DASH diet

The DASH diet (Dietary Approaches to Stop Hypertension) is one of the healthiest models nutrition in the world, which was developed by American scientists in 1990s. It was created as part of research sponsored by the National Institute Institute of Health (NIH) to develop an effective way to lower blood pressure arterial without the need for pharmacotherapy or as a treatment support pharmacological.

The name DASH is an acronym for "Dietary Approaches to Stop Hypertension", which means "A nutritional approach to stopping hypertension". However, over the years, the health benefits of using this have emerged diets go far beyond regulating blood pressure. The DASH diet helps with: prevention and treatment of many lifestyle diseases, supports the maintenance of proper body weight and improves overall health.

In this article, we will provide detailed information about the DASH diet, its scientific basis, principles, health benefits and practical tips regarding its implementation. We will also compare it with other popular diets to help you decide if this eating pattern is right for you.

The scientific basis of the DASH diet

History and clinical research 

The DASH diet was developed as a result of clinical research conducted in in the 1990s by scientists from the American National Heart Institute, Lungs and Hematopoietic System (NHLBI). The first DASH study, published in 1997 year in the New England Journal of Medicine, showed that a diet rich in fruits, vegetables and low-fat dairy products, and low in saturated fats and cholesterol, can significantly lower blood pressure. 

Another study, known as DASH-Sodium, conducted in 1997-1999, showed that combining the DASH diet with limiting sodium intake gives even better results in lowering blood pressure. This study proved that the DASH diet with low sodium content (1,500 mg per day) can reduce systolic blood pressure by up to 8-14 mmHg, which is comparable to the effect of using one antihypertensive drug.

Since then, dozens of clinical studies have been conducted that have confirmed the effectiveness of the DASH diet not only in lowering blood pressure, but also in reducing the risk of cardiovascular disease, stroke, type 2 diabetes, certain types of cancer, and in improving overall health.

Mechanism of action

The effectiveness of the DASH diet in lowering blood pressure is due to several mechanisms:

1. Increased supply of potassium, magnesium and calcium: These minerals play a key role in regulating blood pressure. Potassium helps balance the negative effects of excess sodium, relaxes the walls of blood vessels and supports the excretion of excess sodium from the body. Magnesium dilates blood vessels and calcium supports vascular contractility.
2. Limit sodium intake: Excess sodium causes water retention in the body, which increases blood volume and raises blood pressure. Sodium restriction reduces this effect.
3. High fiber: Fiber helps lower blood cholesterol levels, improves insulin sensitivity and helps maintain a healthy weight, which indirectly affects blood pressure.
4. The right proportion of fats: The DASH diet limits the intake of saturated and trans fats and promotes healthy unsaturated fats, which improves the blood lipid profile and the elasticity of blood vessels.
5. Rich in antioxidants: Vegetables and fruits provide antioxidants that protect blood vessels against oxidative damage and improve their function.
6. Comprehensive impact: The DASH diet is not based on individual ingredients, but on the synergistic effect of all elements of the diet, which gives better results than supplementation with individual ingredients.

Principles and ingredients of the DASH diet

Basic assumptions

1. Increase the intake of vegetables and fruits: They form the basis of the diet, providing vitamins, minerals, antioxidants and fiber.
2. Choosing whole grains: Instead of refined grain products, the DASH diet recommends whole grains, which are higher in nutrients and fiber.
3. Include low-fat dairy products: These are an important source of calcium, protein and vitamin D.
4. Moderate consumption of lean meat, poultry and fish: These provide protein and iron, but their amount should be limited.
5. Regular consumption of nuts, seeds and legumes: They are a source of plant protein, healthy fats, fiber and minerals.
6. Limit consumption of salt, sweets and red meat: These products should be eaten rarely and in small quantities.

Recommended product groups and their portions

The DASH diet specifies the recommended daily intake of individual product groups depending on caloric demand. Below are the recommendations for a 2000 kcal diet:

