Replacing saturated fats with vegetable oils might lower blood cholesterol, but it won’t curb heart disease risk or help you live longer, a new study suggests.
The study, published in The BMJ, throws doubt on the widely held belief that vegetable oils rich in linoleic acid are good for heart health.
A team of researchers in the US, led by Christopher Ramsden at the National Institutes of Health and the University of North Carolina, set out to examine the effect of vegetable oils by analysing data from a large trial that took place 45 years ago.
The trial tested whether replacing saturated fat with vegetable oil rich in linoleic acid reduced the risk of coronary heart disease and death by lowering blood cholesterol levels. The control group ate a diet high in saturated fat.
The diet enriched with linoleic acid lowered cholesterol levels, but didn’t convert to better survival. In fact, participants who had greater reduction in blood cholesterol had higher, rather than lower, risk of death.
The findings “add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid,” researchers say.
So while scientists around the world are looking further at the evidence, the suggestion at this stage is that the best thing to do is just keep on eating what is considered to be a well balanced diet with an emphasis on fish, fruits, vegetables and whole grains.
Researchers also advise avoiding salt, sugar, industrial transfats and over eating.