The average Australian eats about three eggs a week, which isn't that many. Since the 1960s, doctors have linked high blood cholesterol with clogged arteries and our number one killer, heart disease, so avoiding foods rich in cholesterol, like eggs, seems like the right thing to do … or is it?
Dr Andrew Rochford puts his medical know-how where his mouth is to find out if eggs are bad for our heart and if there is a limit to how many we should be eating.
Dr Wanda Howell, professor of nutritional sciences at the University of Arizona in the USA, has analysed over a hundred studies to do with cholesterol and she's learned that we can't live without it.
"It's an essential component of every cell membrane in the body. And that's the reason our body makes most of the cholesterol that is produced and maybe ends up in our bloodstream", she says.
We actually make two types of cholesterol to transport saturated fats around the body LDL and HDL. LDL acts to clog up our artery walls. While the good guy, HDL works to clean up the mess, by helping to excrete saturated fats via the liver. So we want to have high HDL and low LDL.
We know that eggs are loaded with cholesterol, but does it have more of the bad stuff or the good stuff?
It's time for Andrew to give this a test.
The test: Andrew will eat four eggs a day, yolks and all, for two weeks.
This roughly works out to be about nine times the average Aussie consumption. Therefore, if his cholesterol goes up, then it's bad for the eggs and your heart.
Before getting started on the experiment, Andrew has to first check his cholesterol level with a mobile cholesterol testing unit. Andrew drops some of his blood onto a slip, pops it into the machine and it reads the cholesterol level in just three minutes.
A reading above four runs on the high side so anything under four is within the healthy range.
First reading: Andrew's starting cholesterol level is sitting on 3.8, just below the level recommended by the Heart Foundation.
Two weeks later...
Following a high-egg diet, Andrew has found the perfect company to do his second cholesterol test with.
Oscar Mcgill is an 18-year-old body builder who's training for the world championships and he eats a lot of eggs 18 a day! Oscar will also have his cholesterol level taken.
Andrew's result: Low. Andrew's cholesterol levels have actually fallen under 3.8, in fact, they are so low the machine doesn't have a number for it.
Oscar's result: Low also. Another great result, from a bloke whose diet is totally dominated by eggs.
Eggs are rich in nutrients, low in fat, and high in protein. But you shouldn't eat so many that you miss out on other nutritional goodies.
But if eggs are so good for us, what are the foods causing all the damage, contributing to higher cholesterol, and therefore causing heart disease?
Dietitian Sharon Natoli lays the blame at the feet of saturated fats.
"Saturated fat is the type of fat that increases the level of cholesterol in your bloodstream so that's the type that really makes a difference in terms of health if you can cut that down. And we know that the average Australian diet contains twice as much saturated fat as what's ideal," says Natoli.
Saturated fats are often in all those foods we love to eat cakes, full-cream dairy products, fatty meats and takeaways. Here's how they wreak havoc:
Saturated fats cause the body to produce more LDL (the bad cholesterol), the more we produce, the more clogged up our arteries become, and the harder the HDL (good cholesterol), has to work to clean up the mess. Therefore when it gets too hard, a heart attack can result.
According to Brisbane cardiologist Dr Karam Kostner, about 70 people in Australia will have a heart attack every day and bad cholesterol is one of the main risk factors for having these heart attacks.
He believes that eating eggs can actually lower cholesterol levels because they're high in cholesterol but low in saturated fats.
"People who eat a lot of eggs actually shut down their bodies production of cholesterol. So the more eggs somebody eats, the less cholesterol our body produces. So that's why a lot of people who eat a lot of eggs don't get heart disease necessarily," he says.
If you've got a high cholesterol reading, you can reduce it by up to 30 percent in less than six weeks, simply by modifying your diet by including plenty of high fibre foods, lean meats and low-fat dairy.
So it's all good news for egg lovers. Eating eggs won't give you high cholesterol. In fact, eggs are full of high-quality proteins, vitamins and minerals and should be a part of any healthy diet.
But on a more serious note, if you don't know your blood cholesterol, go and get it checked. It's one of the most important and simple ways to ensure that you prevent health problems in the future.
The National Heart Foundation has a Heart Line with health professionals ready to take your call if you would like to know anything more about eggs, eating and heart health. Phone 1300 362 787.
Need some new egg recipes? Try these tasty treats from the Australian Egg Corporation.
- A mother hen turns over her eggs about 50 times a day and it's not just for exercise, she actually does it to prevent the egg yolk from sticking to the sides of the shell. All of which is great for us … it means those little beauties slide straight off the shell into the pan.
- At the time of the French Revolution, the clever French already knew 685 different ways of preparing eggs (including, of course, the omelet).
- White-shelled eggs are produced by hens with white feathers and ear lobes. Brown shelled eggs are produced by hens with red feathers and red ear lobes. There is no difference in taste or nutrition between white and brown eggs.
- An average hen lays 300 to 325 eggs a year. A hen starts laying eggs at 19 weeks of age.
- As a hen grows older she produces larger eggs.
- The egg shell may have as many as 17,000 tiny pores over its surface. Through them, the egg can absorb flavors and odours. Storing eggs in the carton helps keep them fresh.
- To tell if an egg is raw or hard-cooked, spin it! If the egg spins easily, it is hard-cooked but if it wobbles, it is raw.
- The stringy piece of material in the egg is not an embryo but rather a special protein called chalazae, which acts as a shock absorber for the yolk so it doesn't break.