Blood Pressure and Salt: What is the Connection?

Digital blood pressure cuffWhen blood pressure begins to rise, the advice always seems to start with reduce salt intake. While this can be good advice, it fails to consider the complexity and possible other causes of elevated blood pressure. Risk factors for high blood pressure, also known as hypertension, includes:

  • Sedentary lifestyle
  • Excessive sodium intake from processed and fatty foods
  • Low potassium intake
  • Being overweight or obese
  • Excessive alcohol intake
  • Smoking
  • Age greater than 60
  • Race – African American adults are at greater risk than Hispanic or Caucasian adults.
  • Certain diseases or medications

If high blood pressure is caused by another disease or condition, it is termed secondary hypertension. If there is no identifiable cause found, it is termed primary hypertension. Primary hypertension is the most common form and can be related to the risk factors above.

To understand the risk for hypertension, we must understand the physiology of blood vessels. The pressure inside the blood vessel is regulated by hormones that control the blood volume and pressure. When the blood volume increases so does the pressure. Coronary artery disease can also increase pressure inside the blood vessel due to constriction. When the diameter of the vessel wall narrows due to hardening of the arteries (loss of elasticity) or plaque build-up, it increases the pressure. Over time this can lead to more damage of the arteries and gradual increase in blood pressure. High blood pressure is a major risk factor for stroke and heart disease. Unfortunately, there are approximately 75 million people in the U.S. living with high blood pressure.

So, how do we treat high blood pressure? Lifestyle factors should be the first consideration unless blood pressure is dangerously high. If this is the case, medications and/or hospitalization may be required. But for slightly elevated blood pressure, making a few lifestyle changes can go a long way. Weight loss will help if you are overweight or obese. Exercise can also improve blood pressure over time. But be cautious about exercising if blood pressure is very elevated as exercise will make it go up. Avoid tobacco and excessive alcohol intake since these will make hypertension worse. Stress reduction can also help. Dietary changes include reducing intake of processed foods that are high in sodium and fat and eating more fruits and vegetables rich in potassium. Potassium seems to be protective against the effects of excess sodium. Diets such as the Mediterranean or DASH diet are known to reduce blood pressure and heart disease risk.  Some studies also found that getting adequate magnesium and calcium can improve blood pressure. Supplements may be beneficial but nutrients from food is always best.

The question remains however, how much sodium is too much? Americans consume 3,400 mg of sodium per day on average. Current guidelines recommend no more than 2,300 mg of sodium per day. The American Heart Association has lowered the guideline to no more than 1,500 mg of sodium per day for those at risk of heart disease. Some researchers argue that recent studies show limiting sodium too much may do more harm than good. According to them, a very low sodium diet increased the risk for heart disease. Several studies confirm reducing sodium intake improves cardiac risk factors, however the question remains how much should sodium be reduced? We know sodium is necessary for the body to work properly. We do not know for certain how much sodium is needed. Until we can determine this for certain, my advice is “sodium in moderation”. And remember, there is no “one-size-fits-all” when it comes to nutrition. You are an individual so listen to your body and stay healthy!

Blood Pressure and Heart Health

 

Digital blood pressure cuff

Monitoring for Health

You may have noticed your healthcare professional checking your blood pressure at each office visit. But why is knowing your blood pressure so important? To answer that question, we have to understand what blood pressure is and why it matters. Your doctor will give you two numbers after checking blood pressure. The first number is called the systolic blood pressure. This is a measurement of the amount of pressure in your arteries when your heart muscle contracts pushing blood into the arteries. The second number is called the diastolic blood pressure. This is the pressure in your arteries between heart beats or when the heart is not contracting. Numbers are measured in millimeters of mercury (mm Hg) and written as 120/80 for example. Numbers higher than a normal range indicate your heart is working too hard to pump blood to the rest of your body. This can put too much stress on your heart as well as damage the linings of arteries causing damage to blood vessels in the eyes or kidneys for example.

So what is a normal range for blood pressure?       Ideally, you want a systolic blood pressure (first or top number) to be between 90 and 120 mm/Hg. The diastolic blood pressure (second or bottom number) should be between 60 and 80 mm/Hg. So a blood pressure between 120/80 and 90/60 is good. This means your heart is working at optimum efficiency without excessive force against the walls of blood vessels but with enough force to get oxygenated blood to the rest of your body. If blood pressure is too low (below 90/60) then tissues will be deprived of oxygen. Blood pressure that is too high (above 120/80) is called hypertension and blood pressure that is too low (below 90/60) is called hypotension. Your body prefers a happy medium to keep things working well.

