Dietary management of hypertension


Dietary management can go a long way toward controlling high blood pressure. Diets low in salt with sufficient potassium and moderation of alcohol and caffeine intake are all typical areas of focus.   

Salt

High sodium consumption (>2 grams Na++/day, equivalent to 5 g salt/day) and insufficient potassium intake (less than 3.5 grams/day) contribute to high blood pressure and increase the risk of heart disease and stroke. The World Health Organization reports that most people consume too much salt (9 - 12 grams per day), or around twice the recommended maximum level of intake. Sodium is found naturally in a variety of foods, such as milk, meat and shellfish. It is often found in high amounts in processed foods such as breads, processed meat and snack foods, as well as in condiments (WHO, 2016).

Potassium

Increased dietary potassium intake can reduce systolic and diastolic blood pressure in adults. Potassium is commonly found in a variety of unrefined foods, especially fruits and vegetables (WHO, 2016). According to Appel (2006) black individuals are especially sensitive to the BP-lowering effects of reduced salt intake, increased potassium intake, and the Dash Diet.

Some foods high in potassium

Moderation of Alcohol Intake

Appel (2006) and Klatsky (2011) found evidence that supports moderation of alcohol intake effective in lowering blood pressure. Alcohol consumption should be limited to:

One alcoholic drink is defined as 12 oz. of regular beer, 5 oz. of wine (12% alcohol), and 1.5 oz. of 80-proof distilled spirits (Appel, 2006).

Caffeine moderation

Caffeine, most often consumed in coffee or tea, typically causes a short spike in blood pressure. Some studies have shown some regular, high consumers of coffee have higher blood pressure readings than those who are non-coffee drinkers.

According to a recent systematic review and meta-analysis by Mesas, Leon-Munoz, Rodriquez-Artalejo and Lopez-Garcia (2011) the administration of 200-300 mg caffeine produced an average increase of 8.1 mm Hg in systolic blood pressure and 5.7 mm Hg in diastolic blood pressure. The effect lasts less than 3 hours. In habitual coffee consumption, no ongoing elevation of blood pressure was noticed nor was any evidence of a higher risk of CVD. It is difficult to establish a limit to how much caffeine is safe.

Some new research has shown individual differences in caffeine effects due to genetics, particularly the amount of P450 - CYP1A2 enzymes. Some individuals are fast metabolizers of caffeine because of abundant amounts of these biotransforming liver enzymes that metabolize caffeine. The effect of caffeine on their bodies is short lived. They can thus tolerate more cups of coffee. Slow metabolizers will feel the effects of coffee for up to 6 hours.

Researchers caution individuals with uncontrolled hypertension since caffeine immediately elevates blood pressure which can increase their risk of myocardial infarct and stroke. Some foods and medications are known to inhibit the actions of CYP1A2, thus extending the effect of caffeine by slowing down its metabolism.

CYP1A2 Inhibitoring Medications: CYP1A2 Inhibitoring Foods:
  • Artemisinin
  • Atazanavir (Reyataz)
  • Cimetidine (Tagamet)
  • Ciprofloxacin (Cipro)
  • Enoxacin
  • Ethinyl Estradiol
  • Fluvoxamine
  • Mexiletine
  • Tacrine (Cognex)
  • Thiabendazole Zileuton (Zyflo)
  • Curcumin
  • Cinnamon’s component o-methoxy cinnamaldehyde
  • Ginseng extract
  • Peppermint, chamomile, and dandelion tea
  • Grapefruit juice and its component naringenin
  • Starfruit juice
  • African lettuce L. taraxacifolia.
  • Propolis
  • Echinacea purpurea
  • Licochalcone A, a major compound in traditional Chinese herbal licorice
  • Caffeic acid, found at a high level in thyme, sage, spearmint, Ceylon cinnamon, and star anise.
  • Quercetin.
  • Oleuropein, derived from olive oil.
  • Kale ingestion, unlike that of other cruciferous vegetables
  • Apiaceous vegetables (carrots, parsnips, celery, and parsley)
  • Raspberry leaf

Some of the studies showed CGA and other phenolic compounds, magnesium and trigonelline, found in coffee can reduce inflammation and endothelial dysfunction. When consumed in moderation, these beneficial effects may offset harmful effects of caffeine input. The general recommendation for caffeine consumption is 200 milligrams a day - the equivalent of two 12-ounce cups of brewed coffee. It is recommended individuals check their individual response to the caffeine in coffee by checking their blood pressure within 30 to 120 minutes of drinking coffee or other caffeinated beverage (Sheps, 2016).

Instant Feedback:

Which of the following have been shown to lower blood pressure?
Sodium
Potassium
Caffeine
None of the above


References

Appel L., Brands M., Daniels S., Karanja N., Elmer P., Sacks F., (2006). Dietary Approaches to Prevent and Treat Hypertension. Hypertension, 47(2).

DASH Diet Action Plan Sample Menus. http://dashdiet.org/sample_menu.asp

Klatsky, A.L. (2015). Alcohol and cardiovascular diseases: where do we stand today? J Intern Med. 278(3), 238-50.

Mesas, A.L., Leon-Munoz, L.M., Rodriquez-Artalejo, F. & Lopez-Garcia, E. (2011). The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis. Am J Clin Nutr. 94(4),1113-26.

Sheps, S. (2016). How does caffeine affect blood pressure? Retrieved from http://www.mayoclinic.org/diseases-conditions/high-blood-pressure/expert-answers/blood-pressure/faq-20058543

World Health Organization. Salt reduction. Fact sheet 6/2016. http://www.who.int/mediacentre/factsheets/fs393/en/