Is mayonnaise REALLY bad for you? Experts reveal the healthiest type… and the hidden risks you need to know

Marmite may be famous as the nation’s most divisive spread, but mayonnaise can split a room just as quickly.

For some, it is the texture. For others, it is the ingredients, its gloopy appearance, or the assumption that anything made mostly from oil and egg yolk must be bad news.

At its simplest, mayonnaise is an emulsion of egg yolks, oil, vinegar and often mustard. It is used everywhere from sandwiches and chips to tuna mayo, potato salad and coleslaw, helping bind ingredients together while adding creaminess and tang.

It is also cheap, widely available and found in almost every supermarket, with own-brand jars often costing less than £1.

But because mayonnaise is high in calories and fat, and because egg yolks have long been associated with cholesterol, it is often written off as unhealthy – fattening, bad for the heart and best avoided.

So is mayonnaise really as bad as its reputation suggests?

‘Mayonnaise is misunderstood – it’s not inherently bad,’ says Sophie Medlin, consultant dietitian at CityDietitians. ‘A tablespoon in a tuna mayonnaise sandwich can fit into a healthy diet, especially if it helps people have more balanced sandwiches and salads.’ 

From full-fat to low-fat, vegan to Kewpie, store-bought to home-made, we asked Ms Medlin if mayonnaise can be enjoyed as part of a healthy diet, and if so, how… 

 

It’s actually not the unhealthiest condiment

A typical 15g serving of standard mayonnaise – around a tablespoon – has in the region of 100 calories, 10g of fat, and 0g protein. 

On paper, it’s undeniably less ‘healthy’ than similar servings of condiments like mustard which has 15 calories, 1g fat, and 1g protein.

But according to Ms Medlin, this doesn’t necessarily make mayo a no-no. 

‘Compared with ketchup, mustard, or vinegar-based dressings, mayonnaise is much higher in calories,’ she tells the Daily Mail.

‘Condiments like mustard, salsa, yoghurt-based dressings, and hummus are going to be overall better choices than mayonnaise.

‘But in comparison with things like butter, cream cheese, and creamy dressings, however, it can be low in terms of saturated fat, although it’s going to be comparative in terms of calories.’

It can boost vitamin absorption  

It does also offer some nutritional benefits which are lacking in some of the other jars and bottles on the condiments shelf. 

According to Ms Medlin, the main nutritional benefit from mayonnaise comes from the unsaturated fat from the oil, depending on the product and what type of oil has been used.

‘Mayonnaise can also help us to absorb fat soluble nutrients like Vitamin A, D, E, and K that are naturally present in vegetables,’ she says.

In a study following over 120,000 men and women, it was found that replacing saturated fats with either polyunsaturated fats, or monounsaturated fats reduced the risk of coronary heart disease by 25 per cent and 15 per cent respectively.

Ms Medlin agrees with the findings of the study. 

‘We should definitely switch from saturated to unsaturated fats – it’s the best heart health advice,’ she says, adding that it’s guidance backed by both the NHS and experts from the British Heart Foundation. 

Not all mayonnaises are created equal  

There are now endless varieties of mayonnaise on supermarket shelves, from full-fat and light to vegan and Japanese-style Kewpie. But is any one version actually healthier?

According to Ms Medlin, there is no clear winner.

‘Full-fat mayonnaise is mostly oil, so it is high in calories, but it is usually made with unsaturated fats, which are the healthier type of fat,’ she says.

‘Light mayonnaise has fewer calories because it contains less oil, but it often also contains starches, gums, sweeteners and additives to recreate the texture of traditional full-fat mayonnaise.

‘Vegan mayonnaise avoids egg, but how healthy it is depends on the oil used. The egg is often replaced with stabilisers and other processed ingredients to make it behave like mayonnaise.

‘Kewpie is not really healthier. It is more about taste. It is richer and tangier, and made solely with egg yolks rather than whole eggs, but portion size still matters because it can be high in fat.’ 

