A diet that is supposed to lower blood pressure – can it actually work? How sustainable is such a change in diet, and are other dietary principles that are important for long-term health also taken into account? The DASH diet recommends plenty of fruit, vegetables, whole grains, low-fat dairy products, lean meat, fish, poultry, nuts, and beans. Sugary drinks and sweets, as well as red meat, should be avoided in this diet.
The DASH Diet – Nutrition for High Blood Pressure
The DASH diet was developed by the National Heart, Lung, and Blood Institute (part of the National Institutes of Health (NIH) in the USA. The goal of this diet is to lower blood pressure through a change in diet1, because a large part of the US population struggles with this issue. The cause of high blood pressure lies primarily in an unhealthy lifestyle: Too much sugar, wheat, industrially processed foods, trans fats, too few vegetables and fiber, and an unfavorable ratio of omega-3 to omega-6 fatty acids (read more here about healthy fats and a healthy breakfast) are problematic.
In everyday life, these are associated with high blood pressure and elevated LDL cholesterol levels. Lack of exercise and mental challenges (negative stress) are also among the causes.
Studies by the NHLBI have shown that the DASH diet (ideally in combination with more exercise) has many advantages over the typical American diet. Among other things, it was found that the blood pressure and LDL cholesterol of the test subjects had measurably decreased1.
DASH Diet Shopping List – Nutrition for High Blood Pressure
Even though the term DASH diet sounds like a strict diet plan, this way of eating differs from other diets. It is much more about a balanced diet with some basic principles, based on which you should develop a sustainable way of eating. The provided examples of meals and weekly menus are intended to be representative of the nutrients included in the DASH diet1. A diet consisting of the following foods is intended to keep blood pressure and LDL cholesterol low:
+ Vegetables
+ Fruit
+ Whole grains
+ Fish
+ Lean meat
+ Low-fat and fat-free products
+ Nuts
+ Beans
Which foods to avoid with high blood pressure?
Foods that should be avoided:
-
Saturated fatty acids (palm oil, coconut oil, butter)
-
Full-fat dairy products
-
Sugar
-
Sugary drinks
-
Fatty meals
-
Red meat
In addition, approximately 2000 calories per day are recommended.
Does the DASH diet work?
The body of research clearly states that switching to the DASH diet lowers blood pressure and LDL cholesterol levels. However, the wording from the National Heart, Lung, and Blood Institute was also adopted in the first section, which describes the benefits of the diet compared to a "typical American diet". The typical American diet is known to consist of a lot of sugar, industrially processed foods, unhealthily processed trans fats, and little fruit, vegetables, organically produced meat such as grass-fed beef, or good fiber. In addition, the average citizen in the United States generally does not exercise enough – let alone engage in regular, more intense sports. Added to this are mental stress and sleep problems, and the combination of all these things results in a lifestyle that leads to overweight/obesity, diabetes, high blood pressure, as well as elevated LDL cholesterol levels, and consequently promotes cardiovascular diseases and cancer.
So if more natural foods are incorporated into the diet and, above all, sugar, bad fats, and also some processed meat products are eliminated, it is not surprising that the mentioned measurable parameters change positively. The DASH diet is definitely more health-promoting than the "typical American diet". However, it also contains some outdated diet principles that are contradicted by current scientific findings …
Possible criticisms of the DASH diet
The first possible issue on the menu is beans. They belong to the legume family and thus contain so-called antinutrients. These can inhibit digestive enzymes and block the absorption of micronutrients, among other things. The second point worth mentioning is fruit, because too much fruit can also be problematic: fructose is metabolized differently and – especially in cases of overweight and lack of exercise – is converted into body fat or into glucose, which messes up the blood sugar level . Fruit and vegetables themselves have many health benefits, but this is often misunderstood when it comes to fruit, and many uninformed people start drinking smoothies every day. These drinks often contain 4 to 5 fruits per serving, which corresponds to a far too high fructose intake.
The third outdated dietary recommendation of the DASH diet is the drastic reduction of dietary fats. Because today the scientific evidence is clear: naturally occurring fats are essential and must be consumed regularly. They are responsible, among other things, for the absorption of fat-soluble vitamins and the formation of hormones, they preserve cell membranes, stabilize blood sugar, and promote gut health. A long-term low-fat diet can therefore have serious health consequences such as hormonal imbalance, vitamin deficiency, weakened immune system, and gut problems.
(You can find out more about this in the articles "Why Fat Is Not the Same as Body Fat" and "The Low-Fat Diet".)
However, it is important that natural, native fats are used above all, and not industrially processed ones that have been heated, deodorized, or even hydrogenated (as found in ready-made meals).
The fourth possible issue with the DASH diet is dairy products: reduced-fat cow's milk products are recommended, which are now actually being advised against more and more (as are non-reduced-fat products): they are mostly problematic for the health of the intestinal lining, can promote inflammation, trigger immune reactions, worsen the appearance of the skin, and irritate the hormone system. Find out more about this in the article on "Leaky Gut".
Conclusion
The DASH diet definitely has health benefits for people who have developed very unhealthy eating habits and consume a lot of sugar, industrially processed foods, little vegetables, and many hydrogenated unhealthy fats. It can improve this problem in people who already suffer from high blood pressure. However, diets should not be generalized, and blood pressure can also be lowered with somewhat different dietary principles without consuming fat-free cow's milk products.
Literature:
1 National Heart, Lung, and Blood Institute: DASH Eating Plan - Also known as Dash diet. [https://www.nhlbi.nih.gov/health-topics/dash-eating-plan; 09.09.2021]