June 25, 2019
Figure 1: The Effect of the Mediterranean Diet on Sleep. Individuals who adhered to a Mediterranean Diet were much more likely to have good sleep quality. 72% of individuals in the top 25% of adherence to a Mediterranean Diet had good sleep while only 28% had poor sleep. In the bottom 25%, 59% had good sleep and 41% had poor sleep. This relationship was found to be highly significant (p<0.001).
A study on 1,936 Italian adults found that those who ate better were much more likely to sleep well compared to those who did not.
Researchers evaluated diets by calculating how well people stuck to a Mediterranean Diet. This diet, which includes lots of vegetables, fruits, whole grains, and fish, is known to be healthy for the heart. While the Mediterranean Diet is by no means the only good diet, it is a useful proxy for quantifying diet quality.
Among Italians who closely adhered to the diet (75-100th percentiles), 72% had overall good sleep quality with only 28% reporting poor sleep quality.
Among those who did not adhere closely to the diet, only 59% had good sleep and 41% had poor sleep. This relationship was found to be highly statistically significant.
Adherence to the Mediterranean Diet is Associated with Better Sleep Quality in Italian Adults
Figure 2: How Does the Mediterranean Diet Improve Sleep? The increase in sleep quality among individuals who adhered to a Mediterranean diet was driven by the following factors: They were more likely to sleep at least 7 hours, they were far more likely to fall asleep faster, and they were more likely to have few to no sleepy days.
While we do not know the exact mechanisms behind this result, further analysis showed that this effect was driven by improvements in all aspects of sleep.
Those who ate better slept longer, took less time to fall asleep and were less sleepy during the day.
Adherence to the Mediterranean Diet is Associated with Better Sleep Quality in Italian Adults
Figure 3: Effect of BMI on Diet and Sleep. Normal weight individuals were much more likely to benefit from the Mediterranean Diet in terms of sleep. When stratified by BMI, normal weight individuals were 2.3x more likely to have good sleep compared to individuals who ate poorly. Meanwhile, obese individuals were only 1.1x more likely, which was statistically insignificant.
This effect only worked for normal weight and overweight individuals. Researchers are not exactly sure why this is the case.
Those who were normal weight had over twice the odds of getting sleep when they adhered to a Mediterranean Diet, compared to those who did not.
However, obese participants did not show any significant differences based on their diets.
Adherence to the Mediterranean Diet is Associated with Better Sleep Quality in Italian Adults
This adds to the growing amount of evidence showing that diet matters for more than just weight loss. It influences how we sleep and how we age as well.
While the Mediterranean Diet is not the only good diet available, it is a good place to start as it has been well validated by scientific research and includes some delicious recipes from around Italy and Greece.
Endpoints - Researchers used appropriate endpoints to measure sleep quality.
Study Size - The study size was large enough to find significant effects and differences between groups.
Study Type - Researchers used a survey to correlate two variables. While the survey was extensive and the measurements were standardized, this study method still suffers from a significant risk of bias.
The Mediterranean diet is one of the healthy eating plans recommended by the Dietary Guidelines for Americans to promote health and prevent chronic disease. It is also recognized by the World Health Organization as a healthy and sustainable dietary pattern and as an intangible cultural asset by the United National Educational, Scientific and Cultural Organization.
People who sleep only four hours a night are more likely to choose high-carb, sugary, and starchy foods over healthier picks, a recent University of Chicago study found.
The Mediterranean diet varies by country and region, so it has a range of definitions. But in general, it's high in vegetables, fruits, legumes, nuts, beans, cereals, grains, fish, and unsaturated fats such as olive oil. It usually includes a low intake of meat and dairy foods. The Mediterranean diet has been linked with good health, including a healthier heart.
Clearvue Health is not affiliated with above organizations. The information above is provided to highlight and link to useful further reading.
Did you know that the Mediterranean diet has been shown to potentially help your age well?
In a study of 2,258 New Yorkers, researchers found that individuals who strongly adhered to a Mediterranean Diet had a significantly lower risk of Alzheimer's Disease.