A study found no overall association between saturated fat consumption and heart disease, contrary to current advice.
In addition, levels of "healthy" polyunsaturated fats such as omega 3 and omega 6 had no general effect on heart disease risk.
Different specific strains of fat had some impact. Two kinds of saturated fat in palm oil and animal products were weakly associated with heart disease, while dairy fat margaric acid was significantly protective.
Similarly, two types of omega-3 fatty acid found in oily fish - EPA and DHA - and the omega-6 fat arachidonic acid were linked to a lower risk of heart disease.
However, popular omega-3 and omega-6 supplements appeared to have no benefit.
It was found that total saturated fat, whether measured in the diet or the bloodstream, showed no association with heart disease.
The lead researcher was from Cambridge University and the British Heart Foundation co-funded the study.