This and the next installments will explain the importance of salt in health and disease, and how diet affects salt. These concepts are extremely important IN health AND IN THE PREVENTION AND TREATMENT OF ILLNESS.
The body requires salt to maintain what is known as its "internal environment." Chemically, salt is sodium plus chloride. It is the sodium referred to as the major particle, known as "cation" that control where water is distributed within the cells and the fluids of the body. A minimum amount of salt intake is critical to good health. Excess salt may cause fluid retention, congestion, or drowning of organs including the lungs.
As humans evolved, it became necessary to conserve salt in periods of short supply or heat with perspiration. Salt is lost through perspiration. The human body developed active mechanisms for the kidneys to reduce salt excretion for conservation of the "internal environment". The evolution of various hormones over time was adaptive to the problems of salt depravation or loss. The problem is that the same adaptations may now pose impediments to cardiac and kidney function in older age and in states of disease.
Where excessive salt and water retention occurs, edema forms. It usually starts with the swelling of the legs. Edema can become generalized throughout the body. It is particularly troublesome when it fills the lungs. Here you are literally "drowning" in your own salt and water.
Edema is managed by the use of diuretic drugs, i.e. "water pills". Diuretic drugs cause increased elimination of salt by the kidneys. But the excessive use of diuretics can reduce the circulating blood volume and thus lower blood pressure to a harmful level. Thus, the overly aggressive use of "diuretics" is unwise.
How to maintain a salt balance through diet and the judicious use of diuretic drugs is extremely important in health and disease. Subsequent newsletters will elaborate on these important concepts.
I'll be in touch next month.
Thomas Petty, MD
Professor of Medicine,
University of Colorado Health Sciences Center
Snowdrift Pulmonary Conference