Too much light at night may affect heart; avoid bright screens before bed

MUMBAI: New study links excessive nighttime light exposure to changes in heart structure and function; experts advise keeping bedrooms dark and limiting screen exposure before bedtime

Too much exposure to light at night could have implications for heart health, with a new study finding changes in the structure and function of the heart among people exposed to higher levels of nighttime light.

The findings assume significance in India, where cardiovascular diseases account for around

30 lakh deaths annually, or 28% of all deaths, making them the leading cause of mortality in the country.

Night light linked to heart changes

A study published in the

European Heart Journal examined data from around

11,000 participants in the UK Biobank. Participants wore light sensors for seven days and underwent cardiac MRI about three years later.

Compared with people exposed to almost no nighttime light, those exposed to higher levels of nighttime light showed:

- Thicker walls of the heart's left ventricle

- Reduced flexibility of the heart muscle

Researchers, however, stressed that the study was

observational and does not establish that nighttime light directly causes heart disease.

Simple steps to reduce exposure

Health advice highlighted in the report includes:

- Keep the bedroom dark

- Switch off unnecessary lights

- Reduce exposure to bright screens before bedtime

Indians suffer heart attacks roughly a decade earlier than Caucasians, with factors ranging from genetics and lifestyle to inadequate sleep and air pollution. Light pollution is emerging as another area of scientific interest.

Cardiac emergency readiness remains a concern

A survey of

1,500 Mumbaikars conducted by Fortis Hospital, Mulund, also found widespread misconceptions about cardiopulmonary resuscitation (CPR) and automated external defibrillators (AEDs).

The survey found:

- 75% believed an AED can be used only by doctors

- 46% lacked confidence in using an AED

- 68% did not know where the nearest public AED was

- 36% of people trained in CPR said they could not perform it correctly without help

- 32% believed a medical licence was required to attempt CPR

- 32% were unaware of legal protections available to Good Samaritans

Laws and provisions protecting Good Samaritans are intended to shield bystanders who provide help during medical emergencies from certain legal consequences, provided they act in good faith.