The research, which is carried by Harvard University and involved 120,000 adults, found that those who ate the most saturated fat were up to 8 percent more likely to die.
The findings come less than a week after another study found that one tablespoon of butter had no impact on death, heart disease or strokes.
And one leading cardiologist claims that eating butter and other saturated fats are not harmful and may actually help you lose weight.
But this latest study found that slashing the intake of saturated fats by just 5 percent reduced the overall risk of mortality by more than a quarter.
Foods high in saturated fats include butter, cream and cheese, red meat as well as biscuits, cakes and pies.
They are thought to increase the levels of cholesterol in the blood, leading to build up of plaque in the arteries, which in turn cause heart attacks and strokes.
The team from the Harvard Chan school of Public Health in Boston also found that replacing saturated fats with polyunsaturated fats which include low fat vegetable spreads, fish, nuts and seeds lowered the risk of dying from heart disease, cancer, Parkinson’s Disease and Alzheimer’s.
Professor Frank Hu, the senior author, said that in light of all the confusion, the findings highlighted the importance of slashing butter and other saturated fats from the diet and replacing them with unsaturated alternatives.
This would yield ‘substantial health benefits and should continue to be a key message in dietary recommendations’, the study published in the journal JAMA Internal Medicine concluded.
Saturated fat is has also been linked to dementia, by blocking the blood flow to the brain, and cancer as it contains oestrogen which fuels tumour growth.
Other experts broadly agreed with the findings including Dr Ian Johnson, emeritus fellow at the Institute of Food Research, in Norwich, who said: ‘There is nothing in these results consistent with the notion that ‘butter is back’.”
From his side, Associate Professor in Nutrition and Health, University of Reading Dr Gunter Kuhnle, said: ‘The results of the study broadly confirm current dietary recommendation and in particular show that total saturated fat intake is associated with a higher, unsaturated fat with a lower risk for all-cause mortality.’
The study looked at the records of 126,233 men and women in the US over a 32-year period.
Those whose diets were highest in saturated fat were 8 per cent more likely to die over that time – including from cancer, heart disease or degenerative illnesses such as Alzheimer’s and Parkinson’s.
But closer analysis revealed that switching 5 per cent of saturated fats with polyunsaturated fats cut the risk of death by 27 per cent.
Recently however these findings have been disputed by experts including Dr Aseem Malhotra, a cardiologist at Frimley Park Hospital in Surrey and founder of the campaign group Action On Sugar.
Dr Malhotra claims that saturated fat does not necessarily increase the risk of heart disease and may even protect against it.
He also argues that cutting saturated fat from our diets has led to us replacing it with sugar and carbohydrates, which are fuelling obesity.