Can we really cut our risk of heart attack by substituting good fats for bad?
Posted Mar 25 2010 11:42am
A review of previous studies clarifies the current thinking regarding the health benefits of eating polyunsaturated fats.
In the UK heart disease is the most common cause of death. Aloninking reg with smoking & lack of exercise, eating too much saturated fat can be a contributory factor. These fats cause an increase in the level of bad cholesterol in the blood which in turn results in a build up of fatty deposits in the arteries causing them to narrow. A heart attack can occur where an artery becomes totally blocked
For many years we have been advised to cut down on saturated fats such as that found in dairy products & red meat, replacing them instead with the healthier polyunsaturated fats found in vegetable oil & oily fish. These fats are thought to actually lower the levels of bad cholesterol - & with it the risk of heart attack.
Although medical opinion has long thought this to be the case, there has been little research to show that it actually is. Some experts have also expressed concerns that eating high levels of polyunsaturated fats might also eventually increase the risk of heart problems. Now a new study has been done to review the best of previous research studies, & to analyse their pooled results. All of the studies looked at – there were eight studies & 13000 participants - involved some people substituting polyunsaturated fats for saturated fats, & others making no change. The groups were randomly allocated in all cases & the results compared over time, which varied between one & eight years.
The study was carefully carried out & the end results backed up much of the current thinking on the issue. It found that people substituting saturated fats with polyunsaturated fats reduced their risk by nineteen per cent as opposed to the control groups who changed nothing. The longer people were on the changed diet, the lower their risk became. On average with each five per cent increase in polyunsaturated fats there was a ten per cent decrease in the risk.
It wasn’t possible to surmise from the study how much the reduced risk was due to the increase in polyunsaturated fats, & how much due to the decrease in saturated fats. Nor did it look at substituting saturated fats with monounsaturated fats – such as that found in olive oil.
From the review it is clear that we can contribute to a healthy heart by substituting the saturated fat in our diet with polyunsaturated fat. However this remains only one aspect of a healthy heart. Generally eating a healthy diet, cutting down on salt, getting plenty of exercise & not smoking all have a major part to play too.