Hypertension is the most common form of cardiovascular disease in America, affecting about 50 million people.-that's close to one out of four adults. High blood pressure is defined as a reading above 140/90mmHg (systolic/diastolic). (Systolic pressure (the first number) measures the pressure in the arteries when the heart contracts. Diastolic pressure (the second number) measures the pressure in the arteries when the heart is relaxing and filling with blood.)
What causes high blood pressure?
The heart pumps blood through your arteries (large blood vessels), pushing the blood against the artery walls with a force that is measured as our "blood pressure." Normal blood pressure is around 120/80 mm Hg. High blood pressure occurs when the artery walls lose their elasticity and cause the pressure of the blood moving through the arteries to rise. This excessive pressure makes the heart work harder, and can eventually lead to an enlarged heart (cardiomegaly), as well as damage to blood vessels in the kidneys and brain. Hypertension, therefore, increases the risk of heart attacks, stroke and kidney disease.
Doctors cannot pinpoint the precise cause of 90 percent of high blood pressure cases,also known as "essential hypertension." However, they do know that certain factors can increase the risk of developing high blood pressure:
- Stress can cause hypertension by activating the sympathetic nervous system, causing the arteries to constrict.
- Eating large amounts of sodium can cause excess water retention, expand blood volume and ultimately increase blood pressure.
- A diet low in calcium, magnesium and potassium can increase blood pressure
- Insulin resistance can increase blood pressure by causing the kidneys to retain sodium.
- Regular alcohol intake can increase blood pressure.
- Being overweight increases blood pressure.
What can you do to lower your blood pressure?
- Follow the DASH diet. This diet, developed by researchers at the National Institutes of Health's National Heart, Lung, and Blood Institute is based on a large-scale research study that identified the foods that affect blood pressure. The most important parts of the DASH are generous amounts of fruits and vegetables and low fat or fat free dairy products providing an adequate calcium intake. The diet is also relatively low in fat and sodium. DASH researchers have shown that diets rich in potassium, calcium and magnesium, and low in sodium, (2,400 mg or less) play an important role in maintaining healthy blood pressure levels. These are the high points of the DASH diet:
- Eat 8-10 servings of fruit and vegetables servings per day.
- Choose low- or non-fat dairy foods, consuming 2-3 servings per day.
- Limit animal protein to 6 oz per day, emphasizing lean sources.
- Consume 4-5 servings of nuts, seeds and dry beans per week (2 Tbsp nuts or seeds, or 1/2 cup cooked dried beans).
- Eat plenty of fish - Include at least three servings of fish a week, emphasizing cold water fish like salmon and sardines that are rich in omega-3 fatty acids.
- Limit your caffeine intake -- The caffeine in coffee, tea and sodas can contribute to high blood pressure.
- Limit alcohol intake - Blood pressure increases as your body metabolizes alcohol.
- Avoid processed foods -- These are the biggest sources of sodium in today's diet.
- Maintain optimal weight -- Even small amounts of weight lost can improve blood pressure.
- Exercise - As little as 30 minutes of moderate exercise a day, like walking, can lower blood pressure.
- Relax -Meditation, yoga, breathing exercises or biofeedback are all relaxation techniques that can help lower blood pressure.
- Don't smoke - Smoking contributes to all cardiovascular diseases - and many other life-threatening conditions as well.