Photo of a box of eggs
It's time to stop demonising eggs say Chinese researchers [Image: Alvimann - Morguefile]

Go to work on an egg – every day if you like!

5 February, 2013

Natural Health News — Consumption of eggs is not associated with an increased risk of heart disease or stroke, according to a review of decades worth of evidence.

Eggs have been, on and off, a dietary bogeyman for a long time. They are an exceptional and affordable source of quality protein, as well as being a source of vitamin D. They also contain beneficial minerals, proteins, the eye protective antioxidants lutein and zeaxanthin, and unsaturated fatty acids. Indeed most of the fat in eggs is mono- and poly-unsaturated and other fatty acids called phospholipids that can help reduce the absorption of cholesterol thus helping tolp lower the risk of cardiovascular disease.

But eggs are also a source of dietary cholesterol. Over the years focus on this single fact this has led to speculation that they should be restricted in the diet for fear they could raise blood cholesterol levels and therefore the risk of heart failure or stroke.

Our understanding of cholesterol has progressed somewhat from this simplistic view (see below), but the negative view of eggs has remained.

Can half a million egg lovers be wrong?

In a review in the British Medical Journal, Professor Liegang Liu from Huazhong University of Science and Technology, China, searched through data published between 1966 and 2012 and analysed data from eight high quality clinical studies, involving almost half a million people.

Egg consumption was measured buy food frequency questionnaires in all studies and for the purposes of this review ‘high’ egg consumption was defined as up to 1 egg per day.

No significant association between egg consumption and risk of coronary heart disease (CHD) or stroke could be found – even at a high level of consumption (though the study did not examine intake of more than 1 egg per day).

Effects on diabetics not clear

Liu and his team did note that a separate ‘subgroup’ analysis suggested that egg consumption did appear to  raise the risk of heart disease for people suffering form diabetes, while high intake in the general population was associated with a lower risk of haemorrhagic stroke

The researchers comment that these results should be interpreted with caution, however, because only a few studies in their analysis focused on diabetic participants and particular stroke subgroups (in other words the finding is based on incomplete data).

In fact, late in 2012 a small study concluded that a very high consumption of eggs might actually benefit your cholesterol levels if you are diabetic.

A group of adults with metabolic syndrome who ate three eggs daily had no higher total cholesterol levels and better HDL cholesterol levels after 12 weeks than those who ate only egg whites during the same period,  according to the study in the journal Metabolism.

Clearly more research is needed.

Saturated fat more influential

Cholesterol is a necessary nutrient. The brain, for example, is a cholesterol-rich organ and cholesterol is involved in maintaining learning and memory function.

Cholesterol is also what our bodies synthesise vitamin D from. We are, in many experts view, in the middle of an epidemic of vitamin D deficiency in the developed world. Adequate vitamin D is necessary for immunity, bone health and metabolism amongst other things.

When considering potential reasons for their results the researchers pointed out, among other things, that the effects of dietary cholesterol on serum cholesterol levels are relatively small. They also pointed out that overall dietary patterns and saturated fat intake likely have much greater influence on serum cholesterol levels than does dietary cholesterol.

We also know that cholesterol per se is not dangerous. Instead it is the oxidation of  certain types of cholesterol, such as ‘unhealthy’ LDL cholesterol, which appears to cause the kind of damage to blood vessels that can lead to atherosclerosis. This is one reason why we tend to focus on the low hanging fruit of  ‘lowering cholesterol’ – in part because they don’t fully understand the mechanism that influences that oxidation).

To the extent that this is true, the level of antioxidant rich whole foods you include in your diet may be as influential, or more so, then whether you eat eggs (or other cholesterol rich foods like shellfish). Such a diet would, by default, ensure you are not getting more dietary cholesterol than your body can handle and provide some of the means to help metabolise it well.