Disclaimer: I am not a qualified expert in this area – please consult a licensed medical practitioner before making lifestyle changes.
After reading Incubation in Problem Solving and Creativity, I wanted to find out if there was evidence-based advice on ways to increase the duration of slow wave or REM sleep. (The findings discussed in Incubation in Problem Solving and Creativity suggest that the creative incubation process may provide more insights into problem-solving from longer durations of slow wave sleep, while longer durations of REM sleep may help with the generation of creative ideas.)
I searched the PubMed site. Here are some papers that I thought were interesting:
- Diet Composition and Objectively Assessed Sleep Quality: A Narrative Review is a review of individual studies that measure the relationship between sleep and the types of food we eat. Quite a few different diets were explored. Given the evidence summarised here, possibly the simple change with the clearest benefit would be to increase the amount of dietary fibre consumed – this seems to be linked with improved sleep quality overall, as well as increases in the duration of both slow wave and REM sleep. Any increase to dietary fibre intake should be gradual – see the last paragraph of this post for more information.
- Slow-wave activity enhancement to improve cognition suggests that vigorous physical exercise, warm baths, meditation and performing challenging cognitive tasks related to learning and memory can increase the duration of slow wave sleep.
- Evening light environments can be designed to consolidate and increase the duration of REM-sleep reports on a small study showing that reducing our exposure to light containing blue wavelengths may increase the duration of REM sleep without decreasing slow wave sleep.
Give results I’ve seen elsewhere, it’s not clear to me how important the effect of the intensity of blue wavelengths within the ambient light is, compared with the overall brightness of the light. For example, there are studies that consider the impact of dim light in the evening on sleep quality (e.g. Dim light in the evening causes coordinated realignment of circadian rhythms, sleep, and short-term memory, which does not specifically mention REM or slow wave sleep, as far as I can tell).
I’ve found the Australian Food Composition Database to be a useful source of nutrition information. Here’s a list of 18 pages of different types of food and drink, sorted by increasing dietary fibre content.
Important note: I’ve seen advice in several places that any increases in dietary fibre intake should be gradual. Increasing fibre intake too rapidly can cause unpleasant gastro-intestinal symptoms and occasionally more serious problems. A textbook I own (Understanding Nutrition: Australian and New Zealand Edition 2011) suggests that people adopting a higher-fibre diet should increase their intake gradually over several weeks, drink lots of liquids and choose fibre-rich foods from a variety of sources (page 115). Again, please consult a licensed medical practitioner before making lifestyle changes.