Dr's Casebook: What DNA science can tell us

An international study looked at the DNA content of Loch Ness, but found no evidence of ‘monster DNA’ in the water. Photo: StockAdobe

Did you hear about the recent discovery of 166 million year old dinosaur tracks in an Oxfordshire quarry? There were some artist impressions of what they looked like. It is quite mind-boggling to think of such a time period and what it would be like to actually see a dinosaur. I mention this because I was up in Scotland not long ago and visited Loch Ness, the fabled home of ‘Nessie.’

Dr Keith Souter writes: One of the fondly held theories about the elusive Loch Ness Monster is that it could be an aquatic survivor of the dinosaur age. There have been countless searches of the loch for any sign of a creature ever since the famous surgeon’s photograph from the 1930s. Sadly an international study looked at the DNA content of the loch, but found no evidence of ‘monster DNA’ in the water.

DNA science is fascinating and there is a huge amount of research going on into DNA and longevity. A crucial enzyme involved in this is called telomerase. This enzyme fixes and lengthens parts of chromosomes known as telomeres. Shortening of telomeres is recognised as an indicator of disease risk and premature death in some types of cancer. So far, no drug has been shown to affect levels of this enzyme, whereas lifestyle change has.

One study looked at 30 men who were at low risk for the development of cancer of the prostate. They all had their blood levels of the enzyme telomerase measured. They then made lifestyle changes for three months and had their telomerase levels measured again. The lifestyle changes included a diet rich in fruits, vegetables, whole grains, legumes and soy products, moderate exercise such as walking for half an hour a day, and an hour of daily stress management methods such as meditation. At the end of three months they all had increased levels of telomerase of 30 per cent.

In addition to the telomerase levels, the men all lost weight, lowered their blood pressure and generally felt fitter and better. They also had changes in activity in about 500 genes. The activity of disease-preventing genes increasing while some disease-promoting genes, including those involved in prostate cancer and breast cancer was reduced.

If Nessie exists and is an aged survivor of the dinosaur age, then it is lifestyle that has kept it alive, and managed to conceal her DNA.