1. Vegetables: 4-5 servings a day
   • One serving is e.g. 1 cup of raw leafy vegetables, 1/2 cup of cooked vegetables or 180 ml of vegetable juice
   • Vegetables rich in potassium, such as potatoes, tomatoes, spinach and broccoli, are particularly valuable
2. Fruits: 4-5 portions a day
   • One serving is e.g. 1 medium fruit, 1/2 cup fresh, frozen or canned fruit, 1/4 cup dried fruit or 180 ml fruit juice
   • Fruits rich in potassium, such as bananas, oranges, apricots and avocados, are especially recommended
3. Whole grain products: 6-8 servings a day
   • One serving is e.g. 1 slice of bread, 1/2 cup of cooked rice, pasta or cereal
   • You should choose whole grain products, such as wholemeal bread, brown rice, oatmeal, buckwheat
4. Low-fat dairy products: 2-3 servings a day
   • One serving is e.g. 1 glass of milk or yogurt, 40 g of cheese
   • Choose products with reduced fat content (0-2%)
5. Lean meat, poultry and fish: up to 6 portions a day (portions should be small)
   • One serving is 30 g of cooked meat, poultry or fish
   • Lean meat, skinless poultry and fish are recommended, especially fatty sea fish rich in omega-3 acids
6. Nuts, seeds and legumes: 4-5 servings per week
   • One serving is 1/3 cup nuts, 2 tablespoons seeds or 1/2 cup cooked legumes
   • Particularly valuable are walnuts, almonds, flax seeds, chia, lentils, chickpeas, beans
7. Fats and oils: 2-3 servings a day
   • One serving is 1 teaspoon of vegetable oil, soft margarine or mayonnaise
   • Vegetable oils such as olive oil, rapeseed oil and linseed oil are recommended
8. Sweets and added sugar: maximum 5 servings per week
   • One serving is 1 tablespoon of sugar, jam, honey or 15 g of sweets
   • You should limit sweets and replace them with natural sweet products, such as fruit

Restrictions on the DASH diet

1. Sodium (salt): The standard DASH diet recommends limiting sodium intake to 2,300 mg per day (about 1 teaspoon of salt), and the low-sodium version recommends limiting sodium intake to 1,500 mg per day (about 2/3 teaspoon of salt).
2. Saturated and trans fats: You should limit your intake of saturated fats (found mainly in animal products) and completely eliminate trans fats (found in some processed products).
3. Red meat: Red meat consumption should be limited to a maximum of 2 servings per week.
4. Alcohol: If you drink alcohol, do it in moderation - up to 1 serving a day for women and up to 2 servings for men (1 serving is 150 ml of wine, 350 ml of beer or 45 ml of strong alcohol).

Comparison of the DASH diet with other popular diets

DASH diet and the Mediterranean diet

Similarities

• Nutritional basis: Both diets are based on large amounts of vegetables, fruits and whole grains
• Limit meat: Both recommend limiting consumption of red meat and preferring lean poultry and fish
• Healthy Fats: Both promote healthy sources of fats (olive oil, nuts, seeds)
• Health benefits: Both diets have a beneficial effect on the cardiovascular system and reduce the risk of chronic diseases
• Scientific Recognition: Both diets are highly rated by experts and have a solid scientific basis

Differences

• Origin: The Mediterranean diet comes from the traditional dietary patterns of the Mediterranean countries, while the DASH diet was developed specifically to fight hypertension
• Dairy: The DASH diet places greater emphasis on low-fat dairy products as a source of calcium and protein
• Salt: The DASH diet has more stringent recommendations for limiting sodium
• Wine: The Mediterranean diet allows for moderate consumption of red wine, while the DASH diet does not recommend alcohol
• Flexibility: The Mediterranean diet is more flexible in its approach to nutrition, while the DASH diet has more precise guidelines on the number of servings from each food group

Efficacy in the treatment of hypertension

The DASH diet is specifically designed to lower blood pressure and has slightly better results than the Mediterranean diet. Clinical studies have shown that the DASH diet can reduce systolic blood pressure by 8-14 mmHg, while the Mediterranean diet can reduce systolic blood pressure by 7-11 mmHg.

DASH diet and ketogenic diet

Similarities

• Health Purpose: Both diets can be used for health purposes, not only for weight loss
• Limiting simple sugars: Both diets recommend limiting sweets and products with added sugar

Differences

• Macronutrient Ratios: The DASH diet is macronutrient balanced, while the ketogenic diet is extremely low carb (5-10% of calories) and high fat (70-80% of calories)
• Grain products: The DASH diet recommends whole grain cereal products, which are virtually excluded in the ketogenic diet
• Fruits: The DASH diet encourages fruit consumption, while the ketogenic diet significantly limits it due to its sugar content
• Starchy vegetables: They are allowed in the DASH diet, limited in the ketogenic diet
• Fats: The DASH diet recommends limiting saturated fats, while the ketogenic diet often allows for higher intakes

Efficacy in the treatment of hypertension

The DASH diet has been proven effective in lowering blood pressure. The ketogenic diet can also lower blood pressure, but mainly in overweight and obese people, by reducing body weight. The long-term effects of the ketogenic diet on cardiovascular health are less studied and controversial.

