Eggs have suffered from a bad reputation for a long time, demonized for their high fat and cholesterol content.
Despite an expanding body of research that contradicts claims that eggs (and dietary cholesterol and fat) are bad for health, the belief that they are risky is still prevalent.
Research is ongoing, and now another study on eggs and their impact on blood cholesterol levels and cardiovascular health has been published.
The findings are intriguing.
But before we delve into the latest discovery, a brief history lesson is in order.
Where did the idea that eggs are terrible for you originate?
A combination of flawed studies, political bias, and clever marketing by the food industry led to the birth of the low-fat, low-dietary cholesterol, no-egg craze – a trend that has lasted over 40 years. Thankfully, that craze finally appears to be in its death throes.
The idea that dietary fat was bad for health didn’t start until around 1940, when some scientists and physicians started to suspect that diets high in saturated fats and cholesterol were linked to heart disease. This was based on their interpretation of some research, which was not without controversy – some experts were skeptical and didn’t jump on the “fat is bad” bandwagon.
By the 1950s, doctors were recommending low-fat diets to patients who were considered at risk for cardiovascular disease.
Even though some studies did not support what came to be known as the “diet-heart hypothesis”, and there was no proof of a link between dietary fat and cardiovascular disease, the ideology picked up speed.
And the low-fat craze slowly began.
But the ideology wasn’t pushed upon the public at large until 1977 – that’s when the U.S. Senate’s Select Committee on Nutrition and Human Needs, chaired by George McGovern, published its report titled Dietary Goals for the United States. That report encouraged people to switch to nonfat milk and limit the consumption of butter and eggs. Some scientists remained skeptical of these suggestions, but the advice spread like wildfire anyway.
By 1980, the idea that a low-fat diet could help reduce risk of heart disease and cancer was generally accepted within the scientific community. The World Health Organization and the Surgeon General promoted the diet.
But several years into the low-fat craze, some researchers started to realize that the trend wasn’t such a good thing after all:
While the low-fat diet reigned supreme in the 1990s, more scientific dissenters came forward. Dr. Jules Hirsch, a leading obesity researcher at Rockefeller University, found that when the fat content of a diet was less than 20 percent, the body begins to synthesize saturated fat from carbohydrates. Dr. Walter Willett at the Harvard School of Public Health identified that substituting carbohydrates for fats reduced HDL cholesterol and increased triglycerides, both of which increase risk of developing heart disease.
Through the 1990s and into the 2000s, the growing popularity of high-fat diets, such as Atkins or the Mediterranean diets, led to the realization that eating fat does not necessarily make a person fat. (source)
And, this is certainly interesting:
Scientific analysis of 21 earlier studies showed “no significant evidence” that saturated fat in the diet is associated with an increased risk of coronary heart disease. The 21 studies analyzed included nearly 348,000 participants, most of whom were healthy when they were enrolled. They were followed for five to 23 years, during which 11,000 developed heart disease or had a stroke. Looking back at the dietary information collected from these thousands of participants, the investigators found no difference in the risk of coronary heart disease, stroke, or coronary vascular disease between those individuals with the lowest and highest intakes of saturated fat. This goes completely against the conventional medical wisdom of the past 40 years. It now appears that many studies used to support the low-fat recommendation had serious flaws. (source)
Now, about that new study…
Researchers from the University of Eastern Finland found that a high intake of dietary cholesterol was not associated with the risk of coronary heart disease – even in people who are genetically predisposed!
The study, published in The American Journal of Clinical Nutrition, showed that a relatively high intake of dietary cholesterol – or eating one egg every day – is not associated with an elevated risk of incident coronary heart disease.
The findings of this study are striking because it included individuals with the APOE4 phenotype, a hereditary variant that is common among the Finnish population.
In people with the APOE4 phenotype (carriers of the apolipoprotein E type 4 allele) cholesterol metabolism is significantly impacted, and the effect of dietary cholesterol on serum cholesterol levels is greater.
Research data on the association between a high intake of dietary cholesterol and the risk of cardiovascular diseases in this population group hasn’t been available until now.
For this study, researchers analyzed the dietary habits of 1,032 men aged between 42 and 60 years and with no baseline diagnosis of a cardiovascular disease were assessed at the onset the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, in 1984-1989 at the University of Eastern Finland. During a follow-up of 21 years, 230 men had a myocardial infarction, and 32.5 per cent of the study participants were carriers of APOE4.
In the highest control group, the study participants had an average daily dietary cholesterol intake of 520 mg and they consumed an average of one egg per day.
The study found that a high intake of dietary cholesterol was not associated with the risk of incident coronary heart disease – not in the entire study population nor in those with the APOE4 phenotype.
Moreover, the consumption of eggs, which are a significant source of dietary cholesterol, was not associated with the risk of incident coronary heart disease.
The study did not establish a link between dietary cholesterol or eating eggs with thickening of the common carotid artery walls, either.
These findings suggest that a high-cholesterol diet or frequent consumption of eggs do not increase the risk of cardiovascular diseases even in persons who are genetically predisposed to a greater effect of dietary cholesterol on serum cholesterol levels.
This study adds to a solid body of research that shows that for most people, cholesterol in food has a much smaller effect on blood levels of total cholesterol and harmful LDL cholesterol than does the mix of fats in the diet.
Research has shown that trans fats – not saturated – are the most dangerous.
One recent study showed that trans fat consumption was associated with a 34 percent increase in death for any reason, a 28 percent increased risk of CHD mortality, and a 21 percent increase in the risk of CHD.
The researchers analysed the results of 50 observational studies assessing the association between saturated and/or trans fats and health outcomes in adults.
That study found no clear association between higher intake of saturated fats and death for any reason, coronary heart disease (CHD), cardiovascular disease (CVD), ischemic stroke, or type 2 diabetes.
Eggs contain nutrients that may help lower the risk for heart disease, including protein, vitamins B12 and D, riboflavin, and folate. Don’t discarding the yolks! That part of the egg is most abundant in nutrients.
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