HEALTH-ASPECTS OF VARIOUS DIGESTIBLE CARBOHYDRATES

The present review adresses the question whether simple and complex ca rbohydrates may result in different physiological responses with empha sis on glucose tolerance, human energy metabolism, and blood lipid spe ctrum. Furthermore, the implications of possible different physiologic al responses are discussed in relation to diabetes mellitus, obesity, and cardiovascular disease. Previously, it was believed that all starc hes were digested more slowly than simple carbohydrates, resulting in a slower release of glucose into the bloodstream. The presumed higher insulinemic response of simple carbohydrates would eventually give ris e to hyperinsulinemia and diabetes mellitus. At present, thinking in t his area has changed and from many acute experimental studies it has b ecome clear that there is a wide range of glycemic responses to both s imple and complex carbohydrate foods, so that some complex carbohydrat es give comparable glycemic and insulinemic responses to some simple c arbohydrates. These responses to both forms of carbohydrates are appre ciably influenced by certain other food components such as dietary fib re and antinutrients. Long(er) term studies on the relation between ty pe of ingested carbohydrate and glucose tolerance show inconsistent re sults with two recent studies indicating a more beneficial effect of s imple as compared to complex carbohydrates on glucose tolerance. Furth er long term well-controlled studies are necessary to elucidate this i ssue. Obesity develops under circumstances of a positive energy balanc e. Recent evidence indicates that energy balance can only be achieved in the case of macronutrient balance and that fat, protein and carbohy drate balances are regulated separately. Current literature indicates a closer regulation of carbohydrate than fat balance, and carbohydrate s have been reported to have powerful effects on thermogenesis and ene rgy intake. Differences in thermogenesis among simple carbohydrates ha ve been reported with sucrose and fructose being more thermogenic than glucose. Also, a higher carbohydrate oxidation and more pronounced su ppression of lipid oxidation have been reported with fructose ingestio n as compared to glucose. Furthermore, it has been reported that there is no difference in the thermogenic efficiency with which the body ha ndles simple and complex glucose saccharides. The implications of thes e results of acute studies remain uncertain since, there is no evidenc e indicating differences in the effects of various carbohydrates on lo ng(er) term energy and substrate balance. A change from a Western type of diet to a very high carbohydrate diet causes a reduction in HDL an d LDL cholesterol but a possibly transient increase in plasma triglyce rides. In early studies it was claimed that simple carbohydrates, espe cially sucrose or fructose, would have more adverse effects on blood l ipid spectrum than complex carbohydrates. There is, however, no consis tent evidence available to support such a presumption. In fact, the ma jority of studies indicate no difference in the effects of various typ es of carbohydrates on blood lipid spectrum when ingested in amounts c omparable to habitual Western consumption patterns. Hyperlipidemias, o besity, hyperinsulinemia, insulin resistance, diabetes, and hypertensi on have all been implicated as risk factors for cardiovascular disease . There is no evidence to support an independent relationship between any of these factors and the consumption of simple carbohydrates. Taki ng the above considerations into account, it can be concluded that the re is no evidence to implicate an independent role for simple carbohyd rates compared to complex carbohydrates in the etiology of cardiovascu lar disease. The available literature indicates that there is no consi stent evidence indicating differences in the effect of simple and comp lex carbohydrates on glucose tolerance, human energy metabolism and bl ood lipid spectrum. Furthermore, there is no evidence to implicate dif ferences in the effects of simple and complex dietary carbohydrates in the etiology of obesity Diabetes Mellitus or cardiovascular disease.