Researchers have found that stress causes the body to retain more sodium and this leads to high blood pressure. Dr. Gregory Harshfield, hypertension researcher at the Institute of Public and Preventive Health at Georgia Health Sciences University, said that sodium retained by the body due to stress is equivalent to the amount of sodium found in a small portion of French fries or a small bag chips.
Sodium, which is found in full in processed foods or fast foods, causes water retention, and this causes, in turn, high blood pressure. The amount of sodium that body needs daily is about 1500 milligrams. However, the average daily salt consumption is double the daily requirement, that is about 3700 milligrams. Salt increases blood pressure, and this contributes to increased cardiovascular risk. Interestingly, the researchers found that sodium retention caused by stress lead to increased blood pressure for longer periods than usual. In addition, it seems that blood pressure remains high also during the night. Usually sleep must allow the body to recover and it should not be affected by stress.
Dr. Harshfield said that stress causes retention of approximately 160 milligrams of sodium, which leads to increased blood pressure by about 7 points with than normal. In addition, blood pressure remains elevated longer. Studies done by Dr. Harshfield have shown that blacks retain more sodium than whites and for longer period of time. Researchers also found that sodium effects can be blocked by a class of drugs used in cardiology, called angiotensin receptor blockers. This discovery is exciting because it is known that blacks have high levels of angiotensin and this drug is rarely used in this population. Angiotensin receptor blockers prevent angiotensin to bind to its specific receptors, that is angiotensin is a potent vasoconstrictor agent.
Angiotensin is part of the renin-angiotensin-aldosterone system, which plays a role in controlling blood pressure. Renin is an enzyme secreted by the kidney in response to the action of the sympathetic nervous system, which may be triggered by stressfull situations. Once secreted, renin activates angiotensin to bind to receptors from the muscle blood vessels causing vasoconstriction. In addition, angiotensin determine also the release of aldosterone, a hormone secreted by the adrenal gland. Aldosterone also leades to high blood pressure through sodium retention. Angiotensin receptor blockers (ARBs) are found collectively as ARBs: candesartan, valsartan, losartan and others. ARBs are used, as well as converting enzyme inhibitors, for lowering blood pressure, heart failure, and other cardiovascular diseases.