The fridge staple that could lower your risk of Alzheimer’s

Eggs were seen as good for us for a long time because they are high in protein, as well as providing a range of vitamins and minerals.

Quick to prepare, they became the perfect breakfast food, with “Go to work on an egg” the Egg Marketing Board’s long-time slogan until the 1970s.

But their health halo started slipping in the 70s, because of increasing concerns about heart disease being caused by cholesterol and saturated fat, both found in eggs.

For a while, common health advice was that we should avoid eggs, or at least, not eat too many. It led to a craze for omelettes made only from egg whites, as it is the yolk that has the fat and cholesterol.

By 2007, when the board – now the British Egg Information Service – wanted to resurrect its old slogan, the advert was banned on health grounds.

Separated egg whites sold in cartons are now popular with body builders, as they are a source of low-fat protein that helps with “cutting”, when people try to lose body fat while keeping muscle, said Dr Carrie Ruxton, a dietitian and nutrition researcher.

But, as thinking about the causes of heart disease has evolved, the pendulum has swung back to be more pro-eggs. “The science has evolved quite a lot,” said Professor Tom Hill, a nutrition researcher at Newcastle University.

For starters, it turns out the original advice to avoid cholesterol in food was wrong – because most cholesterol in blood does not come from the diet but is made by the body.

Blood cholesterol levels are more affected by how much saturated fat we eat. Eggs do have some saturated fat, but it’s only about 1.5g in a large egg. To put that into context, the NHS advises that women should have no more than 20g a day and men 30g.

These days, the NHS recommends eating eggs as part of a balanced diet, without mentioning an upper limit. The British Heart Foundation says they are a “healthy, affordable source of protein and other important nutrients”.

Thanks to this bundle of nutrients eggs are thought to have a range of other health benefits, including for the brain and eyesight.

Eggs are a rich source of vitamins A, D, B12 and folate, as well as the minerals, iodine and selenium.

All of these substances are often deficient in the British diet, according to the Government’s last National Diet and Nutrition Survey, from 2025.

This survey found, for instance, that one in eight people are not getting enough iodine in their diet. And most people don’t get enough vitamin D during winter, when the body cannot make this compound by the action of sunlight on skin.

Many of these nutrients are important for brain development in the womb and in childhood. Previous research has also highlighted a vitamin-like substance called choline, rich in egg yolks, and essential for foetal brain formation, because it helps build the fatty outer membranes of nerve cells.

The latest study suggests these nutrients may also support brain functioning in later life. It found that people who ate at least five eggs per week had a 27 per cent lower risk of the condition.

It tracked nearly 40,000 middle-aged and older Americans for 15 years, and was published in The Journal of Nutrition.

The research is not clinching proof that eggs ward off Alzheimer’s because it just looked at correlations between diet and brain health, rather than being a randomised trial, the best kind of medical evidence, said Professor Hill. “It doesn’t prove cause and effect.”

But, it is “biologically plausible” that the collection of nutrients in eggs could benefit the brain, he said.

And some research supporting the benefits of eggs on the brain were in the form of randomised trials, including a trial showing that a choline supplement improved memory in older people and eyesight.

Eggs are also suspected to support eyesight function in later life for other reasons, said Dr Emma Derbyshire, a nutrition researcher. They contain other vitamin-like nutrients called lutein and zeaxanthin, which may help slow progression of an eye condition common in older people, called age-related macular degeneration.

But all these nutrients are present in the yolk – so those who eat only the white are missing out. “By just having the whites, you could be forgoing all of these beneficial nutrients,” said Dr Derbyshire.

There’s even a further reason for returning the health halo to eggs. There used to be a risk of catching the bacterial infection salmonella from raw eggs, but the Food Standards Agency said 10 years ago there was no risk from eggs stamped with the “British Lion” mark, as this shows the hens had been vaccinated. Pregnant women can even eat runny eggs, said the agency.

So, from childhood to later life, the evidence is accumulating that eggs should be seen as a health food, rather than something to be cautious about.

It seems that “Go to work on an egg” could have been good advice after all.

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