CARBOHYDRATE QUALITY AND SLEEP PATTERNS

The quality of the carbohydrate you eat and drink may affect your sleep, according to the findings of a new study.

There is increasing evidence suggesting an association between sleep and dietary habits. In this study, Chinese researchers aimed to explore the relationship between carbohydrate (dietary fibre, starches and sugars) consumption and sleep.

The researchers used data from over 17,000 participants in the National Health and Nutrition Examination Survey (NHANES) survey who had completed dietary recalls and sleep questionnaires. NHANES is a research program that collects data to assess the health and nutritional status of adults and children in the United States of America and to track changes over time.

The subjects were divided into four groups based on carbohydrate consumption patterns according to their intake of high-and low-quality carbohydrate foods.

• Pattern 1: subjects whose intake of high-quality carbohydrates was below the median and low-quality carbohydrates above the median.
• Pattern 2: subjects whose intake of both high-and low-quality carbohydrates were below the median.
• Pattern 3: subjects whose intake of high-and low-quality carbohydrates were above the median.
• Pattern 4: subjects whose intake of high-quality carbohydrates was above the median and low-quality carbohydrates was below the median.

Intake of high-quality carbohydrate was determined by adding together the intake of whole grains, legumes, whole fruits, and non-starchy vegetables. Intake of low-quality carbohydrate was determined by adding together the intake of refined grains, fruit juices, starchy vegetables, and added sugars.

The researchers then assessed sleep behaviours by asking about sleep duration, snoring and daytime sleepiness to give a sleep score of 0-3. Individuals with a sleep score of 0–1 were classified as having healthy sleep patterns, while those with a sleep score ranging from 2 to 3 were classified as having poor sleep patterns.

To assess the relationship between carbohydrate intake and sleep, they adjusted for multiple variables that might also affect sleep quality, including age, sex, race/ethnicity, body mass index (BMI), education level, marital status, family income, smoking habits, alcohol consumption status, physical activity, disease and other dietary factors (including total energy intake, total and saturated fat intake and dietary fibre).

The researchers found that higher consumption of high-quality carbohydrates was associated with a lower risk of poor sleep, whereas higher consumption of low-quality and total carbohydrates was linked to poorer sleep. They also found that individuals who had higher intakes of high-quality carbohydrates and lower intakes of low-quality carbohydrates were less likely to experience poor sleep patterns.

They estimated that those following dietary pattern 4 (a high intake of high-quality carbs and low intake of low-quality carbs) had a 24% reduced risk of experiencing abnormal sleep duration, a 14% reduced risk of snoring, and a 31% reduced risk of daytime sleepiness, compared to those following pattern 1 (a low intake of high-quality carbs and high intake of low-quality carbs).

When they looked at specific foods or nutrients, eating more added sugars was linked to an increased likelihood of developing poor sleep patterns. On the other hand, eating more wholegrains, fruit or non-starchy vegetables was associated with a reduced likelihood of having poor sleep patterns.

As this was an observational study, it can only show an association between sleep and carbohydrate intake and can’t prove that carbohydrate quality directly affects sleep quality. Dietary intake and sleep data was also self-reported and the researchers note that they didn’t look at the relationship between timing of carbohydrate and sleep, which may be important. Further studies, including clinical trials, are needed to confirm these findings.

In the meantime, there are many health benefits to eating more high quality and less low-quality carbs, so it’s a bonus if this dietary pattern also improves your sleep!