A doctor looks to separate fact from fiction when it comes to sodium and the heart

For those with heart disease, is less salt actually better?

Dr. Justin Ezekowtiz, physician at the Heart Function Clinic at the Mazankowski Alberta Heart Institute, and the lead researcher of an international study on whether or not it’s necessary for patients with heart disease to consume less sodium, isn’t so sure.

Sound crazy? Here’s the deal. According to Ezekowitz, a body with a diseased heart reacts differently to salt than a body that’s disease-free. In other words, preventing heart disease with lower salt in the diet helps, but does it help when the heart is already damaged?

“As doctors, we sometimes stick to what we’ve always done without testing whether it’s good or bad. Maybe higher salt is better. Maybe lower salt is better. We really need to know the answer for the long-term care of our patients.”

Adult Canadians with heart disease consume an average of about 2.4 grams of sodium per day. Conventional wisdom holds that trimming that amount to around 1.5 grams gives patients living with heart failure a better chance of avoiding such negative results as longer hospital stays, more frequent trips to emergency and, most important, death.

“Salt is a principal cause of high blood pressure and it makes our endothelial cells, the cells that line our entire circulatory system, less functional, causing thicker, harder arteries, less functional kidneys and less functional heart muscle cells,” says Ezekowitz.

But he adds “the amount of scientific evidence around the idea that lowering salt intake improves outcomes for patients with heart disease is pretty slim. We want to see the linkage that tells us what we’re doing is actually best.”

The study is set up to be as life-like as possible. Heart failure patients volunteer for the clinical study. Some are asked to prepare their own meals (usually about 2,400 mg of salt per day) for over a year. Others are asked to use a much lower amount; about 1,500 mg per day.

“We’re not preparing their meals. But we did craft some menus to help them make good choices,” says Ezekowitz.

With research sites in Canada, Australia, New Zealand, Mexico, Colombia and Chile, Ezekowitz’s study has grown into the largest clinical trial ever conducted on the impact of salt on heart patients. “Our findings will influence cardiac care around the world.”

Seed funding for this study, and hundreds of others just like it, came via the University Hospital Foundation’s Medical Research Competition (MRC). Ezekowitz and his team received $30,000 to conduct a small clinical trial of 30 patients.

He leveraged that data to acquire more funding, which in turn led to a $700,000 research grant from the Canadian Institutes of Health Research. From an initial investment point of view, that’s a return of just over 2200 per cent.

Now into its 20th year, the donor funded MRC has provided over $10 million in start-up funding to research projects across the spectrum of care at the University of Alberta Hospital.

“Before you can even apply for the big research dollars, you need data to validate your thesis,” says Ezekowitz. “Without that small start-up grant, this research and many, many others would never get off the ground.”