So how many eggs does it take to negatively affect blood cholesterol and harm the heart? The answer so far has been a bit scrambled. The U.S. Food and Drug Administration recommends eating less than 300 milligrams (mg) of dietary cholesterol per day. A large chicken egg contains 186 mg of this fat-like substance, according to an article published in June 2018 in the journal Nutrients. The National Heart Foundation of Australia advises that people consume no more than seven of these cholesterol bombs per week. But a new investigation from scientists in Finland suggests that eating up to an egg a day may not be a danger when it comes to stroke risk. The report, published in May 2019 in The American Journal of Clinical Nutrition, indicated that men who consumed more than six eggs per week had no greater risk of stroke than those who ate an average of fewer than two per week. “This study — and the majority of other studies — suggests that up to one egg per day should be okay for most people,” says Jyrki Virtanen, PhD, study author and adjunct professor in nutritional epidemiology at the University of Eastern Finland Institute of Public Health and Clinical Nutrition.
Chances of Stroke Did Not Rise With Higher Cholesterol Consumption
Dr. Virtanen and his colleagues analyzed the health and dietary habits of 1,950 men, ages 42 to 60, who had no sign of heart disease at the beginning of the investigation. At the end of a 21-year follow-up period, 217 men had suffered a stroke. Scientists evaluated subjects in four groups ranging from those who ate less than 333 mg of dietary cholesterol a day or less from all food sources to those who consumed 459 mg or more per day. On average, the study participants took in 408 mg of dietary cholesterol daily, with an average of 28 percent derived from eggs. Those in the highest intake category had an average daily cholesterol intake of about 520 mg and they consumed an average of one egg per day. In addition to eggs, sources of high cholesterol include steak, liver, shrimp, and whole milk dairy products, like ice cream. “We did not find any increased risk of stroke among those in the highest egg or cholesterol intake quartiles when compared with the lowest quartile,” says Virtanen. Separate research, published in October 2016 in the Journal of the American College of Nutrition, observed that eating one egg a day might even reduce stroke risk by 12 percent.
A ‘High Cholesterol’ Gene Did Not Pose a Greater Risk
Study authors also examined how dietary cholesterol intake impacted those with the ApoE4 genotype. ApoE is a protein that is involved in transporting cholesterol throughout the bloodstream. People who carry a variant — ApoE4 — are more likely to have higher levels of bad cholesterol (LDL), which builds up and blocks arteries. ApoE4 has been shown to increase the risk for heart disease as well as Alzheimer’s disease. About 10 to 15 percent of the general population have this version of ApoE, according to an article published in April 2017 by Cognitive Vitality, and in Finland, almost one-third are carriers. This study identified 325 men with ApoE4. “In theory, higher egg and cholesterol intake could be more harmful among these people,” says Virtanen. “However, we did not observe any association [with higher stroke risk] among the participants with the ApoE4 genotype. This strengthened our finding that egg or cholesterol intakes were not associated with stroke risk.”
On the Flip Side, Too Many Eggs Might Be Dangerous
Still, egg lovers may want to proceed with caution. Study authors emphasize that their results only applied to those eating up to one egg per day and could not be generalized beyond that level. In fact, research published in March 2019 in the Journal of the American Medical Association warned that consuming more than two eggs per day could heighten the risk of developing cardiovascular diseases and death. In this study, scientists tracked the diets, health, and lifestyle habits of nearly 30,000 adults across the country for up to 31 years and found that cholesterol in eggs, when consumed in large quantities, is associated with negative health effects. According to their findings, each additional 300 mg of cholesterol consumed beyond a baseline of 300 mg per day was linked with a 17 percent higher risk of heart disease and an 18 percent higher risk of death. Satjit Bhusri, MD, a cardiologist at Lenox Hill Hospital in New York City, advises patients that moderation is the key. “Eating one egg a day is moderation,” says Dr. Bhusri, who was not involved in either study. “But three eggs a day may be too much. Heavy consumption of eggs — or anything for that matter — will be unhealthy.” Virtanen and his colleagues point out that their investigation had several limitations — the study population was relatively small and not diverse, and no participants had preexisting cardiovascular disease. “There is a need for clinical trials that would thoroughly investigate the physiological and metabolic effects of high versus low egg intake in humans,” says Virtanen. “Although eggs are a major source of cholesterol in the diet, they are also a rich source of many bioactive compounds, which may have beneficial health effects.”
