Some nutritional researchers appear to be obsessed by fatty acids and their role in cardiovascular disease. They see lipids in the plaques that grow in arteries and they assume that the fat in the diet is the cause of the problem. Years of research money and time has been wasted by simple thinkers who do not understand nutrition and by others who go along with political agendas to feather their own nests. The agenda to vilify saturated fat and cholesterol dates back to the 1960’s, and since this time various recommendations to avoid animal fats and replace them with vegetable fats have been based on little more than dogmatic opinion and anecdotes. The recommendation to replace saturated fat with polyunsaturated fat that was common in the late 1980’s and is still prevalent today has been a disaster for health because it has shifted the omega 6 to omega 3 fatty acid ratio too far towards omega 6 fats. Likewise, the recommendation to consume more monounsaturated fatty acids is based on little evidence that they are of benefit.
Olive oil contains high amounts of the monounsaturated fatty acid oleic acid (OA, C18:1 (n-9)) and is a dietary component of the Mediterranean diet. In turn those that consume the Mediterranean diet are at a lower risk of developing cardiovascular disease. Further, studies feeding subject olive oil have shown beneficial cardioprotective effects. However, olive oil is more than just a monounsaturated fat. In fact extra virgin olive oil contains large quantities of phytochemicals from the olive that have known cardioprotective effects. Combining these findings with studies showing inconsistent benefits for the consumption of monounsaturated oil when not present as extra virgin olive oil and the muddy waters clear somewhat. A recent study investigated the associations between various monounsaturated fatty acids in red blood cells and the risk of coronary artery disease1. Fatty acids were measured in 1000 subjects with coronary artery disease, and these subjects were then pair match to subjects of similar age but who were free from disease.
The results of the study showed that of all the long and very long chain monounsaturated fatty acids tested, none had an association with the risk of coronary artery disease except for erucic acid (EA, C22:1 (n-9)). Erucic acid is interesting, because although it is present in mustard seed oil, the diet is not the main source of this oil in the body. In fact endogenous production of erucic acid through lengthening of oleic acid by the enzymes oleoyl-CoA and malonyl-CoA is the main source. Since oleic acid is present in olive oil, but can also be synthesised in the body, it is not clear as to why erucic acid should be associated with a reduced risk of coronary heart disease, unless it is a marker of olive oil consumption. However, this research does show that enriching red blood cell membranes with monounsaturated fatty acids through consumption of a high intake of monounsaturated fatty acids is not beneficial at protecting from cardiovascular disease, and therefore the recommendation to consume more monounsaturated fats is problematic.
Dr Robert Barrington’s Nutritional Recommendation: The lipid hypothesis of cardiovascular disease is in disarray because the scientific evidence does not support the contention that dietary lipids, when in their natural state, are a cause of cardiovascular disease. Only trans fats, chemically altered fats that are a product of the food industry, have been shown definitively to be a driver of disease. In addition, an imbalance in the omega 6 to omega 3 fatty acid ratio of the diet can also cause inflammation and disease, but these fats themselves when in balance are not disease causing. Extra virgin olive oil is likely beneficial because it is one of the only readily available oils that still retains its key phytochemical content. Other unrefined and unprocessed oils show similar benefits, as it is the phytochemical content that is likely the beneficial factor, not the fatty acids.
RdB
