Why Does Increased Consumption of Carbohydrates/Sugar Elevate Your Blood Pressure?
Hypertension is a risk factor for end-organ disease, morbidity, and mortality. Today's Western diet embraces high-carb, processed food choices that have caused a global pandemic of obesity and chronic diseases. Today, we will elaborate on why the amount of carbohydrates/sugar you eat adversely affects your blood pressure. We will follow an observational cohort study in primary care with 154 recruits who each had either type 2 diabetes or impaired glucose tolerance. This study followed patients over a mean period of two years (Link to study: https://pmc.ncbi.nlm.nih.gov/articles/PMC6695889/).
Salient features of the study:
Initially, a low-carbohydrate diet of less than 130 g/day was instituted as part of a pilot study to help 19 patients with diabetes and impaired glucose tolerance.
It was found that these patients had significant improvement in systolic blood and diastolic blood pressures, and that occurred even as many antihypertensive medications were stopped.
This ‘low carbohydrate’ approach was then instituted on a larger patient group with type 2 diabetes and impaired glucose tolerance with some exclusion criteria that included people with pregnancy, end-of-life issues, eating disorders, etc. The participants included 90 men and 64 women with an age range from 40 to 89 years of age.
Food recommendations given: The reduction in this study was in reference to every form of sugar, including foods like bread, cereals, rice, pasta, peas, corn, potatoes, cakes, biscuits, sweets, and so on. With respect to fats, patients were advised to avoid margarine, vegetable oil, and corn oil. However, they were encouraged to incorporate olive oil, coconut oil, and some butter into their diets. High-sugar fruits (i.e., like bananas, mangoes, pineapples, grapes, oranges, etc.) were also discouraged. The participants were asked to stay away from so-called ‘low-fat’ food options since they often had hidden amounts of sugar and sweeteners to augment their palatability. Study organizers also advised against consuming artificial sweeteners and alcohol. In regard to protein, the participants were urged to eat oily fish, eggs, full-fat yogurt, chicken, and unsalted nuts while avoiding all processed meats and excessive cheese consumption.
After a mean period of 24 months on the diet, patients exhibited a reduction in total cholesterol and triglycerides, an increase in HDL, a decrease in systolic and diastolic blood pressure, and a reduction in body weight after the study.
Postulated mechanism: We are aware that insulin resistance is central in the causation of metabolic syndrome. It is important to note that high insulin levels in diabetic or pre-diabetic patients are associated with high sodium retention through their effect on the kidney—this process directly facilitates elevated blood pressure. Hyperinsulinemia can enhance the SGLT2 system, which facilitates glucose and sodium reabsorption in a dose-dependent manner. This worsens glomerular pressures and contributes to end-organ damage in the kidney. In a diet with a high-carbohydrate intake, people are in a state of high insulin levels secreted by the body to mitigate the high sugar levels in the diet. However, in low-carbohydrate diets, blood pressures are more controlled, and this may be secondary to the sodium loss that is facilitated by the diet, as well as diuresis, which can cause a decrease in plasma volume.
The above findings show us that diet is key to blood pressure control—and this is leaps and bounds away from the low-fat dietary option that is popular in our grocery aisles and in the media. This is more of a common-sense approach to diet and nutrition that can have long-standing effects on your overall well-being. As always, I pray that you keep your health and nutrition in center focus and live long and strong!
