By Dr. Mercola
"White-coat hypertension" is a term used for when a high blood pressure reading is caused by the stress or fear associated with a doctor or hospital visit. This can be a transient yet serious concern.
It's estimated that up to 20 percent of people diagnosed with hypertension actually only have white-coat hypertension, which means their blood pressure was only elevated because they were nervous.1
If your blood pressure is elevated due to white-coat hypertension, you may be prescribed drugs for high blood pressure that you don’t really need. The solution to this problem is simple – check your blood pressure at home or in another location where you’re relaxed to confirm the results from your doctor’s office.
Federal Advisory Board Recommends Confirming Your Blood Pressure Readings at Home
The U.S. Preventive Services Task Force (USPSTF), a federal advisory board, recommends screening for high blood pressure in adults aged 18 years or older.
However, they have updated their clinical guidelines to also recommend that blood pressure measurements be obtained outside of a clinical setting for diagnostic confirmation before starting treatment.2
Their first choice for monitoring is ambulatory blood pressure monitoring. This involves a small portable device (provided by your doctor), which measures your blood pressure automatically every 20 to 30 minutes for 12 to 48 hours.
Alternatively, you can measure your blood pressure at varying times throughout the day using home blood pressure monitoring. According to the report, published in the Annals of Internal Medicine:3
“The USPSTF reviewed the research published since its 2007 recommendation about the accuracy of different methods for confirming hypertension after an initial positive screening result, and about the best frequency for screening.
… The authors found clear evidence that the benefits of screening for hypertension outweigh the risks.
Ambulatory blood pressure monitoring is the best method for diagnosing hypertension, and home blood pressure monitoring may be acceptable if ambulatory monitoring is not possible. Good information about the best frequency for screening is not available.
… The USPSTF recommends screening for high blood pressure in adults aged 18 years or older and taking measurements outside of medical settings to confirm high blood pressure before starting treatment.”
Blood Pressure Readings Higher When Taken by Doctors Versus Nurses
When researchers from the University of Exeter Medical School analyzed blood pressure readings from more than 1,000 patients, they noticed a significant discrepancy in readings taken by doctors and nurses.
Blood pressure readings taken by doctors were significantly higher (by 7/4 mmHg) than those taken by nurses, even though the readings were of the same person on the same day.4
The difference in readings was large enough to push some patients into the high-blood pressure category, which means they could be receiving unnecessary or inappropriate treatment. The researchers described the “white-coat effect” as a subconscious or reflex effect.
In short, when a doctor takes your blood pressure it may trigger your fight-or-flight response, which ramps up your blood pressure. Past research suggests older females are particularly vulnerable to white-coat hypertension, especially when the reading is taken by a male doctor.
The presence of a student or “doctor in training” has also been linked with higher blood pressure readings.5 It’s estimated that 75 percent of patients with high blood pressure may also be affected by the white-coat effect.6
If you find yourself feeling stressed before a blood-pressure screening, to decrease your risk of being falsely diagnosed with hypertension in this situation, take a moment to calm down.
Be sure to arrive for your appointment ahead of time so you can unwind, then breathe deeply and relax when you're getting your blood pressure taken.
What Are the Risks of High Blood Pressure?
Your blood pressure readings can fluctuate from day to day and also due to factors such as stress, physical activity, caffeine, and nicotine.
Many people have high blood pressure without even knowing, but once your readings measure high – and are confirmed as such outside a clinical setting – it’s important to take steps to reduce it.
The number of deaths due to high blood pressure increased nearly 62 percent from 2000 to 2013, according to data from the US Centers for Disease Control and Prevention (CDC).7
Currently, about 70 million US adults struggle with the condition, which amounts to 1 in every 3 adults. Only 52 percent of those who have been diagnosed have their blood pressure levels under control, and another 1 in 3 US adults has pre-hypertension, which means blood pressure is elevated and at risk of progressing to full-blown hypertension.8
If your blood pressure is elevated, it means the force of blood pushing against the walls of your arteries is too high, which can cause damage over time. Many are familiar with the related heart risks this can cause. For instance, high blood pressure increases your risk of heart disease, heart failure, and stroke.