DASH diet and vegetarian/vegan diet

Similarities

• Emphasis on plant foods: Both diets place a heavy emphasis on vegetables, fruits and whole grains
• Meat limitation: The DASH diet recommends limiting meat, especially red meat, which is consistent with the assumptions of a vegetarian diet (and in the case of a vegan diet - complete elimination)
• Health Benefits: Both diets are associated with a lower risk of chronic diseases, including heart disease

Differences

• Animal products: The DASH diet allows for lean meat, poultry, fish and dairy products, while a vegetarian diet excludes meat and fish and a vegan diet excludes all animal products
• Dairy: The DASH diet recommends low-fat dairy products as an important source of calcium and protein, which must be replaced by other sources in a vegan diet
• Structure: The DASH diet has more precise guidelines on the number of servings from each food group, while vegetarian and vegan diets mainly define what not to eat

Diet comparison summary

Health benefits of the DASH diet

Lower blood pressure

The main goal for which the DASH diet was developed was to lower blood pressure without the need for pharmacotherapy or as a support for pharmacological treatment.

• Quick results: Clinical studies have shown that the DASH diet can reduce systolic blood pressure by 8-14 mmHg after just 2 weeks of use
• Efficacy comparable to drugs: In some cases, the effect of lowering blood pressure is comparable to the effect of using one antihypertensive drug
• Efficacy in different groups: The DASH diet is effective both in people with hypertension and in people with normal but higher than optimal blood pressure
• Additional benefits when limiting salt: Combining the DASH diet with limiting sodium to 1,500 mg per day gives even better results in lowering blood pressure

Improving the lipid profile

The DASH diet has a positive effect on the body's lipid metabolism:

• Reduction in total cholesterol: On average by 13-14 mg/dl
• Reducing the level of "bad" LDL cholesterol: On average by 7-9 mg/dl
• Maintaining or increasing the level of "good" HDL cholesterol
• Reduction of triglyceride levels: Especially in combination with physical activity and weight loss

These changes in the lipid profile contribute to reducing the risk of atherosclerosis and cardiovascular diseases.

Reducing the risk of cardiovascular diseases

The DASH diet significantly reduces the risk of developing cardiovascular diseases:

• Reduction of the risk of coronary heart disease: By 20-30% compared to a typical Western diet
• Reduce the risk of stroke: By 19-27% according to observational studies
• Heart failure risk reduction: By 29% according to the Women's Health Study
• Improving the function of the endothelium of blood vessels: Which translates into better vessel elasticity and blood flow

Reducing the risk of type 2 diabetes

The DASH diet has a beneficial effect on glucose and insulin metabolism:

• Improve insulin sensitivity: Thanks to the high content of fiber, magnesium and low content of simple sugars
• Reduction in fasting glucose levels: Especially in people with insulin resistance
• Reduction of the risk of developing type 2 diabetes: By 20-25% according to long-term studies
• Benefits for people with diabetes: Better glycemic control and reduced risk of diabetic complications

Support in weight control

Although the DASH diet was not originally designed as a weight loss diet, it promotes maintaining a healthy weight:

• Natural calorie control: Thanks to the high fiber and water content in vegetables and fruits, which increase the feeling of satiety
• Stabilization of blood sugar levels: Which helps avoid hunger pangs and snacking
• Reduction of body fat: Especially in combination with moderate physical activity
• Long-term maintenance of results: Unlike restrictive diets, the DASH diet is sustainable and can be used for life

Other health benefits

The DASH diet also brings a number of other health benefits:

• Protecting your kidney health: Reducing the risk of kidney stones and slowing the progression of chronic kidney disease
• Bone health benefits: Thanks to adequate supply of calcium, vitamin D, magnesium and potassium
• Potential mental health benefits: Reducing the risk of depression and improving cognitive function
• Reduce inflammation in the body: Lowering levels of inflammatory markers such as C-reactive protein
• Extending life and improving its quality: Reducing the overall risk of mortality by 20-25%

How to implement the DASH diet step by step

It is best to start the DASH diet gradually so that your body can get used to the new way of eating. Below is a practical guide on how to introduce the DASH diet into your life:

Step 1: Increase your fruit and vegetable intake

• Week 1-2: Add one additional serving of vegetables or fruit per day
• Practical tips:
  • Add vegetables to every meal, even breakfast (e.g. spinach with scrambled eggs)
  • Keep washed and chopped vegetables in the fridge as a quick snack
  • Add fruit to cereals, yogurt or as a dessert
  • Try new vegetables and fruits that you haven't eaten before

