Researchers at Uppsala University in Sweden have developed a blood test that could reveal your biological age. They have found a way to measure how the number of proteins in the blood can reveal a body's real age. Your body could biologically be several years younger — or older — than your chronological age. Certain lifestyle factors, like smoking, stress and soda, can speed up the aging process; however, drinking coffee, eating fatty fish (such as this) and exercising have shown to counteract the aging process.

This could be another explanation for why generations of civilizations have fared best in coastal regions: because the seafood that is readily a part of their diet actually keeps them younger and living longer. Add fatty fish to the coffee-loving lifestyle, and we may have a better understanding for why our Swedish forefathers lived long lives near the Baltic Sea.

The study examined blood samples from about 1000 Swedes, ages 14 to 90. In them, researchers found the number of protein markers increases with age, which means the ability to measure a person's age could be done by measuring the number of markers. "The protein profile is influenced by a number of lifestyle choices, and certain factors accelerate the body's biological aging, while others slow it down," said Ulf Gyllensten, professor at Uppsala's Department of Immunology, Genetics and Pathology. Of course drinkers of soda are usually those who also eat more pizza and processed foods that adversely affect health. The same is true on the other end of the lifestyle spectrum: Those who eat a lot of fish are more likely to also consume more fresh vegetables and fruit, which positively affect health. All these things can affect how quickly the body ages.

The study is part of the Northern Swedish Population Health Study, which is part of an extensive 10-year cooperation in Europe that compares how various specific diets in Europe affects health. The study was published in the journal Scientific Reports in December 2015.

Changes can't be made overnight, but here are some observations from people's blood proteins:
- drinking three cups of coffee a day reduces biological age by 5.6 years (as compared to not drinking coffee at all)
- eating fatty fish (salmon, herring, mackerel, trout) three times a week reduces biological age by four years, compared to eating fish once a week.
- A BMI over 40 increases age by six years.
- Getting no exercise increases age by two to five years.