Less well-known, but equally important, is the fact that high blood pressure can contribute to kidney failure (by weakening and narrowing blood vessels in your kidneys) and problems with memory and understanding. High blood pressure has even been linked to an increased risk of developing, and dying from, cancer,9 and is known to trigger and worsen complications of diabetes, including diabetic eye disease and kidney disease.
There Are Risks to Taking Blood Pressure Medications
High blood pressure can be deadly, but you need to think carefully before using drugs to treat it, especially if your levels are only mildly elevated. In the vast majority of cases, drugs are not needed to reverse hypertension, and in some cases the drugs may end up shortening your lifespan instead of extending it.
In one study, diabetic participants received one or more blood pressure medications (a combination of calcium antagonist, beta-blocker, ACE inhibitor, and diuretic) in whatever combination required to achieve a systolic blood pressure less than 130 mm Hg (the standard hypertension guidelines for diabetics).
Researchers discovered that tighter control of blood pressure in these patients was not associated with better outcomes. The uncontrolled group fared worst, which wasn’t surprising, but the group whose systolic blood pressure was held between 130 and 140 actually showed a slightly lower risk of death than the group whose systolic was maintained at the recommended level — under 130 mm Hg.10
Past research has also shown that aggressive blood pressure control may lead to too low of a blood pressure and increased risk of cardiovascular events.11 There is a major difference between achieving a healthy blood pressure number by eating well, exercising and managing stress versus “forcing” your body to produce that number with a drug.
My Top-Recommended Strategies to Prevent Hypertension
If you are diagnosed with high blood pressure, dietary strategies will be crucial to controlling your levels. Avoiding processed foods (due to their being high in sugar/fructose, grains, trans fats, and other damaged fats and processed salt) is my number one recommendation if you have high blood pressure.
Research shows that dietary sugars influence blood pressure and serum lipids independent of the effects of sugars on body weight.12 In a review in the journal Open Heart, the authors also argue that the high consumption of added sugars in the US diet may be more strongly and directly associated with high blood pressure than the consumption of sodium.13
Instead, make whole, ideally organic foods the focus of your diet. As you reduce processed foods, and other sources of non-vegetable carbs from your diet, you’ll want to replace them with healthy fat. Sources of healthy fats to add to your diet include:
Avocados Butter made from raw, grass-fed organic milk Raw dairy Organic pastured egg yolks Coconuts and coconut oil (coconut oil actually shows promise as an effective Alzheimer's treatment in and of itself) Unheated organic nut oils Raw nuts, such as pecans and macadamia, which are low in protein and high in healthy fats Grass-fed meats or pasture raised poultry
It’s not only your diet that matters for healthy blood pressure… a comprehensive fitness program is another strategy that can improve your blood pressure and heart health on multiple levels (such as improving your insulin sensitivity). For example, research shows that men who are fit can stave off increases in blood pressure that tend to occur with age. In men with strong heart fitness, blood pressure levels didn’t start increasing until their mid-50s. However, in sedentary men, signs of high blood pressure appeared in their mid-40s.14
To reap the greatest rewards, I strongly suggest including high-intensity interval exercises in your routine. You’ll also want to include weight training. When you work individual muscle groups you increase blood flow to those muscles, and good blood flow will increase your insulin sensitivity. I encourage you to read through my full list of strategies to prevent hypertension for more guidelines, however below you’ll find some additional highlights.
- Eat an early dinner: Research shows intermittent fasting helps fight obesity and type 2 diabetes, both of which are risk factors for high blood pressure. Your body is most sensitive to insulin and leptin after a period of fasting. While there are many types of fasting regimens, one of the easiest to comply with is an eating schedule where you limit your eating to a specific, narrow window of time each day. I typically recommend that you stop eating at least three hours, and ideally six hours, prior to bedtime to give your body a significant fasting period.
