Grandparents have a unique impact on our children. Kids, particularly teens, feel that their grandparents provide a special kind of guidance, support, and attention. Youngsters appreciate and need this relationship with someone who loves them unconditionally, but is not burdened by the need to be a disciplinarian.

These positive psychological benefits come with a risk, according to research recently conducted by Dr. Stephanie Chambers and her colleagues at the University of Glasgow in England.

The researchers analyzed 56 international studies that examined the impact of grandparents on a variety of kids’ health behaviors, categorizing such effects as beneficial, adverse, mixed or no impact.

The experts found that grandparents pose a serious health threat to our kids in the areas of tobacco usage, physical activity, diet and weight.

It’s easy to ridicule this research and proclaim that it’s the job of a grandparent to spoil the kids and then send them home to the parents.

This may seem cute and harmless, but this research indicates that grandparents, not surprisingly, have a strong impact on their grandkids — which can be either good or bad.

When it comes to smoking, the effect is twofold. Children are not only exposed to the risks of second-hand smoke, but they are also influenced by the behavior of someone they love. Seeing a grandparent smoke sends a much stronger message than any public service announcement on television.

The researchers found that grandparents can have a negative impact on kids’ diets.

When grandparents regularly violate healthy food practices, kids learn such rules don’t matter. If food and physical activity were that important, why would someone who loves them go against healthy practices?

Let’s be reasonable.

No one is suggesting that occasionally treating grandkids in special ways will permanently harm their health.

Rather, this research emphasizes that grandparents are influential and that they need to be mindful of the impact of their behaviors.

Here’s what this means for grandparents:

1. Tone it down a bit. An occasional treat is fine, but don’t undermine parents by allowing bad or unhealthy behaviors.

You love your grandkids. The best way to show that love is to teach them how to develop habits that will serve them well into their adulthood, not undermine their parents’ rules.

2. Be a great role model. You can encourage your grandkids’ physical activity by attending their sporting events or taking them to a park.

Power down the electronics. Let the kids see you eat well, exercise, take good care of yourself.

3. Don’t smoke in front of the kids — ever! Kids inhaling your second-hand smoke increases the likelihood of you giving them cancer.

Loving your grandkids means doing what is right for them, not what feels good to you.

Dr. Gregory Ramey is the executive director of Dayton Children Hospital’s Pediatric Center for Mental Health Resources. Email: Rameyg@childrensdayton.org.