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The DASH diet is an eating plan designed to help lower high blood pressure. It’s built around fruit, vegetables, wholegrains and low-fat dairy, and keeps salt, saturated fat, sugary foods and alcohol low. You don’t need special foods, just the right balance of everyday ones.
What is the DASH diet?
DASH stands for Dietary Approaches to Stop Hypertension. The British Heart Foundation (BHF) explains that it was designed by researchers at the US National Heart, Lung, and Blood Institute in the 1990s.
The idea is simple: eat less salt (sodium) and more fibre, potassium and calcium. According to the BHF, that combination can help lower blood pressure.
There are no banned foods and no set meals. What matters is getting the balance of food groups right across the day.
Does the DASH diet lower blood pressure?
The BHF says many studies show the DASH diet can help bring blood pressure down to a healthy level. A 2019 review it cites, covering 7 meta-analyses, linked the diet to a 5.2mmHg drop in systolic pressure (the top number) and a 2.6mmHg drop in diastolic pressure (the bottom number).
The same review linked it to a 20 per cent lower risk of cardiovascular disease, including heart attack, stroke and coronary heart disease. Research also suggests it may help with cholesterol, blood sugar and weight.
For context, the BHF says high blood pressure is diagnosed at over 140/90mmHg in a clinic, or over 135/85mmHg for home readings. The NHS notes that high blood pressure doesn’t usually cause any symptoms, so the only way to know is to get it checked.
What can you eat on the DASH diet?
Here are the BHF’s daily servings for someone eating around 2,000 calories a day. If you need more or fewer calories, the number of servings changes.
| Food group | How much | One serving is about |
|---|---|---|
| Vegetables | 4 to 5 a day | 2 handfuls of raw leafy veg, or 1 handful of other veg |
| Fruit | 4 to 5 a day | 1 medium fruit, or 3 tbsp unsweetened dried fruit |
| Wholegrains | 7 to 8 a day | 1 slice of wholemeal bread, or 1 handful of cooked wholegrain pasta or rice |
| Lean meat, poultry, fish, eggs | Up to 6 a day | 30g cooked meat or fish, or 1 egg |
| Low-fat or fat-free dairy | 2 to 3 a day | 235ml low-fat milk or yoghurt, or 43g low-fat cheese |
| Nuts, seeds and beans | 4 to 5 a week | 43g mixed nuts, 2 tbsp seeds, or 85g cooked beans |
| Fats and oils | 2 to 3 a day | 1 tsp vegetable oil or soft margarine |
| Added sugar and sweets | Under 5 a week | 1 tbsp sugar or jam |
| Alcohol | Under 1 drink a day, or 14 units a week | A single shot of spirit is 1 unit |
That might look like a lot of servings, but the portions are small. A handful of cooked wholegrain rice and a slice of wholemeal toast already make two wholegrain servings.
How much salt is allowed?
The BHF describes two versions of the DASH diet:
- Standard: no more than 2,300mg of sodium a day, about 6g or one teaspoon of salt.
- Lower sodium: no more than 1,500mg of sodium a day, about 4g or three-quarters of a teaspoon of salt. The BHF says this may lower blood pressure further.
Checking labels makes it easier to stay under the limit. Our guide on how much salt a day shows where it hides and how to spot high-salt foods.
Why does potassium matter?
Blood Pressure UK explains that salt makes your body hold on to water, which upsets the balance of sodium and potassium your kidneys need. Eating more potassium-rich foods helps restore that balance and lets the kidneys help lower your blood pressure.
Good sources it lists include bananas, apricots, potatoes, sweet potatoes, spinach, cabbage, sprouts, fish, yoghurt, nuts and mushrooms. That’s one reason DASH leans so heavily on fruit and veg.
A word of care, though. Blood Pressure UK says that if you have kidney disease or take certain blood pressure medicines, a large increase in potassium could be harmful. It advises avoiding potassium supplements and potassium-based salt substitutes, and checking with your doctor first. The British Dietetic Association adds that if you have kidney disease, speak to your dietitian before changing your diet.
DASH or Mediterranean diet: which is better?
The two have a lot in common. Both are high in fish, vegetables, fruit, wholegrains, nuts and seeds, and low in salt, added sugar, saturated fat and red meat.
The BHF points out a few differences:
- DASH includes several daily servings of low-fat dairy, because calcium is known to help lower blood pressure
- the Mediterranean diet recommends more oily fish, a source of omega-3 fats
- DASH is more structured, with set servings, while the Mediterranean diet is more flexible
The BHF says either can support heart health, so pick the one you can stick with.
Simple ways to start eating the DASH way
You don’t have to change everything at once. A few easy steps:
- add a portion of fruit or veg to each meal
- swap white bread, rice and pasta for wholegrain versions
- switch to semi-skimmed or skimmed milk and plain low-fat yoghurt
- have beans, lentils or unsalted nuts a few times a week
- cook from scratch more often, and taste before adding salt
- keep alcohol within 14 units a week, in line with NHS advice
The NHS also recommends at least 150 minutes of exercise a week alongside a healthy diet. If your blood pressure stays high after lifestyle changes, your GP may suggest medicine. Never stop or change blood pressure tablets yourself; talk to your GP or practice nurse.
Checking meals when there’s no label
Supermarket food has a label, and our guide to reading food labels explains the traffic lights. Meals out and home-cooked dishes don’t. The Dietary Insight app can estimate the salt, sugar and fat in a meal from a photo and suggest a swap that fits a DASH-style plate.
Frequently asked questions
What does DASH stand for?
DASH stands for Dietary Approaches to Stop Hypertension. It was designed by researchers at the US National Heart, Lung, and Blood Institute in the 1990s.
How much salt is allowed on the DASH diet?
The standard version allows up to 2,300mg of sodium a day, about 6g or one teaspoon of salt. A lower-sodium version sets the limit at 1,500mg, about 4g of salt, which the BHF says may lower blood pressure further.
Can the DASH diet replace my blood pressure tablets?
Don't stop or change any medicine on your own. Healthy eating works alongside treatment, so talk to your GP or practice nurse about your blood pressure and your medicines.
Sources
This article is general information, not medical advice. If you have diabetes, high blood pressure or a food allergy, speak to your GP, diabetes nurse or a registered dietitian before changing your diet or medication. Read our medical disclaimer.