Potassium and Your Blood Pressure

The American College of Cardiology (ACC) and American Heart Association (AHA) recently released the first comprehensive, updated guidelines for detecting, preventing, managing and treating high blood pressure since 2003. The big story in this update is the lower definition of high blood pressure to prevent complications and encourage earlier intervention to reduce health risk. High blood pressure causes more deaths due to cardiovascular disease than any other modifiable risk factors, including cigarette smoking/tobacco smoke exposure, diabetes, dyslipidemia (including high levels of low-density lipoprotein cholesterol, high triglycerides, and low levels of high-density lipoprotein cholesterol), overweight/obesity, physical inactivity, and unhealthy diet.High blood pressure, or hypertension, occurs when the force of the heart pumping blood against blood vessel walls is too high. This added pressure causes the heart to work too hard and blood vessels to function less effectively. Over time, the stress damages the heart and circulatory system. High blood pressure is often called ‘the silent killer’ because there often are no obvious symptoms.Hypertension was previously diagnosed at 140/90 mmHg. Here are the new guidelines:

• Normal blood pressure:  120/80 mmHg
• Elevated blood pressure:  120-129/<80 mmHg
• Stage 1 hypertension: 130-139/80-89 mmHg
• Stage 2 hypertension:  >140/>90 mmHg

Our food choices play an important role in preventing high blood pressure, and are a key part of the overall management plan for people with diagnosed hypertension. Lowering the blood pressure levels to diagnose hypertension in the new guidelines emphasizes the crucial role that food choices play in regulating blood pressure.Sodium-Potassium RatioMost people know that consuming less sodium helps lower blood pressure, but the important role of potassium is often overlooked. Potassium relaxes the blood vessels so that blood flows through them more easily, with less pressure. Also, the more potassium you consume, the more sodium your body will excrete in urine.A review of the scientific literature published in Advances in Nutrition in 2014 shows that, in people with high blood pressure, the sodium-to-potassium ratio is more strongly associated with blood pressure levels than either sodium or potassium alone. Our modern diet is higher in sodium from processed foods and dining out, and lower in potassium due to consuming far less fruits and vegetables than recommended.A 2011 study used data from the Third NHANES (National Health and Nutrition Examination Survey) that tracked more than 12,000 adults for 15 years. People who had a higher sodium-to-potassium ratio had increased blood pressure levels and risk of cardiovascular disease, as well as a greater chance of dying for any reason, with no differences for sex, race/ethnicity, body mass index, blood pressure levels, education, or physical activity.The DASH (Dietary Approaches to Stop Hypertension) study clearly showed that changing the way we eat has an important effect on blood pressure and cardiovascular disease risk. The DASH eating plan is based on fruits, vegetables, fat-free or low-fat milk and milk products, whole grains, fish, poultry, legumes, seeds, and nuts. It also contains less sodium, sweets, added sugars and beverages containing sugar, fats, and red meats than the typical American diet. This heart-healthy way of eating is also lower in saturated fat, trans fat, and cholesterol and higher in nutrients that are associated with lowering blood pressure—mainly potassium, magnesium, calcium, protein, and fiber. Following the DASH guidelines decreases sodium intake and increases potassium, and is a practical, simple way to improve your overall health.Use these 7 strategies to improve your health by consuming more potassium and less sodium:

1. Include 3-6 servings of vegetables in your daily food choices. One serving of vegetables is 1 cup raw, leafy vegetables or ½ cup chopped or cooked vegetables. Vegetables are good sources of potassium and are naturally low in sodium.
2. Include 4-6 servings of fruit in your daily food choices. One serving of fruit is 1 medium-size piece of fresh fruit or ½ cup fresh, frozen or canned fruit. Fruit is also a good source of potassium and low in sodium.
3. Avoid using canned or frozen vegetables with added sodium.
4. Replace processed snacks like chips, crackers, pretzels and cookies with fresh fruit or raw vegetables.
5. Fill half your plate at meals with vegetables and fruit to increase potassium.
6. Read the nutrition label on processed foods and look for foods with no more than 140 mg sodium per serving. Take this one step further by keeping total sodium content for each meal at less than 800 mg.
7. Use a variety of salt-free herbs and spices when cooking instead of salt. The good news is that our taste buds adapt to a lower sodium diet, and over time you’ll learn to enjoy foods prepared with less salt.

Most people reach for banana when they want a higher-potassium food, and while bananas are a good source of potassium, there is a wide range of other vegetables and fruit that are also good potassium sources. Here is a chart with some of the fruit and vegetables that are highest in potassium.By Lynn Grieger, RDN, CDE, CPT, CHWCReferences:

1. Whelton PK, Carey RM, Aronow WS, Casey Jr DE, Collins KJ, Dennison Himmelfarb C, DePalma SM, Gidding S, Jamerson KA, Jones DW, MacLaughlin EJ, Muntner P, Ovbiagele B, Smith Jr SC, Spencer CC, Stafford RS, Taler SJ, Thomas RJ, Williams Sr KA, Williamson JD, Wright Jr JT, 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults, Journal of the American College of Cardiology (2017), doi: 10.1016/j.jacc.2017.11.006.
2. Harvard Health Publishing. Harvard Medical School. Sodium/Potassium Ratio Important for Health. https://www.health.harvard.edu/heart-health/sodiumpotassium-ratio-important-for-health Published September 2011. Accessed 11-25-17.
3. Vanessa Perez, Ellen Chang. Sodium-to-Potassium Ratio and Blood Pressure, Hypertension, and Related Factors. Adv Nutr November 2014 Adv Nutr vol. 5: 712-741, 2014
4. Yang Q, Liu T, Kuklina EV, Flanders WD, Hong Y, Gillespie C, Chang MH, Swinn M, Dowling N, Khoury MJ, Hu FB. Sodium and potassium intake and mortality among US adults: prospective data from the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2011 Jul 11;171(13):1183-91. doi: 10.1001/archinternmed.2011.257.  (2)
5. American Heart Association. How Potassium Can Help Control High Blood Pressure. http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/MakeChangesThatMatter/How-Potassium-Can-Help-Control-High-Blood-Pressure_UCM_303243_Article.jsp#  last reviewed October 2016. Accessed 11-25-17
6. National Institutes of Health. National Heart, Lung and Blood Institute. Your Guide to Lowering Your Blood Pressure with DASH. https://www.nhlbi.nih.gov/files/docs/public/heart/dash_brief.pdf  Revised August 2015. Accessed 11-25-17
7. U.S. National Library of Medicine. Potassium in Diet. https://medlineplus.gov/ency/article/002413.htm  Reviewed 4-24-16.  Accessed 11-27-17

*Talk with your healthcare provider before eating grapefruit or drinking grapefruit juice if you are taking a cholesterol-lowering drug.PDF Handout: Potassium and Sodium HandoutSaveSave