April 25, 2002 (press release)

Loma Linda University reveals first study on correlation between high water intake and lowered coronary heart disease

Jacqueline Chan, DrPH and Synnove Knutsen, MD, PhD

In 1999, nearly 530,000 people died from coronary heart disease. More than half of them had no previous symptoms of heart disease. Drinking high levels of water can significantly reduce the risk of coronary heart disease, say researchers at Loma Linda University.

In a press conference held Thursday, April 25, the results of a study to be published in the American Journal of Epidemiology (Vol. 155, No.9) reveal that drinking high amounts of plain water is as important as exercise, diet, or not smoking in preventing coronary heart disease.

“Basically, not drinking enough water can be as harmful to your heart as smoking,” warns Jacqueline Chan, DrPH, principle investigator and lead author of the article.

Dr. Chan and Synnove Knutsen, MD, PhD , second author, chair of epidemiology department, found that California Seventh-day Adventists who drink five or more glasses of plain water a day have a much lower risk of fatal coronary heart disease compared to those who drink less than two glasses per day.

The study, “Water, Other Fluids, and Fatal Coronary Heart Disease,” indicates that whole blood viscosity, plasma viscosity, hematocrit, and fibrinogen which are considered independent risk factors for coronary heart disease, can be elevated by dehydration.

The water study is part of the original Adventist Health Study, which began in 1973. Both researchers are also coinvestigators for the new Adventist Health Study.

The results from this study show that by drinking more plain water, healthy people—without any history of heart disease, stroke, or diabetes—reduced their risk of dying from a heart attack by half or more. This is as much or more than if they had adopted any other well-known preventive measure, including stopping smoking and lowering cholesterol levels, increasing exercise or maintaining ideal weight.

While not as glamorous, the degree of benefit from drinking plain water surpasses that of drinking a moderate amount of alcohol intake and aspirin with none of the adverse side effects (social or physiological). Because drinking more plain water is a simple lifestyle change that anybody can do, this simple practice has the potential of saving tens of thousands of lives each year with minimal cost.

Neither total fluid intake, nor intake of other fluids combined showed this reduced risk. Instead, for women, high intake (5 or more glasses a day) of other fluids showed a greatly increased risk of coronary heart disease.

“People need to be made aware that there is a difference, at least for heart health, whether they get their fluids from plain water or from sodas,” says Dr. Chan.

According to Dr. Chan, this is the first study to record the association between high water intake and reduced risk of coronary heart disease.

“This study needs to be replicated, and if similar results are found, then this would be the cheapest and simplest method of preventing coronary heart disease that could be imagined,”adds Gary Fraser, MD, PhD, cardiologist at the LLU Heart Institute, and principal investigator for the new Adventist Health Study.