Health Benefits of Eggs

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Heart Disease and Cancer

One egg per day associated with 12 percent reduced risk of stroke

On the heels of the 2015 Dietary Guidelines for Americans that placed no daily limit on dietary cholesterol and noted eggs are an affordable, accessible, nutrient-rich source of high quality protein, new research shows eggs are associated with a 12 percent reduction in the risk of stroke, the 5th leading cause of death in the United States.

The study is published in the Journal of the American College of Nutrition (1). Researchers report that consumption of up to one egg per day had no association with coronary heart disease (CHD) and a 12 percent reduction of stroke risk. These findings come from a systematic review and meta-analysis of studies dating back between 1982 and 2015, which evaluated relationships between egg intake and coronary heart disease (total of 276,000 subjects) and stroke (total of 308,000 subjects).

Principal Investigator on this study, Dr. Dominik Alexander of the EpidStat Institute, Ann Arbor, MI, notes that mechanistic work is needed to understand the connection between egg consumption and stroke risk. However, he theorizes that, "Eggs do have many positive nutritional attributes, including antioxidants, which have been shown to reduce oxidative stress and inflammation. They are also an excellent source of protein, which has been related to lower blood pressure."

One large egg boasts 6 grams of high-quality protein and antioxidants lutein and zeaxanthin, found within the egg yolk, as well as vitamins E, D, and A.

Alexander's research lends further support to changes in the recently-released 2015 Dietary Guidelines for Americans, which have eliminated dietary cholesterol limits, and now include regular consumption of eggs among lean protein choices. It also builds on a 2015 meta-analysis in which dietary cholesterol was shown to have no association with cardiovascular diseases, including coronary artery disease and stroke .

Eggs may help prevent heart disease and cancer

One of nature's most perfect foods may be even better for us than previously thought.

While eggs are well known to be an excellent source of proteins, lipids, vitamins and minerals, researchers at the University of Alberta recently discovered they also contain antioxidant properties, which helps in the prevention of cardiovascular disease and cancer.

Jianping Wu, Andreas Schieber and graduate students Chamila Nimalaratne and Daise Lopes-Lutz of the U of A Department of Agricultural Food and Nutritional Science examined egg yolks produced by hens fed typical diets of either primarily wheat or corn. They found the yolks contained two amino acids, tryptophan and tyrosine, which have high antioxidant properties.

After analyzing the properties, the researchers determined that two egg yolks in their raw state have almost twice as many antioxidant properties as an apple and about the same as half a serving (25 grams) of cranberries.

However, when the eggs were fried or boiled, antioxidant properties were reduced by about half, and a little more than half if the eggs were cooked in a microwave.

"It's a big reduction but it still leaves eggs equal to apples in their antioxidant value," said Wu.

The findings were published in the peer-reviewed journal Food Chemistry.

The discovery of these two amino acids, while important, may only signify the beginning of finding antioxidant properties in egg yolks, said Wu, an associate professor of agricultural, food and nutritional science.

"Ultimately, we're trying to map antioxidants in egg yolks so we have to look at all of the properties in the yolks that could contain antioxidants, as well as how the eggs are ingested," said Wu, adding that he and his team will examine the other type of antioxidant already known to be in eggs, carotenoids, the yellow pigment in egg yolk, as well as peptides.

In previous research, Wu found that egg proteins were converted by enzymes in the stomach and small intestines and produced peptides that act the same way as ACE inhibitors, prescriptions drugs that are used to lower high blood pressure.

That finding defied common wisdom and contradicted the public perception that eggs increased high blood pressure because of their high cholesterol content. Additional research by Wu suggests the peptides can be formulated to help prevent and treat hypertension.

Wu is convinced the peptides also have some antioxidant properties, which leads him to suggest that when he completes the next step in his research, the result will likely be that eggs have more antioxidant properties than we currently know.

Egg white protein may help high blood pressure

Scientists reported new evidence today that a component of egg whites — already popular as a substitute for whole eggs among health-conscious consumers concerned about cholesterol in the yolk — may have another beneficial effect in reducing blood pressure. Their study was part of the 245th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society, which continues here through Thursday.

