Impact of Dietary Cholesterol on Clinical Biomarkers
The Blood Cholesterol Equation
Blood cholesterol levels are largely dependent on an individuals genetic profile, which can impact both sides of the blood cholesterol equationendogenous cholesterol production and dietary cholesterol absorption. About one-third of individuals experience an increase in their blood cholesterol levels when they eat dietary cholesterol. This group is often referred to as hyper-responders.2
LDL/HDL Ratio
Early studies examined total serum cholesterol as the primary marker for cardiovascular disease risk and placed significant emphasis on the role of dietary cholesterol in total serum cholesterol levels. Modern research has identified a number of clinical biomarkers used to assess cardiovascular disease risk, one of which is lipoprotein ratios. Clinical trials demonstrate that the LDL/HDL cholesterol ratio is predicted to increase 0.01 mmol per 100-mg/d increase in dietary cholesterol. This increase is unlikely to significantly affect cardiovascular disease risk.3
Studies have looked at the effect of egg consumption on blood cholesterol levels and have found little impact. Egg consumption has been found to slightly elevate LDL cholesterol, but HDL cholesterol rises as well and so does not significantly impact the LDL/HDL ratio. This is important because a review of more than 30 studies published in the Journal of the American College of Nutrition suggests that the LDL/HDL ratio is a much better indicator of heart disease risk than either LDL or HDL alone.4
Researchers at the University of Connecticut found that healthy older adults who eat three eggs a day for one month do not experience an increase to their LDL/HDL ratio or to the ratio between total cholesterol and HDL cholesterol, another major indicator for heart disease risk.5
Another Piece of the Puzzle: Saturated Fat
Research has shown that saturated fat may be more likely to raise a persons serum cholesterol than dietary cholesterol.6 As previously mentioned, international dietary guidelines do not set upper limits for dietary cholesterol, rather they focus on messages to control intake of saturated fat and trans fat.
A number of animal-protein foods such as meats and dairy contain both dietary cholesterol and saturated fat, but other foods such as eggs and shrimp are unique in that they are rich in cholesterol but relatively low in saturated fat.
For Healthy Adults, An Egg a Day is OK
More than 40 Years of Research
Years of mixed messages regarding dietary cholesterol have led to avoidance of foods, such as eggs, to prevent chronic diseases. However, avoiding such foods could negatively impact intake of other nutrients such as high-quality protein and other essential vitamins and minerals.
A study published in Medical Science Monitor including 9,500 people demonstrates that eating one or two eggs a day does not increase the risk of heart disease or stroke among healthy adults. The study notes that eating eggs may actually be associated with a decrease in blood pressure.7
A review of more than 25 studies that appeared in the Journal of the American College of Nutrition shows that eating an egg a day is not associated with increased risk of heart disease in healthy men and women, even after taking into account other aspects of their diet that may increase the risk for heart disease.8
Nutrition Bulletin also published a review of scientific studies from the past 30 years showing that eating eggs daily does not have a significant impact on blood cholesterol or heart disease risk. The authors note several benefits of egg consumption, such as the high-quality protein eggs provide, and argue that consumption of one to two eggs a day should be actively encouraged as part of a calorie-restricted weight loss plan.9
Dietary Guidelines: Eggs on MyPlate
The 2010 Dietary Guidelines for Americans state that the daily consumption of a whole egg does not result in increased blood cholesterol levels nor does it increase the risk of cardiovascular disease in healthy people.10 Additionally, eggs are cited by the Guidelines as a desirable protein source and included in the Protein Foods section on MyPlate.
When helping patients and clients build a healthy plate, give eggs the company that they deserve. Too often eggs are associated with high-fat meats and other pan-fried accompaniments, but that does not have to be the case. Vegetables, whole grains and low-fat dairy make perfect partners with eggs for more recipes and information, check out the below links.
- Downloadable ENC MyPlate Resources
- MyPlate
- Dietary Guidelines for Americans 2010
- Recipes on IncredibleEgg.org
Powerful Nutrient Package with Less Cholesterol Than Ever Before
One large egg has 13 essential vitamins and minerals in varying amounts, high-quality protein and antioxidants, all for 70 calories a piece. The nutrients found in eggs can play a role in weight management, muscle strength, healthy pregnancy, brain function and more.
| Nutrient | Whole Egg | % Daily Value |
|---|---|---|
| Calories | 70 | 4% |
| Total Fat | 5 g | 7% |
| Saturated Fat | 1.5 g | 8% |
| Cholesterol | 185 mg | 60% |
| Protein | 6 g | 13% |
| Folate | 24 mcg | 6% |
| Iron | 0.88 mg | 4% |
| Zinc | 0.65 mg | 4% |
| Riboflavin | 0.2 mg | 10% |
| Selenium | 15.4 mcg | 20% |
| Vitamin D | 41 IU | 10% |
| Choline | 126 mg | 23% |
The United States Department of Agriculture (USDA) recently reviewed egg nutrient data to update the USDA National Nutrient Database for Standard Reference. The results show that the average amount of cholesterol in a Grade A large egg is 185 mg, 12 percent lower than the 212 mg previously reported. The latest version of the USDA database, release 23, includes the most up-to-date nutrition information from this analysis.