Knowing that changing your habits could save your life does not mean you will do it, a study has revealed.
Mail-order DNA testing has fast become a booming business, with people sending off their saliva to find out what their body needs to be healthier and prevent disease.
However, when eighteen people – eight of which were in the US – were told exactly which diseases they were predisposed to, none of them significantly changed their lifestyles to become healthier.
Their habits involving diet, exercise, alcohol consumption, smoking, protecting their skin from the sun and getting disease screenings remained the same.
The evidence appeared to prove that direct-to-consumer DNA analysis that companies are now selling for up to $200 might not even be that effective in keeping people healthier longer.
There is evidence that expensive DNA testing is not beneficial because even if people do know which diseases they are predisposed to they probably will not change their lifestyle behaviors that will make them less likely to contract the diseases (file photo)
The market for DNA testing for disease risk has expanded recently but new evidence said the technology might not be beneficial to consumers who want to change their lifestyle.
23andMe was the first company who sold approved DNA testing kits, which told consumers their chances of developing diseases such as obesity, diabetes, heart disease or cancer.
The company only got approval to sell their kits in April after being warned not to sell them without regulators’ approval three years ago.
The hope for these kits – which are now also being sold by a company called Helix – is that their analysis can give people specific directions for how to lead a healthier life.
So, conceivably, they would tell people who are likely to become obese to exercise more and those who have a high chance of getting cancer to stop smoking.
These tests do not provide definite evidence that a person will or will not get a certain disease – it only predicts likeliness that it will happen.
Genetic risk is only part of a person’s overall risk, which includes influence from other things like a person’s lifestyle.
A company called Helix started providing similar services just last month.
Helix decodes a consumer’s DNA and passes the results along to another company for analysis.
A consumer’s request for the tests must be approved by a physician’s group that looks at their medical history.
A 23andMe test that includes ancestry information costs $199. Helix’s decoding test costs $80. Both companies use a saliva sample for the test.
The 18 people involved in the study got their analyses from medical clinics or other establishments.
CAN THIS TEST PREDICT WHETHER YOU WILL GET A DISEASE?
In short: no.
The genes analyzed by 23andMe are not enough to predict whether or not you will get a certain disease.
Rather, the test will be able to show if you have an increased risk.
For most people, the science will not be conclusive enough to generate a percentage risk factor.
Even for those that do have risky gene mutations, their risk will still be low.
The N370S variant in the GBA gene increases one’s risk of Parkinson’s three-fold.
However, the average risk factor is 0.3 percent.
That means the increased risk factor would still be less than 1 percent.
The study concluded that having access to analysis of your DNA ‘has little if any impact on changing routine or habitual behviors,’ said study author Theresa Marteau.
Co-founder of Helix Dr James Lu said that the evidence on whether people change their lifestyles in response to DNA information is mixed.
But he said it is more likely to happen if they get the right information, education and support.
‘We’re learning a lot as the field evolves,’ he said.
While most people will not change their behavior even if they know it will be beneficial for them, some people have and it has turned their lives around.
Dr Francis Collins, director of the US National Institutes of Health, found out through DNA testing he was predisposed to Type 2 diabetes – which is more likely to develop in someone overweight or obese.
He lost 35 pounds after finding out.
Dr Collins said: ‘It was a kick in the pants. It was an opportunity to wake up and say, “Maybe I’m not going to be immortal and maybe there are things I am doing to myself that aren’t healthy that I ought to change”.’
Experts disagree on whether or not the technology will be beneficial for most people.
Dr Robert C. Green thinks DNA test results can change a person’s behavior.
He said it is very hard to get people to improve health habits and – even when they do – it is hard for researchers to prove that DNA test results were responsible.
‘It doesn’t necessarily mean that it doesn’t help people,’ Dr Green said.
There is also evidence that simply going through the process of DNA testing may slightly improve diet and exercise habits, regardless of what the results reveal.
It is possible that the experience in itself motivates people to practice beneficial health behaviors.
Dr Green also said that people get the testing for a number of reasons, including simple curiosity, so the value of DNA testing should not be judged simply by whether it changes health behavior.