High blood pressure, also known as hypertension, is the most common cardiovascular disease.
Blood pressure refers to the force of blood pushing against artery walls as it courses through the body. Like air in a tire or water in a hose, blood fills arteries to a certain capacity. Just as too much air pressure can damage a tire or too much water pushing through a garden hose can damage the hose, high blood pressure can threaten healthy arteries and lead to life-threatening conditions such as heart...
"Salt," he said firmly, scribbling something in my chart. "Pretzels, chips, French fries, anything with added salt. Let's give it a try and see if we can get these numbers down a bit. Otherwise we may want to start you on a blood pressure medication."
Ouch. If anything could get me to swear off salty goodies, it's the threat of having to take a pill for the rest of my life. But can cutting down on salt really lower blood pressure?
For years, the advice on salt has flip-flopped. Some experts say too much can send blood pressure climbing. Others have said that for most people salt isn't a problem. Now, I learned, a landmark study promises to settle the debate.
A DASH of prevention
Since 1972, cutting back on salt has been a cornerstone of the National Blood Pressure Education Program. The advice is based on dozens of studies showing that high levels of salt are linked to hypertension. Most recently, in the February 2000 Journal of Cardiovascular Risk, British hypertension expert Malcolm Law concluded that reducing sodium intake could reduce blood pressure by an average of 10 points (10 mmHg) -- exactly how far mine needs to fall.
Not everyone has been convinced that Law's advice was good. In 1984, analyzing nutrition data gathered from around the country, researchers at the Oregon Health Sciences University in Portland found no evidence that dietary salt was linked to blood pressure. Four years later, results from 7,300 men enrolled in the Scottish Heart Health Study came to the same conclusion. The amount of salt they consumed had no effect on blood pressure.
Systolic pressure is the higher number, which measures the maximum pressure exerted when the heart contracts. Diastolic is the lower number, which measures the pressure when the heart is at rest. Normal systolic pressure is approximately 120 mmHg, and normal diastolic pressure is approximately 70 to 80 mmHg.
One thing has long been certain: High blood pressure is dangerous. In findings published this year in The New England Journal of Medicine, for instance, scientists followed the fate of 12,000 men between the ages of 40 and 59. Those with sustained increases of 10 mmHg in systolic blood pressure and 5 mmHg in diastolic blood pressure were 28% more likely to die of heart disease than those with normal readings.