Dietetics - Controlling your Potassium Intake: Step 1

Why have I been given this leaflet?

This leaflet has been given to you as you have reduced kidney function and you have been advised by your doctor, kidney specialist nurse or dietitian that your blood contains high levels of potassium.

What is potassium and why is it important?

Potassium is an important mineral that affects the heart’s rhythm. If your level of potassium is too high, or too low, it can cause heart palpitations and cause your heart to stop beating (heart attack)

What level should my potassium be?

If you are pre-dialysis, the level of potassium in your blood should be between 3.5 and 5.5mmol/l.

If you are on haemodialysis, the level of potassium in your blood should be between 4 and 6mmol/l.

If you are on peritoneal dialysis, the level of potassium in your blood should be between 3.5 and 5.5mmol/l.

Why is the potassium in my blood high?

The level of potassium in your blood is usually controlled by the kidneys. There are several reasons why your potassium level may rise when your kidneys are not working properly, these include:

• High blood sugar levels – speak with your GP or Diabetes team about improving your blood sugar levels
• Inadequate dialysis due to missing or reducing your time on dialysis or problems with line access
• Having lots of high potassium food and drinks in your diet
• Constipation – this can prevent potassium being removed from your body in your stool. It is important to include fibre in your diet to help keep your bowels opening regularly. Your doctor or pharmacist can help with advice on laxatives if needed

This leaflet will provide advice on changes you can make to your diet to help reduce your potassium by:

1. Avoiding potassium additives, which are in salt substitutes and some manufactured foods
2. Using cooking methods to remove some potassium from foods
3. Avoiding snacks and drinks that are high in potassium
4. Preventing constipation by including fibre in your diet
5. Choosing foods which are lower in potassium

1.    How can I avoid potassium additives?

Do not use salt substitutes such as Lo Salt® as these contain potassium additives.

Check ingredient labels of pre-packaged foods such as savoury snacks and cordials for potassium additives. Here are a few examples of potassium additives commonly added to food in the UK:

E228 Potassium hydrogen sulphite
E261 Potassium citrates
E340 Potassium phosphates
E508 Potassium chloride
E632 Dipotassium inosinate

Example of a food label

Ingredients:

Maize, rapeseed oil, pickled onion seasoning, onion powder, sugar, flavour enhancers, (monosodium glutamate, disodium 5’ ribonucleotide), salt, potassium chloride, garlic powder, hydrolysed soya protein, citric acid.

2.    Use the following cooking methods to reduce potassium in foods:

Potatoes and vegetables: Boil or par-boil potatoes and where possible, vegetables, in a large pan, filled with water. To reduce the potassium further, peel and chop vegetables into small pieces prior to boiling. Discard the water - do not use for making gravy or sauces.

Do not use a steamer, microwave or air-fryer to cook potatoes and vegetables.

Jacket potatoes: Prod with a skewer then parboil for ten minutes, before baking as usual in microwave, oven or air-fryer.

Chips and wedges: Soak the chipped potatoes for a few hours in a large volume of cold water, before removing and patting dry. Cook as usual in a deep, fat-fryer, air-fryer or oven.

Stews and curries: Par-boil vegetables and discard the water before adding to the pot.

Lentils and beans: Tinned pulses are lower in potassium than dried. Just rinse thoroughly in tap water before adding to your dish.

Soak dried lentils overnight in 3 cups water for 1 cup lentils, then cook in your usual way.

3.    Snacks, drinks and other foods to limit or avoid:

Snacks

• Crisps – potato crisps are high in both salt and potassium. Instead choose popcorn, plain rice cakes or wheat or maize-based snacks that do not contain potassium additives
• Chocolate is high in potassium. Choose thinly coated chocolate biscuits or wafers instead of bars of chocolate
• Dried fruit – try to avoid as a snack or in biscuits, cakes and breakfast cereals. Eat fresh, frozen or tinned fruit instead
• Fudge and toffee - choose marshmallows, boiled or jelly sweets mints or chewing gum instead
• Liquorice

Drinks

• Limit coffee to one cup a day. Choose water, tea or herbal teas instead
• Avoid smoothies, fruit juice and vegetable juices. Drink water, no added sugar flavoured water, or cordial instead
• Avoid milkshakes and milky drinks such as Ovaltine, Horlicks, hot chocolate, cappuccino and latte
• Drink less beer, wine and cider as these are high in potassium. If you drink alcohol, choose spirits with low-calorie mixers instead. Remember to limit alcohol to 14units a week, spread over 3 days or more and include in your fluid restriction if you have been advised to limit fluid intake

4.    Increasing your fibre intake

Constipation can lead to a high level of potassium in your blood. Increasing the amount of fibre, you eat can help prevent constipation.

