CHICAGO --- The heart is more forgiving than you may think -- especially to adults who try to take charge of their health, a new Northwestern Medicine® study has found.

When adults in their 30s and 40s decide to drop unhealthy habits that are harmful to their heart and embrace healthy lifestyle changes, they can control and potentially even reverse the natural progression of coronary artery disease, scientists found.

The study was published June 30 in the journal Circulation.

“It’s not too late,” said Bonnie Spring lead investigator of the study and a professor of preventive medicine at Northwestern University Feinberg School of Medicine. “You’re not doomed if you’ve hit young adulthood and acquired some bad habits. You can still make a change and it will have a benefit for your heart.”

On the flip side, scientists also found that if people drop healthy habits or pick up more bad habits as they age, there is measurable, detrimental impact on their coronary arteries.

“If you don’t keep up a healthy lifestyle, you’ll see the evidence in terms of your risk of heart disease,” Spring said.

For this paper, scientists examined healthy lifestyle behaviors and coronary artery calcification and thickening among the more than 5,000 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study who were assessed at baseline (when participants were ages 18 to 30) and 20 years later.

The healthy lifestyle factors assessed were: not being overweight/obese, being a nonsmoker and physically active and having low alcohol intake and a healthy diet. By young adulthood (at the beginning of the study), less than 10 percent of the CARDIA participants reported all five healthy lifestyle behaviors. At the 20-year mark, about 25 percent of the study participants had added at least one healthy lifestyle behavior.

Each increase in healthy lifestyle factors was associated with reduced odds of detectable coronary artery calcification and lower intima-media thickness -- two major markers of cardiovascular disease that can predict future cardiovascular events.

“This finding is important because it helps to debunk two myths held by some health care professionals,” Spring said. “The first is that it’s nearly impossible to change patients’ behaviors. Yet, we found that 25 percent of adults made healthy lifestyle changes on their own. The second myth is that the damage has already been done -- adulthood is too late for healthy lifestyle changes to reduce the risk of developing coronary artery disease. Clearly, that’s incorrect. Adulthood is not too late for healthy behavior changes to help the heart.”

The bad news is that 40 percent of this sample lost healthy lifestyle factors and acquired more bad habits as they aged.

“That loss of healthy habits had a measurable negative impact on their coronary arteries,” Spring said. “Each decrease in healthy lifestyle factors led to greater odds of detectable coronary artery calcification and higher intima-media thickness. Adulthood isn’t a ‘safe period’ when one can abandon healthy habits without doing damage to the heart. A healthy lifestyle requires upkeep to be maintained.”

Spring said the healthy changes people in the study made are attainable and sustainable. She offers some tips for those who want to embrace a healthy lifestyle at any age:

Keep a healthy body weight

Don’t smoke

Engage in at least 30 minutes of moderate to vigorous activity five times a week

No more than one alcoholic drink a day for women, no more than two for men

Eat a healthy diet, high in fiber, low in sodium with lots of fruit and vegetables

This research was funded by contracts N01-HC-48047 through 48050 and N01-HC-95095 from the National Heart, Lung, and Blood Institute and from the National Institutes of Health, by HL075451 to Bonnie Spring and by CA154862 to Juned Siddique.