Step 2: Switch to whole grains

• Week 3-4: Replace white bread, rice and pasta with whole grain equivalents
• Practical tips:
  • Start by mixing (e.g. half white, half brown rice)
  • Try different types of groats (buckwheat, millet, pearl barley)
  • Read labels and choose products in which whole grains are the first ingredients
  • Experiment with lesser-known grains like quinoa or amaranth

Step 3: Change your protein sources

• Week 5-6: Limit red meat and replace it with lean poultry, fish and plant-based protein
• Practical tips:
  • Introduce at least 2 meatless days a week
  • Add legumes to salads, soups and stews
  • Choose fish rich in omega-3 fatty acids (salmon, mackerel, herring) twice a week
  • Experiment with different nuts and seeds as snacks

Step 4: Switch to low-fat dairy products

• Week 7-8: Replace full-fat dairy products with low-fat equivalents
• Practical tips:
  • Switch gradually (e.g. from 3.2% milk to 2%, then to 1.5% or 0.5%)
  • Try different types of low-fat natural yogurt
  • Choose cheeses with reduced fat content (e.g. light mozzarella, light cottage cheese)
  • Remember that "0% fat" products often contain more sugar - read the labels

Step 5: Limit salt

• Week 9-10: Gradually reduce the amount of salt and avoid highly processed products
• Practical tips:
  • Reduce the amount of salt added by half, then another half
  • Replace salt with herbs and spices (basil, oregano, thyme, turmeric, garlic)
  • Avoid ready-made sauces, powdered soups and other highly processed products
  • Rinse canned foods to reduce sodium content
  • Read labels and choose low-sodium products

Step 6: Limit sweets and sweetened drinks

• Week 11-12: Reduce your intake of added sugar and sweetened drinks
• Practical tips:
  • Replace sweetened drinks with water with lemon, mint or cucumber
  • Instead of sweets, choose fresh fruit or small amounts of dried fruit
  • Reduce the amount of sugar added to coffee and tea by half, then eliminate it completely
  • Try natural sweeteners like cinnamon or vanilla

Step 7: Introduce healthy fats

• Week 13-14: Replace saturated fats with healthy unsaturated fats
• Practical tips:
  • Use olive oil or rapeseed oil instead of butter or lard
  • Add avocado to salads and sandwiches
  • Eat a handful of nuts or seeds as a snack (watch your portions)
  • Choose methods of preparing dishes that require less fat (boiling, baking, stewing)

Practical tips for success

1. Plan your meals in advance: Prepare a weekly meal plan and shopping list
2. Cook at home: Then you have control over the ingredients and the amount of salt
3. Prepare meals in advance: Cook larger portions and freeze them for later
4. Read labels: Pay attention to sodium, sugar and saturated fat
5. Eat regularly: 4-5 meals a day at regular intervals
6. Drink plenty of water: 1.5-2 liters a day, more during hot weather and physical exercise
7. Be physically active: Add at least 150 minutes of moderate physical activity per week
8. Monitor your progress: Keep a food diary and measure your blood pressure regularly
9. Be patient: The full effects of the DASH diet may take 8-12 weeks to become visible
10. Don't completely give up your favorite foods: Allow yourself small deviations from time to time

Sample menu for a week

Monday

Breakfast: Oatmeal porridge with blueberries, banana and walnuts, a glass of milk 1.5%

Second breakfast: Natural yogurt 2% with a handful of homemade granola and fresh fruit

Lunch: Baked salmon with herbs, baked sweet potatoes, stewed broccoli, arugula salad with olive oil and lemon juice

Afternoon tea: Hummus with carrots and peppers

Dinner: Salad with quinoa, baked pumpkin, spinach, sunflower seeds and light feta cheese

Tuesday

Breakfast: Scrambled eggs with spinach and tomatoes, a slice of whole grain bread, a glass of orange juice

Second breakfast: Smoothie with blueberries, banana, spinach and natural yogurt

Lunch: Turkey goulash with vegetables (carrots, celery, parsley, onion, tomatoes), buckwheat, cabbage salad

Afternoon snack: A handful of almonds and an apple

Dinner: Pumpkin cream soup with pumpkin seeds and a spoon of natural yogurt, a slice of wholemeal bread

Wednesday

Breakfast: Sandwiches made of whole grain bread with avocado paste, hard-boiled egg and sprouts

Second breakfast: Kefir cocktail with strawberries and banana

Lunch: Baked chicken breast with herbs, brown rice, stewed vegetables (zucchini, peppers, eggplant)

