Cuba

The flax-PAD study: An international research collaboration

It is becoming increasingly evident that cardiovascular disease is strongly influenced by dietary habits. Nutritionally poor diets with a high proportion of trans fats can have a significant negative impact upon cardiovascular health. It is not surprising, therefore, that we are slowly beginning to realize that the corollary is also true: beneficial nutritional interventions can influence cardiovascular disease in a positive manner. A common dietary intervention used to alter cardiovascular disease is 0-3 fatty acid supplements.

Fish are highly enriched in these fatty acids. Diets including fish reduce the severity of cardiovascular disease in both animal and human models; however, compliance with fish oil supplementation is poor. The taste of fish oil is not generally well accepted. Thus, alternative sources of omega-3 fatty acids in the diet are needed. One alternative source is flaxseed. It has a pleasant nutty flavor and is one of the richest plant sources of 0-3 fatty acids. Furthernore, flaxseed also contains potent antioxidants and fibre, which is known to be beneficial in controlling circulating cholesterol levels. Thus, flaxseed enriched foods have the potential to provide dramatic beneficial effects on cardiovascular health and be tolerated by the general public. Animal studies have shown dramatic anti-atherogenic, anti-arrhythmic and anti-inflammatory effects of dietary flaxseed. These studies support a clinical trial to determine whether dietary flaxseed has similar beneficial cardiovascular effects in humans.

The Flax-PAD trial is a one year, double blinded, placebo controlled study designed to examine and compare the effects of dietary ground flaxseed supplementation in volunteers with claudication secondary to lower extremity atherosclerotic arterial disease (peripheral arterial disease). This patient population is likely to benefit from flaxseed because there is a high prevalence of accelerated atherosclerosis and a higher than normal incidence of arrhythmias, myocardial infarctions and stroke. This study will be focus on whether dietary flaxseed can reduce clinical manifestations of peripheral arterial disease and increase exercise capacity in these patients.

Two general hypotheses are being tested in this proposal. First, we have hypothesized that fewer primary and secondary events (all-cause mortality, cardiovascular mortality, stroke, myocardial infarctions) will occur in patients who ingest flaxseed in their diet. Secondly, we have hypothesized that dietary flaxseed supplementation will be associated with beneficial effects on angina, arrhythmias, exercise performance, blood pressure and circulating lipid levels. This trial will generate data on the safety, tolerability, cardiovascular efficacy to a diet rich in flaxseed in patients with peripheral arterial disease (PAD).

This project has involved personnel from both Winnipeg Canada and Holguin Cuba in it. It represents a very real, very exciting international col1aboration that has resulted in many important publications to advance the field of cardiovascular health. The results have been so promising that it has spawned the creation of spin-off trials and further research from which both countries may benefit.