David Katz, M.D. |
New short-term findings from a study by Dr. David Katz and his colleagues at the Yale-Griffin Prevention Research Center at Griffin Hospital in Derby provide suggestive evidence that it may be time to start questioning this advice.
Due to a general belief in the medical community that dietary cholesterol raises cholesterol levels in the blood, health professionals routinely advise patients with coronary disease to restrict dietary cholesterol from eggs and other sources. However, Katz cites a lack of consistent evidence that dietary cholesterol actually impacts blood cholesterol levels.
He notes that recent epidemiological and clinical studies seem to show a lack of association between eating eggs and harmful cardiovascular effects.
In the last few years, Katz and his team have conducted two clinical trials of egg ingestion – one with healthy adults, and one with adults at risk for coronary disease – which showed daily egg intake over a span of six weeks had no adverse effects on cardiac risk factors in these adults.
Short-term findings from a recently completed study, published in the January 2015 issue of the American Heart Journal, demonstrated similar results - this time with adults with coronary artery disease. This study compared the effects on cardiac risk factors of six weeks of daily intake of either two eggs, ½ cup of a commercially-available egg substitute, or a high-carbohydrate breakfast (choice of bagels, waffles, pancakes, or cereal), as part of an otherwise unrestricted diet.
Results showed that after six weeks of either eggs or egg substitute, when compared to a high carbohydrate breakfast, participants’ endothelial function (the ability of their blood vessels to constrict and dilate properly with blood flowing through them) did not significantly change, i.e., it neither improved nor deteriorated significantly. Their body weight, body mass index, blood pressure, and serum lipids also did not significantly change, when compared to 6 weeks of a high carbohydrate breakfast.
“Our short-term findings, and the overall weight of evidence, argue against excluding eggs from heart-healthy diets, even among those with actual coronary disease,” Katz said. “There may be net harm to overall diet quality and health from excluding eggs from the diet.”
Good source of micronutrients
According to Katz, eggs, in contrast to other sources of animal protein, have relatively little total fat and proportionately little saturated fat. They provide protein at a relatively low cost, and are a good source of micronutrients.
In the last few years, Katz and his team have conducted two clinical trials of egg ingestion – one with healthy adults, and one with adults at risk for coronary disease – which showed daily egg intake over a span of six weeks had no adverse effects on cardiac risk factors in these adults.
Short-term findings from a recently completed study, published in the January 2015 issue of the American Heart Journal, demonstrated similar results - this time with adults with coronary artery disease. This study compared the effects on cardiac risk factors of six weeks of daily intake of either two eggs, ½ cup of a commercially-available egg substitute, or a high-carbohydrate breakfast (choice of bagels, waffles, pancakes, or cereal), as part of an otherwise unrestricted diet.
Results showed that after six weeks of either eggs or egg substitute, when compared to a high carbohydrate breakfast, participants’ endothelial function (the ability of their blood vessels to constrict and dilate properly with blood flowing through them) did not significantly change, i.e., it neither improved nor deteriorated significantly. Their body weight, body mass index, blood pressure, and serum lipids also did not significantly change, when compared to 6 weeks of a high carbohydrate breakfast.
“Our short-term findings, and the overall weight of evidence, argue against excluding eggs from heart-healthy diets, even among those with actual coronary disease,” Katz said. “There may be net harm to overall diet quality and health from excluding eggs from the diet.”
Good source of micronutrients
According to Katz, eggs, in contrast to other sources of animal protein, have relatively little total fat and proportionately little saturated fat. They provide protein at a relatively low cost, and are a good source of micronutrients.
In addition, since protein is associated with satiety, eggs may be of benefit in weight control.
“This study highlights an important consideration: when coronary disease patients are advised to avoid or limit a food or food category, what do they eat instead?” Katz said. “While some alternatives to eggs, such as oatmeal, might offer benefits, others are far more suspect. Many popular breakfast choices are starchy and or sugary, and foods high in starch and sugar are potentially associated with increased morbidity and mortality. To our knowledge, there is no published population-level data to indicate that replacing eggs with these foods confers net benefit, or avoids net harm. Further research is much needed.”
These studies were conducted with funding from the Egg Nutrition Center. Katz and his team are now conducting a study of egg intake by people with Type 2 Diabetes, since diabetes is a risk factor for cardiovascular disease, and consuming excess high-carbohydrate foods can be particularly harmful for these individuals.
