If you clicked on the BBC website this week, you’d have seen an article called ‘‘Good fat’ cuts heart risk by a fifth, study shows’ and if you read it you’ll be led to believe that by increasing your consumption of polyunsaturated fat (PUFA) there would be fall in heart disease by 10%.
What the article fails to tell you is that the Editor’s Summary of the full study from the Public Library of Science says:
“Furthermore, the small number of trials identified in this study all had design faults, so the risk reductions reported here may be inaccurate.”
More importantly, whilst the study reviews CHD (Coronary Heart Disease) events, it totally omits to identify any increases in other chronic illnesses or total mortality.
As polyunsaturated fats in today’s diet are predominately omega-6 (eg soy oil or sunflower oil), they play a significant role in the imbalance of our omega-3 vs omega-6 ratios. As discussed previously in my blog (Not too much, not too little, but just right) this rise in omega imbalance has been accompanied by increased rates of many diseases – the so-called diseases of civilization – that involve inflammatory processes. In summary, omega-6 is inflammatory and omega-3 is anti-inflammatory, so:
- too much omega-6 can result in increased tendency to form blood clots, inflammation (the possible cause of heart disease), high blood pressure, irritation of the digestive tract, depressed immune function, sterility, cell proliferation, cancer and weight gain.
- Too little omega-3 has been associated with asthma, heart disease and learning deficiencies including ADHD (attention deficit/hyperactive disorder).
One of the papers referenced in the study – The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases – summarises their findings as:
“Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1. Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established.
Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today’s Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects…
A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies, as well as in the developing countries.”
Plus trans-fats caused by heating PUFAs are now being realised to be extremely bad for our health (see my blog ‘Betty bought some butter’)!
None of this is mentioned in the original study or in the BBC news article. So much for researched, informed reporting…
So by raising your polyunsaturated fat intake & lowering your saturated fat levels you MAY slightly lower your risk of CHD but I believe you’re highly increasing your risk of developing other chronic diseases such as cancer. But once again I have to state – to ensure your omega 6 ratios are kept low, the saturated fats must come from grass fed animals (not corn or grain fed. Read ‘Providence of Provenance’ for more detail).
So is the bad guy saturated fat or is it omega 6? I’ll leave you to decide…