Neurologist warns common habit before bed could risk brain health

A neurologist has shared something he “never” does before going to bed, to protect his brain. He warned that this habit could expose the organ to potentially dangerous particles.

In a video uploaded to social media platform TikTok, Doctor Baibing Cheng explained to his more than 160,000 followers why you should avoid scented candles. More specifically, he advised against leaving them burning when you go to sleep.

Not only is this an obvious fire risk, but it can cause lasting damage to the brain. Dr Cheng, who is better known as Dr Bing, said: “I'll never leave candles burning when I go to sleep.

“This is more than just a fire risk because scented candles can release fine particles and VOCs [volatile organic compounds] that can affect your brain health over time, especially with poor ventilation.”

VOCs are chemicals that easily evaporate at room temperature and can contribute to air pollution and health problems. One study, published in Nature Communications in 2024, stated that VOCs can have “significant adverse effects” on human health.

Researchers also noted that they could not only cause respiratory issues, but could increase the risk of cancer. A separatestudy, published earlier this year, found that pollution from candles could lead to cognitive decline.

The study highlighted significant cognitive impairment in subjects following exposure to candle smoke. The findings, published in Nature Communications, detailed that even temporary contact with particulate matter (PM) pollution could hinder a person’s ability to process emotions or concentrate on tasks.

Commenting on the research, Dr Thomas Faherty from the University of Birmingham, said: "Our study provides compelling evidence that even short-term exposure to particulate matter can have immediate negative effects on brain functions essential for daily activities, such as doing the weekly supermarket shop."

On top of the warning about candles, Dr Bing shared two other habits he avoids for his brain health. He continued: “I don't take scalding hot showers.

“I know there are people out there who like to turn that handle all the way to the end and standing scalding hot shower for 20 to 30 minutes, which might not be great for you. This is because exposure to really hot water can cause your blood vessels to dilate and on top of that you're standing upright in a closed humid space which can cause blood to pool in your legs.

“All of this means that there's less blood going to your head and when you don't get enough blood going to your brain that's when you can faint. As a neurologist I see this relatively commonly, mostly in older individuals but sometimes in younger people too and people will come in with brain injuries, neck injuries and even brain bleeds.

“So if you do this at least make sure you drink enough water everyday. Try not to stay in the shower for too long.”

Dr Bing also warned he never mixes caffeine and alcohol. He added: “I never mix coffee or energy drink with alcohol.

“This is because caffeine makes you feel alert but alcohol is still slowing your reaction time and judgement and this is a dangerous mismatch that can lead to accidents. And I've seen neurological emergencies result from this, so if you drink alcohol try to pair it with water and keep it simple.”