Guidelines urging people to eat less "unhealthy" fat may be too simplistic, new research from Cambridge academics suggests.
An international study found no overall association between saturated fat consumption and heart disease, contrary to current advice.
And levels of "healthy" poly-unsaturated fats - such as omega 3 and omega 6 - had no general effect on heart disease risk.
Lead researcher Dr Rajiv Chowdhury, from Cambridge University, said: "These are interesting results that potentially stimulate new lines of scientific inquiry and encourage careful reappraisal of our current nutritional guidelines.
"Cardiovascular disease, in which the principal manifestation is coronary heart disease, remains the single leading cause of death and disability worldwide. In 2008, more than 17 million people died from a cardiovascular cause globally.
"With so many affected by this illness, it is critical to have appropriate prevention guidelines which are informed by the best available scientific evidence."
Saturated fat is the kind of fat found in butter, cakes and biscuits, fatty cuts of meat, cheese and cream.
At the moment the NHS recommends the average man should eat a maximum of 30g a day and women should eat 20g a day.
On average most of us eat around 20% more than that.
The team of academics based their findings on data from 72 different studies involving 600,000 participants from 18 countries.
They also found that different specific strains of fat did have some impact. Two kinds of saturated fat found in palm oil and animal products were weakly associated with heart disease, while a dairy fat called 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 despite the fact that popular omega-3 and omega-6 supplements appeared to have no benefit.
Professor Jeremy Pearson, associate medical director at the British Heart Foundation which co-funded the study, said: "Alongside taking any necessary medication, the best way to stay heart healthy is to stop smoking, stay active, and ensure our whole diet is healthy - and this means considering not only the fats in our diet but also our intake of salt, sugar and fruit and vegetables."