Examples of antioxidants include vitamins C and E, selenium, and carotenoids, such as beta-carotene, lycopene, lutein, and zeaxanthin. This fact sheet provides basic information about antioxidants, summarizes what the science says about antioxidants and health, and suggests sources for additional information. Key Points Vegetables and fruits are rich sources of antioxidants.
Proteins, among the most complex of all organic compounds, are composed of amino acids (see Figure 2-4), which contain carbon, hydrogen, oxygen, and nitrogen atoms. Certain amino acids also have sulfur atoms, phosphorus, or other trace elements such as iron or copper.
Protein and the human body. The average human body is made up of 60% water, 17% fat and only 5% carbohydrate. Protein comprises a similar proportion of the body as fat at 17% and forms essential components of all body tissues structure such as cell membranes and genetic material and plays a major role in metabolic systems in the form of blood hormones, antibodies and enzymes.