A new study reveals seed oils to be better for you than olive oil.
That sounds like quite a statement to make. An analysis of dozens of studies shows that when saturated fat is replaced in the diet with unsaturated fat, the level of low-density lipoprotein (LDL) cholesterol drops. That probably isn’t particularly new news given what has been reported about avocado consumption in past years. However it also reveals that the unsaturated fats in seed oils are better for you than those obtained from olive oil. Coconut oil incidentally is not that good at all.
The researcher, Dr. Lukas Schwingshackl based at the German Institute of Human Nutrition Potsdam-Rehbruecke, proauced this study.
The team looked at many studies going back to the 80s that considered how various nutritional oils impacted on blood lipid levels. They used the statistical technique of network meta-analysis. It allows you to examine massive amounts of data using both direct and indirect comparisons.
What is Network Meta-Analysis ?
The method is a very powerful statistical technique that is a better alternative in many cases to the giant studies conducted when comparing the effects of many interventions on a single result. It means according to Dr. Schwingshackl :-
“The beauty of this method is that you can compare a lot of different interventions simultaneously.”
It means the technique can reduce levels of uncertainty in the patterns of data and certainly between the results of so many studies. It was from this that they found seed oils were a better choice in the diet than olive oil. That does however almost fly in the face of received wisdom about olive oil – one which has been considered at the heart of the Mediterranean Diet.
The new study looked at 55 studies that examined the effects of consuming the same amount of calories from two or more different oils on the blood lipids of the subjects. Each study had to compare the effect of two or more fats or oils on LDL levels, blood lipids including total cholesterol, HDL-cholesterol and triglycerides for at least three weeks.
The statistical method allowed the team to make a quantitative comparison between say sunflower oil and butter even though there had never been a direct comparison of the two.
The study only measured blood lipids. Dr. Schwingshackl stated:-
“This is not a hard clinical outcome, LDL is a causal risk factor for coronary heart disease, but it’s not coronary heart disease.”
Even though there limitations in meta-analysis, the top performing oils were sunflower oil, rapeseed oil, safflower oil and flaxseed oil. The study reinforced the view that butter and lard are the worst for lowering LDLs.
There are some caveats. The oils that are best for lowering LDL are not the best for lowering triglycerides or increasing levels of HDL-cholesterol, which is the ‘good’ cholesterol. Having a high level of HDL cholesterol is good for you whilst having a high LDL-cholesterol level is not. At the moment it is cardiovascular disease which is the number one killer, not cancer. In the United Kingdom, it kills 73,000 people every year. In 2016, 15.2 million people died from cardiovascular diseases throughout the world.
Dr Schwingshackl predicts that those living in the mediterranean might not be too happy by his findings.
“Some people from Mediterranean countries probably are not so happy with this result, because they would prefer to see olive oil at the top. But this is not the case.”
References
http://www.jlr.org/content/59/9/1771
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