
Colour variation in foods throughout the seasons and the effects of processing and storage often make color addition commercially advantageous to maintain the color expected or preferred by the consumer. Some of the primary reasons include:
lOffsetting colour loss due to light, air, extremes of temperature, moisture, and storage conditions.
lMasking natural variations in color.
lEnhancing naturally occurring colors.
lProviding identity to foods.
lProtecting flavors and vitamins from damage by light.
lDecorative or artistic purposes such as cake icing.
Food colourings are tested for safety by various bodies around the world and sometimes different bodies have different views on food color safety.
Most other countries have their own regulations and list of food colours which can be used in various applications, including maximum daily intake limits.
According to Stephenson (2008) Synthetic food dyes are hazardous to health. He claims that many food dyes used in Canada and the US are banned throughout Europe for good reasons. Many synthetic food dyes used today have been proven to cause cancer, hyperactivity (particularly in children), inattentiveness, asthma, and in rare cases death.
Stephenson’s evidence is based on two studies commissioned by the UK Food Standards Agency in 2003.
Both in-depth studies concluded that food dyes adversely affect children. Some increased behaviors include lack of concentration, lack of focusing, interrupting conversations, talking too much and fiddling with objects or their own body.
This 2003 study coincided with results from an informal study conducted with 8 and 9 year old students at a school near Toronto, Canada in 2008. For one week, students were asked what they ate for breakfast and their snack and lunch foods were recorded. Behaviors were monitored throughout the day. Those students who ingested a minimum of three food dyes demonstrated increased levels of lack of concentration, restlessness and fiddling with their shoes or their own body. It’s also interesting to note that the children with increased behaviours also take a daily multi-vitamin that contains synthetic food colouring.

Know what food dyes are unsafe
The following is a brief description of some known food dyes that can cause adverse health effects:
FD&C Yellow 5 (tartrazine): breakfast cereals, jams, snack foods, packaged noodles, soups, dry drink powders, candy, pudding. May cause palpitations, hives and itching in children, restlessness, sleep disturbances, asthma and allergic reactions.

FD&C Blue 1 (brilliant blue dye): dairy products, jellies, icings, syrups, extracts, drinks and candies. Cause of death in some elderly patients due to enteral (tube) feeding. Banned in many countries but not the US or Canada. This is derived from petroleum distillates.

By Zodwa Baartjies