Even as a child, I remember my family doctor telling my parents about how they should eat to make sure they don't end up with heart disease, high blood pressure or strokes. My parents are significantly older now, in their 70s, but they still pay attention to their diet because they've heard all along that their diet significantly impacts their health. Over the last few years, their attention on their diet has increased tremendously. When they strayed from a "healthy diet," their blood pressure, fasting sugar and cholesterol levels usually worsened, so now they have personal empiric evidence of the benefits of a "healthy diet."
It's no surprise that if I grew up listening to these teachings that I, myself, would be teaching these ideas to my patients as well. But, what's great about modern research is that we now have study results that back up what we inherently knew all along about how our bodies really are reflections of what we eat.
In a Nov. 2011, article published in the Journal of Human Hypertension by Q. Chen, et al., researchers found that a diet rich in fruits, vegetables, low-fat dairy products and low saturated fat/total fat/cholesterol significantly lowered blood pressure by blunting the counter-regulatory response of the renin-angiotensin system. What this means is that a healthy diet like this could help our body regain a more healthy normal blood pressure range by helping our own body's signals do what it needs to do to achieve that.
The renin-angiotensin system is a regulatory system in our body such that when our blood pressure drops, the plasma renin-angiotensin (PRA) level rises to try to counteract that drop and increase blood pressure to support blood flow to our organs. This is also a system that is utilized in therapies for hypertension to help patients with hypertension to obtain more normal blood pressure levels. In prior studies where they used diet to decrease hypertension using the DASH diet (Dietary Approaches to Stop Hypertension diet), this diet seemed to affect the PRA level.
In this November study, researchers used data from the DASH trial to further evaluate the impact of various diets on hypertension and the PRA system. In this study, 459 people consuming a fruits and vegetables diet, DASH (Dietary Approaches to Stop Hypertension) diet or typical American diet were evaluated for associations between those diets and the plasma renin-angiotensin response. The fruits and vegetable diet along with the DASH diet were both rich in minerals and fiber, and low in saturated and total fat and cholesterol. Whereas the "typical American Diet," which was used as the control diet, is low in nutrients and high in saturated and total fat and cholesterol. Sodium in the diets was similar across all diets for this study.
The study participants were aged 22 and older and were not on medications for hypertension. They were followed for three weeks on the control diet and then were randomly assigned to one of the three diets for another eight weeks. The plasma renin-angiotensin levels were available for 83 percent of the patients.
For patients in the fruits and vegetable group and DASH diet group, when blood pressure was reduced, the plasma renin-angiotensin levels did not rise as much as the control group's, thus allowing for correction of hypertension without a rebound effect of the PRA system. In other words, the patients in the fruits and vegetables diet group and the DASH diet group were able to retain the blood pressure reduction without a rebounding PRA system that auto-corrected that. The body's PRA system in the patients of the healthy diet groups allowed for the appropriate drop to remain in the blood pressure in order to correct the hypertension.
In this study, it seems that foods rich in nutrients and minerals and low in pro-inflammatory components seem to act as medicine in our body to positively affect our own PRA system in our favor when we have hypertension, such that when hypertensive people have lowering of their blood pressure, the body knows not to increase PRA so as to allow blood pressure to normalize.
My interest in this article is that I have always been a firm believer of using food as medicine. It is the least-likely option to cause side effects as compared to synthetic medications, and it is likely to benefit multiple aspects of our health at once instead of addressing one medical issue at a time like most medications. While I am a fan of medications when they are needed because our bodies sometimes just need some additional support, I am a bigger fan of using mother nature to help our bodies right itself when there is disarray.
The minerals, vitamins and phytonutrients in the fruits/vegetable diet and the DASH diet allow our body to act intelligently to find its equilibrium instead of doing its automatic gut reaction of increasing PRA just because blood pressure reduction occurred.
I have always said to my patients that our bodies are miraculous machines and if given what they need to function optimally, they know what to do to heal and strike the perfect balance. This study shows us that a diet rich in the fundamental building blocks needed by our bodies for optimal functioning will allow our bodies to know what to do with their signals to achieve optimal health outcome.
So, the next time you hear your doctor tell you to eat your vegetables and to avoid fatty processed pro-inflammatory foods, just remember that it's not just your doctor who's telling you that... your body is screaming to you for the same thing as well. It just needs your help to give it the fundamental nutrients it needs to do its job; and once you do that, your body knows exactly what to do to achieve its main purpose of repairing and healing itself so that you can function at your ultimate best.
Chen, et al. Journal of Human Hypertension. The Effects of Dietary Patterns on Plasma Renin Activity: Results from the Dieatary Appraoches to Stop Hypertension Trial. November 3, 2011.