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

摘要

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 Mediterraneantype of diet. Western type of diets are known to predispose inflammation and increase in free fatty acids causingendothelial cell and beta cell dysfunction leading to the epidemic of cardiovascular diseases (CVDs). The cell signalingand the changes in cell membrane properties of the tissues induced by dietary lipids may have important consequences onthe development of obesity, atherosclerosis and hypertension. The structural properties and function of cell membraneproteins appear to be modified in hypertensive humans and animal models of hypertension and atherosclerosis. Diet inducedalterations in membrane lipid composition of hypertensive subjects have been associated with alterations in thetransmembrane fluxes of Na+ and K+, including Na+-Li+ countertransport, which is a marker of essential hypertension, andin cell signaling proteins that participate in the control of blood pressure. It has been demonstrated that dietary lipids havean effect on membrane lipid composition and cell signaling proteins. Since changes in the dietary lipid composition yieldto variations in the biophysical properties of the plasma membrane, it is likely that cellular functional changes could resultfrom alterations in the structure of the lipid membrane properties under influence of the diet. Thus, the changes in membraneproperties induced by dietary lipids may have important consequences on blood pressure regulation. The Mediterraneandiet has been associated with changes in membrane structure and function. Consumption of olive oil-rich diets increasesthe concentration of oleic acid in plasma membrane lipids of different rat and human cells, with beneficial consequenceson membrane functionality. In contrast, very little is currently known regarding the effects of nuts, another keyingredient of such diets, on membrane lipid composition and structure. CVD, diabetes mellitus and obesity, that are associatedwith increased production of thromboxane A2(TXA2), leukotrienes, prostacyclin, interleukins-1 and 6, tumor necrosisfactor-alpha and C-reactive proteins in the tissues, is the major issue. Increased dietary intake of w-6 fatty acids isknown to enhance all these biomarkers as well as atherogenicity of cholesterol in the tissues which have adverse proinflammatoryeffects resulting in CAD. Mediterranean diet rich in fruits, vegetables, nuts, mustard oil, and olive oil characterizedwith low w-6/w-3 ratio in the diet, can modulate inflammation and endothelial dysfunction of the tissues andmay be protective against risk of coronary artery disease (CAD) and all-cause mortality. Inflammation appears to be animportant unifying hypothesis, because in the absence of inflammation in the tissues, total cholesterol and other lipidsmay have neutral effects in the arterial tissues and myocardium. Therefore, it seems that endothelial dysfunction and inflammationin the tissue is the main issue for treatment.