Battery farmed or organic eggs – there’s little difference for your health

It’s been a bumpy old road for the humble egg, praised and vilified in turn by health experts over the years. Scientists now better understand cholesterol, fat and the importance of protein (especially as we age), so eggs are firmly back on the menu. But which ones should we choose?

These pocket-sized marvels are economical, delicious, versatile, quick to prepare and brimming with nutrients – all in a reasonably low-calorie package. And there’s lots of choice, from supermarket own-brand eggs to pricey specimens with blue shells or satsuma-coloured yolks. Choice is eggcellent, of course, but it can be confusing. 

Under recent government proposals, producers in the future might not have to re-label their eggs during an outbreak of bird flu, a move that would save them significant extra costs. But it could mean that eggs labelled as free range come from hens raised in a barn. So, is there any difference between eggs when it comes to our health? 

Is it worth spending more on free range/organic?

The nutrients in eggs come from what they’re fed, says Andrew Joret from the British Egg Industry Council. In the UK, hens – whether raised in a barn or reared organically – basically eat a similar feed that’s been scientifically developed for egg laying. In the UK, this is mostly made from wheat, as well as soya, sunflower seeds, limestone (which contains calcium for the shells), a range of vitamins and minerals, as well as pigments that give yolks their colour. A few producers of exclusive, pricier eggs enhance the basic feed with extra ingredients like maize, or tailor-make it to produce enriched eggs.

“Free range or organic hens eat about 10 per cent more than hens that are kept indoors because they’re more active,” Joret says. “And organically reared hens get the same type of feed mix, except the ingredients themselves are organic.” But essentially they tuck into the same stuff as cage or barn-raised hens.

Organic and free range birds do have the chance to forage for insects and plants, as they can spend more time outdoors. “But this forms a tiny part of their diet,” Joret says. “What they eat is almost identical to hens reared in barns, unless they’re on some sort of special diet to produce enriched eggs.”

That means, all standard eggs are equally nutritious. “If there is a difference, it wouldn’t be nutritionally significant,” says Dr Carrie Ruxton, a dietician and adviser to the British egg industry.

Organic and free range eggs cost more because it’s more expensive to rear higher welfare hens – not because the eggs are better for our health.

Is it worth paying more for enriched eggs?

Some egg producers enrich the hen feed with extra vitamin D, selenium (an important  mineral) and/or omega-3 (an essential fatty acid that promotes brain and heart health). Is it worth paying extra for these?

“When it comes to omega-3, standard eggs contain 60 mg of DHA, a type of omega-3, whereas enriched eggs contain more than double this amount,” says Bridget Benelam, a nutrition scientist with the British Nutrition Foundation. “However, oily fish are a richer source.”

Similarly, standard eggs contain 23 micrograms of selenium per 100g [100g is about two standard eggs], so they qualify as a rich source. “Enriched eggs contain higher levels, for example, over 30 micrograms per 100g, but standard eggs are still a useful source of selenium in the diet,” Benelam says. But snacking on one or two Brazil nuts is another way to up your selenium intake.

A standard egg contains 1.6 micrograms of vitamin D, which makes them one of the best sources.  “The recommendation is 10 micrograms per day, so one egg is giving you just under a fifth of what you need,” Dr Ruxton says. However, it might be worth considering vitamin D-enriched eggs if your budget allows. There are few other good food sources of vitamin D apart from oily fish and fortified mushrooms. Some brands of enriched eggs contain twice the vitamin D of standard.

Does the colour of the shell matter?

No, the breed of the hen determines the colour of the shell. There’s no nutritional difference between eggs with brown, white or blue shells, according to the British Egg Industry Council.

Are bright orange yolks healthier than standard yellow?

No. All hen feed in Britain contains pigments – commonly paprika and/or marigold extract – to give yolks their yellow colour. (In some countries, hens are fed maize, which contains pigments called carotenoids, and this gives yolks an orange colour. British hens are fed wheat instead of maize, so pigments need to be added to the feed or the yolks would be extremely pale and unappealing). 

“The producers with the deeper-coloured orange yolks are basically just adding more of those pigments,” Joret says, adding there’s no evidence these eggs are healthier. However, some studies suggest that lutein, a chemical in marigold pigment, supports eye health.

Should we worry about the cholesterol in eggs? 

In the past, official health advice recommended limiting our egg intake because yolks contain cholesterol. But the idea that cholesterol in food causes high blood cholesterol has now been disproved. 

For most people, cholesterol in food has a smaller effect on cholesterol levels than the fat in their diet.

Are eggs high in saturated fat?

Eggs are low in saturated fat. One medium egg contains around 1.5g of saturated fat, and virtually all the fat is in the yolk. 

If I have a high cholesterol problem. Should I stick to egg whites?

If you’re concerned about high cholesterol levels, discuss your diet with a health professional. “People with high cholesterol or a condition that affects their blood cholesterol control may be advised by a health professional to limit cholesterol-containing foods such as eggs,” Benelam says. 

Is it safe to eat two or three eggs a day?

There’s no recommended limit on how many eggs people should eat, and opinions vary on the optimum number. 

“I reviewed the evidence and found the sweet spot was seven to 14 eggs per week, so one to two eggs a day,” Dr Ruxton says. 

Benelam says “moderate consumption” shouldn’t pose a health risk. “That’s provided the diet overall is balanced,” she says. “Eggs are a good source of protein and some essential nutrients but it’s a good idea to eat a variety of protein-rich foods.”

Harvard Medical School suggests “up to one egg per day is not associated with increased heart disease risk in healthy individuals”.

Are eggs really a good source of protein?

Eggs are one of the best sources of high-quality protein: a medium egg contains around 6.4g and a large egg 7.5g. The yolk contains a higher concentration of protein than the white. However, because an egg is made up of more white than yolk, the white provides more protein overall.

One large egg contains roughly the same amount of protein as 100g of boiled red lentils or canned chickpeas. One standard grilled chicken breast contains around 57g of protein, roughly the same amount of protein in seven large eggs.

Is it safe to eat raw eggs?

“Provided these are hens eggs produced under the Lion Code with a British Lion mark, it is safe to eat these lightly cooked or raw,” says Benelam. The Lion Mark means egg producers have adhered to a strict code of practice, including the compulsory vaccination of flocks for salmonella.