The role of healthy food choices in the new blood pressure guidelines
The American College of Cardiology (ACC) and the 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.1
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.2
In the United States, high blood pressure, called ‘the silent killer’ because there are often no obvious symptoms, accounted for more deaths due to cardiovascular disease than any other modifiable risk factor, and was second only to cigarette smoking as a preventable cause of death for any reason.1 Modifiable risk factors for cardiovascular disease include 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.1
Hypertension was previously diagnosed at 140/90 mmHg. Here are the new guidelines1:
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/gt;90 mmHg
With the revised guidelines, 46% of adults are now identified with high blood pressure, compared to 32% under the previous definition. A blood pressure of less than 120/80 mmHg still will be considered normal, but levels at or above that, to 129/80 mmHg, will be called “elevated,” meaning that it’s important to take steps with lifestyle changes such as food choices, exercise, and not smoking to lower blood pressure.2 While more people may need medication to control blood pressure levels, the new guidelines encourage physicians to focus on a wide range of healthy lifestyle behaviors for everyone.1
Important role of food choices in blood pressure
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. The foods we eat also play a major role in overall cardiovascular disease risk as well preventing and managing metabolic disease, which includes high blood pressure, high cholesterol levels, and elevated blood sugar levels. The primary areas of concern include1:
- overweight and obesity
- calcium and magnesium
There is a direct relationship between body weight and blood pressure levels, and an even stronger relationship between amount of body fat, even in people at a healthy weight, and blood pressure levels. In combined data from 4 longitudinal studies begun in adolescence with repeat examination in young adulthood to early middle age, being obese continuously, or gaining weight to become overweight or obese, was associated with almost triple the risk of developing hypertension. Losing weight and body fat to healthy levels decreases risk of developing high blood pressure, and is a key strategy to managing blood pressure levels in people diagnosed with hypertension.1
Table salt, and the salt added to foods during processing, is composed of sodium and chloride. Consuming high amounts of sodium is independently associated with increased risk of stroke.1 The AHA recommends no more than 2300mg of sodium per day, and ideally no more than 1500mg per day for people with hypertension, African Americans, and middle-aged and older adults who tend to be more sensitive to sodium. The average sodium intake in the United States is 3400mg per day with more than 75% of the sodium we consume found in processed foods and restaurant foods.4
Try these ideas to reduce sodium intake:
- Choose fresh vegetables, or vegetables canned or frozen without added sodium.
- Read nutrition labels and choose foods with less sodium.
- Prepare meals at home instead of using frozen dinners or eating out.
- Beware the ‘salty six’ foods that provide the most sodium in our diet: cold cuts and cured deli meat (up to 1,050 mg sodium per serving), pizza (over 760mg sodium per slice), canned soup (over 1,000 mg sodium per cup), breads and rolls (230 mg sodium per slice), breaded chicken (over 600 mg sodium per serving), tacos and burritos (2 teaspoons of packaged taco/burrito seasoning has over 400 mg sodium).5
It’s probably not a surprise that most Americans tend to consume too much sodium and too little potassium. Potassium is a mineral found in a wide range of foods, yet because only 9% of adults meet the recommendation for vegetable intake, and only 12% meet the recommendation for fruit, our diets tend to be low in potassium.6 The more potassium we eat, the more sodium we pass out of the body through urine. Potassium also helps relax blood vessel walls, which helps lower blood pressure. The recommended potassium intake for adults is 4,700mg per day. On average, adult males consume almost 3,200mg per day, and adult females consume about 2,400mg per day. Fruit, vegetables, milk and yogurt are good sources of potassium.7
Try these ideas to increase potassium in your food choices:
- Include 3-6 servings of vegetables each day. One serving is 1 cup of raw leafy vegetables like lettuce, spinach or kale; or ½ cup cut-up raw or cooked vegetables.
- Choose 4-6 servings of fruit each day. One serving is 1 medium-size piece of fresh fruit like an apple, orange or pear; ½ cup fresh, frozen or canned fruit; or ¼ cup dried fruit.
- Include 2-3 one-cup servings of non-fat milk or non-fat, plain yogurt each day.7
Calcium and Magnesium
Epidemiological studies show that people who consume higher levels of the minerals calcium and magnesium tend to have lower blood pressure levels. The Dietary Approaches to Stop Hypertension (DASH) study included goals to increase intake of these minerals, primarily by eating more fruits, vegetables, and low-fat milk and yogurt.7 People who consume more calcium in their diets also weigh less, have less body fat, and have lower risk of developing type 2 diabetes.8
Try these ideas to increase calcium and magnesium in your food choices:
- Consume 2-3 one-cup servings of non-fat milk or plain, non-fat yogurt each day. If you prefer non-dairy milk alternatives, choose ones that contain added calcium and no added sugar.
