Health

March 9, 2024

Experts say less than 6 hours sleep daily raises type 2 diabetes risk

A group of experts found those who slept between 3 to 4 hours had a 41 per cent higher risk

Not getting enough sleep may lead to type 2 diabetes, a study has suggested. Managing less than six hours each night was linked to a 16 per cent higher risk of developing the condition.

And the odds remained elevated even when people ate healthily, suggesting that eating well cannot compensate for sleep deprivation.

Swedish researchers, who tracked nearly 250,000 Brits, said their findings ‘should not cause concern’. Instead, they should act as a ‘reminder that sleep plays an important role in health’.

Study author Dr Christian Benedict, sleep researcher at Uppsala University, said: “I generally recommend prioritising sleep. Although I understand that it is not always possible, especially as a parent of four teenagers.”

Although they found a healthy diet couldn’t counteract the risks of a lack of sleep, experts acknowledged that people who get the recommended seven to nine hours ‘tend to consume less sugar and fewer calories”. Benedict said this “likely contributes to better long-term metabolic health.”

Other factors that might raise the risk of type 2 diabetes in poor sleepers include leading a sedentary lifestyle, he added.

Type 2 diabetes is a condition which causes a person’s blood sugar to get too high. Type 2 diabetes is associated with being overweight and you may be more likely to get it if it’s in the family.

The condition means the body does not react properly to insulin – the hormone which controls absorption of sugar into the blood – and cannot properly regulate sugar glucose levels in the blood.

Excess fat in the liver increases the risk of developing type 2 diabetes as the buildup makes it harder to control glucose levels, and also makes the body more resistant to insulin. Weight loss is the key to reducing liver fat and getting symptoms under control.

Symptoms include tiredness, feeling thirsty, and frequent urination. It can lead to more serious problems with nerves, vision and the heart. Treatment usually involves changing your diet and lifestyle, but more serious cases may require medication.

Dr Lucy Chambers, head of research communications at Diabetes UK, said: “No one thing causes type 2 diabetes. Genetics, age, and body weight are well-known contributors, but inadequate sleep is often an under-recognised factor.

“This research suggests that a healthy diet alone won’t counteract the heightened risk of type 2 diabetes from too little sleep, and is a reminder that nutrition, exercise and sleep are all essential components of good health.”

Other studies have linked a lack of sleep to a higher risk of high blood pressure, heart disease and even strokes. Brits involved in the study were quizzed on their sleeping patterns and dietary habits including their consumption of processed meat, fish and vegetables. 

Healthy eating was defined as consuming less than two servings of unprocessed red meat per week, or fewer than two of processed meat.

It also involved eating four or more tablespoons of vegetables per day, two or more pieces of fruit per day, and two or more servings of fish products per week.

But writing in the journal JAMA Network,  Benedict and colleagues claimed the link between a lack of sleep and type 2 diabetes ‘persisted even for individuals following a healthy diet’.

Those who three to four hours each night were 41 per cent more likely to get the condition, compared to those who got a ‘normal’ amount (defined as seven or eight hours). Meanwhile, those who got five hours of shut-eye each night had a 16 per cent higher risk of developing the condition.

There was no ‘statistically significant difference’ between participants who reported normal sleep duration and those who reported six hours. Researchers adjusted for factors which could have skewed their findings, including weight, smoking status, antidepressant use and activity levels. 

They said that further research was needed to understand why a lack of sleep was associated with increased diabetes risk. 

“The high prevalence of individuals with short sleep duration may contribute to the projected global escalation of type 2 diabetes prevalence.”

Type 2 diabetes occurs when the body doesn’t make enough insulin or the insulin it makes doesn’t work properly. This hormone is needed to bring down blood sugar levels.

Having high blood sugar levels over time can cause heart attacks and strokes, as well as problems with the eyes, kidneys and feet. Sufferers may need to overhaul their diet, take daily medication and have regular check-ups.

Symptoms of the condition, which is diagnosed with a blood test, include excessive thirst, tiredness and needing to urinate more often. But many people have no signs.

Approximately 90 per cent of diabetes cases are type 2 diabetes, which is linked with obesity and is typically diagnosed in middle age, rather than type 1 diabetes, a genetic condition usually identified early in life.

How much sleep you should get daily (averagely)

– Preschool (3-5 years): 10-13 hours

– School-age (6-13 years): 9-11 hours

– Teen (14-17 years): 8-10 hours

– Young adult (18-25) 7-9 hours

– Adult (26-64): 7-9 hours

– Older adult (65 or more) 7-8 hours

What you should do to get more sleep

1) Limit screen time an hour before bed: Our bodies have an internal ‘clock’ in the brain, which regulates our circadian rhythm. Mobiles, laptops and TVs emit blue light, which sends signals to our brain to keep us awake.

2) Address your ‘racing mind’: Take 5-10 minutes before you go to sleep to sit with a notebook and write down a list of anything that you need to do the following day.

3) Avoid caffeine after 12pm: If you want a hot drink in the afternoon or evening, go for a decaffeinated tea or coffee.

4) Keep a cool bedroom temperature: Try sleeping with your bedroom window open to reduce the temperature and increase ventilation.

5) Limit alcohol in the evenings: While you might initially fall into deep sleep more easily, you then wake up frequently during the night and have poorer deep sleep overall.

6) Supplement vitamin D: Vitamin D plays a role in sleep. It is widely available online and from most pharmacies. If you are unsure if this is appropriate or how much you need, seek advice from your doctor.

7) Ensure sufficient intake of magnesium and zinc: Foods high in magnesium include spinach, kale, avocado, bananas, cashews, and seeds. Foods high in zinc include meat, oysters, crab, cheese, cooked lentils, and dark chocolate.