Keto diet + exercise: Good for narcoleptics?

A 10-week study presented at EAN 2024 has shown that a ketogenic or “keto” diet plus regular physical exercise may be beneficial for people with narcolepsy.

People with narcolepsy – caused by a lack of the brain chemical hypocretin – experience overwhelming and persistent sleepiness at various times of the day, which can be disruptive to work and social relationships. They may unwillingly fall asleep while driving, eating, or talking, putting them at risk for accidents.

Narcoleptics may also exhibit cataplexy (sudden muscle weakness that makes them unable to move), sleep paralysis, and hallucinations.

While there is no cure for narcolepsy, medications such as stimulants and lifestyle changes can help manage the symptoms.

“When we take a closer look at the European guidelines on narcolepsy, especially in the patient opinion section, there is a request for more nonpharmacological treatment options,” said study investigator Dr Frederike Tepel from the Centre for Narcolepsy and Hypersomnia, Witten/Herdecke University, Witten, Germany. “However, specific guidance regarding physical activity and nutrition are lacking.”

Tepel and her team sought to evaluate the efficacy of regular physical activity and keto diet in 60 adult patients (41 female, mean age 34 years) with type 1 narcolepsy (NT1).

“Average BMI was >20. This was because the advising nutritionist theorized that many patients would lose weight in the trial,” she explained.

The patients were randomly assigned to receive regular physical activity (n=20), a keto diet (n=20), or best clinical practice (n=20) for 10 weeks. Patients on physical activity adhered to a training plan, the keto group followed a high-fat/low-carb diet, and controls maintained routine. Daily step counts were logged, and so were the training hours. Nutrition counselling was provided, with weekly measures of capillary ketone bodies, weight, and waist circumference. [EAN 2024, abstract OPR-101]

Favourable outcomes

At the end of the study, diet and exercise improved the primary outcome of excessive daytime sleepiness (EDS) as measured by the Epworth Sleepiness Scale (ESS). “This is to a point where the results were clinically significant and in the range of those seen with drug treatment,” Tepel reported.

“The most important finding was that patients on regular physical activity had an improvement of 2.9 points on the ESS (from 13.9 to 11 points; p<0.009) while those on the keto diet had a reduction of over 3 points (16.3 to 13.2 points; p< 0.005). By contrast, the control group remained stable during the 10 weeks,” said Tepel.

Similarly, patients’ sleep quality improved as measured by the Pittsburgh Sleep Quality Index (PSQI), as did fatigue and quality of life. The keto diet also led to a significant weight loss (an average of -6 kg over 10 weeks) relative to best clinical practice.

“The treatments offer a convenient, cost-effective, and efficient therapeutic option alongside pharmacological measures. It is worth noting that these interventions are available everywhere and inexpensive,” she pointed out. “We also couldn’t document any adverse effects associated with the interventions.”

While the study was limited by the small patient size, “to our knowledge, this was the biggest thus far,” Tepel added. “Patients anecdotally report improvements in narcolepsy with low-carbohydrate diets.”

Session co-chair Dr Rolf Fronczek of the Sleep-Wake Center SEIN, the Netherlands, couldn’t agree more. “I think the more practical advice is to follow a low-carb diet because adopting a keto diet is difficult to sustain and expensive,” Fronczek commented. “I see it more that we should add guidance to incorporate a low-carb diet to the behavioural advice we give to patients with narcolepsy.”

“If a low-carb diet, rather than a keto diet, is recommended, it’s good to stick to a maximum of 50 g of carbohydrate daily,” Tepel suggested.