Whether eggs are good for heart health has been a contentious issue for decades, but a new review of existing data covering around 300,000 people suggests eating up to one egg a day may lower stroke risk by 12 per cent.
The health effects of eggs have been debated for years. Eggs, which contain cholesterol, were thought to increase risk of heart disease by raising cholesterol levels.
The review, part-funded by the Egg Nutrition Centre, looked at studies between 1982 and 2015, over 13 years, on the relationship between egg intake and heart disease with a total of 276,000 subjects and stroke with a total of 308,000 subjects.
They were from the USA, Japan, Australia, Spain and the UK and had varying follow-up periods ranging from six to 26 years.
Specifically, the review of the evidence on the link between eating eggs and the risk of stroke and heart disease published in the Journal of the American College of Nutrition compared high egg intake of about one egg per day with low egg intake of less than two eggs per week.
The research team from the EpidStat Institute in Michigan and DLW Consulting Services in Utah, both in the US, also, found that daily intake of one egg does not appear to be associated with risk of heart disease.
The research supports the idea that eggs can be part of a healthy diet. However, it didn’t look at people’s whole diet, so we don’t know what else they were eating, or how the eggs were prepared.
Also, the researchers didn’t find that more was better. There was no evidence that people reduced their risk in line with the number of eggs they ate.
Although the findings are unable to determine why eggs could have this stroke-busting ability, its lead author Dominik Alexander believed that eggs have many positive nutritional attributes, including antioxidants, which have been shown to reduce oxidative stress and inflammation.
He noted that eggs are also an excellent source of protein, which has been related to lower blood pressure, adding however that more research will be needed to figure out which aspects of the egg may be ultimately responsible.
Eggs are a good source of nutrients like protein, folate, iodine and vitamins D, A, B2 and B12 as well as lutein and zeaxanthin in the yolk. Yet a single large egg also contains about 186 mg of cholesterol.
The American Heart Association recommends healthy adults limit dietary cholesterol intake to no more than an average 300 mg per day. Other recommendations have advised individuals at high risk of cardiovascular disease to keep this below 200 mg.
Previously, researchers at Purdue University published a study indicating that carotenoid absorption from a salad that boasts a variety of colourful vegetables was improved by the presence of whole cooked eggs. Carotenoids are fat-soluble nutrients, so the fat in the eggs increased nutrient absorption.
Jung Eun Kim, a postdoctoral researcher in Purdue’s Department of Nutrition Science, in a comment in the 2016 edition of the Journal of Nutrition, stated, “We found Vitamin E absorption was four to seven fold higher when three whole eggs were added to a salad.”
Historically, the role of egg intake on cardiovascular health has been an area of controversy, with apparent scientific misperceptions but the researchers declared that a growing number of guidance committees suggest that there should be no restrictions on dietary cholesterol intake.
According to them, “Eggs are a nutrient-dense food, providing a good and affordable source of protein, essential fatty acids, antioxidants, choline, vitamins, and minerals. Thus, recommendations regarding the consumption of eggs should consider them as a whole food.”
The British Heart Foundation (BHF) said the review reinforced previous findings that eggs could be eaten as part of a healthy diet without increasing the risk of heart disease in healthy individuals. However, the foundation urged caution when interpreting the results.
BHF senior dietician Victoria Taylor, saying that importance should also be placed on how the eggs are cooked and what they are eaten with declared: “The fact that eggs can reduce your risk of having a stroke is interesting; however more research is needed to fully understand this association.”