"Our research suggests that there may be another reason to call it 'the incredible, edible egg,'" said study leader Zhipeng Yu, Ph.D., of Jilin University. "We have evidence from the laboratory that a substance in egg white — it's a peptide, one of the building blocks of proteins — reduces blood pressure about as much as a low dose of Captopril, a high-blood-pressure drug."

Yu and colleagues, who are with Clemson University, used a peptide called RVPSL. Scientists previously discovered that the substance, like the family of medications that includes Captopril, Vasotec and Monopril, was an angiotensin-converting-enzyme (ACE) inhibitor. It has a powerful ability to inhibit or block the action of ACE, a substance produced in the body that raises blood pressure.

They set out to further document RVPSL's effects, using laboratory rats that develop high blood pressure and are stand-ins for humans in such early research on hypertension. The results of feeding the substance were positive, showing that RVPSL did not have apparent toxic effects and lowered blood pressure by amounts comparable to low doses of Captopril.

"Our results support and enhance previous findings on this topic," Yu said. "They were promising enough to move ahead with further research on the effects of the egg white peptide on human health."

Yu noted that the research was done with a version of the peptide that was heated to almost 200 degrees Fahrenheit during preparation — less than the temperatures typically used to cook eggs. He cited evidence from other research, however, that egg whites may retain their beneficial effects on blood pressure after cooking.

One, for instance, published in the ACS' Journal of Agricultural and Food Chemistry, showed that fried egg protein, cooked at high temperatures, actually showed greater ability to reduce blood pressure than eggs boiled at 212 degrees F.

Yu believes that egg white peptides, either in eggs or as a supplement, could become useful as an adjunct to high-blood-pressure medication. For now, he said people with high blood pressure should consult their health care provider before making any changes.

And he noted that findings about egg white and high blood pressure add to the emerging nutritional image of eggs. Once regarded as a food to avoid in a healthy diet, studies in recent years have concluded that many people can eat eggs without raising their blood cholesterol levels, benefiting from an inexpensive food low in calories and rich in protein, vitamins and other nutrients.

Miscellaneous

Eating eggs reduces risk of type 2 diabetes

Egg consumption may reduce the risk of type 2 diabetes,  according to new research from the University of Eastern Finland. The findings were published in American Journal of Clinical Nutrition.

Type 2 diabetes is becoming increasingly widespread throughout the world. Research has shown that lifestyle habits, such as exercise and nutrition, play a crucial role in the development of the disease. In some studies, high-cholesterol diets have been associated with disturbances in glucose metabolism and risk of type 2 diabetes. In contrast, in some experimental studies, the consumption of eggs has led to improved glucose balance, among other things. However, there is no experimental data available on the effects of egg consumption on the incidence of type 2 diabetes. In population-based studies, too, the association between egg consumption and type 2 diabetes has been investigated only scarcely, and the findings have been inconclusive. Egg consumption has either been associated with an elevated risk, or no association has been found.

The dietary habits of 2,332 men aged between 42 and 60 years were assessed at the baseline of the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, at the University of Eastern Finland in 1984-1989. During a follow-up of 19.3 years, 432 men were diagnosed with type 2 diabetes.

The study found that egg consumption was associated with a lower risk of type 2 diabetes as well as with lower blood glucose levels. Men who ate approximately four eggs per week had a 37 per cent lower risk of type 2 diabetes than men who only ate approximately one egg per week. This association persisted even after possible confounding factors such as physical activity, body mass index, smoking and consumption of fruits and vegetables were taken into consideration. The consumption of more than four eggs did not bring any significant additional benefits.

A possible explanation is that unlike in many other populations, egg consumption in Finland is not strongly associated with unhealthy lifestyle habits such as smoking, low physical activity or consumption of processed meats. In addition to cholesterol, eggs contain many beneficial nutrients that can have an effect on, for example, glucose metabolism and low-grade inflammation, and thus lower the risk of type 2 diabetes. The study also suggests that the overall health effects of foods are difficult to anticipate based on an individual nutrient such as cholesterol alone. Indeed, instead of focusing on individual nutrients, nutrition research has increasingly focused on the health effects of whole foods and diets over the past few years.

