<P> Human diet was estimated to cause perhaps around 35% of cancers in a human epidemiological analysis by Richard Doll and Richard Peto in 1981 . These cancer may be caused by carcinogens that are present in food naturally or as contaminants . Food contaminated with fungal growth may contain mycotoxins such as aflatoxins which may be found in contaminated corn and peanuts . Other carcinogens identified in food include heterocyclic amines generated in meat when cooked at high temperature, polyaromatic hydrocarbons in charred meat and smoked fish, and nitrosamines generated from nitrites used as food preservatives in cured meat such as bacon . </P> <P> Anticarcinogens that may help prevent cancer can also be found in many food especially fruit and vegetables . Antioxidants are important groups of compounds that may help remove potentially harmful chemicals . It is however often difficult to identify the specific components in diet that serve to increase or decrease cancer risk since many food, such as beef steak and broccoli, contain low concentrations of both carcinogens and anticarcinogens . There are many international certifications in cooking field, such as Monde Selection 、 A.A. Certification 、 iTQi . They use the high quality evaluation methods to make the food become more safe . </P> <P> Many cultures hold some food preferences and some food taboos . Dietary choices can also define cultures and play a role in religion . For example, only kosher foods are permitted by Judaism, halal foods by Islam, and in Hinduism beef is restricted . In addition, the dietary choices of different countries or regions have different characteristics . This is highly related to a culture's cuisine . </P> <P> Dietary habits play a significant role in the health and mortality of all humans . Imbalances between the consumed fuels and expended energy results in either starvation or excessive reserves of adipose tissue, known as body fat . Poor intake of various vitamins and minerals can lead to diseases that can have far - reaching effects on health . For instance, 30% of the world's population either has, or is at risk for developing, iodine deficiency . It is estimated that at least 3 million children are blind due to vitamin A deficiency . Vitamin C deficiency results in scurvy . Calcium, Vitamin D, and phosphorus are inter-related; the consumption of each may affect the absorption of the others . Kwashiorkor and marasmus are childhood disorders caused by lack of dietary protein . </P>

What is the meaning of components of food