A new study [1] published three days ago in the Canadian Journal of Cardiology followed 444,027 people from England, Wales and Scotland, ages 37 to 73 over a median time of 12.3 years and found that people using their mobile phone 6 hours a week or more had a higher risk of cardiovascular disease (CVD) than people using their mobile phone only one hour a week or less.
The authors found this association to be especially significant in smokers and in people with diabetes.
The authors note that the people who used their cell phone 6 hours per week or more tend to be people who don’t sleep well and who are more anxious and experience higher levels of psychological distress. The authors conclude that poor sleep, anxiety and neuroticism can explain the increased risk of cardiovascular disease in cell phone users.
The authors also note that it is the frequency of cellular use, not the total duration of the calls, that is associated with higher risk of cardiovascular disease.
This raises uncertainty about what the study’s results tell us. For example, the physiological link between cell phone use and heart disease is complicated because the radiated power from cell phones is highest when calls begin. Thus, several short phone calls may actually expose users to higher total doses of radiation than many fewer calls having longer total durations.
Moreover, other research shows that the transient peak power of very short exposures to microwave radiation that cell phones emit could be far more damaging to tissues than much longer exposures to low peak power cell phone emissions.[6]
There are other reasons the study’s results don’t mean that cell phone radiation, by itself, contributes to heart disease. Specifically, behavioral/emotional factors that correlate with frequent cell phone use, could play an important role.
For instance, people who are more anxious and have poor quality sleep, could be more sedentary, see friends face-to-face less often and prefer short, frequent, mobile phone interactions. And poor sleep and anxiety increase the risk of cardiovascular disease by themselves without any cell phone use [4][5].
Additionally, frequent cell usage could increase stress, which, in turn, promotes heart disease.[7],
The study also didn’t address cell phone usage for purposes other than voice communication, such as web surfing, social media, gaming, and texting. Thus, if cell phone radiation does influence heart disease, we can’t be certain what type of cell usage might be most associated with heart disease.
How can we explain this association? Can cell phones directly cause cardiovascular disease?
Decades of research have shown that cell phones emit radiofrequency electromagnetic fields that can affect biological tissue [2]. The mechanism of action may be via oxidative stress, inflammation or heating just like a microwave oven with electromagnetic fields getting exponentially stronger the closer the body is to the cell phone.
The same electromagnetic field can also stimulate nerve fibers [3] which are plentiful in the heart.
But the fact that cell phone use correlates with an increased risk of cardiovascular disease doesn’t mean that cell phone use directly causes heart disease. Correlation doesn’t mean causation.
So what’s the takeaway?
First, if you want to keep your heart healthy, it is recommended that you quit smoking, eat less sugar, do more physical activity, which will help you sleep better, find tools to be less anxious, and try to get together face to face with friends instead of spending time on your cell.
However, cell radiation has been shown to heat tissues of the body, directly stimulate nerves, alter proteins in neurons, and change ion flows across nerve cell membranes.[7]
Therefore, in case cell radiation could promote cardiovascular disease–through these effects or others– to be on the safe side, don’t put your phone close to your heart (or your brain), even when you’re not using the cell. The reason is that mobile devices constantly emit radiation to establish connections.
Also, consider using an earpiece or your speakerphone when you talk.
And don’t talk too long, given the general principle that, for optimum health, we need moderation in all things, including cell phone use.