Consuming eggs with raw vegetables increases nutritive value

There is burgeoning research showing that co-consuming cooked whole eggs with your veggies can increase carotenoids absorption. With the recent scientific report from the 2015 Dietary Guidelines Advisory Committee lessening past concern over cholesterol in eggs, this is particularly good news.
"Americans under consume vegetables, and here we have a way to increase the nutritive value of veggies while also receiving the nutritional benefits of egg yolks," said Wayne Campbell, Ph.D., Professor of Nutrition Science, Purdue University.

Campbell, working with postdoc fellow Jung Eun Kim, Ph.D., R.D., conducted a study to assess the effects of egg consumption on carotenoid absorption from a raw mixed-vegetable salad. Sixteen healthy young men ate three versions of the salad -- one with no egg, one with 1.5 scrambled whole eggs, and another with 3 scrambled whole eggs. Those who ate the highest egg amount with the salad of tomatoes, shredded carrots, baby spinach, romaine lettuce, and Chinese wolfberry increased absorption of carotenoids 3-9 fold. This is a very significant effect, said Campbell. The carotenoids found in the salad include beta-carotene, alpha-carotene, lycopene, lutein, and zeaxanthin, the latter two being found in egg yolk as well.

The research grew out of his group's previous study showing that by adding certain oils to mixed raw vegetables, the consumer experienced enhanced absorption of carotenoids.

"Next time you visit a salad bar, consider adding the cooked egg to your raw veggies," said Campbell. "Not only are lutein and zeaxanthin available through whole eggs, but now the value of the vegetables is enhanced."

The research findings will be presented at the American Society for Nutrition's Annual Meeting during Experimental Biology 2015. Campbell believes the beneficial effects seen in this college-age population will extend to all populations and ages. His group would like to expand their research to explore the effects on other fat-soluble nutrients including vitamin E and vitamin D.

Eat spinach or eggs: Tyrosine helps you stop faster, think better and cheer up

A child suddenly runs out into the road. Brake!! A driver who has recently eaten spinach or eggs will stop faster, thanks to the amino acid tyrosine found in these and other food products. Leiden cognitive psychologist Lorenza Colzato publishes her findings in the journal Neuropsychologia.

The German philosopher Ludwig Feuerbach has already said it: Der Mensch ist was er iβt. You are what you eat. Substances that we ingest through our food can determine our behaviour and the way we experience our environment. Researchers at Leiden University and the University of Amsterdam have carried out the first-ever study to test whether the intake of tyrosine enhances our ability to stop an activity at lightning speed. The findings seem to indicate that this is the case.

Stopping task

Colzato and her colleagues created a situation in which test candidates had to interrupt a repetitive activity at a given instant. The researchers tested this using a stopping task: the participants were told to look carefully at a computer screen. Whenever a green arrow appeared, they had to press a button as quickly as possible. At the same time they had to make sure the button they chose matched the direction of the arrow. If a red arrow appeared on the screen, the candidates had to keep their hands off the keyboard altogether.

Tyrosine or a placebo

The participants had two sessions in the test lab. On one occasion they were given orange to drink that contained tyrosine, and on the other occasion the orange juice contained a placebo. The tests showed that the candidates performed better on the stopping task if they had drunk the juice with tyrosine.

Benefits

The positive effect of tyrosine on our reaction speed can have benefits for road safety. For example, if a queue suddenly forms, fast reflexes can prevent an accident. But there are many more examples.

Colzato: 'Tyrosine food supplements and tyrosine-rich food are a healthy and inexpensive way of improving our intellectual capabilities. This makes them preferable to Ritalin and Modafinil, products that students often reach for to improve their academic performance. Tyrosine is safe and doesn't need a doctor's prescription.


What is tyrosine?

Tyrosine is found in such foods as spinach, eggs, cottage cheese and soya. Anyone who doesn't eat enough of these foodstuffs produces too little dopamine, which can lead to depression and apathy.