HQ Team
May 5, 2023: People who talk on their cellphones for more than 30 minutes a week risk a 12% increase in their blood pressure because of radio frequency energy, a study by Southern Medical University, Guangzhou, China, found.
“It’s the number of minutes people spend talking on a mobile that matters for heart health, with more minutes meaning greater risk,” said study author Prof Xianhui Qin of the university.
Mobile phones emit low levels of radio frequency energy, which has been linked to rises in blood pressure after short-term exposure.
Results of previous studies on mobile phone use and blood pressure were inconsistent because they included calls, texts, and gaming.
Almost three-quarters of the global population aged 10 and over own a mobile phone. Nearly 1.3 billion adults aged 30 to 79 worldwide have high blood pressure (hypertension). Hypertension is a major risk factor for heart attack and stroke and a leading cause of premature death globally.
New-onset hypertension
The researchers analyzed the relationship between mobile phone usage and new-onset hypertension after adjusting for age, sex, body mass index, race, deprivation, and family history of hypertension, among other factors.
The study used data from the UK Biobank. 212,046 adults aged 37 to 73 years without hypertension were included. Participants who used a mobile phone at least once a week to make or receive calls were defined as mobile phone users.
Information on using a mobile phone to make and receive calls was collected through a self-reported touchscreen questionnaire at baseline, including years of use, hours per week, and using a hands-free device or speakerphone.
The average age of participants was 54 years, 62% were women, and 88% were mobile phone users. During a median follow-up of 12 years, 13,984 (7%) participants developed hypertension.
Mobile phone users had a seven percent higher risk of hypertension than non-users. Those who talked on their mobile for 30 minutes or more per week had a 12% greater likelihood of new-onset high blood pressure than participants who spent less than 30 minutes on phone calls.
The results were similar for women and men.
Five minutes to six hours
The researchers compared participants who spent less than five minutes per week making or receiving mobile phone calls, weekly usage time of 30-59 minutes, 1-3 hours, 4-6 hours, and more than 6 hours was associated with an 8%, 13%, 16% and 25% raised risk of high blood pressure.
Among mobile phone users, years of use and employing a hands-free device/speakerphone were not significantly related to the development of hypertension.
“Years of use or employing a hands-free set-up had no influence on the likelihood of developing high blood pressure. More studies are needed to confirm the findings,” Mr Qin said.
Genetic risk was determined using data from the UK Biobank.
The analysis showed that the likelihood of developing high blood pressure was greatest in those with high genetic risk who spent at least 30 minutes a week talking on mobile – they had a 33% higher likelihood of hypertension than those with low genetic risk.
“Our findings suggest that talking on a mobile may not affect the risk of developing high blood pressure as long as weekly call time is kept below half an hour,” Prof Qin said. “More research is required to replicate the results, but until then it seems prudent to keep mobile phone calls to a minimum to preserve heart health.”
The study was published in the European Heart Journal —Digital Health of the European Society of Cardiology, which brings together healthcare professionals from more than 150 countries working to advance cardiovascular medicine.
