For the first time levels of choline and omega-3 fatty acids in UK eggs have also been quantified, with the data showing that eggs are a significant source of both nutrients. This, alongside the fact that eggs now contain less fat and calories, suggests that they are an even more valuable part of a healthy balanced diet than previously realised.

The research paper, entitled ‘New data on the nutritional composition of UK hens eggs’ will be published in the December issue of the British Nutrition Foundation’s Nutrition Bulletin.

The higher levels of vitamin D are of particular interest as in the UK 20 per cent of adults and 18 per cent of older children have inadequate levels of vitamin D and there is emerging evidence that low vitamin D status may be linked to increased risk of heart disease and some cancers as well as to poor bone health.

The paper shows that today’s eggs contain around 20 per cent less fat, more than 20 per cent less saturated fat and around 13 per cent fewer calories than previous surveys suggested. An average medium egg now contains 66 calories (compared to the previous figure of 78 calories) and an average large egg 78 calories (previously 91 calories).

The data, produced by the UK Foodcomp project consortium, funded by the Department of Health as part of their rolling programme of nutrient analysis surveys, provides the first update on the nutrient content of eggs since the 1980s.

Professor Judith Buttriss, Director General of the BNF, explained: ‘This is the latest in a series of analyses from the DH-funded UK Foodcomp project that provide up to date information on the composition of the food we eat. These particular data reinforce the contribution to essential nutrients that eggs can make as part of a varied diet, for people of all ages.’

The new analysis found that two medium eggs can provide 64 per cent of the RDA (Recommended Daily Amount for EU labelling purposes) for vitamin D, and 42 per cent of the RDA for selenium. Two medium eggs would also provide about 50-65 per cent of the US AI (Adequate Intake) for choline and, with Omega 3 analysed, eggs are now an official ‘source of’ the fatty acid DHA.

The changes are believed to be the result of improvements to hens’ feed, an increase in the ratio of white:yolk in an average egg, and improved analytical methods since the last official Government analyses were carried out in the 1980s. Since then vegetable oils have replaced meat and bonemeal in UK hens’ feed and it is believed that better quality oils, together with other enhancements to hens’ feed, have improved the hens’ absorption of fat-soluble vitamins and the take-up of nutrients.