Afternoon tea: Pear and 2 squares of dark chocolate (70% cocoa)

Dinner: Greek salad with tomatoes, cucumber, peppers, red onion, olives and light feta cheese, a slice of whole grain bread

Thursday

Breakfast: A bowl of 2% Greek yogurt with homemade granola, nuts and fresh fruit

Second breakfast: Kale, banana, apple and linseed cocktail

Lunch: Baked cod, mashed potatoes with celery, boiled green beans with roasted almonds

Afternoon snack: Rice waffles with peanut butter and banana slices

Dinner: Minestrone soup with beans, vegetables and whole grain pasta

Friday

Breakfast: Omelet with vegetables (peppers, tomatoes, spinach), a slice of whole grain bread

Second breakfast: Fruit salad with natural yogurt and nuts

Lunch: Whole grain pasta with tomato sauce, lentils and vegetables, sprinkled with a small amount of grated cheese

Afternoon tea: Smoothie with mango, pineapple and yogurt

Dinner: Salad with baked beetroot, arugula, goat cheese and walnuts

Saturday

Breakfast: Oatmeal pancakes with apple and cinnamon, natural yogurt

Second breakfast: A handful of cashews and an orange

Lunch: Brown rice risotto with mushrooms, green peas and chicken, tomato salad

Afternoon tea: Cocktail with kefir, banana and berries

Dinner: Sandwiches made of whole grain bread with tuna paste, cucumber and lettuce

Sunday

Breakfast: Wholegrain pancakes with ricotta and fruit

Second breakfast: Natural yogurt with chia seeds, honey and fruit

Lunch: Roasted turkey, bulgur, roasted root vegetables (carrots, parsley, celery)

Afternoon snack: Apple with peanut butter

Dinner: Cream soup with baked tomatoes and peppers with whole grain croutons

Who is the DASH diet best for?

The DASH diet is especially recommended for:

• People with hypertension or increased blood pressure
• People at risk of cardiovascular diseases
• People with lipid disorders (high cholesterol)
• Overweight or obese people who are looking for a healthy and balanced diet
• People who prefer a structured approach to diet with clear guidelines regarding the number of servings

The DASH diet may not be optimal for:

• People on a very restrictive low-carbohydrate diet (e.g. for the treatment of epilepsy)
• People with certain kidney diseases that require potassium restriction
• People who choose a vegan diet for ethical reasons (although the DASH diet can be adapted to a vegan version)

Summary

The DASH diet is one of the healthiest nutritional models that was developed on the basis of solid scientific research. Its effectiveness in lowering blood pressure and reducing the risk of cardiovascular diseases has been confirmed in numerous clinical studies. However, the health benefits of the DASH diet go far beyond the cardiovascular system - it supports the health of the entire body and can be followed throughout life.

The key to success with the DASH diet is to gradually introduce changes that will become habits over time. It is not a restrictive or short-term diet, but rather a healthy lifestyle that can be maintained for years. Thanks to the variety of allowed products, the DASH diet is tasty, filling and easy to adapt to individual preferences.

Remember that before starting any diet, especially if you have health problems, it is worth consulting a doctor or dietitian. A specialist will help you adapt the DASH diet principles to your individual needs and health condition.

Sources

1. National Heart, Lung, and Blood Institute. "DASH Eating Plan." https://www.nhlbi.nih.gov/health-topics/dash-eating-plan
2. Appel, L. J., et al. (1997 ). A clinical trial of the effects of dietary patterns on blood pressure. New England Journal of Medicine, 336(16), 1117-1124.
3. Sacks, F. M., et al. (2001). Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. New England Journal of Medicine, 344(1), 3-10.
4. Chiavaroli, L., et al. (2019). DASH Dietary Pattern and Cardiometabolic Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses. Nutrients, 11(2), 338.
5. Siervo, M., et al. (2015). Effects of the Dietary Approach to Stop Hypertension (DASH) diet on cardiovascular risk factors: a systematic review and meta-analysis. British Journal of Nutrition, 113(1), 1-15.
6. Liese, A. D., et al. (2009). The Dietary Patterns Methods Project: synthesis of findings across cohorts and relevance to dietary guidance. The Journal of Nutrition, 145(3), 393-402.
7. National Institute of Public Health - National Institute of Hygiene. "DASH diet - a star among diets." https://ncez.pzh.gov.pl/abc-zywienia/dieta-dash-gwiazda-wsrod-diet/
8. Practical Medicine. "DASH Diet." https://www.mp.pl/pacjent/nadcisnienie/informacje/dietaiwysilek/60147,dieta-dash