Fasting and epilepsy

Why do people choose to fast?

There are various reasons why you might want to fast. This may include religious reasons. Or, because you are dieting to lose weight or improve your general health.

A medical professional may ask you to fast before you have an anaesthetic. This is a drug that temporarily numbs or puts you to sleep during a medical procedure.

Is fasting with epilepsy safe?

Many people can fast safely with epilepsy. But there are some things to think about. This includes:

• Your seizure triggers
• If fasting will affect how and when you take your epilepsy medicines
• The impact having a seizure might have. Could it trigger a seizure if your seizures are normally well controlled? Would it affect you working or driving?
• The type of epilepsy you have. Research shows fasting might trigger seizures in people with some rare types of epilepsy. For example, GLUT1 deficiency syndrome

Sometimes fasting may mean that you do not drink as well. This can cause dehydration, which may increase the risk of having a seizure.

It will help to get medical advice from your GP, epilepsy specialist nurse or epilepsy specialist. They can explain the potential risks and help you decide if fasting is right for you. They may also be able to help you find ways to stay safe while fasting.

We talk about some of the safety considerations you might have with different types of fasting in the sections below.

Fasting for religious reasons

Fasting at certain times is an important part of many religions. This includes Judaism, Christianity and Hinduism. Muslims also fast during the Islamic month of Ramadan, which is one of the longest periods of fasting.

Fasting during Ramadan

It is unclear exactly how fasting during Ramadan affects people with epilepsy. The results from research are mixed. Many of the studies only look at fasting in a small number of people.

Some research found that people with epilepsy had more seizures when fasting. Other research found that some people with certain seizure types had fewer seizures during periods of fasting. This included focal, myoclonic and absence seizures.

Another study found that some people had fewer seizures for a month after Ramadan. But this only looked at a small number of people over a short time. The researchers did not report what type of seizures the people had, or if some seizure types were reduced more than others.

Risks during Ramadan

There are a few ways that fasting during Ramadan may affect your epilepsy and cause more seizures. You may change the times you take your epilepsy medicines to fit around fasting. Eating and doing activities later at night might cause disturbed sleep. Tiredness can be a seizure trigger for some people.

Islamic law says that you don’t need to fast during Ramadan if it might cause you harm. For example, if it might make your health worse. Whether this applies to you might depend on several different things.

You might be at a higher risk of having a seizure if you:

• Are older
• Have uncontrolled seizures
• Take more than one epilepsy medicine
• Have other health conditions
• Have had status epilepticus in the past

Your epilepsy specialist nurse, GP or epilepsy specialist can help you decide what is best for you. If possible, try to have this conversation a few months before Ramadan starts. They should consider your health, seizure management, values and beliefs.

They will be able to advise you about how to stay safe while fasting. For example, the best times to take your medicines if you need to take them twice a day but still want to fast.

Fasting before general anaesthetic

You may need to stop eating and drinking for a set amount of time if you are having a general anaesthetic before any type of operation (surgery).

Your hospital should give you clear information about:

• If you need to stop eating and drinking in the hours before your operation
• How and when to take your epilepsy medicines

It is important to follow the instructions given to you before an operation. Talk to the medical professional organising your operation or your epilepsy specialist nurse if you have any questions.

There is more information about having a general anaesthetic on the NHS website. The Royal College of Anaesthetists also has a page of frequently asked questions to help you prepare.

You may have to fast for other medical tests. For example, a colonoscopy or some types of blood tests. You will be told before your appointment if you will need to fast. Speak to your doctor or epilepsy nurse if you have any questions or concerns.

Fasting as part of a diet

There are several diets that involve periods of fasting. This is called intermittent fasting.

Speak to your GP, epilepsy specialist nurse or epilepsy specialist before starting any diet. They can give you advice about how to do this safely. It’s also important to research what type of foods are good to eat and how many calories you should have.

Fasting is not recommended if you:

• Have had or currently have an eating disorder
• Are pregnant or breastfeeding

The NHS Better Health page has information about ways to lose weight healthily. It also explains what calories

Types of intermittent fasting include:

• • 5:2 fasting  This involves eating a normal diet for five days a week and eating less for two days a week. It’s recommended to eat one quarter (25%) of your usual calorie intake on fasting days
  • Time-restricted eating – This involves eating within a specific time frame each day. An example of this is the 16/8 method. This is where you fast for 16 hours a day, and eat within an 8-hour period

There is some research to show that intermittent fasting can help people in the general population to lose weight. But studies have only looked at how these diets have affected people for a short amount of time. There is less evidence to show how they can help to manage weight long term.

Can intermittent fasting help epilepsy?

Some animal studies have found that intermittent fasting can have a positive effect on the brain. This includes better seizure control. But there are very few studies in humans to check if intermittent fasting has the same impact in people. More research needs to be done.

Some people say that missing meals can be a trigger for their seizures. But there has not been enough research yet into this topic. Missing meals can cause people to feel tired or fatigued, which can be a seizure trigger for some people. Missing meals might trigger seizures in people with some rare types of epilepsy. For example, GLUT1 deficiency syndrome.

Following a ketogenic diet

A ketogenic diet is a specialist medical diet that some people use as a treatment option for epilepsy. It does not involve fasting, but it makes the body think that it is in a state of fasting. This diet should only be done under the supervision of specialists who are experts in the diet.

Find out more about ketogenic diets.