Eggs: Should we eat them, and why is advice still polarized?

Eggs are one of those controversial foods that we were warned against for almost half a century. However, recent years have seen both the American Heart Association and Dietary Guidelines for Americans reverse their restrictions on eggs and dietary cholesterol intake. Rightly so – the evidence didn’t support them, and their redirected emphasis on dietary patterns takes us in a better direction. In this article, you’ll find out why eggs, including choline-rich egg yolks, are a valuable part of a varied, nutrient-dense (and epinutrient nutrient-dense!) diet, and why we should value them for longevity. – DrKF

The great egg controversy

No food has generated such debate among nutrition experts over the years as the humble egg. The primary reason for this controversy is their cholesterol content that nay-sayers warn can clog your arteries. And of course the decades of dietary guidelines that recommended limiting egg intake or avoiding eggs altogether, even as those have now changed to acknowledge that eggs are not harmful as once thought. As the Scientific Report of the 2015 Dietary Guidelines Advisory Committee stated: “Cholesterol is not a nutrient of concern for overconsumption.” Actually, overconsumption of anything could be a concern if it leads to nutrient imbalance, but nevertheless, that’s a pretty clear statement.

A recent scientific review paper looking at all the studies that have been conducted on eggs available at that time found that most studies on egg consumption have found that moderate egg intake (1 egg per day) is not associated with any increased risk for heart disease, stroke, or type 2 diabetes in individuals who are otherwise healthy.

We know now that the cholesterol-heart disease theory was oversimplified. And there is no direct evidence to support any link between egg consumption and heart disease in healthy people. In addition, the effect of dietary cholesterol consumption on serum cholesterol turns out to be rather small for most of us, and not as concerning as other foods that can increase the risk for atherosclerosis (arterial plaque) such as refined carbohydrates and sugars. Or even the lack of a phytonutrient-rich diet (those epinutrient plant components are so important for heart health too!). 

Not least, total cholesterol values are of negligible concern in relation to heart disease. It’s the oxidized form of LDL-cholesterol that we want to pay attention to. Oxidized LDL is measurable through advanced lipid panels which are widely accessible through standard labs – you should be able to obtain this through your doctor.

Eggs are egg-cellent for longevity

Eggs are a good food for longevity in part because they provide a rich source of nutrition needed for healthy DNA methylation. And we know that healthy, balanced DNA methylation directly impacts biological age. 

Don’t throw out the egg yolks! They are one of the best food sources of choline (aside from liver), which is a regularly under-consumed yet vital methyl donor (as well as being helpful for brain function, mood, liver health, pregnancy, and more). Only about 10 percent of Americans meet the recommended intake for choline. That’s concerning! Its methyl donor action is what we call “back-door” methylation support. Here’s how that works: choline is resource-intensive for your body to make by itself, and the process sucks up S-adenosylmethionine (SAMe) – the universal methyl donor that donates methyl groups to be used in epigenetic activity. If you supply enough choline through your diet, you preserve SAMe. This can help plug any holes in the methylation process, leaving more SAMe available for DNA methylation.

Choline can also be used in the body to form betaine. Betaine is important since it’s a cofactor for the metabolism of homocysteine to methionine, helping to reduce a compound (homocysteine) that is potentially harmful in high amounts, and form a precursor (methionine) to make more SAMe.

Incidentally, other foods which contain reasonable amounts of choline include mushrooms, cauliflower, and seaweed. You can find a list of choline-containing foods in my Younger You book on page 414.

And if you need a supplemental choline top-up, here are some good options:

In addition to choline, eggs are an excellent and still relatively inexpensive source of protein – about 6g in one large egg. Protein intake is an essential consideration as we get older – it helps preserve muscle mass, which helps maintain physical function and better metabolic health (less insulin resistance, diabetes, and heart disease). Read more about the essentiality of protein as we age here: Dr. Kara Fitzgerald – The Protein Magic Formula.

They also provide important B vitamins including folate and vitamin B12, and can be one of the only sources of the latter animal food-based nutrient for vegetarians. Not least, they are excellent sources of vitamin A, vitamin E, biotin, selenium, calcium, zinc, and antioxidants like lutein and zeaxanthin. Most of the fat-soluble vitamins and antioxidants are found in the yolk, as is the most controversial egg nutrient, cholesterol.

Are there any instances in which we would reduce or avoid eggs?

Although for healthy people, egg consumption seems to be fine and even beneficial, there are some areas where we (the scientific and clinical communities writ large) are still teasing out the nuances. Some data do suggest a difference in how some individuals, including those with genetic hyperlipidemias or who already have pre-existing heart disease or type 2 diabetes, respond to dietary cholesterol. But the link isn’t yet clear. When we work with such individuals in our clinic, (and indeed healthy individuals who want to be proactive about managing any future disease risk) we track cholesterol levels, and especially the levels of cholesterol subtypes, inflammation, and related factors (through advanced lipid profile tests), closely. This allows us to work on improving risk profiles, and be able to track any impact of dietary cholesterol intake on those numbers. It may be that in the future, we will be able to predict who is a “hyper-responder” to dietary cholesterol and saturated fats through genomic (and likely genomic plus other analyte/omic) testing.

Another potential reason for reconsidering dietary egg intake is in the case of allergy or food sensitivity. Eggs are one of the top allergenic foods, and must be avoided by those who have a true egg allergy. They can also be a cause of delayed food sensitivity which can drive a myriad of seemingly-disconnected symptoms such as headaches, joint pain, fatigue, poor mood, and digestive symptoms. Delayed sensitivity to egg is not that common, but it’s best to work with your functional medicine practitioner if you suspect this kind of reaction to receive guidance on testing and/or a trial food elimination.

What are the egg recommendations within the Younger You program?

Because of the concentrated amount of epigenetically-targeted and methylation-supportive nutrients within eggs, they feature prominently in the Younger You program, especially in the 8-week Younger You Intensive, which is the protocol used in our research studies. 

For the 8-week Younger You Intensive, participants aim to consume 5-10 eggs per week (equivalent to 0.7 – 1.4 eggs per day), leaning on the higher end especially if not also eating liver. 

The nutritional profile of eggs, including vitamins, minerals, types of fat (unsaturated or saturated), and antioxidants, directly reflects the composition of nutrients in a hen’s diet. It’s in this way that eggs can be labeled “omega-3” eggs since they come from hens fed a diet that contains flaxseed (a rich source of omega-3 fats). In addition, hens that are “free range” usually produce eggs that are higher in vitamin E and lutein as compared to battery cage and organic-only hens. Our recommendations are to look for the labels free-range, organic, and omega-3.

We don’t recommend consuming raw, unpasteurized eggs since there is a danger of food-borne illness (especially Salmonella), and because of the presence of certain proteins in raw egg such as avidin which can bind biotin, inhibiting its absorption and use in the body. Cooking denatures avidin, solving the potential problem.

My favorite ways to eat eggs

My best advice is to eat eggs along with other DNA methylation superstars – add some turmeric to scrambled eggs, add shiitake mushrooms to an omelet and sauté greens in the same pan, or pop a hard-boiled egg on a spinach and beet salad. 

Here’s one of my favorite egg recipes: Middle Eastern Shakshuka