Not getting enough sleep may raise your risk of developing type 2 diabetes, a new study suggests.
Researchers found that people who slept fewer than six hours increased their chances of developing the disease. Notably, having what the researchers considered a healthy diet didn’t negate that risk.
The study, published in JAMA Network Open, adds to a growing body of evidence suggesting that adequate sleep is important in preventing type 2 diabetes.
Type 2 diabetes is a chronic condition that develops when your body either doesn’t make enough of the hormone insulin or doesn’t use it properly. Insulin helps blood sugar move into the body’s cells for energy. Deficiencies in insulin can cause blood sugar to rise, over time leading to type 2 diabetes.
“Previous research, encompassing both cohort studies like ours and experimental studies, has demonstrated that repeated short sleep duration is associated with an increased risk of developing type 2 diabetes,” study author Diana Aline Nôga, PhD, a neuroscientist at Uppsala University in Sweden, told Health.
What her study makes clear, she added, is that the link between sleep deprivation and type 2 diabetes persists even among people who eat healthily.
The importance of sleep hasn’t always received attention, but that’s changing as a result of research like this new study, said Jing Wang, MD, clinical director of the Mount Sinai Integrative Sleep Center and associate professor of medicine specializing in pulmonary, critical care, and sleep medicine at the Icahn School of Medicine at Mount Sinai.
“I think it’s something that, in recent years, has really risen to greater public and scientific awareness,” she told Health.
The authors pulled data on 247,000 people collected between 2006 and 2010 for the UK Biobank, an extensive biomedical database.
The team divided the participants into groups based on whether they slept seven to eight, six, five, or three to four hours daily.
Researchers also analyzed participants’ dietary habits and ranked them on a scale from zero (unhealthiest) to five (healthiest). The ranking took into consideration whether participants regularly ate red or processed meats, fruits, vegetables, and fish.
The researchers tracked the participants for a median of 12.5 years to study the relationship between poor sleep, diet, and the development of type 2 diabetes.
“This analysis controlled for potential confounders such as age, sex, socioeconomic status, [and] frequency of insomnia symptoms, among others,” Nôga said.
The team found no association between eating a healthy diet and a reduced risk of type 2 diabetes in participants who slept less than six hours daily.
Experts said the study shows that there’s more to staying healthy than simply diet and exercise.
“Sleep, diet, and exercise together are foundational to health and wellness,” Nancy Foldvary-Schaefer, DO, MS, director of the Sleep Disorders Center and professor of neurology at Cleveland Clinic, told Health. “Diet and exercise cannot achieve optimal results with inadequate sleep quality or quantity.”
Though multiple studies have also linked insufficient sleep to type 2 diabetes, Nôga said there’s still not enough evidence to say that sleep deprivation causes the condition. “Making such a direct claim is challenging,” she said, given the research we have right now.
Researchers noted several limitations of the study, including that it only had white participants and that it didn’t examine how specific eating plans, such as time-restricted eating or the Mediterranean diet, influence type 2 diabetes risk in people with varying sleep routines.
Conditions aside from type 2 diabetes have also been linked to poor sleep.
“Poor sleep leads to impaired daytime functioning, [which can cause] academic underachievement, workplace conflicts and errors, mental health difficulties, and motor vehicle accidents,” Foldvary-Schaefer said. “Many forms of cardiovascular disease, diabetes, obesity, and central nervous system disorders are now associated with poor sleep.”
While many people think they can function at their best when sleep deprived, “only 1 to 2% of the population is genetically predetermined to require less sleep,” she said.
Despite sleep’s connection to negative health consequences, she noted, as many as one in three adults in the U.S. don’t get sufficient sleep.
The typical adult should aim for seven to nine hairs daily, she said, though that could change depending on a person’s unique circumstances.
If you think you’re getting enough sleep but still don’t feel well-rested, Wang recommends speaking to a healthcare provider about what may be causing your symptoms. “If you sleep nine hours, but you have really bad obstructive sleep apnea, you may still feel tired,” Wang said. “There are several nuances.”
Given sleep’s importance in overall health, she suggests immediately establishing a healthy sleep routine if you don’t currently have one.
“Sleep serves key functions in restoring our bodies and brains from a day of wakefulness and work,” added Foldvary-Schaefer. “It effectively resets every cell in every organ of our bodies and brains.”