Coming to terms with your age is one thing, but what about your biological age? That’s how “old” your body really is, regardless of how many years ago you were born.

Researchers in China say they have found a way to detect biological aging through a simple urine test. The hope is the test can be used in preventative medicine to determine the risk of a person developing age-related diseases.

There are many theories behind what causes aging in the body.

One is that aging is brought on by oxidative damage to cells and tissues. It’s this biomarker that the researchers said they are able to measure.

“Oxygen by-products produced during normal metabolism can cause oxidative damage to biomolecules in cells, such as DNA,” said Dr. Jian-Ping Cai, a researcher involved in the study. “As we age, we suffer increasing oxidative damage, and so the levels of oxidative markers increase in our body.”

One of these markers, referred to as 8-oxoGsn, was found in animal urine studies to increase with age.

Cai and his colleagues set out to see if this was true for humans as well, so they measured 8-oxoGsn in 1,228 residents of China between the ages of 2 and 90.

They found an age-associated increase in the biomarker for participants who were older than 21.

Researchers hope the test can be used to predict the likelihood of developing age-related diseases as well as determine the effectiveness of future treatments designed to slow the aging process.

“What I think is most promising from this particular study is that if there is a way to accurately and consistently quantify the physiological age of a person or organism, it would provide an amazing tool for further studying treatments against aging. It would mean that we could follow a treatment for a few months or years to determine efficacy rather than the lifespan of the subject,” Jae Hur, PhD, assistant professor of biology at the Harvey Mudd College in California, told Healthline.

Actual age vs. biological age

The average lifespan of a person in the United States is around 78 years, but the biological age of two 78-year-olds could be vastly different.

“No two people age alike, and this is something we don’t really understand,” Judith Campisi, PhD, a professor at the Buck Institute for Research on Aging in California, told Healthline.

Campisi said it’s important to have a measure of biological age that doctors can use in preventative medicine.

“Aging is the single largest risk factor for 90 percent of everything that you would see in a hospital in a developed country. Aging is the biggest risk factor for the development of cancer, neurodegeneration, type 2 diabetes, kidney failure, lung failure, heart failure, the list goes on and on,” she said.

But having a biological marker of aging shouldn’t be mistaken as a quick fix for slowing down the aging process.

“If it were a simple case of aging being this chemical building up in the body… we would have solved that a long time ago. We don’t have unified knowledge about what exactly aging is, and it’s probably not so simple,” Campisi said.

Aging is still a mystery

There are still many mysteries around why the body ages and at what rate.

The more biologically aged a person is, the less able they are to confront any biological stress placed on their body.

This increases the chance of developing a disease or becoming injured.

It’s believed a person’s biological age can be influenced by a number of factors, including genetics, lifestyle choices, and public health factors.

“It makes sense that if your parents live to very advanced ages, you work hard to take care of yourself, get top-notch medical care, and you live in a healthy environment, you stand a better chance of living a long life than if both your parents pass away at relatively young ages, you do not take care of yourself, you grow up eating or drinking toxic waste, and you don’t have access to good medical care,” Dr. Russell Swerdlow, a professor of neurology at the University of Kansas and director of the University of Kansas Alzheimer’s Disease Center, told Healthline.

The urine test developed by Cai and his colleagues, as well as blood tests currently available that can measure age biomarkers, may be useful for physicians, but Swerdlow notes the average person shouldn’t need such a test to try to increase their lifespan.

“You shouldn’t need a test like this to know if you want to age better. It is in your interest to make lifestyle choices that are associated with better health. For example, you don’t need a test like this to know that smoking is bad for your health,” Swerdlow said.

So what does he suggest is the best way to maximize your lifespan?

“Live in a safe and healthy environment, with a good public health infrastructure. Have good doctors. Pursue a lifestyle that cares for, as opposed to abuses, your body, and choose your parents wisely,” he advised.