Are identical twins really identical?

February 29 2016

They share the same genes and are the same age in years (give or take a few minutes), so how can a set of identical twins have a different biological age? It’s all down to lifestyle choices…

Ever wondered whether all that hard work in the gym pays off? Or whether those occasional takeaways, trips to the pub and sneaky cigarettes actually affect your health? To prove that lots of exercise and healthy eating really does make a difference, we asked five sets of identical twins to take part in a BioScore assessment.

BioScore assessment is a simple health and fitness assessment that calculates the age that your body actually is in comparison to your age in years. For example, you may be 29 years old, but because of certain lifestyle choices, your body may be 32 years old biologically.

Every BioScore assessment includes an evaluation on general health, lifestyle (which includes nutrition, stress levels and sleep habits) and physical fitness, all of which are given an individual age score. Looking at those individual outcomes allows you to see the areas in which there needs improvement, whether it's getting more sleep at night, eating less sugar or doing more heart rate-increasing activity. All of the individual scores are then combined to give an overall BioScore age.


Meet identical twins Ruth and Cat Edmondson, 29; Zoe and Gail Spink, 63; Neshah and Nyah Hines, 25; Jonathan and Edward Saxby, 35; and Brett and Scott Staniland, 22, in the above video who all limbered up for a BioScore assessment. Beforehand, nearly all sets of twins, what with their identical genetics and identical age in years, assumed their biological age would also be near identical too, but the results, however, proved otherwise.

Participants Brett and Scott, 22, who are both teetotal, non-smokers and very active, both said they expected their bodies to be "quite young." After their BioScore assessment, the twins were proved right with Scott's biological age coming in at just 17.5 years old and Brett's at a very young 16 years old.

Ruth and Cat, 29, suspected their biological age would be older than their 29 years due to their hectic lifestyle playing in their band. Ruth anticipated that her real body age would actually be older than twin Cat’s due to her smoking habit. When the BioScore results came in, Ruth wasn’t wrong. Her biological age was determined as 32 years old, while Cat’s was 31 years old.

The twins that demonstrated the biggest difference in biological age were Nyah and Neshah, 25. While Neshah admitted to mild sleep problems and a naughty biscuit habit, Nyah confessed to a lack of exercise ("I would like to go to the gym – I do have a membership!", says Nyah). Their final BioScores fared very differently, with Neshah's coming out at 24.5 years and Nyah's being 27.5 years. Clearly the difference in their daily routines has had an impact on their body’s health.

See the full results of the twins who took part in our BioScore assessment in our video below. Talk about sibling rivalry...

UPDATE: As of May 2017, Bio Score testing is no longer available at Fitness First.

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