The yolk contains two important carotenoids: lutein and zeaxanthin.
These compounds are found in the retina, particularly in an area called the macula.
The macula plays an important role in central vision.
Lutein and zeaxanthin are associated with antioxidant activity and help protect the eyes from certain forms of oxidative stress.
Egg yolks contain these compounds in a form that the body can absorb.
This makes eggs a useful addition to a diet that also includes leafy green vegetables and other colorful plant foods.
However, it would be misleading to claim that eating one boiled egg every morning can prevent cataracts or eliminate the risk of age-related macular degeneration.
Eye health depends on multiple factors, and regular eye examinations remain important.
3. Supporting healthy bones and teeth
Eggs contain vitamin D and phosphorus, both of which contribute to normal bone health.
Vitamin D helps the body absorb calcium.
Calcium is essential for maintaining bone structure and supporting normal muscle function.
Phosphorus also contributes to healthy bones and teeth.
Although eggs contain some vitamin D, they should not be considered a complete solution for people who have inadequate vitamin D intake.
Other dietary sources, appropriate sunlight exposure, and supplements when medically recommended may also be relevant.
Older adults should pay particular attention to their overall intake of bone-supporting nutrients.
4. Helping maintain normal energy metabolism
Eggs contain several B vitamins.
These nutrients participate in the processes that allow the body to convert food into usable energy.
Riboflavin, vitamin B12, and pantothenic acid are examples of nutrients found in eggs.
Vitamin B12 also plays a role in normal nervous system function and the formation of red blood cells.
This is especially important for people who may have inadequate B12 intake.
However, eggs are not stimulants.
They do not provide the immediate energy boost associated with caffeine or sugar.
Their nutritional contribution supports normal metabolic processes over time.
5. Supporting a balanced diet for older adults
As people get older, appetite may change.
Some individuals eat smaller portions, while others find it increasingly difficult to prepare complicated meals.
Boiled eggs can be useful because they are relatively inexpensive, easy to portion, and simple to combine with other foods.
Their protein content may help older adults meet daily protein requirements.
They can also be included in soft-textured meals for people who have difficulty chewing certain foods.
For example, a boiled egg can be mashed with a small amount of yogurt or avocado and served with soft whole-grain bread.
However, people with swallowing difficulties should follow advice from their healthcare professionals regarding appropriate food textures.
6. Why the whole egg matters
Some people choose to eat only egg whites because they want to avoid dietary cholesterol.
While egg whites provide protein, the yolk contains many of the egg's vitamins, minerals, and carotenoids.
Removing the yolk therefore changes the nutritional value of the food.
Whether someone should eat whole eggs or egg whites depends on individual dietary needs and health considerations.
There is no single approach that is suitable for everyone.
7. Eggs are nutritious, but they are not medicine
It is important to avoid exaggerated claims.
Eggs do not cure high blood pressure.
They do not directly eliminate body fat.
They cannot reverse diabetes or repair damaged arteries.
Their value comes from providing nutrients that contribute to normal body functions.
A balanced diet, regular movement, adequate sleep, and appropriate healthcare remain essential.
The 2025 umbrella review of research on egg consumption found that the overall evidence linking eggs to health outcomes was limited in quality, but it did not find sufficient evidence to recommend discouraging egg consumption altogether.
Chapter 3: The Truth About Eggs and Cholesterol β Should You Worry About Eating the Yolk?
For many years, eggs were surrounded by controversy.
Some people were told to avoid egg yolks because they contain cholesterol. Others believed that eating eggs every day could increase the risk of heart disease.
As a result, many households began separating egg whites from yolks or limiting eggs to occasional meals.
But what does current research actually say?
The answer is more complicated than the popular claim that eggs are either completely healthy or dangerous.
1. Why do egg yolks contain cholesterol?
Cholesterol is a waxy substance that the body needs to function normally.
It is involved in producing certain hormones, building cell membranes, and making substances needed for digestion.
The liver produces much of the cholesterol circulating in the body.
Foods from animal sources, including eggs, also contain dietary cholesterol.
A large egg contains approximately 185β190 milligrams of cholesterol, most of which is concentrated in the yolk.
This is why egg consumption has traditionally received attention in discussions about heart health.
However, dietary cholesterol and blood cholesterol are not exactly the same thing.
Eating a food containing cholesterol does not automatically mean that blood cholesterol will increase by the same amount.
The body's response varies between individuals.
2. Understanding LDL and HDL cholesterol
When discussing cholesterol, two terms frequently appear: LDL and HDL.
LDL stands for low-density lipoprotein.
It transports cholesterol through the bloodstream. Elevated LDL cholesterol is associated with an increased risk of cardiovascular disease because LDL particles can contribute to plaque formation in artery walls.
HDL stands for high-density lipoprotein.
It participates in transporting cholesterol away from tissues toward the liver.
These two types of lipoproteins are often described as bad and good cholesterol, respectively.
However, cardiovascular health is more complicated than looking at one number.
Blood pressure, smoking, diabetes, genetics, physical activity, and other dietary factors also influence cardiovascular risk.
3. Can eating eggs increase LDL cholesterol?
Some controlled studies have found that consuming more eggs can increase LDL cholesterol in certain individuals.
However, the response varies.
Other research suggests that the overall dietary pattern, particularly saturated fat intake, may have a substantial influence on blood cholesterol.
A randomized crossover study published in the American Journal of Clinical Nutrition in 2025 examined the effects of dietary cholesterol and saturated fat.
Researchers compared different dietary patterns, including one containing two eggs per day alongside a low-saturated-fat diet.
The study found that saturated fat intake was positively associated with LDL cholesterol, while dietary cholesterol was not independently associated with LDL changes in the same analysis.
The findings suggest that the foods eaten alongside eggs matter considerably.
For example, two boiled eggs served with vegetables and whole-grain bread represent a different dietary pattern from eggs regularly eaten with large portions of bacon, sausage, butter, and processed meat.
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4. Is eating the yolk better than eating only egg whites?
The answer depends on individual nutritional needs.
Egg whites provide protein with very little fat and no dietary cholesterol.
However, the yolk contains many important nutrients, including choline, vitamin B12, vitamin A, selenium, and carotenoids.
Removing the yolk means losing some of these nutrients.
For healthy adults without specific dietary restrictions, eating the whole egg can be a reasonable choice.
People who need to limit dietary cholesterol or manage particular medical conditions may benefit from discussing their egg intake with a healthcare professional.