by Dr. Miles Nichols and Nicola Schuler, CNTP, MNT
Hypertension or high blood pressure: Blood pressure is the pressure against blood vessels and arteries created by the heart pumping blood around the body. The force of this pressure against the arteries is blood pressure. It increases and decreases throughout the day. If it remains too high, then it is high blood pressure or hypertension. If blood pressure stays too high, it puts a strain on the heart and arteries, possibly resulting in cardiovascular disease, a heart attack or a stroke.
According to the CDC:
- 32% of Americans or 1 in every 3 adults has high blood pressure (1)
- About 1 in 3 American adults has prehypertension; blood pressure numbers that are higher than normal but is not yet hypertension (1)
- This means 2 out of 3 Americans has an issue with blood pressure – either prehypertension or hypertension (1)
- Only about half (54%) of people with high blood pressure have their condition under control (2)
How is BP calculated?
Two numbers are used to calculate blood pressure. First, systolic blood pressure is the pressure in blood vessels when the heart beats. The second number is diastolic blood pressure and is the pressure in blood vessels when the heart rests between beats (3). See the chart below (3) to identify if a BP reading is high, low or normal:
|Blood Pressure Levels|
|Normal||systolic: less than 120 mmHgdiastolic: less than 80mmHg|
|At risk (prehypertension)||systolic: 120–139 mmHgdiastolic: 80–89 mmHg|
|High||systolic: 140 mmHg or higherdiastolic: 90 mmHg or higher|
Types of hypertension:
There are different types of hypertension. Primary or essential hypertension is when the cause is unknown. Secondary hypertension is caused by another disease and is a symptom of that disease. If the root cause of that disease can be addressed, then often blood pressure is reduced or even becomes normal. Less common types of hypertension are:
- Malignant hypertension has very obvious symptoms like changes in vision, chest pain, anxiety, nausea, numbness or weakness in arms or legs, shortness of breath, headache or reduced urination (4).
- Resistant hypertension is persistent even after dietary & lifestyle changes have been made and/or the person is taking blood pressure medication (4). It is difficult to treat and may have an underlying cause that has yet to be identified.
- Pulmonary hypertension is often indicated by a shortness of breath during routine activity, fatigue, chest pain, racing heartbeat, pain in the abdomen near the liver or decreased appetite (4).
- White coat hypertension is when a person’s blood pressure measures high in the doctor’s office but is normal when the reading is taken at home (4).
- Isolated systolic hypertension is when the systolic number is too high while the diastolic number is normal (4). It typically affects older people and is normally due to a condition or issue elsewhere in the body.
The exact cause of hypertension is currently unknown. Certain factors are believed to contribute to high blood pressure (3):
- Being overweight or obese
- Excessive alcohol consumption
- Too much salt or too little salt in the diet
- Insufficient intake of potassium, calcium, and magnesium
- Lack of physical activity
- Kidney disease, Diabetes, Sleep apnea, Hormone disorders
One study has found that high blood pressure is associated with gut microbiota dysbiosis, both in animal and human hypertension (5). Dysbiosis is when there are too few health-promoting, good bacteria and too many harmful or pathogenic bacteria in the gut.
So what can you do about hypertension?
Fortunately there are numerous action steps you can take to manage hypertension which include diet, supplements and lifestyle factors. Hypertension is part of metabolic syndrome which is very much a lifestyle disease. Thus diet has a strong impact on the incidence and management of hypertension. We will concentrate on diet changes that can help lower BP (blood pressure) in this article. We will run a second article to cover supplements and lifestyle factors that can help reduce blood pressure.
What Diet Changes can you make to reduce and manage your BP?
- Reduce Sugar and Refined Carbohydrates: Multiple studies have found that reducing sugar intake in all forms leads to lower blood pressure (6, 7, 8).
