The Many Health Benefits of the DASH Diet

Author: Christian Maino Vieytes, B.S. Nutritional Sciences, University of Maryland, College Park, M.S. Candidate, Division of Nutritional Sciences, University of Illinois at Urbana-Champaign

Several diets have been advertised in the media as being “silver bullets” but the reality is that the reported benefits of such diets are not backed by science. Only a handful of  these “diets” have been investigated using trusted research methods. Among the most studied diet patterns are the Healthy Eating Index (HEI), the Alternative Healthy Eating Index (AHEI), the Alternate Mediterranean Diet Score (aMED), and the Dietary Approaches to Stop Hypertension (DASH). The focus of this discussion will center on the DASH Diet and its use for reducing the risk of hypertension and other chronic conditions. 

The Underlying Issue

Hypertension, or high-blood pressure, is defined in the clinic as having a systolic blood pressure ≥130 mmHg and/or a diastolic pressure ≥80 mmHg¹. Unfortunately, a large proportion of Americans, today, live with this condition. It has been estimated that approximately 45.6% of Americans were affected by hypertension in 2017^1,2. Initially, combating hypertension involves medications. Although they are important, the medications themselves do not eliminate the underlying condition, as they only control and manage blood pressure from causing more and potentially life-threatening outcomes for these patients³. As such, efforts for treating hypertension have turned to identifying lifestyle factors that can be improved. Diet and exercise are two factors that can be improved with the potential to benefit outcomes for patients with hyptertension^4,5.

The DASH Diet

So what does the DASH Diet say about what individuals with hypertension should eat? Well, the diet is not a strict list of foods, but rather a general pattern of eating that stresses certain foods over others. The main idea behind the DASH Diet is a low intake of sodium while focusing on foods high in potassium, magnesium, and fiber—namely fruits, vegetables, legumes (beans, chickpeas, lentils), whole-grains, and low fat dairy products⁶. Moreover, this dietary pattern emphasizes low intake of saturated fat and cholesterol containing foods⁷.

Let’s Talk About Table Salt

So what is it about too much sodium—a common mineral found in table salt—that makes hypertension worse? Sodium and potassium are the two important electrolytes used by the body to maintain water balance. Simply put, too much sodium in the diet tells the body to hold onto water, which results in increased blood pressure⁸. As such, low-sodium diets have been shown to be helpful in lowering blood pressure⁹. High potassium diets (diet rich in fruit, vegetables, whole grains, and legumes), on the other hand, have been shown to lower blood pressure¹⁰.

Other Benefits and Adherence to the DASH Diet

The DASH Diet has been used to fight other diseases as well, not just hypertension. The diet has been shown to be protective against metabolic syndrome and obesity¹¹. Additionally, several forms of cancer have been investigated for their relationship to the DASH Diet. Among several studies, it has been shown that the DASH Diet has the potential to protect against colorectal cancer and various other types of cancer^12,13.

The Mayo Clinic provides an easy to understand guide for following the DASH Diet (link to this website is provided below). First, the DASH Diet outlines that individuals consume, at most, 2,300 milligrams of sodium daily. This requires more deliberate thought about the sources of sodium making their way into your palate—many people are often surprised by the number of ways sodium finds its way into the diet!

Some ways to limit sodium intake:

• Avoiding processed/cured meats
• Rinsing canned vegetables/foods or choosing low-sodium options when possible
• Limiting high-sodium condiments (and also paying attention to serving sizes)
• Restricting the use of table salt
• Eating at home as opposed to eating out—restaurant foods are common sources of high amounts of added salt and sodium

In summary, the DASH Diet may be effective for managing high blood pressure. The diet may also be helpful in promoting a healthier lifestyle, as it focuses mainly on the consumption of healthy food items (vegetables, grains, fruits, lean meats, and low-fat dairy).

Mayo Clinic link: https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/dash-diet/art-20048456

References

1. Brent Egan. The prevalence and control of hypertension in adults. https://www.uptodate.com/contents/the-prevalence-and-control-of-hypertension-in-adults.
2. Muntner P, Carey RM, Gidding S, et al. Potential US Population Impact of the 2017 ACC/AHA High Blood Pressure Guideline. Circulation. 2018;137(2):109-118. doi:10.1161/CIRCULATIONAHA.117.032582
3. Rahmawati R, Bajorek BV. Self-medication among people living with hypertension: a review. Fam Pract. 2017;34(2):147-153. doi:10.1093/fampra/cmw137
4. Diaz KM, Shimbo D. Physical activity and the prevention of hypertension. Curr Hypertens Rep. 2013;15(6):659-668. doi:10.1007/s11906-013-0386-8
5. Ozemek C, Laddu DR, Arena R, Lavie CJ. The role of diet for prevention and management of hypertension. Curr Opin Cardiol. 2018;33(4):388-393. doi:10.1097/HCO.0000000000000532
6. Juraschek SP, Miller ER, Weaver CM, Appel LJ. Effects of Sodium Reduction and the DASH Diet in Relation to Baseline Blood Pressure. J Am Coll Cardiol. 2017;70(23):2841-2848. doi:10.1016/j.jacc.2017.10.011
7. Talaei M, Koh W-P, Yuan J-M, van Dam RM. DASH Dietary Pattern, Mediation by Mineral Intakes, and the Risk of Coronary Artery Disease and Stroke Mortality. J Am Heart Assoc. 2019;8(5):e011054. doi:10.1161/JAHA.118.011054
8. Bankir L, Perucca J, Norsk P, Bouby N, Damgaard M. Relationship between Sodium Intake and Water Intake: The False and the True. Ann Nutr Metab. 2017;70 Suppl 1:51-61. doi:10.1159/000463831
9. Aburto NJ, Ziolkovska A, Hooper L, Elliott P, Cappuccio FP, Meerpohl JJ. Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ. 2013;346:f1326. doi:10.1136/bmj.f1326
10. Adrogué HJ, Madias NE. The impact of sodium and potassium on hypertension risk. Semin Nephrol. 2014;34(3):257-272. doi:10.1016/j.semnephrol.2014.04.003
11. Akhlaghi M. Dietary Approaches to Stop Hypertension (DASH): potential mechanisms of action against risk factors of the metabolic syndrome. Nutr Res Rev. July 2019:1-18. doi:10.1017/S0954422419000155
12. Mohseni R, Mohseni F, Alizadeh S, Abbasi S. The Association of Dietary Approaches to Stop Hypertension (DASH) Diet with the Risk of Colorectal Cancer: A Meta-Analysis of Observational Studies. Nutr Cancer. August 2019:1-13. doi:10.1080/01635581.2019.1651880
13. Ali Mohsenpour M, Fallah-Moshkani R, Ghiasvand R, et al. Adherence to Dietary Approaches to Stop Hypertension (DASH)-Style Diet and the Risk of Cancer: A Systematic Review and Meta-Analysis of Cohort Studies. J Am Coll Nutr. 2019;38(6):513-525. doi:10.1080/07315724.2018.1554460

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