More than 90 percent of North Americans will develop high blood pressure. A new study shows that a diet high in potassium appears to protect teenagers from high blood pressure in adulthood, while a low-salt diet has no effect (JAMA Pediatr, June 2015;169(6):560-568). A high-potassium and low-salt diet is achieved by eating mostly plants, and people who eat lots of plants have the lowest rates of high blood pressure. Meats are high in salt and plants are high in potassium.
The Study
Researchers followed the diets and blood pressures of 2,185 nine- and ten-year-old girls for up to ten years. The amount of salt that the children ate had nothing to do with their chances of developing high blood pressure, but those who ate the most potassium had lower blood pressure than girls who ate less. The conclusion of the study is that adolescents get more health benefits from eating potassium-rich foods (fruits, vegetables, beans, nuts and whole grains) and that it is not necessary for most people with normal insulin levels to try to restrict salt. High insulin levels can cause high blood pressure and are associated with eating a lot of added sugars or red meat (blocks insulin receptors).
Low-Salt Diets Usually Are Not Effective
Many doctors believe that a high-salt diet is a major cause of high blood pressure, but low-salt diets reduce systolic blood pressure by less than 5 mm Hg in most adults with hypertension, and the average reduction in diastolic blood pressure associated with a low-salt diet is 2.5 mm Hg (JAMA Intern Med, 2014;174(4):516-524).
The people who are most likely to get high blood pressure from taking in too much salt are those whose cells are insulin resistant. Their cells do not respond well to insulin (Hypertension, Jan 2013), so the pancreas keeps on releasing large amounts of insulin to try to lower high blood sugar levels. High levels of insulin constrict arteries to cause high blood pressure. People with high insulin levels are the ones who get high blood pressure when they take in too much salt (Am J Hypertens, 1998 (Apr);11(4 Pt 1):397-402). For them, a high salt intake increases blood pressure, insulin and blood sugar.
How Sugar-Added Foods Contribute to High Blood Pressure
More than 80 percent of people who have high blood pressure also have insulin resistance, an inability to respond normally to insulin. This means that when they eat or drink sugar-added foods, their blood sugar levels rise, causing their insulin levels to rise which constricts arteries to cause high blood pressure (British Medical Journal: Open Heart, Dec. 11, 2014).
Are You Insulin Resistant?
People who are insulin resistant usually have what is called metabolic syndrome, or they may already be diabetic. You probably have metabolic syndrome if you have any three of the following:
• storing fat primarily in your belly
• having small hips
• being overweight
• having high blood triglycerides (>150)
• having low blood HDL cholesterol (<40)
• having high blood pressure
• having a fatty liver
• having a fasting blood sugar >100 (HbA1c >5.7)
• having high insulin levels (morning fasting >5)
Plants Help to Prevent High Blood Pressure
Unprocessed vegetables, beans, whole grains, nuts, other seeds and most fruits contain complex carbohydrates and fats that are not released rapidly into the bloodstream. These nutrient-rich foods do not cause a high rise in blood sugar and insulin.
Lifestyle Changes, Not Drugs, Can Cure High Blood Pressure
You cannot cure high blood pressure with drugs; you can only control it as long as you continue to take the drugs (Hypertension, 2002;40(5):612-618). Most of the time, your blood pressure cannot be controlled with just one drug and most people end up with three or more drugs to treat their high blood pressure. On the other hand, some people are able to cure their high blood pressure by making lifestyle changes:
• Eat large amounts of vegetables, seeds and fruits.
• Restrict sugared drinks, sugar-added foods and red meat.
• Restrict all refined carbohydrates. Whole grains are seeds with a fiber coating that forms a thick capsule which cannot be broken down efficiently in your intestines, so blood sugar and insulin levels barely rise after you eat them. However, when you grind grains into flour, you break the capsule so the starches can be absorbed quickly. Foods made from flour, such as bakery products or pasta, cause a high rise in blood sugar and insulin.
• Exercise. Resting muscles draw no sugar from the bloodstream. On the other hand, contracting muscles draw sugar rapidly from the bloodstream and don’t even need insulin to do so. The more intensely you exercise, the less insulin is needed by muscles to withdraw sugar from the blood and this effect lasts for up to 17 hours after you finish exercising.
• Avoid smoking. Smoking damages every cell in your body.
• Avoid being overweight. Your liver controls blood sugar levels. When blood sugar levels rise, insulin drives sugar from the bloodstream into the liver. However, the more fat you have stored in your liver the harder it is for sugar to enter liver cells in response to insulin. A fatty liver will raise blood sugar levels even higher by releasing stored sugar from its cells into the bloodstream.