- Sodium and Potassium: Despite conventional wisdom, studies have found that too much or too little sodium can increase blood pressure in some individuals (9). For most healthy individuals, we recommend consuming between 3’000 and 6’000 mg of sodium per day (9). Below 3’000 mg of sodium per day was associated with a 27% increase in cardiovascular disease and death (9). Consuming more than 6’000 mg per day was associated with a 15% increase in cardiovascular disease and mortality (9). It appears that there are a subset of sodium-sensitive individuals whose BP increases from excessive sodium intake. However, this is not everyone. We recommend that those with high blood pressure do an experiment with salt and measuring BP (see action steps at the end of this article). In addition to sodium, other minerals like potassium have a significant influence on BP as well. Another study found diets rich in potassium to be more effective than an aggressive salt reduction to prevent hypertension (10). Recommended potassium intake per day is 4’000-5’000 mg but the average person only gets 2’800 mg daily (11). Increase your potassium by eating high potassium foods like banana, sweet potato, white potato, orange, winter squash, white beans, beets, parsnip and spinach. It may be necessary to supplement potassium in addition to adding potassium to the diet.
(Note: One teaspoon of salt is approximately 2’300 mg sodium. One medium banana has 422 mg of potassium.)
- Magnesium and Calcium: Consuming a healthy diet that provides the recommended amount of the mineral magnesium can be help control BP (12). The RDA (Recommended Daily Allowance) for magnesium is 310–420 mg for adults and can be found in these foods high in magnesium: nuts, spinach & other greens, seeds, avocados, dark chocolate. Calcium, along with potassium and magnesium, may improve blood pressure levels and reduce coronary heart disease and stroke (13). It is recommended to get these minerals through increased consumption of fruits and vegetables (13). Calcium-containing foods include seeds, cheese, yogurt, bone-in fish like sardines, legumes, almonds and whey protein. The RDA for calcium varies depending on age and gender. Adults between 51 and 70 years are recommended to get 1’000- 1’200 mg per day.
- Reduce Alcohol: It is well established that excessive alcohol consumption is a significant predictor of the development of hypertension and that alcohol reduction in patients with high BP can significantly lower systolic and diastolic blood pressure (14).
- The DASH Diet: DASH or Dietary Approaches to Stop Hypertension is often regarded as the diet to follow for hypertension. In research, it has a reducing effect on both systolic and diastolic blood pressure but there is variation in the extent of the fall in blood pressure in different subgroups of patients (15). We think a generally healthy diet would be equally effective, as long as the sodium potassium balance is well managed and there are sufficient levels of other minerals.
- Specific Foods can help to reduce blood pressure include: hibiscus tea (16), beets (17), fatty fish such as salmon (18), olive oil (19) and nuts (20).
- Improve Gut Health: One study indicates that diet changes to re-balance gut microbiota could be a new strategy using nutrition to help reduce hypertension (5). This study goes on to say that probiotics affect BP. Trials showed a significant decrease in both systolic and diastolic BP in patients who took a daily dose of probiotics (21).
In Part 2 on Hypertension, we will discuss the supplements and some lifestyle factors that will significantly work to reduce hypertension. Please stay tuned for these tips.
Here are the abbreviated action steps you can take based on the information in this article:
- Significantly reduce sugar and refined carbohydrates by skipping dessert, avoiding pastries, cookies, cakes, and anything made with white flour. You can take it a step further if you like and avoid all gluten and sugar, choosing a moderate amount of fresh fruit and a small amount of raw, unfiltered local honey to satisfy any sweet needs. You could even try avoiding all grains for a period of time and use stevia as an alternative to sweeteners. Allow sweet potatoes, squash, beets, plantains, and carrots to become satisfying sweets. Possibly add a square or two of dark chocolate (75% and higher cocoa content) as this can help with nutrients that can regulate BP.
- Increase potassium intake by having plenty of starchy tubers like potatoes and sweet potatoes, plantains, avocados, bananas (eat them on the green side to have less blood sugar impact and get more resistant starch for good gut bacteria to feed on), and lots of leafy greens and some fresh fruits. Track with an app like MyFitnessPal for a few days and make sure you are getting at least 4’700mg/day. If BP is high, you may want to shoot for 6’000mg daily (some hunter-gatherer cultures have been reported to get as high as over 10’000mg daily on average).
- Do a salt experiment by taking precisely 1.5 teaspoons sea salt (just over 3’000mg on the low end of intake that was found to be in the healthy range for cardiovascular disease prevention) and putting it into a small dish. Make this your salt for the day. Cook all your meals at home and consume only food that has no added salt (nothing packaged that has any sodium content to it). Add salt from the dish to food you are cooking and to food on your plate that day. Make sure you have finished the salt in the dish by the end of the day (you will have to adjust things if you are cooking for more than just yourself so that you are getting the full dish worth of salt that day). Take your blood pressure first thing in the morning on this day and 2-3 times throughout the day. Notice if it is higher, lower, or the same as usual. Also keep a note on how it felt. Did that seem like a lot of salt? A small amount? Or about usual for you? Then do the experiment again another day but this time use 2.5 teaspoons of sea salt (just under the 6’000mg high end for healthy salt intake). How did your blood pressure do that day?
