Preventing Hypertension Before It Surprises You by, Christina Badaracco, MPH
Updated: Nov 14, 2019
I see many patients with high blood pressure or hypertension at the hospital where I work. This, and other common diseases like diabetes and kidney disease, can complicate treatments and patients’ nutritional needs. But hypertension is often preventable. My penchant for public health motivates me to teach people how to improve their diets to maximize their health before developing this disease. How is hypertension diagnosed? Until recently hypertension was defined by having a blood pressure of 140/90 mm Hg or above. The first number represents the systolic blood pressure, or the pressure in the arteries while the heart contracts; the second number represents the diastolic blood pressure, or the pressure between beats when the heart relaxes. In November 2017, the American College of Cardiology (ACC) and American Heart Association (AHA) released new Guidelines for the Prevention, Detection, Evaluation and Management of High Blood Pressure, lowering the criteria for hypertension. While blood pressure is still considered normal below 120/80 mm Hg, Stage 1 Hypertension, the point at which people have twice the risk for cardiovascular disease (CVD), now begins at 130/80 mm Hg—increasing the prevalence of hypertension among American adults to 46%.
These changes in blood pressure categories were based on the 2015 Systolic Blood Pressure Intervention Trial (SPRINT), which found that keeping systolic blood pressure below 120 significantly reduced CVD and increased longevity. While there is disagreement about the generalizability of these results, the new guidelines suggest that preventing high blood pressure may be an effective way to reduce the health-care burden associated with CVD. Why is high blood pressure a problem? One-third of Americans currently have hypertension and another third have elevated blood pressure. High blood pressure increases the risk of heart disease and stroke and costs the country $48.6 billion each year, due to necessary medical management and reduced productivity. According to the AHA, the top risk factors for hypertension include family history, age, gender (with men having a higher risk before age 45 and women after age 55), race, lack of physical activity, overweight, excessive alcohol intake, smoking and elevated stress. While the first four factors are not modifiable, the rest can be mitigated by early interventions to maximize health and quality of life. Dr. Robert Carey, one of the lead authors of the guidelines, suggests that lifestyle changes should be the primary means of reducing risk. Additional approaches include following the Dietary Approaches to Stopping Hypertension (DASH) diet, increasing potassium intake, exercising and limiting alcohol consumption.
How is blood pressure regulated? A number of mechanisms control blood pressure, including hormones, nerves and derivatives of fatty acids. Nutrition also plays a role. Blood pressure increases with a high intake of sodium, primarily in the form of sodium chloride, or table salt. High sodium in our blood causes our kidneys to retain more water, which translates to more fluid in the body and a higher blood pressure. Potassium exists predominantly inside our cells and counterbalances sodium in our blood. Since the beginning of the Neolithic period, humans have been eating too much sodium and not enough potassium. A 2014 systematic review by Drs. Vanessa Perez and Ellen Chang found that the ratio of dietary sodium to potassium is more closely associated with blood pressure in adults with hypertension than either electrolyte alone. According to the Dietary Guidelines for Americans (DGAs), we currently consume a daily average of 3500 mg of sodium. A 2017 study published in Circulation showed that 71% of the salt in our diets comes from packaged and restaurant foods, while only 11% comes from salt we add to our food. Last year, Americans spent $720 billion at restaurants. That number represents half of our overall food spending and reflects a 19% increase since 2012, suggesting the predominance of food—likely high in sodium—consumed away from home. Of course, people vary in their sensitivity to salt. Some people retain more fluid in response to sodium than do others. Also, people who already have elevated blood pressure have a greater risk of developing full hypertension or CVD, making it more important to restrict their dietary sodium and perhaps to a lower level than is recommended for the general population. Some instances of elevated blood pressure, such as preeclampsia or primary hyperaldosteronism, are not preventable through nutrition and must be managed medically. How can you eat for a healthier blood pressure? Regulating either the intake or function of sodium in our bodies can help to maintain a healthy blood pressure. The current DGAs recommend consuming up to 2300 mg (or about one teaspoon of salt per day), with the AHA and Institute of Medicine suggesting just 1500 mg. A Chinese takeout meal can provide more than a single teaspoon in just one sitting. To improve the balance in your intake of potassium and sodium, aim to reach the Adequate Intake of 4.7 grams of potassium per day recommended by Institute of Medicine. Based on a 2012 assessment by the US Department of Agriculture, the average American consumed only 51–70% of this recommended value. Thus, incorporating more foods such as baked potatoes, watermelon, beets or the foods shown in the photo below into your daily meals can help to maximize intake of this important electrolyte.