- Magnesium is found in vegetables, fruit, lean meat and poultry, nuts, seeds and legumes (dried beans and peas like kidney beans, lentils, pinto beans, black beans and chickpeas).9
In the United States, it seems likely that alcohol may account for close to 10% of cases of hypertension under the old guidelines, and will play a larger role with the new guidelines.1 However, incidence of heart disease is lower for people who drink alcohol in moderate amounts than in non-drinkers. The best known beneficial effect of alcohol is a small increase in HDL cholesterol that protects against heart disease. However, regular physical activity and consuming more vegetables and fruit that are high in antioxidants provide similar benefits.10 Current guidelines recommend no more than 2 alcoholic drinks per day for men, and no more than 1 per day for women. 1 standard drink contains roughly 14 g of pure alcohol, which is typically found in 12 oz of regular beer (usually about 5% alcohol), 5 oz of wine (usually about 12% alcohol), and 1.5 oz of distilled spirits (usually about 40% alcohol).1 The American Heart Association does not recommend drinking wine or any other type of alcohol to gain any possible health benefits.10
Caffeine is the most widely used drug in the world, with 80% of adults in the United States routinely consuming caffeine in coffee, tea, soft drinks and energy drinks. It’s well known that caffeine increases blood pressure levels, especially in people with diagnosed or uncontrolled hypertension.11 The ACC/AHA updated guidelines recommend limiting caffeine to less than 300 mg per day and to avoid herbal supplements that have caffeine-like effects, including guarana and yerba maté.1
Typical amounts of caffeine in beverages:
- Home-brewed coffee contains about 100mg caffeine per 8-oz cup; most coffee mugs hold 12-16 oz of coffee.
- 1 oz espresso contains 60mg caffeine.
- 8 oz tea contains 14-70mg caffeine.
- 12 oz soft drinks contain 30-60mg caffeine2
Try these ideas to reduce caffeine:
- Choose decaf coffee and decaf tea.
- Avoid energy drinks, which in addition to caffeine also contain large amounts of added sugar.
- Enjoy a smaller amount of your favorite coffee beverage to reduce the amount of caffeine you consume.
The bottom line to lower blood pressure levels and achieve overall good health: Choose a diet that is based on vegetables and fruit and includes sources of non-fat dairy for plenty of potassium, magnesium and calcium. Cook more meals at home from scratch and read food labels to reduce sodium. Make water your primary beverage to reduce amounts of caffeine and alcohol.
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. American Heart Association News. Nearly half of U.S. adults could now be classified with high blood pressure, under new definitions. https://news.heart.org/nearly-half-u-s-adults-now-classified-high-blood-pressure-new-definitions/ Published 11-13-17. Accessed 11-25-17
3. American Heart Association. How Much Sodium Should I Eat Per Day?” https://sodiumbreakup.heart.org/how_much_sodium_should_i_eat Accessed 11-25-17
4. American Heart Association. A Closer Look at the Salty Six. https://sodiumbreakup.heart.org/closer-look-salty-six Published 12-7-16, accessed 12-28-17.
5. Centers for Disease Control and Prevention. Only 1 in 10 Adults Get Enough Fruits or Vegetables. https://www.cdc.gov/media/releases/2017/p1116-fruit-vegetable-consumption.html published 11-16-17. Accessed 11-28-17.
6. American Heart Association. A Primer on Potassium. https://sodiumbreakup.heart.org/a_primer_on_potassium Accessed 1-25-17
7. 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
8. Zemel MB. J Am Coll Nutr. 2001 Oct;20(5 Suppl):428S-435S; discussion 440S-442S.Calcium modulation of hypertension and obesity: mechanisms and implications.
9. National Institutes of Health, Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ Updated 2-11-16. Accessed 11-27-17.
10. American Heart Association. Alcohol and Heart Health. http://www.heart.org/HEARTORG/HealthyLiving/HealthyEating/Nutrition/Alcohol-and-Heart-Health_UCM_305173_Article.jsp#.Whzb60qnH4c Accessed 11-27-17
11. Hypertension Risk Status and Effect of Caffeine on Blood Pressure. Terry R. Harley, Bong Hee Sung, Gwendolyn A. PIncomb, Thomas L. Whitsett, Michael F. Wilson, William R. Lovallo. Hypertension. 2000;36:137-141.
12. International Food Information Council Foundation. Everything You Need to Know About Caffeine. http://www.foodinsight.org/everything-about-caffeine-science-amount-safety last updated 9-1-15. Accessed 11-27-17