Saturday, February 23, 2013

Saturated fat is not the enemy

Can we just throw out the misguided and dangerous recommendations on fat and heart disease – please?

A recent Australian study, published in the British Medical Journal (BMJ), clearly goes against the tide of prevailing dietary advice.

What it says is that saturated fat is not so bad after all!

The BMJ paper was an update of a previous meta-analysis by the same investigators, looking at the consequences for cardiovascular health of replacing dietary saturated fats (i.e. butter) with polyunsaturated, omega-6 fatty acids (PUFAs). 

This time around, the group reassessed the results of the Sydney Diet Heart Study (SDHS), a randomized, controlled trial involving 458 patients that compared the rates of cardiovascular disease among subjects who increased the amount of omega-6 PUFAs – specifically, linoleic acid from safflower oil – in their diet with patients who continued their normal diet. As well as reanalyzing the results, the investigators incorporated them into their previous meta-analysis.

The SDHS results were clear: replacing dietary saturated fats with omega-6 PUFAs increased all-cause mortality, cardiovascular mortality and mortality from coronary heart disease. 

In addition to that, “An increase of 5% of food energy from [omega-6 PUFAs] predicted 35% and 29% higher risk of cardiovascular death and all cause mortality, respectively”

Along those lines, the updated meta-analysis found that increasing dietary omega-6 PUFAs in isolation was associated with increased mortality risk from both coronary heart disease and cardiovascular disease overall. And Omega-6’s are the main components of polyunsaturated fats in the Western diet – and they are found in vegetable oils and margarines — the very things we were told to start eating more of forty or so years ago when we were warned that saturated fats would give us heart disease!

By contrast, the SDHS found that when dietary omega-3 PUFAs were increased alongside omega-6 PUFAs, to more closely resemble the 1:1 ratio enjoyed by our ancestors, both coronary heart disease and cardiovascular disease risk were reduced.

Time for some new thinking

According to our current dietary wisdom, this shouldn’t have happened – and the so called experts are busily trying to pretend that they haven’t. 

The current mainstream recommendation still holds fast to the ‘lipid hypothesis’, which proposes that the cholesterol found in saturated fats raises blood cholesterol, particularly low-density lipoprotein (LDL-C) or ‘bad’ cholesterol. Because the major part of this theory is that raised blood LDL-C is a major contributor to atherosclerosis and heart disease, then statin drugs can be considered the ‘golden child’ of the lipid hypothesis.

Oxidation is the true culprit

Experts like Dr Dwight Lundell have for some time pointed to oxidation as the true culprit in atherosclerosis and heart disease. According to this alternative theory, dubbed the ‘degenerative hypothesis’, LDL-C only becomes a problem when it becomes oxidized. 

In fact, LDL-C is a red herring, since all LDL molecules contain cholesterol. LDL isn't ‘bad’ in any way. LDL is absolutely vital for life, since the body uses it to transport important nutrients, including cholesterol, from the liver to tissues and organs.

Lipoproteins, such as LDL, consist of a core of fats (triglycerides) and fat-soluble vitamins, surrounded by a phospholipid membrane penetrated by cholesterol molecules. This way water-insoluble cholesterol can be transported around the body in water-soluble lipoproteins. 

Some of the membrane lipids are delicate PUFAs, and these can become oxidized – and toxic – in people who eat a poor diet or don’t exercise, among other factors.  Not only is oxidized LDL a marker for heart disease risk, it is strongly implicated in the development of atherosclerosis.

Protect your heart by using saturated fats and antioxidants

So it then makes sense that a diet high in antioxidants will protect against LDL oxidation. Glutathione has been described as 'the bulletproof vest’ that protects against dangerous oxidation. Glutathione-boosting strategies include exercise, cruciferous vegetables, sulphur-containing foods like garlic and onion, nutrients including alpha-lipoic acid, selenium, vitamins B12 and B6, folate and glycine, and botanicals such as milk thistle, cordyceps, gotu kola, and broccoli seed.
Also, since it is the delicate PUFAs in the LDL membrane that become oxidized, a diet high in PUFAs will increase the risk of oxidation, since more PUFAs will be available to be packaged into LDL membrane. This is especially true in modern, Western diets with their high omega-6:omega-3 PUFA ratios. 

On the other hand, saturated fats may well be protective, since their chemical structure makes them highly resistant to oxidation

Accept the new reality

This new thinking is a long way from arteries are like pipes and cholesterol is sticky gunk that accumulates and eventually blocks them up. 

As an hormone precursor and constituent of cell membranes, cholesterol is vital to life, as is the crucial transporter LDL. You would think that it shouldn't be long before the medical establishment and even dieticians would take notice and change.

All this to say that we make sure that our diet is loaded with saturated fat, especially coconut oil, and full of good anti-oxidants.

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