No doubt about it, sleep is good food. Did you know that poor sleep could be associated with an increased risk of, at minimum, two chronic illnesses? According to new research, you’d better get those ZZZs.

Using the Whitehall II Cohort study, a study published in PLOS Medicine evaluated the effects of sleep duration on health in over 7,000 women and men aged 50, 60, and 70.

The connection between the time that each subject slept and mortality (as well as whether they’d been diagnosed with two or more chronic illnesses such as cancer, diabetes, or heart disease) was examined over the course of 25 years. 

Individuals that reported five or fewer hours of sleep at the age of 50 were 20% more likely to have been diagnosed with a chronic illness and 40% more likely to be diagnosed with two or more chronic illnesses in 25 years compared to individuals who got up to seven hours of sleep.

In addition, in those who slept five or fewer hours when aged 50, 60, or 70, a 30 to 40% increased risk of multi-morbidity was observed compared to those who got up to seven hours of sleep per night. 

A sleep duration of five hours or less at age 50 was linked with a 25% higher risk of mortality over the 25 years of follow-up. It appears that a short sleep duration raises the risk of chronic illness(es), which in turn results in an increased risk of death. 

Dr. Severine Sabia, the study's lead author,* said: "Multimorbidity is on the rise in high-income countries, and more than half of older adults now have at least two chronic diseases. This is a major challenge for public health, as multimorbidity is associated with high healthcare service use, hospitalizations, and disability.” He further noted, “As people age, their sleep habits and structure change. However, it is recommended to sleep for 7 to 8 hours a night -- as sleep durations above or below this have previously been associated with individual chronic diseases.”

His research indicates that short sleep duration is linked with multimorbidity. The team emphasizes the importance of good sleep hygiene, including a quiet, dark bedroom and a comfortable temperature for sleep. They also suggest avoiding big meals before bed and getting rid of electronic devices in the bedroom. Regular physical activity and light exposure during the day also support good sleep. 

The researchers further evaluated whether sleeping for a long duration (9 hours or more) affected health outcomes. Clear links between long sleep at age 50 and health outcomes were not observed in healthy people. If a subject had been previously diagnosed with a chronic illness, then long sleep duration was connected with roughly a 35% higher risk of developing another disease. That may be due to underlying health conditions affecting sleep, at least according to the researchers. The Whitehall II study only included members of the civil service, who were all employees when recruited to the study and were probably healthier than the general population.**

Jo Whitmore, the senior cardiac nurse at the British Heart Foundation, asserts, "Getting enough sleep allows your body to rest. There are a host of other ways that poor sleep could increase the risk of heart disease or stroke, including by increasing inflammation and increasing blood pressure. This research adds to a growing body of research highlighting the importance of getting a good night's sleep."

How can you encourage better sleep in your clients?

• Encourage a bedtime routine. Encourage them to go to bed at roughly the same time each night and wake up at the same time in the morning.

• Discontinue all screen use and social media at least 2 hours before bedtime.

• Stop eating at least 3 hours before bedtime.

• Avoid caffeine after 2 PM to prevent insomnia.

• Exercise regularly to decrease stress and improve sleep.

• Get outside daily for adequate sun exposure.

• Turn off hall lights, nightlights, and other lights that could impact sleep.

• Use a fan or white noise machine if needed at night.

By Lisa Andrews, MEd, RD, LD

Reference:

Séverine Sabia, Aline Dugravot, Damien Léger, Céline Ben Hassen, Mika Kivimaki, Archana Singh-Manoux. Association of sleep duration at age 50, 60, and 70 years with risk of multimorbidity in the UK: 25-year follow-up of the Whitehall II cohort study. PLOS Medicine, 2022; 19 (10): e1004109 DOI: 10.1371/journal.pmed.1004109

*UCL Institute of Epidemiology & Health, and Inserm, Université Paris Cité

**Limitations of the study include self-reported sleep data, which can be subject to reporting bias. However, data used on 4,000 subjects whose sleep was tracked with an electronic device confirmed their results. Information on sleep quality was only attainable in individuals aged 60 and 70.