Phytochemical Levels in Plants

A number of phytochemicals have been shown to have beneficial health effects in humans. This means that foods which contain higher concentrations of these chemicals may have better health effects. To understand the phytochemical concentrations in plants it is necessary to know why plants produces them. Some chemicals are produced to attract insects, and these are generally the ones found in petals. For example, the red and blue colours of most petals are caused by the presence of anthocyanins, phytochemicals from the flavonoid group. However as we do not eat petals these are not of great nutritional interest. Of more interest are the phytochemicals in fruits and vegetables that we eat. Plant generally produce phytochemicals in fruits and vegetables as defence mechanisms against pathogens such as fungus. For this reason organic foods that do not have pesticides to protect them tend to have higher levels of certain phytochemicals. For example organic grapes grown without fungicide have levels of resveratrol significantly higher than conventionally grown produce where fungicides have been used. This is because in response to invading pathogens, plants increase levels of these protective chemicals.