A team of researchers at Trinity College Dublin is investigating ways to reduce heart disease without resorting to drug treatments, reports Dick Ahlstrom
A few minor changes to the way we live might be enough to prevent heart disease in later life. A research group at Trinity College Dublin is using rigorous scientific methods to identify the kinds of changes to make.
"The number of people who are diagnosed with existing or impending cardiovascular disease is growing rapidly," states Prof Christopher Bell, professor of physiology at TCD.
Bell is also the head of TCD's Cardiovascular Health Unit, which studies lifestyle factors that contribute to cardiovascular disease. These include factors such as stress levels, smoking, lack of exercise and obesity.
The research team includes Dr Saoirse O'Sullivan and research students Maeve Barry and Etain Tansey. It maintains close links with colleagues at the St James's and Tallaght Hospital campuses and relies on contributions made by Dr Simon Green of the department of physiology, an expert in peripheral vascular disease.
The unit "evolved after I arrived six years ago", says Bell. "We are really interested in lifestyle factors" as a way to develop treatment strategies that don't require drug therapies, he explains. Work at TCD and elsewhere has shown that "quite trivial adjustments in lifestyle" are enough to make a real difference to cardiovascular health, he maintains.
"The most obvious things are exercise and the intake of dietary supplements - for example, to scavenge free radicals in the system."
Other key issues are smoking and the Western world's attachment to a high-fat diet.
The team pursues two particular research routes. "Most of the stuff that we do has two aims. One aim is to use non-invasive monitoring of cardiovascular function," says Bell. The second is to pick apart the complex web of biochemistry involved in our bodies' responses to positives such as exercise and negatives such as stress and smoking.
Studies have shown that even very moderate exercise can counteract the rises in blood pressure and cardiac work caused by mental stress. This is the stress associated with work and a busy lifestyle, but similar effects result from normal stressors, such as walking, doing maths, mowing the lawn and so forth.
Smokers, on the other hand, show exaggerated increases in cardiac work at times of mental stress.
These research findings, Bell says, offer new insights into the benefits of exercise but also possible mechanisms by which smoking acts as a cardiac risk factor.
The team is developing non- invasive ways to measure heart-pumping output, blood flow through limbs or muscles and the way this flow changes under normal stresses. Researchers can monitor blood pressure "beat by beat" to measure the minute changes as tasks are pursued.
"We are interested in those reactions as an indicator of how healthy the cardiovascular system is," Bell says. "We have got some very nice evidence that if people undertake some low-key exercise, you can have very dramatic changes in the way the cardiovascular system responds to stresses."
The general assumption is that it takes rigorous and persistent exercise to see any benefit - but this is not so, says Bell. A half-hour of "very moderate" walking three times a week can deliver much of the benefit of an hour's intensive exercise seven days a weeks. "It is not a big change in lifestyle for anyone to do," Bell says.
HE IS tackling the damage caused by cigarettes on several fronts using biochemistry techniques.
"I think people will smoke, no matter what you do," he says. The goal is to find simple ways to help protect smokers without relying on drugs.
Some of the damage from smoking is caused by chemical reactions that produce free oxygen in the body. Oxygen is highly reactive and immediately tries to bond to tissues, disrupting normal biochemistry and causing damage. Antioxidants, such as vitamins C and D, offer one means of countering this damage.
The team is in the middle of a large study looking at the "absolute differences between heavy smokers and non-smokers" in terms of their biochemistry. It is trying to see if it can reverse or prevent the biochemical changes seen in smokers, using dietary antioxidants.
Preliminary data looks very good, Bell says, and suggests that, yes, they can bring about positive changes. "We would anticipate that we can reverse some of these changes or prevent them from happening in smokers," Bell says. The team is also trying to optimise the dose rates to get the best results with the minimum amount of vitamins.
The TCD Cardiovascular Health Unit is eager to recruit male and female volunteers of all ages for these studies. There is a particular need for heavy smokers and people with a family history of heart disease or high blood pressure. If you would like to participate, contact the unit at 01-608-2723 or physiol@tcd.ie