For years cheese has been demonised and we’ve been told to limit our intake — the thinking was that it contains large amounts of saturated fat, which is associated with an increased risk of heart attack and stroke.
But has cheese been misunderstood? Some experts now believe the distinctive ‘matrix’ of cheese – i.e. its molecular structure and unique components – means it may actually be beneficial for health.
In fact, research suggests that cheese has a positive effect on heart, gut and cognitive health, and may protect against type 2 diabetes.
One of the latest studies, published in the journal Nutrients, found that regularly eating cheese is linked to better brain health in older people.
Researchers in Japan analysed the diets of more than 1,500 over-65s – those who reported eating cheese regularly (any type, and anything between once a week to every day) scored better in cognitive tests and had a lower risk of dementia, compared with those who didn’t consume it at all.
Separately, research presented at the American Society for Nutrition’s conference in July suggested a type of probiotic (or ‘good’ bacteria), Lactobacillus rhamnosus GG, which is found naturally in parmesan and yoghurt, improved memory and brain function in older people with mild cognitive impairment, a precursor to dementia.
It’s thought that the probiotic – which was given in drink form – rebalanced the gut microbiome, the bacteria, fungi and viruses which live in the digestive tract and, in turn, affected brain function.
As James Goodwin, a professor in the physiology of ageing at Loughborough University, explains, these gut microbes stimulate the immune cells that send messages via nerves to the brain.
The gut microbiome also acts directly on the brain via the vagus nerve – which connects the brain to the gut. And some chemicals made in the brain – including serotonin and dopamine – are also made in the gut.
‘Healthy gut, healthy brain,’ says Professor Goodwin, the author of Supercharge Your Brain.
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Cheese – and other dairy products, such as milk and yoghurt – help maintain the diversity of the microbiome because they contain a variety of ‘good’ bacteria, with unpasteurised cheese, such as most blue cheese, containing a greater diversity of bacteria.
‘Cheese also contains high levels of anti-inflammatory molecules, called oleamide and dehydroergosterol, which are exceptionally beneficial to the brain,’ adds Professor Goodwin.
When it comes to heart health, despite long-standing fears that saturated fats in cheese increase the level of LDL (or ‘bad’) cholesterol in our blood, recent research suggests the opposite. In 2018, Dr Emma Feeney, an assistant professor in the Institute of Food and Health at University College Dublin, led a six-week trial where 164 over-50s with slightly raised cholesterol levels were split into three groups and given 42g of dairy fat a day.
One group received this in the form of 120g of mature cheddar. Another in a combination of butter and reduced-fat cheddar while a third group was given it in the form of separate components that mimic cheese (butter, a calcium supplement and calcium caseinate powder, similar to the protein found in cheese).
The study, published in the American Journal of Clinical Nutrition, found that the full-fat cheese group had a greater reduction in overall cholesterol and LDL cholesterol than the other two groups.
Dr Feeney believes the matrix of cheese and how fat is held within its structure is key. ‘It is thought that the fatty acids in cheese bind with the calcium in it, making it more difficult for our enzymes to break it down when it is in the cheese structure compared with in butter,’ she says.
‘This means less saturated fat enters the bloodstream when it is in cheese.
‘It’s thought that some of the fat binds to calcium to form ‘soaps’ — these are not absorbed in the intestine and are removed in faeces.
‘There seems to be something special about the cheese matrix.’ The theory that calcium reduces fat absorption was supported by a follow-up study led by Dr Feeney and published in the European Journal of Nutrition earlier this year.
The seven participants consumed 240g of high-calcium cheddar daily (made for the study) for two weeks and then the same amount of lower calcium cheddar for the same time.
The high calcium cheese led to a greater reduction in LDL cholesterol. Higher calcium cheeses include mature, hard, white cheese such as cheddar and parmesan; ricotta is a low calcium cheese.
One explanation, according to Dr Oliver Guttmann, a consultant cardiologist at St Bartholomew’s Hospital and the Wellington Hospital in London, is that components in cheese known as sphingolipids may reduce the uptake of cholesterol from the gut.
‘There’s a theory that you get a lot of good things from cheese, such as beneficial microbes and nutrients, but also that maybe the cheese itself inhibits the uptake of its unhealthier elements,’ he says.
Low fat or low salt: The best type for you
Softer cheeses – such as mozzarella, feta and cottage cheese – tend to be lower in fat, so may be better for people who are concerned about gaining weight.
Most studies about cheese have used hard cheese, so it is not clear if soft types offer the same benefits, says Dr Emma Feeney, from the Institute of Food and Health at University College Dublin. ‘It’s likely that softer cheeses will have a slightly different matrix [molecular structure] as they have a higher moisture content and less fat, but also differ in calcium content.’
Another consideration is the salt, added to cheese as a preservative.
High salt cheeses include feta, Stilton and cheddar; mozzarella and ricotta contain less.
‘High salt’ is more than 1.5g per 100g.
Dr Feeney is currently leading a study looking into whether or not changing the structure of cheese by melting it makes a difference to its impact on health.
It’s thought that when cheese is heated, the fat droplets come together to form larger pools of fat which may make it easier for our enzymes to access it.
But while some experts are focused on the matrix of cheese, others suggest that one of the components, the saturated fat that comes from dairy, may in itself be beneficial and even protect against type 2 diabetes.
‘Saturated fats are a whole range of substances, and the ones from dairy don’t seem to have the same detrimental impact as other saturated fats, such as processed fats,’ explains Dr Frankie Phillips, a spokeswoman for the British Dietetic Association.
While most fatty acids (building blocks of fat) have an even number of carbon atoms, dairy contains two unique odd-chain fatty acids – C15 and C17 – which are not found in other foods.
A major study – the EPIC-InterAct study, published in the Lancet Diabetes & Endocrinology in 2014 – looked at the diets of around 19,000 people in Europe.
Professor Jules Griffin – director of the Rowett Institute at the University of Aberdeen and a member of the research team – told Good Health that it found C15 and C17 were associated with a lower risk of type 2 diabetes.
Douglas Twenefour, head of care at Diabetes UK, says those with diabetes or who are at risk of developing the disease are advised to eat cheese and other dairy products.
‘We don’t quite know why cheese has a positive impact in terms of type 2 diabetes, but one hypothesis from animal studies is that C15 and C17 are associated with reducing insulin resistance (where the body’s cells don’t respond to the hormone, allowing glucose to build up in the blood), which is key in the development of the disease.’
For those with diabetes, cheese does not increase blood sugar, so is a good food to eat, he adds.
While Dr Feeney would not recommend people eat the same quantities given to participants in her trials, she says her research suggests eating more than 30g of cheese a day (around the size of a matchbox) will not have a negative impact on heart health, and may even be beneficial.
She adds that her 2018 study found those with the highest starting levels of cholesterol had the greater reductions, suggesting they could benefit most from including cheese in their diet.
‘Unfortunately, they are the people still being told to exclude it,’ she says.
Dr Guttmann is more cautious. ‘Research suggests up to 30-40g a day is probably very good for you,’ he says, adding that because cheese is high in salt and is an energy-dense food, making it more likely to lead to weight gain, eating more than this a few days a week may tip the balance in terms of its health benefits.