Drink milk, eat cheese: it’s healthier than you think

But Forouhi’s is the latest study to suggest the story is not that straightforward. Reflecting results from other papers, her findings, published in the Journal of the American Heart Association, showed no link between the amount of saturated fats consumed and incidence of heart disease when compared with intake of other fats. Yet when Forouhi looked in more detail at the food sources of saturated fats in the diet she found that some were more harmful than others. People who ate more saturated fats from red meat and butter, for example, were more likely to develop heart disease whereas those who consumed more from cheese and yoghurt had some protection against it. Consumption of milk — even the full-fat variety — had a neutral effect on heart health.

We still need to think of butter as an occasional, or ‘sometimes’ food

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“It was very telling when we looked more closely at food sources because they really mattered,” Forouhi says. “We’ve become very reductionist in the way we view foods, but in fact all foods are very complex and contain a cocktail of nutrients that might help or harm health through multiple mechanisms.” She gives the example of cheese, often criticised for its saturated fat content. “It also contains other things that have a different impact on factors that affect cardiac heart disease,” she says. “Cheese is produced by the fermentation of milk and so contains some probiotics as well as vitamin K2 which, overall, are good for heart health.”

In the second new paper, researchers from the University of South Australia and the University of Maine reported how eating dairy — yoghurt in particular — can help to reduce blood pressure levels in people with hypertension, another risk factor for heart disease. “Traditionally we have been wary of dairy foods due to their saturated fat content,” says Dr Alexandra Wade, a research associate at the University of South Australia’s department of health and human performance and a lead author on the paper. “That’s now starting to shift, as dairy foods like milk, cheese and yoghurt appear to have a neutral, or even positive, effect on heart health.”

Forouhi says that guidelines about saturated fat consumption “will need to change in time” but that her results are not a licence to gorge on cheese. “Foods have multiple good and bad effects and just because we have shown milk, yoghurt and cheese don’t affect heart disease in the way that was once thought, we should not eat them to excess,” she says. “The message is still moderation, aiming for more of what is good for us and less of what is bad.” Here’s what we need to know about dairy:

Yoghurt

It’s hard to find a food with a better health profile than yoghurt. Like milk, it is a good source of protein and calcium and contains vitamins D, B12, B2 and zinc. It is the vitamin K2 in yoghurt and the probiotics, a result of the bacteria such as Lactobacillus bugaricus and Streptococcus thermophilis added to ferment the naturally occurring milk sugar lactose, that the Cambridge team suggest may have a beneficial effect on heart disease. They say the array of nutrients in yoghurt might help to control or reduce blood sugar, inflammation and cholesterol levels. Forouhi has also shown that replacing meat with yoghurt, cheese or nuts helps to ward off type 2 diabetes and that yoghurt eaters have a 28 per cent reduced risk of the condition compared with non-yoghurt eaters.

There was a further boost to yoghurt’s reputation in a new study published this month, which added to the evidence that a daily dose of plain yoghurt could also help people with raised blood pressure. According to Wade, all dairy foods contain a range of micronutrients such as potassium and magnesium that are involved in the regulation of blood pressure — but it’s the beneficial bacteria in yoghurt that makes it particularly effective.

“Because it’s fermented with probiotics, yoghurt contains bioactive peptides, or proteins, that are capable of lowering blood pressure in a similar way to blood pressure medication,” Wade says. “In our study the greatest benefit was in people who consumed one or more servings of yoghurt each day, a serving of yoghurt being 200g, or a small dish.”

Although the study looked at people with existing hypertension, Wade says yoghurt-eating can still be helpful. “If your blood pressure is already in a healthy range, it’s not likely to drop any lower from consuming yoghurt,” she says. “That being said, it could help to maintain a healthy blood pressure.”

As long as it is natural and not plied with sugar and other unwanted extras such as colourings and thickeners, yoghurt can be full fat or low fat, plain or Greek, and still provide health benefits. “In the past, only low-fat options have been recommended,” Wade says. “But the latest research indicates that there isn’t a clear relationship between low-fat or full-fat dairy and the risk of heart disease, so either can be consumed as part of a healthy diet.”

Nutrients in milk can regulate blood pressure

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Milk

It may have fallen out of fashion in the wake of arguably more sustainable non-dairy alternatives, but there’s no disputing cow’s milk wins hands down on nutrients. It is packed with potassium, magnesium, riboflavin, vitamins A and B12 and calcium, important for bone health, and provides all nine essential amino acids needed for body tissue growth and repair. A single 200ml glass provides 70mcg — almost half the recommended daily intake (150mcg) — of iodine, a trace mineral that’s important for fertility and how our metabolism functions.

