To Japan where DNA testing to pre-screen for disease is growing in popularity. In one of the fastest aging societies in the world, people are taking matters into their own hands in search of a long and healthy life. Our correspondent Mayu Yoshida has more on the trend.  

Yusuke Kawase is eating more vegetables and less fatty foods these days. He has changed his eating habits after a DNA test recently revealed he's at risk of contracting esophageal cancer. Both of his grandparents also suffered from the disease.

YUSUKE KAWASE DNA TEST TAKER "Before I got my DNA tested, I would just eat meat or rice. But after I got the results, I started to exercise more and eat more vegetables because I want to stay fit and watch my daughter grow old. My wish is to walk on my own feet until the day before I die."

Like many Japanese, Kawase believes in 'pin pin korori' - which means to stay healthy until you drop dead. That’s why in this health-conscious, aging society, there's growing demand for home DNA testing kits. Testing firms, like Genesis, are benefitting from the trend. The company has screened DNA samples from more than 600,000 users since 2004.

YUSUKE NAKANISHI, COO GENESIS HEALTH CARE "In Japan, people are very focused on 'health life expectancy'. It's not about living a long life, but about how long you can stay fit and be active. Japanese users are using DNA kits to prevent cancer risks or delay diseases so they can boost health expectancy."

MAYU YOSHIDA TOKYO "In exchange for a saliva sample, this DNA kit will reveal clues to more than 300 types of diseases, illnesses, and allergies, including over 30 types of cancer. It will also give you dieting and beauty care tips based on your DNA. All I need to do is mail in my DNA sample in this envelope and wait for the results in about a month."

The global direct-to-consumer genetic testing sector is expected to triple over the next five years to US$300 million. In Japan, recent data suggests the market will grow into a US$59 million market by 2022. Analysts say growth will depend on how effective DNA testing will be in solving Japan's demographic issues.

UMIYOSHI SAKAI, DIRECTOR EQUITY RESEARCH AT CREDIT SUISSE SECURITIES JAPAN "For now, home DNA test kits can only alert risks to individual users. But once we take these findings and cross-reference them into more systematical data, we can use these technologies to prevent diseases. This will help reduce social security spending because Japan's health insurance costs are ballooning as the population grow older."

At the moment, there are no legal restrictions on home genetic testing in Japan. But officials are raising concerns over the quality of some DNA testing kits. And skeptics say test results may screen for predisposed illnesses, but it's still up to the person to lead a healthy lifestyle. For some, though, it may be comforting to know than to not know what's in their genes.