About American Heart Journal (http://www.ahjonline.com)
American Heart Journal has been a trusted resource for cardiologists and general practice physicians for more than 80 years. In addition to publishing results of important clinical investigations, the Journal addresses such topics as cost-effectiveness, design of clinical trials, reports of negative clinical trials, and the changing organization of medical care.
About Dr. David L. Katz (http://www.davidkatzmd.com)
David L. Katz, MD, MPH, FACPM, FACP, a board-certified preventive medicine physician, is the founding director of the Yale-Griffin Prevention Research Center, and is currently serving as President of the American College of Lifestyle Medicine. Recipient of numerous awards, including an honorary doctorate and nominations for U.S. Surgeon General, Katz is recognized globally for expertise in nutrition, weight management and chronic disease prevention.
About the Yale-Griffin Prevention Research Center (http://www.yalegriffinprc.org)
The Yale-Griffin Prevention Research Center (PRC) was established in 1998 through funding from the Centers for Disease Control and Prevention. One of 26 Prevention Research Centers nationwide (http://www.cdc.gov/prc) representing academic/community partnerships, the PRC is engaged in interdisciplinary applied prevention research in collaboration with community partners, federal, state, and local health and education agencies, and other universities. The goal is to develop innovative approaches to health promotion and disease prevention that will directly benefit the public's health.
About the Egg Nutrition Center (http://www.eggnutritioncenter.org)
The Egg Nutrition Center (ENC) is dedicated to providing balanced, accurate information on eggs, nutrition, and health, and sponsors scientific research on this topic. Research grants are openly solicited and reviewed by a Scientific Advisory Panel of authorities in health research and clinical practice. Independent scientists guide many of the research projects and provide analysis and interpretation of scientific literature. The ENC is funded by the American Egg Board, which uses funds from egg farmers for promotion and research. The U.S. Department of Agriculture provides oversight of its activities.
“This study highlights an important consideration: when coronary disease patients are advised to avoid or limit a food or food category, what do they eat instead?” Katz said. “While some alternatives to eggs, such as oatmeal, might offer benefits, others are far more suspect. Many popular breakfast choices are starchy and or sugary, and foods high in starch and sugar are potentially associated with increased morbidity and mortality. To our knowledge, there is no published population-level data to indicate that replacing eggs with these foods confers net benefit, or avoids net harm. Further research is much needed.”
These studies were conducted with funding from the Egg Nutrition Center. Katz and his team are now conducting a study of egg intake by people with Type 2 Diabetes, since diabetes is a risk factor for cardiovascular disease, and consuming excess high-carbohydrate foods can be particularly harmful for these individuals.
About American Heart Journal (http://www.ahjonline.com)
American Heart Journal has been a trusted resource for cardiologists and general practice physicians for more than 80 years. In addition to publishing results of important clinical investigations, the Journal addresses such topics as cost-effectiveness, design of clinical trials, reports of negative clinical trials, and the changing organization of medical care.
About Dr. David L. Katz (http://www.davidkatzmd.com)
David L. Katz, MD, MPH, FACPM, FACP, a board-certified preventive medicine physician, is the founding director of the Yale-Griffin Prevention Research Center, and is currently serving as President of the American College of Lifestyle Medicine. Recipient of numerous awards, including an honorary doctorate and nominations for U.S. Surgeon General, Katz is recognized globally for expertise in nutrition, weight management and chronic disease prevention.
About the Yale-Griffin Prevention Research Center (http://www.yalegriffinprc.org)
The Yale-Griffin Prevention Research Center (PRC) was established in 1998 through funding from the Centers for Disease Control and Prevention. One of 26 Prevention Research Centers nationwide (http://www.cdc.gov/prc) representing academic/community partnerships, the PRC is engaged in interdisciplinary applied prevention research in collaboration with community partners, federal, state, and local health and education agencies, and other universities. The goal is to develop innovative approaches to health promotion and disease prevention that will directly benefit the public's health.
About the Egg Nutrition Center (http://www.eggnutritioncenter.org)
The Egg Nutrition Center (ENC) is dedicated to providing balanced, accurate information on eggs, nutrition, and health, and sponsors scientific research on this topic. Research grants are openly solicited and reviewed by a Scientific Advisory Panel of authorities in health research and clinical practice. Independent scientists guide many of the research projects and provide analysis and interpretation of scientific literature. The ENC is funded by the American Egg Board, which uses funds from egg farmers for promotion and research. The U.S. Department of Agriculture provides oversight of its activities.
This is a press release from Griffin Hospital.