How to increase your fibre intake:

• Eat 5 portions of whole fruit and vegetables a day. One portion is about 80g
• Eat whole grains such as brown rice, wholemeal pasta, wholegrain cereals like Weetabix®, Shredded Wheat® and oats, and wholemeal or granary bread
• Try to include some pulses such as beans, lentils and chickpeas on a regular basis

5.    Foods to avoid or limit and lower potassium alternatives

High Potassium Starchy Foods

• Cassava, potato, sweet potato and yam should be limited to 150g once daily. These should be boiled or par-boiled initially. Then they can be mashed, roasted, chipped or sauteed
• Chips-unless par-boiled
• Jacket potatoes
• Frozen roast potatoes, chips, fries and wedges
• Potato waffles and hash browns
• Breads and cereals containing dried fruit, nuts or seeds or chocolate
• Potato flour

Low Potassium Starchy Foods:

• White, granary and wholemeal breads, chapatti, naan bread, noodles, pasta, wraps and plain cream crackers or water biscuits
• Plain cereals that do not contain dried fruit, nuts or chocolate such as Weetabix®, Shredded Wheat®, cornflakes, porridge
• White or brown rice
• Wheat, corn, maize, rice or semolina flour

High Potassium Dairy products to avoid or restrict:

• Condensed and evaporated milk or foods containing these
• Cow’s and soya milk: restrict to no more than 300mls or ½ pint per day
• Yoghurts and milky puddings: limit to 3-4 times a week
• Dried milk powder or products containing milk powder

Lower Potassium Dairy Products:

• Rice milk, almond milk and oat milk that don’t contain potassium additives
• Eggs
• Hard cheese, cottage cheese, soft cream cheese spread such as Philidelphia® or soft continental cheeses like Brie

Fruit and Vegetables

• Try to eat up to 5 portions of fruit and vegetables a day
• One portion of vegetables is 2 heaped tablespoons
• One portion of fruit is 80g
• Tomato-based dishes such as bolognaise and chilli con carne, should be served with rice, pasta, a bread or other lower potassium accompaniment. No potato-based dishes should be eaten on the same day

High potassium vegetables to avoid or restrict:

• Artichoke
• Baked beans
• Beetroot (raw/boiled)
• Brussel sprouts
• Butternut squash
• Celeriac
• Mushrooms
• Okra
• Parsnips
• Spinach
• Tomatoes are high in potassium, however a few slices in a sandwich or on a salad is fine.

Lower potassium vegetables to choose instead:

• Aubergine
• Beansprouts
• Broccoli
• Carrots
• Cabbage
• Cauliflower
• Courgette
• Cucumber
• Green beans
• Peppers
• Leeks
• Mangetout
• Marrow
• Mixed vegetables from freezer section
• Mushrooms in cans or jars
• Onion
• Peas
• Runner beans
• Swede
• Sweetcorn
• Turnip

High potassium fruits to avoid or restrict:

• Avocado
• Banana
• Blackcurrants
• Dried fruit such as raisins, apricots, sultanas, dates and figs
• Mango
• Melon
• Pineapple
• Rhubarb

Star fruit is toxic to patients with kidney disease and should be avoided altogether.

Grapefruit can interact with some medications. Please check with your pharmacist or Doctor to check if you should avoid it.

Lower potassium fruits to choose:

• Apples
• Blueberries
• Blackberries
• Cherries
• Cranberries
• Clementines
• Fresh figs
• Grapes
• Nectarines
• Oranges (small)
• Peaches
• Pears
• Raspberries
• Strawberries
• Satsumas and tangerines
• Tinned fruit without the juice

Other foods to avoid or restrict your intake of:

• Passata and tomato puree
• Tomato ketchup and brown sauce. Instead choose mayonnaise or salad cream
• Salt substitutes such as Lo Salt R. Instead use pepper, garlic, lemon juice, spices and herbs or vinegar to flavour food

Name:

Dietitian:

Telephone: 0161 206 1994
Email: renaldietitians@nca.nhs.uk

Useful resources and websites:

Kidney Kitchen
Kidney Care UK
National Kidney Foundation

Notes/Plan