More than 13 million Americans have survived a heart attack or have been diagnosed with coronary heart disease (CHD), the number one cause of death in the United States. In addition to medications, lifestyle changes, such as a healthy diet and exercise, are known to reduce the risk for subsequent cardiac events. Despite this evidence, a high proportion of heart attack survivors do not follow their doctor’s advice to adhere to a healthy diet, according to researchers at the University of Massachusetts Medical School (UMMS).
Many studies have centered on determining dietary risk factors for developing CHD, but few investigations have studied the diets of CHD patients following diagnosis. Researchers measured the diet quality of 555 CHD patients one year after a diagnostic coronary angiography. Using the Alternative Health Eating Index (AHEI) to assess diet quality, they found that a high proportion of those patients had not made the necessary improvements to their diets to help reduce the risk of a secondary CHD event. Proven to be a strong predictor of CHD, the AHEI is a measure that isolates dietary components that are most strongly linked to CHD risk reduction.
“This study found that CHD patients’ diets had not improved in the year after being diagnosed,” said Yunsheng Ma, MD, PhD, MPH, assistant professor of medicine and one of the study’s lead authors. “We know that a healthy diet is one of the most important components of a healthy lifestyle, especially for patients following a cardiac event, and yet patients are not acting on this knowledge.”
To determine the quality of CHD patients’ diets, Dr. Ma and colleagues collected data from a 24-hour dietary recall one year after the participants’ CHD diagnoses. The dietary recall is an assessment tool administered by a dietitian, who interacts with the patient to examine the patient’s entire food intake from a 24-hour period, including complete food descriptions, preparation and amount. Prior to the recall, patients were given food models that identified different foods and serving sizes, to improve recall and estimation. Nutrient scores were computed, and the AHEI was then calculated to determine dietary quality, which included intake of fruits, vegetables, nuts and soy, ratio of white to red meat, cereal fiber, trans-fat, ratio of polyunsaturated fat to saturated fat, and alcohol.
Of a maximum 80 points—which indicates the healthiest diet—the average AHEI score was 30.8, with individual scores ranging between 5.1 and 69.8. The mean AHEI score was poorer than scores reported for samples of healthy individuals from the Health Professional’s Follow-up Study and the Nurses’ Health Study. In a previous study by Ma and colleagues, the AHEI of several popular weight loss plans was calculated; the highest scoring diet was the Ornish Diet (AHEI = 64.6) and lowest scoring diet was the Atkins diet (AHEI= 42.3).
The fact that one year after a coronary event patients with known CHD still have lower AHEI scores than these popular diets may be indicative of the complex issues of effecting and sustaining behavioral change and the confusion patients may face in navigating through dietary recommendations. When examining AHEI components, only 12.4 percent of the participants met the optimal daily consumption of vegetables and 7.8 percent for fruit. Only 8 percent of the patients met the cereal fiber recommendation, and 5.2 percent of the participants limited their trans-fat intake to 0.5 percent of total calories or less. In addition, nearly 11 percent of calories were from saturated fat (less than 7 percent is recommended), while total fiber was only 16.8 grams per day (25 grams or more per day is recommended).
The researchers evaluated the association of each patient’s diet in relation to his or her sociodemographic and clinical standings and found that low dietary quality was associated with smoking, lower educational levels, obesity, high-fat intake and a lower calorie intake. On average, smokers scored six units lower than non-smokers; participants with education beyond high school scored three units higher than participants with a high school education; and obese participants scored four units lower than normal weight or overweight participants.
“An overwhelming number of CHD patients, roughly 80 percent, do not attend cardiac rehabilitation programs, which instruct CHD patients about proper diet and exercise,” said Ira Ockene, MD, the David and Barbara Milliken Professor of Preventive Cardiology and professor of medicine at UMMS and cardiologist at UMass Memorial Medical Center. “Changing one’s eating habits is a long-term process, and optimal care should include cardiac rehabilitation and appointments with dietitians, which can build upon the patient’s initial foundations to improve his or her diet and overall health.”
According to study co-author and UMass Memorial Medical Center registered dietitian Barbara Olendzki, RD, MPH, an assistant professor of medicine at UMMS, “Physicians and health care providers should consider placing more of an emphasis on dietary counseling, along with exercise, for CHD patients. Nutrition counseling and patient dietary changes can lead to significant improvements in subsequent CHD risk and better quality of life.”
Dr. Ma agreed and suggested that, “It is important for physicians to refer CHD patients to the cardiac rehabilitation programs and encourage attendance. Future studies should be conducted and directed toward integrating nutrition education materials in cardiac rehabilitation programs. Nutrition education can have a significant impact on a patient’s overall dietary quality and body-weight control and on subsequent cardiac events and mortality.”
The study, “Dietary Quality 1 Year after Diagnosis of Coronary Heart Disease,” was published in the February issue of the Journal of the American Dietetic Association. This research was supported by a grant from the National Heart, Lung and Blood Institute.
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