brain against blue medical background with dna and ecg

Your genes, your heart, your brain

A family history of heart disease and stroke can double your risk. Here’s how you can protect yourself.

The link between genetics and heart disease and stroke is an important one that researchers are working hard to understand. How important? If your family has a history of these diseases, your risk is doubled. It’s that simple.

Dr. Robert Hegele holding genetic model

Dr. Robert Hegele

Dr. Robert Hegele, an endocrinologist and professor of medicine and biochemistry at Western University, has spent much of his career studying the way genes influence heart disease. We asked him how genetic research is changing our understanding of heart disease and stroke, and what it could mean for diagnosis, treatment and prevention.

Building a genetic map

It’s long been established that certain genes can increase your risk of heart disease and stroke. Mapping out which genes increase which specific risk is an important first step, Dr. Hegele says.

Take the example of familial hypercholesterolemia. It’s one of the most common inherited conditions, affecting 1 in 300 Canadians. Having hypercholesterolemia means you live with a gene variant that impedes your body’s ability to process cholesterol. High cholesterol can clog arteries, reducing blood flow and increasing your risk of heart attack or stroke.

Before the 1980s, people with the condition were at risk of having a heart attack or stroke in their 30s. Once researchers identified the gene causing hypercholesterolemia, they were able to develop, using a natural compound from a mushroom, the drugs that became known as statins.

Statins effectively extend – by decades – the lives of people with genetic hypercholesterolemia. But researchers have found that they also benefit patients whose blood cholesterol levels are higher than normal, but who don’t have the inherited condition. Today more than four million Canadians take statins to bring their cholesterol levels to a healthy range, and are living longer lives as a result.

Statins are a genetic research success story. We wouldn’t have these important medications without the research that revealed the genetic causes of hypercholesterolemia, says Dr. Hegele.

Where will the next statins emerge? That’s one question that keeps him and other scientists chipping away at the genetic puzzle.

The challenge ahead

So far, researchers have identified 20 per cent of the genes known to increase risk of heart disease and stroke. With only a partial picture of the genes that cause problems, doctors tend to err on the side of caution.  

In cases where the causative gene is known, it is becoming possible to test whether it has been passed down from parent to child. Typically, it is 50-50 whether the child has inherited the parent’s genetic tendency; having a test available allows for 100% certainty.

In a case where no genetic test yet exists, it’s safest and logical to develop an effective screening and prevention plan in order to minimize the risk. This would include addressing other risk factors that contribute to heart disease, including high blood pressure, high cholesterol, inactivity and smoking.

Ultimately as researchers map out the remaining 70-80 per cent of the genes that cause heart disease and stroke, they will develop new screening tests, new ways to target the inherited risks and new, personalized treatments for heart disease and stroke.  

Meanwhile, says Dr. Hegele, your genes are not your destiny. Genetic inheritance is like being dealt a hand of cards. “A skilled card player can go far, even with a bad hand. You can still win the round and play a good game. You just have to focus. You can’t ignore it.”

So how do you ensure you play a good game?

Family history matters

Knowing your family history is a good place to start. You’ll want to look at the health history of first-degree relatives such as parents, siblings and even your children. If you have a male relative under 55 or a female relative under 65 who has experienced any type of heart disease, stroke or vascular disease, you could be at risk of developing the same conditions.

If you know that you have a family history, you can extend your life by making some changes that bend the curve. That doesn’t mean you need to overhaul your habits all at once. Instead focus on what you can manage right now. That might mean eating more green vegetables at dinner or taking the stairs instead of the elevator during the day. Small changes add up and they can work especially well in patients who have genetic susceptibility.

Genes may increase risk but living healthy can do a lot to counteract that risk and put you on a path toward better health.

  •  Ready to take small steps to a healthier you? Try the Foundation’s new <30 Days app.


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