Eating ghee or butter, high in saturated fats, may not increase the risk of heart disease, an Indian-origin scientist has claimed, challenging the medical guidelines that urge people to avoid the 'unhealthy' fat.
A new study found that the current level of evidence does not support guidelines restricting saturated fatty acid consumption to reduce coronary risk nor does it support high consumption of polyunsaturated fats - such as omega 3 or omega 6 - to reduce coronary heart disease.
An international research collaboration led by the University of Cambridge analysed existing cohort studies and randomised trials on coronary risk and fatty acid intake.
The researchers also found insufficient support for guidelines which advocate the high consumption of polyunsaturated fats (such as omega 3 and omega 6) to reduce the risk of coronary disease.
When specific fatty acid subtypes (such as different types of omega 3) were examined, the effects of the fatty acids on cardiovascular risk varied even within the same broad 'family' - questioning the existing dietary guidelines that focus principally on the total amount of fat from saturated or unsaturated rather than the food sources of the fatty acid.
These are interesting results that potentially stimulate new lines of scientific enquiry and encourage careful reappraisal of our current nutritional guidelines, said Dr Rajiv Chowdhury, lead author of the research.
"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," Chowdhury said.
The researchers analysed data from 72 unique studies with over 600,000 participants from 18 nations.
They found that total saturated fatty acid, whether measured in the diet or in the bloodstream as a bio-marker, was not associated with coronary disease risk in the studies.
Similarly, when analysing the studies that involved assessments of the consumption of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids, there were no significant associations between consumption and cardiovascular risk.
Researchers found that different subtypes of circulating long-chain omega-3 and omega-6 fatty acids had different associations with coronary risk, with some evidence that circulating levels of eicosapentaenoic and docosahexaenoic acids (two main types of long-chain omega-3 polyunsaturated fatty acids), and arachidonic acid (an omega-6 fat) are each associated with lower coronary risk.
The study was published in the journal Annals of Internal Medicine.
