A new study shows something we’ve always figured was true: our health and habits as children and teens affect our health as adults. And not just our health, but how long we live.

What did the study measure and find?

The International Childhood Cardiovascular Cohorts Consortium Outcomes Study has been collecting data on almost 40,000 people from the United States, Finland, and Australia. They started enrolling them as children in the 1970s through the 1990s, and have been following them ever since.

The researchers have been looking at the effects of five risk factors:

• body mass index, or BMI, a calculation that shows if a person is within a healthy weight range
• systolic blood pressure, which is the top number in a blood pressure reading and is a measure of how much pressure is exerted on the arteries when the heart beats
• total cholesterol value, a measure of how much of the waxy substance is in your blood. While cholesterol is important for doing things like building cells and hormones, having too much of it can lead to heart disease and stroke.
• triglyceride level, a measure of how much of this fatty substance is in the blood. As with cholesterol, too much of it increases the risk of heart disease and stroke.
• smoking in youth.

From 2015 to 2019, the researchers followed up on all of these people, who were 46 on average, which is not very old. They found that almost 800 of them had had cardiovascular events (like a heart attack or stroke), of which more than 300 were fatal.

When the researchers matched outcomes to values for the five factors, they found that they were indeed risk factors:

• People who had higher than normal values for all of the risk factors had almost triple the risk of cardiovascular disease.
• Smoking was the biggest risk factor, followed by BMI, systolic blood pressure, triglycerides, and cholesterol.
• You didn’t need to have all five factors to be at risk; for example, people who were obese as children were more than three times more likely to have cardiovascular disease — and those whose blood pressure was either high or close to high had double the risk.

None of this is a surprise, but seeing it so clearly should be a wake-up call, especially to parents.

What can parents do to help steer a course toward healthy adulthood?

Parents can take these four important steps:

1. Know if your child is at risk. Understandably, many parents don’t pay close attention to the numbers at their child’s checkup, or the results of blood tests. But those numbers are important.

• Make sure you know your child’s BMI — and if it is healthy or not. In adults, we say that a BMI of 19 to 25 is healthy. In children and teens, it’s a bit more complicated; we look at the BMI percentile based on age and gender. If the percentile is between 85 and 95, the child is overweight; if it’s over 95, the child is obese. The Centers for Disease Control and Prevention has a calculator you can use to get the BMI and percentile.
• Know your child’s blood pressure — and whether it is healthy or not. Again, this depends on age, gender, and height. Sadly, many pediatricians miss abnormal blood pressures because numbers that seem normal can be unhealthy for some children, so it’s important to ask your doctor to be sure. Your child’s blood pressure should be measured at every checkup starting at age 3.
• Ask about checking your child’s cholesterol and triglyceride levels. This is generally done in adolescence, but may be done earlier if a child is overweight, or if there is a family history of elevated levels. If you or a close family member has high cholesterol or triglycerides, make sure your child’s pediatrician is aware.
• Ask your child about smoking (and other substance use). Don’t assume you know.

2. Take what you learn — and this study — seriously. An “it’s just baby fat” or “they have plenty of time to get healthy” approach can be dangerous.

• If your child has an elevated BMI, blood pressure, cholesterol level, or triglyceride level, talk with your doctor about what you can do — and do it. 
• No matter what your child’s numbers are, make sure they have a healthy diet, rich in fruits, vegetables, whole grains, healthy fats, and lean protein. Limit added sugar (especially in beverages), processed foods, and unhealthy fats.
• Same goes for exercise: children should be exercising for an hour a day. That doesn’t have to be a team sport, if your child is not a team sports kind of person (or your life doesn’t lend itself to team sports); active play, going for walks, doing exercise videos, or even just dancing in the living room is fine.

3. Talk to your kids about not smoking. Start early — well before adolescence, when peer pressure becomes powerful. Make sure they know the facts, and help them learn and practice ways to say no.
4. See your doctor regularly. Children should see their doctor at least yearly, and if your child has one of the five risk factors, they will need more frequent visits. Make these visits a priority — your child’s life might literally depend on it.

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About the Author

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio View all posts by Claire McCarthy, MD