For people who already have hypertension, doctors and dietitians commonly recommend the DASH diet. It is perhaps the most rigorously studied and evidence-based dietary prescription and has been consistently shown to lower blood pressure in both healthy populations and those with high blood pressure. Results of the original clinical trial in 1997 showed that blood pressure began to fall in patients with Prehypertension or Stage 1 Hypertension within two weeks and was maintained for the remaining six weeks of the trial when put on the DASH diet. This diet emphasizes vegetables, fruits, and low-fat dairy, with moderate amounts of whole grains, fish, poultry and nuts.
Practical tips for a healthier blood pressure
Aim to limit packaged foods and make at least one more meal at home each week. This can be easier if you get in the habit of batch-cooking vegetables, whole grains, beans and meats over the weekend to throw together quick lunches and dinners during the week.
Explore new spice, herb and vinegar combinations in your cooking to see how you can maintain flavor while cutting down on the need for salt. A few recommendations include balsamic vinegar and rosemary, lemon juice and oregano, and cider vinegar and cumin.
For adults who wish to consume alcohol, women should have up to one drink per day and men up to two per day.
Aim to maintain a healthy body weight, perhaps through losing a few pounds by increasing activity and moderating portion sizes. Accumulating multiple short bouts of activity by taking the stairs, walking instead of driving or doing yard work can be great ways to fit in physical activity on a busy day.
Appel, L, et al. "A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure." April 17, 1997. The New England Journal of Medicine336:1117—1124. www.nejm.org/doi/full/10.1056/NEJM199704173361601
Berg, S. “For most, diet and exercise—not meds—key path to lower BP.” AMA Wire. November 30, 2017. wire.ama-assn.org/delivering-care/most-diet-and-exercise-not-meds-key-path-lower-bp?utm_source=BulletinHealthCare&utm_medium=email&utm_term=120917&%20utm_content=physicians&utm_campaign=article_alert-morning_rounds_weekend
Hoy, MK & JD Goldman. “Potassium Intake of the U.S. Population, What We Eat in America,” NHANES 2009–2010. US Department of Agriculture. Sep. 2012. www.ars.usda.gov/ARSUserFiles/80400530/pdf/DBrief/10_potassium_intake_0910.pdf
Lenz, TL, EM DeSimone, and JM Pomeroy. "Implementing Lifestyle Medicine in Hypertensive Patients." US Pharmacist. 2011;36(2):44—50. www.uspharmacist.com/article/implementing-lifestyle-medicine-in-hypertensive-patients-26628.
Muntner, P, et al. “Potential U.S. Population Impact of the 2017 American College of Cardiology/American Heart Association High Blood Pressure Guideline.” November 2017. Circulation 136(22).
Perez, V & ET Chang. “Sodium-to-Potassium Ratio and Blood Pressure, Hypertension, and Related Factors.” November 2014. Advances in Nutrition 5;712—741.
“High Blood Pressure Fact Sheet.” Centers for Disease Control and Prevention. Updated June 16, 2016. www.cdc.gov/dhdsp/data_statistics/fact_sheets/fs_bloodpressure.htm
“Know Your Risk Factors for High Blood Pressure.” American Heart Association. Updated December 15, 2017. www.heart.org/HEARTORG/Conditions/HighBloodPressure/UnderstandSymptomsRisks/Know-Your-Risk-Factors-for-High-Blood-Pressure_UCM_002052_Article.jsp#.WniGy5PwZE6
“Top 10 Potassium-Rich Foods and Potassium Benefits.” Dr. Axe. draxe.com/top-10-potassium-rich-foods/.
“Understanding Blood Pressure Readings.” American Heart Association. Updated Jan.11, 2018. www.heart.org/HEARTORG/Conditions/HighBloodPressure/KnowYourNumbers/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp#.WniHlZPwZE4
Christina Badaracco, MPH
Christina is a dietetic intern at Massachusetts General Hospital. She recently earned her Master of Public Health degree from the University of California, Berkeley. She is pursuing a career in nutrition to improve access to healthy and sustainable food and educate Americans about the connections between food and health. She loves to experiment with healthy recipes in the kitchen and share her creations to inspire others to cook. She graduated with a degree in Ecology and Evolutionary Biology from Princeton University, after conducting her thesis on sustainable agriculture and energy in Kenya. She has done clinical nutrition research at the National Institutes of Health, menu planning and nutrition education at the Oakland Unified School District, and communications at the Environmental Protection Agency’s Office of Water. She has also enjoyed contributing to children’s gardens, farmers’ markets, and a number of organic farms.
To subscribe to the SOULFUL Insights health and wellness newsletter click here.