Eating To Reduce Hypertension: Plant-Based, DASH, or Very Low Carb Meal Plans?

Adults living with high blood pressure (a reading higher than 140/90 mm Hg) often present with a host of comorbidities, most often pre-diabetes/type 2 diabetes, high levels of LDL cholesterol, and obesity. Such conditions render these individuals more vulnerable to such serious health complications as stroke, kidney disease, and cardiac issues. Sadly, this dynamic affects as much as 40-50% of the population in the United States. Eating specific diets to reduce hypertension is often the first recommendation offered by medical providers.

Certified personal trainers with a background in nutrition/health coaching often help steer clients towards healthier meal plans to support their workouts, especially in light of the prevalence of the aforementioned medical conditions. Studies currently underway point to three very viable options, which we shall discuss in this article: plant-based diets, very low carbohydrate diets, and the trusty DASH Diet recommended to reduce hypertension. 

Limiting Salt via DASH

The DASH diet (Dietary Approaches to Stop Hypertension) emerged as a healthy meal plan specially formatted by the American Heart Association to prevent or reduce hypertension. High blood pressure and high LDL cholesterol levels represent two of the most serious risk factors for heart disease and stroke.

This meal plan encourages eating foods rich in potassium, calcium, and magnesium, while limiting foods containing high amounts of sodium and sugar, such as vegetables, fruits, whole grains, fish, poultry, beans, and nuts.

While curbing salt consumption to 2,300 mg/day (the amount found in a mere teaspoon of table salt), the DASH diet also limits fatty meats and full-fat dairy products*, to reduce serum cholesterol levels.

The American Heart Association’s reasoning for allowing the consumption of meat and dairy when adopting the DASH diet is palatability. They felt that the general public would not be willing to accept a vegetarian diet without specifically allowing for some meat and dairy consumption. Including these food groups will also supply additional calcium and protein. No distinction is made between organic and non-organic, grain-fed or grass-fed origins but research indicates there may be a significant difference in health outcomes. 

*It’s worth noting that dairy products are often not easily digested and are the leading source of saturated fat in the diet. Late in childhood or early adulthood, most people lose the enzymes (lactase) that digest the lactose sugar in milk and other dairy products. This is why we have the term lactose-intolerant. It is not a disease but a human condition. 

A new study, the results of which appeared in  Annals of Family Medicine, compared a very low-carbohydrate diet to the DASH diet for adults with hypertension, type 2 diabetes, and/or obesity. While both interventions led to improvements in HbA1c (a marker for diabetes), systolic blood pressure, and body weight, the subjects in the low-carb group showed substantially greater improvements.

The study involved 94 adults. Those assigned to a very low-carb diet (VLC) attempted to keep intake below 50 grams of non-fiber carbs per day. The DASH diet participants limited sodium intake to less than 2,300 mg/day, and fat intake to no more than 30% of daily calories. Of course, both groups could consume ample amounts of fruits, lean meats/low-fat dairy, vegetables, and whole grains.

Over 4 months, the VLC diet resulted in greater improvements not only in systolic blood pressure, but also in glycemic control and weight, than the DASH diet. Reducing refined carbohydrates may be a good recommendation to reduce hypertension.

What about Paleo?

The Paleo diet, a popular diet based on the types of foods presumed to have been consumed by early humans. It mainly consists of meat, fish, vegetables, and fruit. It excludes dairy, grain, and processed foods. This is not a diet generally recommended for someone managing hypertension/high blood pressure.

A study published in the European Journal of Clinical Nutrition indicated that the Paleo diet increased TMAO (Trimethylamine N-oxide: small colorless amine oxide generated by choline, betaine, and carnitine by gut microbial metabolism) levels which are associated with heart disease. The paleo subjects had an increase in cholesterol, fat, and saturated fats which increased the amount of gut bacteria species linked to heart disease and inflammation.

This study on the Paleo diet does include vegetables and fruits. However, if the subjects were consuming higher quantities of fruits and vegetables it would likely balance out the gut bacteria. A more plant-based Paleo diet approach may actually reduce the increased heart disease risk observed in this study.

A meta-analysis looked at the effects of a paleo diet on heart disease risk. It determined that many risk factors were indeed reduced such as body weight, waist circumference, body fat %, total and LDL cholesterol, tryglycerides, even C-reactive protein (a marker of inflammation), and an increase in HDL.

However, the authors qualify these findings by stating that a “sensitivity analysis revealed that the overall effects of a PD on lipid profile, systolic blood pressure, and circulating CRP concentrations were sensitive to removing some studies and to the correlation coefficients, hence the results must be interpreted with caution.”

Better studies are needed to draw more definitive conclusions on whether a paleo diet is effective to reduce hypertension.

www.annfammed.org/content/annalsfm/21/3/256.full.pdf

www.cambridge.org/core/journals/british-journal-of-nutrition/article/verylowcarbohydrate-ketogenic-diet-v-lowfat-diet-for-longterm-weight-loss-a-metaanalysis-of-randomised-controlled-trials/6FD9F975BAFF1D46F84C8BA9CE860783