The next question is how do we maintain a healthy blood pressure? Lifestyle plays a major role and includes a healthy diet, exercise, maintaining a healthy weight, not smoking, avoiding excessive alcohol intake and stress management. If you have a family history of high blood pressure (hypertension) you will want to be even more diligent about these things. Key dietary factors for controlling blood pressure include getting enough fruits and vegetables and reducing excess sodium. This provides the right balance of minerals (potassium, magnesium, etc.) for blood pressure control. Too much salt in the diet can increase sodium in the blood stream which reduces the kidneys ability to get rid of excess fluid. The fluid retention causes an increase in blood pressure. The more salt you consume, the more fluid you will retain and the higher your blood pressure will be. This is why lowering your salt intake with diets such as the DASH diet can help. Limiting salty snacks, eating out less frequently and using less salt when cooking can all contribute to a healthier diet for your heart. The American Heart Association recommends guidelines based on research showing what is effective for reducing blood pressure and heart disease. They recommend no more than 2,300 milligrams of salt (equal to a teaspoon) per day or 1500 milligrams (3/4 teaspoon) for those who already have high blood pressure. For a review of research regarding the relationship between sodium intake and blood pressure, check out this 5-minute video by Dr. Michael Greger at NutritionFacts.org. These are just a few of the compelling arguments for reducing sodium intake. Limiting caffeine may also help in some people. Incorporating omega 3 fatty acids from fish or flaxseed, getting enough magnesium, potassium and calcium from fruits, vegetables and low fat dairy as well as increasing fiber with whole grains can help. Taking a CoEnzyme Q10 (CoQ10) supplement can also be beneficial especially if you take a statin drug to lower cholesterol. Exercise helps to strengthen the heart muscle making each heartbeat more efficient. Aerobic exercise such as walking, biking or swimming for at least 30 minutes a day 5 days a week is good for the heart. Exercise can also help with stress management. And we all know stress can wreak havoc on our health. Maintaining a healthy weight, especially as we age, is a great way to keep blood pressure controlled. A healthy diet and exercise will help with weight loss. If you have a family history of high blood pressure, be sure to have it tested often and reduce your other risk factors as much as possible.

 

 Blood Pressure Number              What it Means       
<120 / 80    Normal
121-139 / 81-89    Prehypertension
140-159 / 90-99    Hypertension, stage I
>160 / >100    Hypertension, stage II
>180 / >110    Hypertensive Crisis

To be diagnosed with high blood pressure (hypertension) your blood pressure reading must be above 140/90 for several readings. One elevated blood pressure is not enough for a diagnosis. Your doctor may want to test it frequently over several days or weeks or have you monitor at home. If your blood pressure remains elevated, then diet and lifestyle interventions should be recommended first. If this is not sufficient to lower the numbers, then medication will be considered next. If your blood pressure is extremely high (above 160/100), your doctor may want to run some tests to determine if there is a specific cause. High blood pressure should be taken seriously since it is a major risk factor for heart attacks and stroke as well as kidney disease and dementia. Here is my checklist for getting blood pressure under control.

  1. If you are overweight or obese, start making changes to lose weight today. Even a small reduction in bodyweight can make a difference.
  2. If you smoke, stop! Get help as needed. Smoking causes vasoconstriction (narrowing of the blood vessels) which can make blood pressure go up.
  3. Limit your salt! Look at labels and avoid canned soups and packaged foods with more than 400 milligrams of sodium per serving. Other high sodium foods include hotdogs, bacon, luncheon meats and pickled foods.
  4. Eat more fruits and vegetables. These are naturally low in sodium but provide potassium, magnesium and even some calcium. They are also low in calories and can help with weight loss.
  5. Limit alcohol to no more than 2 drinks for men and 1 drink for women per day.
  6. Relax! Find ways to reduce your stress by engaging in hobbies you enjoy, listening to music, taking a walk, getting a massage or talking to a close friend. Deep breathing can also help you feel more relaxed.

Take care of your heart so it can take care of you!