- Optimize your vitamin D levels: Arterial stiffness (atherosclerosis) is a driving factor for high blood pressure. As your blood travels from your heart, cells in the wall of your aorta, called baroreceptors, sense the pressure load, and signal your nervous system to either raise or lower the pressure.
However, the stiffer your arteries are, the more insensitive your baroreceptors become, and the less efficient they become at sending the appropriate signals. Vitamin D deficiency is, in turn, linked to stiff arteries, which is why optimizing your levels is so important.
- Address your stress: The link between stress and hypertension is well documented. Suppressed negative emotions such as fear, anger, and sadness can severely limit your ability to cope with the unavoidable every day stresses of life. It's not the stressful events themselves that are harmful but rather is your lack of ability to cope. I recommend the Emotional Freedom Techniques (EFT) to transform your suppressed, negative emotions and relieve stress.
- Normalize your omega-6:3 ratio: Most Americans get too much omega-6 in their diet and far too little omega-3. Consuming omega-3 fats will help re-sensitize your insulin receptors if you suffer from insulin resistance. Omega-6 fats are found in corn, soy, canola, safflower, and sunflower oil. If you're consuming a lot of these oils, you'll want to avoid or limit them. For omega-3s, your best bet is to find a safe source of fish, or if this proves too difficult or expensive, supplement with a high-quality krill oil, which has been found to be 48 times more potent than fish oil.
- Optimize your gut flora: Compared to a placebo, people with high blood pressure who consumed probiotics lowered systolic blood pressure (the top number) by 3.56 mm Hg and diastolic blood pressure (the bottom number) by 2.38 mm Hg.15 The best way to optimize your gut flora is by including naturally fermented foods in your diet, which may contain about 100 times the amount of bacteria in a bottle of high-potency probiotics.
- Maintain an optimal sodium-potassium ratio: An imbalanced ratio may lead to hypertension. To ensure yours is optimal, ditch all processed foods, which are very high in processed salt and low in potassium and other essential nutrients. Instead, eat a diet of whole, unprocessed foods, ideally organically and locally-grown to ensure optimal nutrient content. This type of diet will naturally provide much larger amounts of potassium in relation to sodium.
- Eliminate caffeine: The connection between coffee consumption and high blood pressure is not well understood, but there is ample evidence to indicate that if you have hypertension, coffee and other caffeinated drinks and foods may exacerbate your condition.
- Vitamins C and E: Studies indicate that vitamins C and E may be helpful in lowering blood pressure. If you're eating a whole food diet, you should be getting sufficient amounts of these nutrients through your diet alone. If you decide you need a supplement, make sure to take a natural (not synthetic) form of vitamin E. You can tell what you're buying by carefully reading the label. Natural vitamin E is always listed as the "d-" form (d-alpha-tocopherol, d-beta-tocopherol, etc.) Synthetic vitamin E is listed as "dl-" forms.
- Olive leaf extract: In one 2008 study, supplementing with 1,000 mg of olive leaf extract daily over eight weeks caused a significant dip in both blood pressure and LDL ("bad") cholesterol in people with borderline hypertension. If you want to incorporate olive leaves as a natural adjunct to a nutritionally sound diet, look for fresh leaf liquid extracts for maximum synergistic potency.
You can also prepare your own olive leaf tea by placing a large teaspoon of dried olive leaves in a tea ball or herb sack. Place it in about two quarts of boiling water and let it steep for three to 10 minutes. The tea should be a medium amber color when done.
- Quick tricks: Increasing nitric oxide in your blood can open constricted blood vessels and lower your blood pressure. Methods for increasing the compound include taking a warm bath, breathing in and out through one nostril (close off the other nostril and your mouth), and eating bitter melon, rich in amino acids and vitamin C.