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Millions of people around the world spit into vials in the hope of learning more about their genes. But they are not just looking for information about their origins.
People are increasingly interested in how their genes can influence their health, nutrition, fitness potential and risk of injury.
The global market for these direct-to-consumer genetic tests is expected to skyrocket in the coming years, from $1.9 billion in 2023 to $8.8 billion in 2030, according to a market analysis report from Grand View Research. North Americans lead the way, with 60.5% of the market share, although Europe is expected to become the fastest growing market over the next six years, the analysis shows.
In 2013, about 20 companies offered direct-to-consumer genetic tests focused on sports performance and injury risk — a number that had risen to about 70 in 2019, according to a study review. Additionally, a 2020 study published in the Indian Journal of Orthopedics, that Uzbekistan and China use genetic testing in their Olympic talent identification programs, while Australia’s National Rugby League players use DNA testing to tailor their training for sprinting or explosive power lifting.
Despite all this buzz, many researchers said there is too much hype and not enough solid science behind these tests. One of those skeptics is Dr. Timothy Caulfield, a professor at the law school and school of public health at the University of Alberta in Edmonton.
“I’ve been following this field since the late 1990s, and the progress hasn’t been substantial,” Caulfield said.
Excitement at first
There was a lot of excitement about genetic testing when scientists discovered the BRCA1 and BRCA2 genes in 1994 and 1995, respectively. Women with mutations in one of these genes were found to have a 60% to 80% lifetime risk of breast cancer. Furthermore, a mutation in BRCA1 carried a 40% to 50% lifetime risk of ovarian cancer, while a mutation in BRCA2 carried a 10% to 20% lifetime risk.
“There was hope that we would find a lot of genes like this that would be very predictive, and allow you to take steps to make a difference in your health,” Caulfield said. “But it really didn’t happen that way.”
Instead, he said, scientists have discovered how our genes work is a complex topic, especially when it comes to fitness and sports. For example, Caulfield took a genetic test, which showed that he was unlikely to excel at sprinting. Still, he was talented in sports and competed throughout his youth and in college.
“There’s no doubt that genes matter, but the question is how much?” said Caulfield. “Even if you look at Olympic-level long jumpers, who need very explosive movements, not all of them have the sprinting skills. If it really mattered, they should have it all.”
Scientists say there are so many additional factors when it comes to sporting talent and success, such as nutrition, sleep, training, motivation, socio-economic background and even experiences in the womb. Likewise, there are countless variables when it comes to the risk of injury.
Another concern among researchers is the scientific validity behind these tests. While the accuracy of the actual genetic tests is likely good, the science behind how the companies interpret the results can be problematic, says Dr. Dylan MacKay, an assistant professor of nutrition and chronic diseases at the University of Manitoba in Winnipeg, Canada. .
“Often these tests are based on associations, rather than randomized, controlled trials looking for a causal effect,” MacKay said. “For example, watermelon consumption has been linked to drowning – because more people swim in the same season as they eat watermelons. But that’s just an association.”
The advice that companies give based on your test results is also often vague or standard. Caulfield’s results indicated he was at risk for certain cardiovascular problems and cancer.
“What was my personal advice to stay healthy? Eat well, exercise regularly, don’t smoke and drink in moderation,” Caulfield said.
Still, some are intrigued
Despite these issues, many remain intrigued by DNA fitness testing. One of those people is Devin Maier, co-owner of Balance Gym in Washington, DC. Balance Gym recently teamed up with FitnessGenes, a British-based company that sells genetic tests, to help its customers get better results from their workouts.
While the tests don’t provide precise instructions on how to get fitter, Maier said he believes they can be useful. One of his clients was trying to build muscle by lifting heavier weights, but with fewer reps. His test results showed that his muscle type would do better with higher volume training, so Maier had him switch to lifting lighter weights with more reps. Within a month or two, the client saw the desired muscle growth.
These tests can also help you distinguish between your strengths and weaknesses, Maier said, so you can address them.
“You may not have the genes to be a good endurance athlete,” he said, “but if you want to run a marathon, we can help you train better so you can.”
Maier said he thinks there is a lot of potential in the field as well.
“Our DNA doesn’t change, but the science and information does, and it will continue to do so,” says Maier.
Time and further scientific advances may shed more light on whether DNA fitness testing is or could be useful. But MacKay remains doubtful.
“I have been in this field for a long time, and while genetic testing continues to improve, there are no new findings that are groundbreaking,” he said.
Caulfield said he hopes parents won’t use these tests to force their child into a specific sport or activity.
“Genes do not determine whether you like a sport or are good at it,” he said. “You should do what you love, and don’t let these genetic tests make it more complicated than it needs to be.”
Melanie Radzicki McManus is a freelance writer specializing in hiking, travel, and fitness.
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