Head of explosions at Wats.on consultancy, mum of two and spreader of science love...

What do humans and bananas have in common?

I don’t know about you but last time I checked I didn’t look anything like a banana, yet 50 per cent of our DNA is identical. So if your DNA is the recipe and your genes the ingredients for you, then how is this possible? Is there more to it?

I found myself thinking about these questions after reading a news story on research showing that diet during pregnancy can be linked to obesity and disease not only in your children but also in your grandchildren.

I was particularly interested because I was a complete vomiting mess with both my pregnancies and managed to survive only on ice cubes, peanut butter and bananas for pretty much the entire nine months.

Here was a whole new level of motherly guilt opening up before me…I couldn’t handle adding “responsible for health of grandkids” to my list, so I started to investigate.

It turns out that there is an extra level to inheritance that we are only just starting to understand, and it is one of the most exciting areas of research around. It is called Epigenetics.

Epigenetics controls how DNA works and how your genes are read. Reading a gene is tricky business, not only because it is a code, but also because it is incredibly precious. It must be done carefully to avoid damage and error. There are on and off switches that control when and which genes are read.

These switches can get damaged by things we do, such as the food we eat, the chemicals we are exposed to and our environment. A damaged switch, for example one that gets stuck in the “on” position attached to a gene for obesity, will mean that you are more likely to be obese. T

he really interesting bit is how the grandkids come into it. Changes to our epigenetic make up will be passed on to our children along with our DNA. But all is not lost. There is a clever reboot stage early in pregnancy where a lot of the DNA is essentially wiped clean.

So your child may not inherit the damaged epigenetic tags from you or your partner. But the egg or sperm in your baby, that will one day become your grandchild, is protected from the reboot, leaving your grandchild more likely to get that damaged tag. The good news is that as we understand more about how epigenetic changes affect our genes we can start to fight back.

It opens up new treatment possibilities for cancer, diabetes and heart disease as well as problems we normally associate with lifestyle such as obesity.

It also means we don’t have to leave it all up to the scientist, although we can’t change our inner banana, we can do things everyday to keep our DNA in good shape.