There's new research linking insufficient sleep to heart-disease risk factors. By snoozing a little more each night, you might stay healthy longer. That's just one of many new insights emerging from research on a disease that kills nearly 50,000 Canadians every year. Some of the newly identified factors are interconnected with other well-known risks (poor diet, a sedentary lifestyle, smoking, high blood pressure and diabetes), and unravelling them may soon lead to better prevention. Here's what's changing the way we think about heart disease.

Hearts and minds
The brain may not be the only organ affected by depression. A 2013 study out of Columbia University in New York has linked depression, stress, anger and anxiety with a buildup of fatty deposits in the arteries of rheumatoid arthritis patients. While further investigation is needed, researchers suggest heart-disease risk factors associated with mental illness—such as negative lifestyle changes (including alcohol abuse and poor attention to diet) and use of psychiatric medications that impact the body—are the causal link. Interestingly, the relationship goes both ways; those with heart disease are also prone to depression. Researchers speculate that screening and treatment of mental illness may reduce the risk of heart disease in some patients.

What you can do: If you're experiencing symptoms of mental illness, seek help. And talk to your doctor about the benefits of undergoing cardiovascular assessments before and after receiving psychiatric meds.

Under the sheets
We know a restful sleep is crucial to feeling good, but getting the right amount may be the sign of a healthy heart. In a South Korean study published in 2015, people who slept too much (nine or more hours each night) had stiffer arteries and more calcium deposits on their artery walls than those who regularly logged about seven hours of sleep. People who routinely clocked just five hours or less had the same risks as those who slept excessively. Researchers don't fully understand the correlation, but one explanation is that too much or too little sleep may disrupt the body's ability to repair itself and to carry out other functions that happen while asleep.

A separate 2015 study linked sleep apnea with an increased risk of coronary heart disease, enlargement of the heart, heart failure and death in women. Sleep deprivation can also lead to overeating and, in turn, high blood pressure, diabetes and obesity, says Dr. Michael Farkouh, a cardiologist at Peter Munk Cardiac Centre in Toronto.

What you can do: Improve your sleep habits and, if you have insomnia or sleep apnea, seek medical help. Increasing your physical activity can help, too. "When you get exercise regularly, you will sleep better," says Simon Bacon, Heart and Stroke Foundation of Canada spokesperson and professor in the department of exercise science at Montreal's Concordia University.

Gut reaction
Could bacteria be making your heart sick? As researchers probe the role of bacteria (good and bad) in our bodies, it's becoming clear that certain microbes are associated with heart disease. A 2015 Swedish study found that the bacteria behind gum disease can flip a genetic switch that leads to inflammation and plaque buildup—the culprits in coronary artery disease. Meanwhile, in a 2012 study, subjects with a certain strain of gut bacteria had a lower risk of developing clogged arteries.

Researchers have already found a connection between gut bacteria and obesity, which is a major risk factor for heart disease.

What you can do: Keep gum-disease bacteria in check by practising good oral hygiene—thoroughly brushing, flossing and using mouthwash. Researchers are still figuring out how we can tweak our gut flora. For now, be sure to keep your diet varied to help good bacteria thrive.

In the air
We've long known that inhaling the toxins in cigarette smoke is harmful to the heart, but now, researchers are looking at chemicals in polluted air, too. In a 2015 large-scale study, chemical particles in polluted air were linked to a 10 percent increased risk of death resulting from heart disease. The particles, usually made up of harmful chemicals, evade the body's defences and get absorbed deep into the lungs and the bloodstream, contributing to the development of potentially fatal heart and lung diseases.

Environment Canada warns that people with conditions such as angina, congestive heart failure and arrhythmia, as well as those who have previously suffered a heart attack, are more sensitive to air pollution, which can make breathing difficult and can trigger heart attacks.

What you can do: It's not easy to pick up and move, but people with heart problems "should be aware that living in high-pollution areas could be linked to worsening heart disease," says Dr. Farkouh.  

Watch for the Canadian Association of Cardiovascular Prevention and Rehabilitation's upcoming guidelines for exercising outdoors on days with poor air quality, recommends Bacon. We'll likely be advised to avoid extended runs or walks on bad air days, he says.

Sugar shock
Fat and cholesterol have long been considered the bad guys. Now, some fats (like those found in olives and avocados) are considered healthy, and eggs are no longer villainized (yolks are high in cholesterol). Meanwhile, sugar has taken over the hot seat.

Nutritional biologist Kimber Stanhope, associate researcher at the Davis campus at the University of California, has conducted multiple studies showing that excessive sugar intake—high-fructose corn syrup in particular—may lead to a heightened risk of cardiovascular disease. Two weeks of drinking as little as 1 1/2 cans of soda each day results in a spike in blood markers associated with cardiovascular disease.

What you can do: Reduce your sugar intake, especially added sugars (those that aren't found naturally in the food). Aim for no more than about 100 calories a day from added sugars—that's less than a single can of pop or about six teaspoons of the white stuff. Currently, most of us consume about 16 teaspoons daily, according to an estimate from the Heart and Stroke Foundation of Canada.

For more on taking care of your heart, check out these tips on how to improve your heart health.

This content is vetted by medical experts

This story was originally part of "Take This News To Heart" in the February 2016 issue. Subscribe to Canadian Living today and never miss an issue!