In the Cambridge study milk was found to have no adverse effect on heart disease and Wade says that micronutrients such as calcium, magnesium and potassium in milk “are involved in the regulation of blood pressure, so it’s really important that we get enough of them in our diets”.

There are concerns that some people might be cutting out cow’s milk for the wrong reasons. Rayman says that self-diagnosis of dairy allergies is a problem. “People might have a skin or gut problem and assume milk is to blame,” she says. “Often it’s not the case and it takes a clinical immunologist to diagnose an allergy.”

Last week researchers from the University of Bristol, Imperial College London, St George’s, University of London and King’s College London suggested that international guidelines developed to help doctors diagnose cow’s milk allergy may actually lead to overdiagnosis of the condition in children. Symptoms of cow’s milk allergy include gut and skin problems, constipation or loose stools and colic or vomiting — all common in young children but not necessarily linked to milk.

For their study, the team asked the parents of 1,303 infants to report any responses to milk consumption in the first year of life. Three quarters of the children in the study, who were aged between 3 and 12 months, had symptoms that guidelines say might be caused my cow’s milk allergy, despite the condition affecting only 1 in 100. More symptoms were reported when the children were three months old and fully breastfed, suggesting they weren’t caused by cow’s milk.

“Our findings come against a background of rising prescription rates for specialist formula for children with cow’s milk allergy which is completely out of proportion to how common we know the condition is,” says Dr Michael Perkin, a consultant paediatric allergist at St George’s Hospital and one of the authors.

Cheese

Consumption of cheese in the UK soared by 48 per cent during successive lockdowns, with UK cheesemakers celebrating a record £2.7 billion of sales last year. And while many cheeses are high in total fat and therefore will add pounds to your waistline if you eat too much, some cheese is a positive addition to the diet. Like milk, it is a complete protein food, with all the essential amino acids needed for health, along with a similarly long list of nutrients. Most aged cheeses — including cheddar, parmesan and gruyère — are fermented and contain a range of beneficial bacteria that boost the microbiome.

Dental studies have shown that eating cheese lowers acidity levels in the mouth, helping to prevent tooth erosion. It has a low glycaemic index (GI), meaning it won’t trigger unhealthy blood sugar spikes after eating it, and consuming both low and full-fat cheese regularly has been shown to reduce insulin resistance, a condition that can lead to high blood-sugar levels and a raised a risk of cardiovascular disease and type 2 diabetes.

Forouhi says that cheese contains much less palmitic acid, a type of saturated fat that has been shown to have a detrimental effect on blood cholesterol, than red meat, but more pentadecanoic acid, associated with lower risks of heart disease. Previously, in a study that involved nearly 64,000 adults from 16 countries, she and her team found that people with higher levels of biomarkers of cheese and other dairy, measured by types of fat in the body tissue that reflect dairy fat consumption, had a lower risk of developing type 2 diabetes.

Cheese might even help to protect your brain. Data collected from 1,787 older adults through the UK Biobank by nutritionists at Iowa State University reporting in the Journal of Alzheimer’s Disease last year revealed that “cheese, by far, was shown to be the most protective food against age-related cognitive problems”.

Butter

Despite the dairy revival, butter remains something of a dietary outcast. In her study Forouhi found that it was people who ate a higher amount of saturated fats from butter and red meat who were more likely to develop heart disease. “Butter is mostly pure fat — there are 11g of fat, mostly saturated, and over 100 calories per tablespoon — with minimal protein or calcium,” Rayman says. “It does contain some vitamins but in levels too low to make much difference.” Most positive research findings for milk, cheese and yoghurt don’t extend to other higher-fat dairy foods like butter, Wade says, “So we still need to think of it as an occasional, or ‘sometimes’ food.”

If you really can’t resist it, stick to about two teaspoons a day and not more than one tablespoon (14g). A meta-analysis of studies involving 636,151 participants by scientists at Tufts University in Massachusetts found a daily serving of this amount of butter consumption was only weakly associated with a greater risk of death and was not associated with heart disease. However, the Tufts researchers said butter should be considered “a middle of the road food” that’s more healthy than sugar, but not a route to good health.