By Dr. Eduardo Gonzales
Q: I read a newspaper article that says a recent scientific study showed that eggs increase one’s risk for heart disease and stroke. I thought that it has already been established by previous research that eggs do not increase this risk? I’m confused? Are eggs good or bad for health? —firstname.lastname@example.org
I empathize with you. Just when we thought the debate on eggs and heart disease has been finally put to rest in favor of eggs, new findings published in the March 15 issue of the Journal of the American Medical Association (JAMA) has rekindled the issue. In this latest report, researchers analyzed data from six prospective studies that followed close to 30,000 American men and women for up to 31 years and arrived at the conclusion that eating an extra half-egg a day on top of one’s regular diet increased the risk of cardiovascular disease (six percent) and premature death (eight percent) over the study period.
The debate’s timeline
The debate on the relationship between egg consumption and heart disease began in the 1960s when the American Heart Association (AHA) advised people to limit their intake of eggs to three-four per week (two for people with known coronary heart disease) because eggs contain a lot of cholesterol, which if abundant in the bloodstream is deposited in the walls of blood vessels, a condition (atherosclerosis) that is a major underlying cause of heart attack and stroke. A medium-sized egg contains 177mg cholesterol, which already represents 60 percent of the recommended daily consumption of the substance for adults.
In 2000, however, AHA made a turnaround on its recommendation on egg intake because newer research, including a large US study published in 1999, has shown that consumption of one egg per day is unlikely to have any substantial overall impact on the risk for coronary heart disease or stroke in healthy people. That year, the AHA has decided to no longer make any recommendation on how many eggs can be eaten per week.
In terms of nutritional value, an egg is unrivaled by any other food item, and it is incredibly cheap.
Since then, several other studies like the 2013 analysis of three million adults published in the British Medical Journal (BMJ) confirmed that egg consumption has no impact on the incidence of heart disease. A Chinese study published in May, 2018 in Heart, a reputable journal, has in fact concluded that eggs are good for the heart and blood vessels. The study tracked half a million subjects over nine years and analysis of the data showed that daily egg-eaters compared to non-egg consumers had an 18 percent lower risk for cardio-vascular disease death (i.e., heart attacks, arrhythmias, etc.) and a 28 percent lower risk for hemorrhagic stroke death.
What would be the impact of the latest research findings?
All told, although this latest study does not establish a causal link between egg consumption and cardiovascular disease. It presents a good argument that eggs and overall dietary cholesterol intake remain important in affecting the risk of (cardiovascular disease) and more so the risk of all-cause mortality. But it will unlikely change the current dietary guidelines on egg consumption by medical experts’ groups in the different countries of the world because this is just a single study while the contrary evidence is overwhelming.
Incidentally, in terms of nutritional value, an egg is unrivaled by any other food item, and it is incredibly cheap.
Although not a good source of calories—a medium-sized chicken egg supplies a mere 66 calories, which amount to only around three percent of the average energy requirement of an adult—an egg is loaded with proteins and micronutrients (i.e., vitamins and minerals).
The proteins in eggs are easily digestible and of high quality. A medium-sized egg contains about 6.1 grams of proteins, enough to supply about 10 percent of a person’s daily requirement. These proteins contain all the essential amino acids that are needed for growth and development.
Eggs are excellent sources of essential minerals including iodine, necessary to produce thyroid hormone; phosphorus and calcium, required for bone health; zinc, vital for wound healing, growth, and fighting infection; iron, the essential component of red blood cells; and vitamins A, D, B6 and B12, thiamine, riboflavin, niacin, and folate.
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