Get involved! Readers’ questions answered by Science Museum experts

“Is eating fish really good for your brain?”


Yes, especially really oily fish which are rich in omega-3 fatty acids called Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). Omega-3 is vital for brain growth/development, functioning and production of neurotransmitter – the chemicals which relay signals between the brain cells. The human body cannot easily synthesise these fatty acids and so a constant supply is very important. Just like a healthy machine your brain needs oil, and this comes in the form of omega-3.

Rik Sargent

Why is radiation so dangerous?

There are many different types of radiation, for example visible light is a form of radiation. Some are more harmful than others. For example, there are on average 15,000 radioactive particles travelling through your body every second!

With all this radiation exposure, why aren’t we all dying of cancer? Well, it is not the amount of radiation which you come into contact with, as every single one of these particles has the potential to cause cancer, it’s just the probability of that occurring is about one in 30 quadrillion! Only approximately one per cent of fatal human cancer is caused by these 30 trillion radioactive particles which pass through our bodies in a typical lifetime.

Ionising radiation has the energy to detach electrons from their associated atoms, therefore causing the atom to become positively charged. These charged particles are referred to as radicals and are highly reactive due to their unstable nature. Radicals are very important for certain processes in the body such as the killing of bacteria. However, many unwanted effects such as mutation of cells can be a problem. Scientists have found lots of evidence to suggest that these radicals cause mutations in cells which can give rise to cancer.

Rik Sargent
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