- Consume magnesium and calcium-rich foods and/or supplement to get adequate intake of both of these minerals. Be sure to have some nuts, seeds, plenty of greens including spinach, avocado, and some dark chocolate (1-2 squares at 75%+ cocoa content). Also eat a couple of servings of grass-fed full fat dairy if you tolerate dairy (yogurt, kefir, cheese, etc.) and/or bone-in canned fish (canned wild salmon with the bone or canned sardines with the bones – the canning process makes the bones soft enough to eat – of course do not eat bones from fresh fish that are hard and brittle).
- Limit alcohol consumption to 3 drinks per week (men) or 2 drinks per week (women) or less. And make sure a drink is actually a single drink (i.e. 4 oz pour for wine and not 6 or 8 oz). If it has been a while since you’ve gone a month without alcohol, try stopping entirely for 30-60 days.
- Drink 2-3 cups of hibiscus tea daily by brewing a gallon of tea using loose leaf hibiscus flowers. Brew it strong and store in the fridge to drink over a few days.
- Eat fermented foods and/or take probiotics daily. For example you can eat sauerkraut, kimchi, fermented beets, make beet kvass and drink it, unsweetened grass-fed kefir, etc. Or get professional-grade probiotics to take. Also consume prebiotic rich foods like lentils, green bananas, green plantains, potatoes that have been cooked then cooled 24-hours, onions that are still a bit crunchy (not fully caramelized), leeks, and dandelion greens.
- Nwankwo T, Yoon SS, Burt V, Gu Q. Hypertension among adults in the US: National Health and Nutrition Examination Survey, 2011-2012. NCHS Data Brief, No. 133. Hyattsville, MD: National Center for Health Statistics, Centers for Disease Control and Prevention, US Dept of Health and Human Services; 2013.
- Farley TA, Dalal MA, Mostashari F, Frieden TR. Deaths preventable in the U.S. by improvements in the use of clinical preventive services. Am J Prev Med. 2010;38(6):600–9.
- Centers for Disease Control and Prevention. Division for Heart Disease and Stroke Prevention. 2016. High Blood Pressure Fact Sheet. https://www.cdc.gov/dhdsp/data_statistics/fact_sheets/fs_bloodpressure.htm. Accessed March 12, 2019.
- 2018. Types of Hypertension – Understanding the Differences. https://www.resperate.com/blog/hypertension/facts/definition-symptoms/types-of-hypertension. Accessed March 12, 2019
- Yang T, Santisteban MM, Rodriguez V, Li E, Ahmari N, Carvajal JM, Zadeh M, Gong M, Qi Y, Zubcevic J, Sahay B, Pepine CJ, Raizada MK, Mohamadzadeh M. 2015. Gut dysbiosis is linked to hypertension. Hypertension. 2015 Jun ;65(6):1331-40.
- Chen L, Caballero B, Mitchell DC, Loria C, Lin PH, Champagne CM, Elmer PJ, Ard JD, Batch BC, Anderson CA, Appel LJ. 2010. Reducing consumption of sugar sweetened beverages is associated with reduced blood pressure: a prospective study among United States adults. Circulation. 2010 Jun 8;121(22):2398-406. doi: 10.1161/CIRCULATIONAHA.109.911164.
- Malik AH, Akram Y, Shetty S, Malik SS, Yanchou Njike V. 2014. Impact of sugar sweetened beverages on blood pressure. Am J Cardiol. 2014 May 1;113(9):1574-80. doi: 10.1016/j.amjcard.2014.01.437.
- Brown IJ, Stamler J, Van Horn L, Robertson CE, Chan Q, Dyer AR, Huang CC, Rodriguez BL, Zhao L, Daviglus ML, Ueshima H, Elliott P. 2011. Sugar sweetened beverage, sugar intake of individuals, and their blood pressure: international study of macro/micronutrients and blood pressure. Hypertension. 2011 Apr;57(4):695-701. doi: 10.1161/HYPERTENSIONAHA.110.165456.9.
