Eating plenty of yoghurt, cheese, butter and milk could stave off a heart attack, according to new research.
They are rich in a particular saturated fat that protects against cardiovascular disease, say scientists.
The study of 75,000 Brits and Danes over nearly two decades found those who ate the most were less likely to be struck down.
It adds to a growing body of evidence that full fat dairy products are good for us – contrary to popular belief.
Lead investigator Dr Ivonne Sluijs, a nutritional epidemiologist at Utrecht University in The Netherlands, said: “Our analysis of the diets of large groups of individuals in two countries over time shows the type of saturated fats we consume could affect our cardiovascular health.”
Doctors once thought all cholesterol was bad, until they discovered it came in both ‘good’ and ‘bad’ forms.
The same phenomenon is emerging with saturated fats, with a realisation they are not all the same – and some may be beneficial.
A saturated fatty acid is a string of carbon atoms chained together, but the length varies from four (butyric acid) to 24 carbons (lignoceric acid).
The most common include palmitic acid (16 carbons) and stearic acid (18 carbons) that are found in meats.
Participants whose diets contained relatively little of these longer-chain fats and more plant-based proteins instead were less likely to suffer a heart attack.
Moreover, those who ate more shorter-chain saturated fats with 14 or fewer carbon atoms typically found in dairy reduced their risk further.
Dr Sluijs said: “We found eating relatively little of the longer chained saturated fatty acids and consuming plant-based proteins instead was associated with a lowered risk.
“Substitution of those saturated fats with other energy sources such as carbohydrates did not affect the risk to develop myocardial infarction (heart attack).”
Although diets vary by nationality and other factors, the most frequently consumed saturated fat is palmitic acid followed by stearic acid – both of which are found in meat.
Consumption of saturated fats that have shorter carbon atom chains and are present in dairy products is less prevalent.
The study, published in the International Journal of Cardiology, lasted 18 years during which time nearly 3,500 participants experienced a heart attack.
Since the 1960s, when diets high in saturated fat were linked to elevated ‘bad’ LDL cholesterol and coronary heart disease, dietary guidelines recommended restricting saturated fatty acids across the board.
However, despite the latest findings, Dr Sluijs and colleagues recommend proceeding with caution before changing dietary guidelines.
She said: “Our study only allowed us to draw conclusions on the level of associations between saturated fatty acids and the development of myocardial infarction (heart attack).
“We do not know whether those fatty acids are actually the cause of differences between the occurrences of myocardial infarction we observed.
“To further explore this, we need experiments in which the consumption of saturated fatty acids is more controlled and, for instance, compared with consumption of unsaturated fatty acids.”
Dr Jun Li and Dr Qi Sun, both at the Harvard T.H. Chan School of Public Health in the United States but who weren’t involved in the study, advised that shifts in fat intake should align with the recommended healthy dietary patterns.
These emphasise limiting consumption of red and processed meat and added sugars, reducing salt intake, replacing refined grains with whole grains and eating more fruit and vegetables.
Writing in an editorial, Dr Li said: “The study is applaudable for its large size, prospective cohort study design, and detailed assessment of diet and lifestyle factors.
“In addition, it is among the few studies that specifically examined individual saturated fatty acids in relation to coronary heart disease risk and compared with different macronutrients.”
Recent research has shown people with higher levels of 16 and 18 carbon saturated fatty acids in the bloodstream – caused by eating too much meat – had a higher risk of heart disease.
But those with more saturated fatty acids with a length of 15 or 17, which is linked to eating dairy, had a lower risk. The same pattern was found in type 2 diabetes.
Last year a US study found eating full-fat dairy reduced the risk of dying from a stroke by 42 per cent.
By Ben Gelblum and Mark Waghorn