High fat foods and diets, and in particular saturated fats have long been maligned, many of us are encouraged to eschew a high fat diet for the benefit of our cardiovascular system. However, more recently, research appears to be turning the tide on fat. So how bad or good is it for us?
Saturated fat is needed by the body for numerous functions including cell membrane integrity and hormone production, as well as being a vital source of energy and fuel. You only have to think of the brain – largely composed of fat to see how important fat is. Over the last 40 years or so dietary advice has been to follow a low-fat, low saturated fat diet in order to help prevent heart disease. But this advice has come into question, with recent reviews of the data and ongoing research suggesting that this recommendation does not, as was once believed, hold the key to a healthier cardiovascular system.
According to studies, adopting a low fat diet does not seem to protect against mortality from cardiovascular disease (CVD). What studies suggest is that whilst trans-fats, found in fried foods, fast food and bakery items are indeed related to increased mortality, saturated fats are seemingly not. This is borne out around the world when looking at those populations whose diet consists of large amounts of saturated fats but conversely low levels of heart disease. Inuit, the indigenous people living in the Arctic regions and the French, living just a hop over the channel, are cases in point.
Compelling evidence comes from a review in 2016 which looked at the prevalence of CVD in 42 European countries against specific dietary elements. The authors concluded that results ‘do not support the association between CVDs and saturated fat, which is still contained in official dietary guidelines’ and that ‘current dietary recommendations regarding CVDs should be seriously reconsidered’.
So if saturated fat is not the bad guy, what is causing the problem? The answer, it appears, lies in what is consumed in its place.
Often it is replaced by Omega 6 rich polyunsaturated fats. Interestingly a review published last year concluded that whilst replacement of saturated fat in the diet with Linoleic acid (Omega 6) effectively lowers serum cholesterol, it does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or death from all causes. It has been proposed by many that this might be due to the pro-inflammatory nature of Omega 6 fats.
Other emerging data suggests that CVD risk is linked with the high glycaemic index/load of carbohydrate-based diets, as saturated fat is replaced by carbohydrates and sugars whilst following a low saturated fat diet.
With the finger pointing more firmly in the direction of increased consumption of foods with a high glycaemic index, there seems perhaps a stronger argument for more of a focussed approach towards cutting down on sugars and carbohydrates in the diet, rather than religiously cutting down on saturated fat sources, or swapping them for too many Omega 6 rich vegetable oils and margarines like sunflower oil.
Saturated fats are not all equal; short chain fatty acids such as butyric acid found in butter are vital for gut flora, whilst medium chain ones including lauric acid found in coconut oil are perfect for energy production and gut health.
The essential fats, and in particular those from the Omega 3 family, must by their very nature be included in the diet. Like saturated fats, they too play a pivotal role in brain health and cellular membrane function. The omega 3 oils are also vital for making anti-inflammatory messengers in the body. Many of today’s degenerative diseases, including metabolic syndrome, osteoporosis, CVD as well as the more obvious inflammatory conditions such as arthritis, reveal an inflammatory component.
Let’s not also forget too the heart health benefits that a Mediterranean diet rich in oleic acid from olive oil confers.
So where does that leave us? The answer probably lies in good old moderation. A diet focussed around olive oil, coconut oil, oily fish, omega 3 seed oils such as flax, walnut and hemp with the inclusion of butter instead of low fat spread would seem to be the way forward as far as fats are concerned.
Or as your mum or grandma probably used to say ‘a little of what you fancy does you good!’