A new research has revealed that replacing saturated fat with polyunsaturated fatty acids is good for the heart.
The study has appeared in PLoS Medicine.
Dariush Mozaffarian and colleagues from Harvard Medical School and Harvard School of Public Health conducted a systematic review and meta-analysis of randomised controlled trials studying the effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat.
They reviewed 8 trials involving over 13,000 participants and found that among those substituting SFA for PUFA (the intervention group), there was a 19 percent reduced risk of CHD risk compared to participants in the control groups. The consumption of PUFA accounted for 15percent of total energy intake in the intervention groups on average but only 5 percent of total energy intake in the control groups. As such, the researchers report that each 5 percent increase in the proportion of energy obtained from PUFA reduced the CHD risk by 10percent.
Moreover, they found that the benefits associated with PUFA consumption increased with greater duration of the trials.
While reducing consumption of saturated fat (contained in meat, cheese, and butter, for example) is recommended as a way to prevent CHD, recent large meta-analyses of observational studies have suggested no overall benefits of reducing SFA consumption on CHD events.
Few clinical studies have examined the effects on CHD events of replacing saturated fat in the diet with specific alternative energy sources like carbohydrate, protein, or other types of fat such as polyunsaturated fats, which include vegetable oils.
In fact, some experts argue that eating PUFA actually increases CHD risk and some guidelines recommend PUFA consumption should be limited. As a result, there has been a strong need for more scientific study.
The authors say: "Rather than trying to lower PUFA consumption...a shift toward greater population PUFA consumption in place of SFA could significantly reduce rates of CHD."