For as long as I can remember, a debate has raged over the relative merits of butter and margarine. Food purists contend, as far as flavour is concerned, that butter wins hands down. However, doctors and dieticians have generally been quick to point out that butter is rich in artery-clogging saturated fat, a fact that puts it firmly in a nutritional no-go area. Running alongside the battering butter has been getting have been glowing reports for it’s main contender: slick advertising campaigns extol the virtues of margarine’s cholesterol-reducing and heart-healthy effects. However, despite margarine’s apparent pedigree, I have for a long time had difficulty reconciling how a heavily processed, chemicalised food could really have a healthy edge over what is essentially a natural and untainted one. This week I thought I’d see whether margarine really does deserve its reputation as a knockout winner in the battle against butter.

Most margarines are made of vegetable oils that have been treated in a way which forms chemical entities known as trans fatty acids (also known as partially hydrogenated fats). These are essentially damaged fats, the like of which have only been seen in the human diet in appreciable quantities over the last half-century or so. Increasing amounts of research suggests that trans fatty acids actually increase the risk of heart disease, and perhaps other conditions including cancer too. Increasing concerns about trans fats have led some margarine manufacturers to look for alternative ingredients for their products. As a result, some spreads are now based on what is known as interesterified fat. These are fats that have been chopped up chemically, and then reassembled into novel fats. The long-term effects of interesterified fats remains unknown, but personally I’m nervous about the concept of eating any food that is fundamentally new to the human species.

In recent times, margarine manufacturers have been adding value to some of their products by lacing them with plant-based substances known as stanols and sterols. These help block the absorption of cholesterol in the gut, and can therefore help reduce cholesterol levels in the bloodstream. Even though the marketeers and admen seem keen to shove this fact down our throats, it seems that cholesterol reduction is not the panacea we’ve been led to believe it is. Not one study has found that taking dietary steps to lower cholesterol has brought a reduction in overall risk of death.

Although fatty in nature and yellow in hue, butter only bears a passing resemblance to margarine. Butter’s predominant fat is saturated in variety, and something we are told can only help speed our demise through heart disease. However, a close look at the scientific literature reveals that there is a stack of evidence that simply fails to bear this out. It appears the idea that saturated fat is a potent risk factor for heart disease is the result of quotation bias – essentially researchers using studies to support a theory, while at the same time being unaware of or simply ignoring other evidence to the contrary. Plus, no study that has examined the effect of reducing saturated fat in the diet has found that it actually reduces funeral rates. Despite it’s unwholesome reputation, the available evidence reveals that the saturated fat on which butter is based is not nearly the dietary spectre it’s made out to be. To my mind, the science suggests what our taste buds knew all along: butter really is better.

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