Transcript Document
Lecture 8 : Lifestyle Factors(2) Overview • FOOD COMPONENTS – – – – – – – Carbohydrates Fats Proteins Minerals Vitamins Fibre Additives • GEOGRAPHICAL IMPLICATIONS Food Components a) Carbohydrates (sugars and starches); b) Fats (fats, oils, etc.); c) Proteins (made up from amino acids); d) Minerals (e.g. calcium); e) Vitamins; f) Fibre; g) Additives. Major Components • Carbohydrates. Western diets tend to be too rich in carbohydrates, especially sugar (which is often used as a food additive) • Fats. Western diets are also believed to contain too much fat. Rates of cancer of the breast, womb and bowel increase with fat intake. • Coronary heart disease is also associated with fat-rich diets. However, it is argued that neither the rise nor the subsequent decline in CHD rates was associated with dietary changes. • Proteins. Proteins are essential for health as they are broken down into amino acids and reassembled by the body into new proteins. Breast cancer rates and fat consumption Minor Food Components • Minerals are essential in trace quantities for good health. • Vitamins are also essential in small quantities. Many diseases are known to be caused by a deficiency of a particular vitamin. • Fibre contains no nutritional value and passes through the body. However, it is believed to reduce the risk of bowel disorders. Its bulk also helps reduce the risk of over-eating. • Additives. Processed food contains various additives (e.g. stabilisers, emulsifiers, colouring) to preserve shelf-life and to disguise what might otherwise be unpalatable. Some are believed to cause health complications. Vitamin Deficiency Diseases B1 (thiamine) Beriberi B3 (niacin) Pellagra B12 Pernicious Anaemia C Scurvy D Rickets ‘B17’ (nitriloside, laetrile, amygdalin) Cancer ? Geographical Implications • Diets vary between countries. Malnutrition and undernutrition are obvious factors in global health inequalities. • Diets also vary within countires. They may therefore account for some of the observed spatial variations in health. • Diet also contributes to social class inequalities in health. More people in the higher social classes eat the recommended foods. Diet And Social Class A B C D White Bread 18.0 25.0 28.0 31.0 Brown Bread 4.9 3.4 2.8 3.3 Sugar 9.3 11.0 13.0 15.0 Potatoes 29.0 39.0 49.0 52.0 Fruit 23.0 24.0 20.0 17.0 Ounces consumed per week of different foods by social class (A=high)