Effect of Diet and Nutrient on Cell Signaling: Is the Tissue the Main Issue, Proposes Dr. Wilson?

Abstract

Western diet is characterized with energy dense, refined, ready prepared foods with a high glycemic index (e.g. refined starches; bread, biscuits, candies, cornflakes, pizza, potato chips, cola drinks and sugar) and unhealthy lipids (e.g. trans fats, saturated fat , w-6 rich oils) poor in w-3 fatty acids, phytochemicals and fiber that are abundant in the Mediter- ranean type of diet. Western type of diets are known to predispose inflammation and increase in free fatty acids causing endothelial cell and beta cell dysfunction leading to the epidemic of cardiovascular diseases (CVDs). The cell signaling and the changes in cell membrane properties of the tissues induced by dietary lipids may have important consequences on the development of obesity, atherosclerosis and hypertension. The structural properties and function of cell membrane proteins appear to be modified in hypertensive humans and animal models of hypertension and atherosclerosis. Diet in- duced alterations in membrane lipid composition of hypertensive subjects have been associated with alterations in the transmembrane fluxes of Na + and K + , including Na + -Li + countertransport, which is a marker of essential hypertension, and in cell signaling proteins that participate in the control of blood pressure. It has been demonstrated that dietary lipids have an effect on membrane lipid composition and cell signaling proteins. Since changes in the dietary lipid composition yield to variations in the biophysical properties of the plasma membrane, it is likely that cellular functional changes could result from alterations in the structure of the lipid membrane properties under influence of the diet. Thus, the changes in mem- brane properties induced by dietary lipids may have important consequences on blood pressure regulation. The Mediterra- nean diet has been associated with changes in membrane structure and function. Consumption of olive oil-rich diets in- creases the concentration of oleic acid in plasma membrane lipids of different rat and human cells, with beneficial conse- quences on membrane functionality. In contrast, very little is currently known regarding the effects of nuts, another key ingredient of such diets, on membrane lipid composition and structure. CVD, diabetes mellitus and obesity, that are asso- ciated with increased production of thromboxane A2(TXA2), leukotrienes, prostacyclin, interleukins-1 and 6, tumor ne- crosis factor-alpha and C-reactive proteins in the tissues, is the major issue. Increased dietary intake of w-6 fatty acids is known to enhance all these biomarkers as well as atherogenicity of cholesterol in the tissues which have adverse pro- inflammatory effects resulting in CAD. Mediterranean diet rich in fruits, vegetables, nuts, mustard oil, and olive oil char- acterized with low w-6/w-3 ratio in the diet, can modulate inflammation and endothelial dysfunction of the tissues and may be protective against risk of coronary artery disease (CAD) and all-cause mortality. Inflammation appears to be an important unifying hypothesis, because in the absence of inflammation in the tissues, total cholesterol and other lipids may have neutral effects in the arterial tissues and myocardium. Therefore, it seems that endothelial dysfunction and in- flammation in the tissue is the main issue for treatment.