- O’Donnell M, Mente A, Rangarajan S, McQueen MJ, Wang X, Liu L, Yan H, Lee SF, Mony P, Devanath A, Rosengren A, Lopez-Jaramillo P, et al. 2014. Urinary Sodium and Potassium Excretion, Mortality, and Cardiovascular Events. N Engl J Med. 2014; 371:612-623. DOI: 10.1056/NEJMoa1311889.
- Lelong H, Blacher J, Baudry J, Adriouch S, Galan P, Fezeu L, Hercberg S, Kesse-Guyot E. 2017. Individual and Combined Effects of Dietary Factors on Risk of Incident Hypertension. Hypertension. 2017;70:712–720. org/10.1161/HYPERTENSIONAHA.117.09622.
- Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. 2005. Origins and evolution of the Western diet: health implications for the 21st Am J Clin Nutr. 2005 Feb;81(2):341-54.
- Kostov K, Halacheva L. 2018. Role of Magnesium Deficiency in Promoting Atherosclerosis, Endothelial Dysfunction, and Arterial Stiffening as Risk Factors for Hypertension. Int J Mol Sci. 2018 Jun 11 ;19(6).
- Houston MC, Harper KJ.2008. Potassium, magnesium and calcium: their role in both the cause and treatment of hypertension. J Clin Hypertens (Greenwich).2008 Jul;10(7 Suppl 2):3-11.
- Collart F, de Timary P, Dom G, Dor BD, Duprez D, Lengelé JP, Matthys F, Peuskens H, Rehm J, Stärkel P. 2015. Alcohol-induced hypertension: an important healthcare target in Belgium. Acta Clin Belg. 2015 Dec;70(6):389-95. doi: 10.1179/2295333715Y.0000000039.
- Saneei P, Salehi-Abargouei A, Esmaillzadeh A, Azadbakht L. 2014. Influence of Dietary Approaches to Stop Hypertension (DASH) diet on blood pressure: a systematic review and meta-analysis on randomized controlled trials. Nutr Metab Cardiovasc Dis. 2014 Dec;24(12):1253-61. doi: 10.1016/j.numecd.2014.06.008.
- McKay DL, Chen CY, Saltzman E, Blumberg JB. 2010. Hibiscus sabdariffa L. tea (tisane) lowers blood pressure in prehypertensive and mildly hypertensive adults. J Nutr. 2010 Feb;140(2):298-303. doi: 10.3945/jn.109.115097.
- Coles LT, Clifton PM. 2012. Effect of beetroot juice on lowering blood pressure in free-living, disease-free adults: a randomized, placebo-controlled trial. Nutr J. 2012; 11: 106. doi: 1186/1475-2891-11-106.
- Ramel A, Martinez JA, Kiely M, Bandarra NM, Thorsdottir I. 2010. Moderate consumption of fatty fish reduces diastolic blood pressure in overweight and obese European young adults during energy restriction. 2010 Feb;26(2):168-74. doi: 10.1016/j.nut.2009.04.002.
- Moreno-Luna R, Muñoz-Hernandez R, Miranda ML, Alzenira F, Jimenez-Jimenez CL, Vallejo-Vaz AJ, Muriana FJG, Villar J, Stiefel P. 2012. Olive Oil Polyphenols Decrease Blood Pressure and Improve Endothelial Function in Young Women with Mild Hypertension. J.of Hypertension, Volume 25, Issue 12, 1 December 2012, Pages 1299–1304, https://doi.org/10.1038/ajh.2012.128.
- Mohammadifard N, Salehi-Abargouei A, Salas-Salvadó J, Guasch-Ferré M, Humphries K, Sarrafzadegan 2015. The effect of tree nut, peanut, and soy nut consumption on blood pressure: a systematic review and meta-analysis of randomized controlled clinical trials. The Amer. J. of Clncl Nutr., Volume 101, Issue 5, 1 May 2015, Pages 966–982, https://doi.org/10.3945/ajcn.114.091595.
- Khalesi S, Sun J, Buys N, Jayasinghe R. Effect of probiotics on blood pressure: A systematic review and meta-analysis of randomized, controlled trials. 2014;64:897–903.