Americans have
significantly increased egg intake over the last decade, consuming on average
3-4 eggs per week. Part of their renewed appeal stems from U.S. Dietary
Guidelines that dropped the long standing recommendation to limit dietary
cholesterol to less than 300mg. However, the controversy over eggs, dietary
cholesterol, and heart disease was recently reignited by a recent study that
found an association between egg and dietary cholesterol consumption and higher
rates of heart disease.
Cholesterol is a waxy substance
produced by the body to synthesize hormones, produce bile for digestion, make
vitamin D, and maintain healthy cell walls.
Advice to limit dietary cholesterol dates back 50 years, but randomized
trials conducted over the last 15 years have indicated healthy human bodies
control the amount of cholesterol in the bloodstream, and can detect and adjust
the body’s cholesterol production if dietary cholesterol increases or decreases. It also appears that our systems can excrete
unneeded dietary cholesterol, especially if individuals consume adequate
dietary fiber. As a result, even though
yokes contain nearly 200 mg of cholesterol, there has been growing consensus
that low to moderate egg intake is not significantly associated with a higher
risk of CVD. Eggs also contain nutrients
that have been linked to a lower risk of heart disease. Eggs pack 7g of high-quality protein with
about half of this found in the white. Yolks also contain a significant amount
of the brain-nutrient choline, plus vitamin B12 and iron. Eggs are also one of
the few dietary sources of vitamin D and are a good source of the carotenoids
lutein and zeaxanthin that have been linked to lower odds of macular
degeneration.
In terms of dietary
drivers of heart disease unhealthy saturated and trans fats have been found to
be much more significant that dietary cholesterol. Recommendations to limit saturated fats (the
fats found in meat, chicken skin, and dairy) and completely avoid trans fats
(artificial fats used to manufacture baked goods, frosting, and spreads) are
still in place. Most foods high in
cholesterol are also high in saturated fats.
However, some foods high in cholesterol are not high in saturated fats
including egg yokes, shellfish, and liver.
The new analysis of
eggs and heart disease, drawn from the pooled data of six observational studies
that followed nearly 30,000 Americans for up to 31 years, found that eating 3-4
eggs per week was associated with a 6% higher risk of cardiovascular disease
and an 8% higher risk of any cause of death.
And, eating at least 300mg of dietary cholesterol per day was associated
with 17% higher risk of cardiovascular disease and 18% higher risk of all-cause
deaths.
Experts caution that
the recent analysis has many limitations that may have lead to misleading
conclusions. One shortcoming was
participants' long-term eating patterns were not assessed. Participants self-reported their typical
intake at a single visit at the outset of the studies while heart health
outcomes were assessed up to 30 years later. During this time, individuals may have significantly
changed their diet. So, this one snapshot may not have accurately captured
their eating habits over time.
When evaluating whether
or not eggs are healthy, it is also important to look at eggs not only on their
own, but in context of the entire diet, especially when compared to foods they
may replace. There is widespread
consensus that eggs are a better choice than options high in saturated fat
(e.g. butter, pastries, cheese, bacon), refined grains, and/or sugars. And, eggs are one of the few typical breakfast
foods that are not high in carbohydrates.
A recent study illustrates one of the benefits of eating a lower carb
breakfast for those with diabetes. It
found that when a person with diabetes takes a low carb breakfast their blood
sugar response to meals later in the day is less pronounced than when they have
a higher carb breakfast (e.g. oatmeal, cereal, toast). To the cardiovascular system, scrambled eggs,
salsa, and a 100% whole-wheat English muffin is a far different meal than
scrambled eggs with cheese, sausages, home fries, and buttered white toast.
What
to do: Even though
cholesterol is still in bold on the nutrition facts labels, focus your gaze
more on the amount of saturated and trans fat listed above cholesterol. To control your blood cholesterol eat a
healthy diet rich in plant-derived fats (i.e. olive oil, nuts, avocado), fruits
and vegetables, whole grains, and lean proteins. Emphasize foods high in
soluble fiber such as beans, oats, barley, and gummier fruits and vegetables
including avocado, okra, plums, apples, oranges, green beans, and carrots. Control your weight, exercise regularly, don’t
smoke, and take cholesterol lowering medicine as prescribed by your provider.
As for the eggs, looking
at the body of research on this topic, there is not strong evidence that
limiting consumption of cholesterol-rich foods lowers the amount of
artery-clogging LDL cholesterol that ends up in our blood. For those without
heart health problems, average intake of up to 1 egg per day is likely a
healthy choice. Experts still caution
diabetics and others at high risk for heart disease to be mindful of cholesterol
intake. Some advise diabetics have no
more than 3-4 egg yolks weekly. The
whites, a fantastic source of lean protein contain almost no cholesterol. Discuss dietary cholesterol intake with your
healthcare provider to determine what a safe level of egg consumption is for
you given your health situation.
Sources
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FB, Stampfer MJ, Rimm EB, et al. A
prospective study of egg consumption and risk of cardiovascular disease in men
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Jacobson TA, Maki
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Department of Health and Human Services and U.S. Department of
Agriculture. 2015 – 2020 Dietary Guidelines for
Americans; 2015. Available
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Adapted
from articles available at:
