You are what you eat:

Mount Sinai Hospital’s Dr. Alexander Logan has discovered a new and easy way for physicians to check the overall quality of their patients’ diet, and help them improve their long-term health. In a study published in the April 2009 issue of The Journal of Nutrition, Dr. Logan shows that the quality of a person’s diet can be easily assessed through a standard test that analyzes the level of potassium in the urine. 

“Poor eating habits are common and contribute to many diseases in Canada,” said Dr. Logan, Senior Investigator at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital. “Potassium is a reliable indicator of overall diet quality so this test provides a more accurate indication of diet quality than self-reported information.”

Dr. Logan points out that the urine test is low-cost and can be easily integrated into a typical check-up. Healthy diets have been shown to lower blood pressure, reduce mortality rates in patients with coronary heart disease and mitigate salt sensitivity. They are also associated with a lower BMI (Body Mass Index). In people eating a typical North American diet, a high quality diet has been shown to be as effective as drug treatment in lowering high blood pressure.

“Preventative care is a matter of improving one’s diet by applying the simple rule of ‘3 x 5’ – three portions of dairy plus five portions of fruit and vegetables per day. This will greatly improve a person’s diet and their overall health,” says Dr. Logan.

Dr. Logan’s study looked at the urine samples of more than 200 young adults with kidney stones, who submitted samples as part of a routine assessment. The patients provided a single 24-hour urine specimen (collected every time they urinated for a full day) and were not given any specific dietary instructions. People who ate recommended amounts of vegetables, fruit, low-fat dairy, whole grains, fish, poultry and wine had high levels of urinary potassium, indicating a high-quality diet while those who consumed red meat, fast food and high-energy drinks had low levels of urinary potassium. Those eating a high quality diet also weighed less and had lower blood pressure. The findings are applicable as dietary guidelines regardless of health.

“This is a fascinating study that could help to make a positive change in a patient’s life relatively quickly,” said Dr. Jim Woodgett, Director of Research, Samuel Lunenfeld Research Institute of Mount Sinai Hospital. “Dr. Logan’s work is an excellent example of how research can inform both patients and physicians about healthy lifestyle choices and behaviours.”

The study was funded by the Dairy Farmers of Canada.