These pre-made mayos can contain around 90 to 100 calories per serving, while some low-fat versions have as little as 15. But lower-calorie options may contain more additives and are often more processed than traditional full-fat mayonnaise.

And although ‘low-fat’ is often seen as shorthand for healthy, research has suggested that people eating more ultra-processed diets may be more likely to gain weight than those eating less processed foods.

This might inspire you to whizz up your own mayo from scratch at home, but even that has to be enjoyed in moderation. 

‘Homemade mayonnaise does let you choose the type and amount of oil you use, and it can help you avoid additives,’ says Ms Medlin. ‘But it is not automatically healthier, because it is still made with the same basic high-fat ingredients.’

Ultimately, Ms Medlin says the healthiest choice depends on what matters most to you.

‘If weight management is the priority, then lighter mayonnaise may be the best choice,’ she says. ‘But if avoiding processed foods is more important to you, homemade may be better.’

What about cholesterol?  

While egg yolks were once blamed for raising cholesterol, experts now say that concern has been overstated.

One major study of 146,011 people across 21 countries found no significant difference in blood lipid levels or total cholesterol between people who ate one egg a week and those who ate seven.

Ms Medlin explains: ‘We used to think eggs had to be limited for cholesterol management, but we no longer think that.

‘Egg yolks do contain cholesterol, but dietary cholesterol does not translate directly into cholesterol in the blood.

‘What matters more is saturated fat – the type that is solid at room temperature, such as butter or the fat on a steak.

‘That kind of fat has a much stronger link with raised blood cholesterol and fat accumulating around the organs than the relatively small amount of cholesterol found in eggs.

‘Essentially, when it comes to cholesterol, we don’t need to worry about eggs.’

There’s a food poisoning risk  

Making homemade mayonnaise may feel healthier – and give you something to show off about – but it is not without risks.

Although the Food Standards Agency says raw eggs stamped with the British Lion mark are safe for most people to eat, homemade mayonnaise still needs to be handled carefully to reduce the risk of food poisoning.

Ms Medlin explains: ‘It’s really important to follow food safety guidance with homemade mayonnaise because it contains raw egg, so commercial mayonnaise may actually be a safer option.

‘We are lucky in the UK because chickens are vaccinated against salmonella and rates are very low. But it is still something to be aware of, especially if you are pregnant or immunosuppressed.

‘Mayonnaise should be kept in the fridge after opening and used by the guidance date. Don’t leave it out for long periods, especially in the sun, and be extra careful with homemade mayonnaise if you are going to attempt making it.

‘Not following this guidance can increase the risk of food poisoning.’

Who needs to be wary   

Mayonnaise can be an issue for some people taking certain medications, particularly if they eat it in large or inconsistent amounts.

The main concern is for people taking blood thinners such as warfarin.

Mayonnaise is made with oils such as soybean or olive oil, as well as egg yolk, which can contain varying amounts of Vitamin K – a nutrient involved in blood clotting.

 Suddenly eating much more mayonnaise than usual could potentially affect how well warfarin works.

People taking cholesterol-lowering medication may also want to be mindful of how much they eat. Mayonnaise is high in fat and calories, so regularly consuming large amounts could make it harder to improve cholesterol levels, even with medication.

It can also cause problems for people using some weight-loss treatments, such as orlistat, which works by blocking fat absorption. High-fat foods, including mayonnaise, can trigger unpleasant side effects such as diarrhoea, wind and stomach cramps.

Mayonnaise is also usually made with egg and often contains soya-based oils, meaning it may not be suitable for people with egg or soy allergies.

Then there is the question of calories. Mayonnaise is energy-dense, so while it does not need to be avoided altogether, it can contribute to weight gain if eaten too freely.

Ms Medlin says: ‘Mayonnaise is not really the villain, but it is a high-calorie condiment, and we do need to be aware of how much of it we’re consuming.

‘The healthiest approach is not to ban it altogether, but to choose it deliberately and use it sparingly. It can become problematic if you eat too much of it.’