LOST AND FOUND – THE FAT FACTS (Sydney Diet Heart Study)

Dr. Neville Wilson – 10 Feb 2013.

According to a recent report in the British Medical Journal new research has revealed “previously hidden data” that saturated fats may , after all, be the kind of fats that, contrary to conventional wisdom, promote heart health and prevent disease. (1)

While this “revelation” is not new to the forward thinking clinicians who have long challenged the traditional dogma about dietary fats, it may come as a blow to the national health and dietary bodies who repeatedly dispense public warnings to avoid saturated fats “because they raise cholesterol levels and cause heart disease”. (2)

Not only is such dietary advice contrary to the findings of critical science, it is also a major stumbling block for those who seek to make healthy dietary choices, but who unwittingly deny themselves the many health benefits of dietary saturated fats by following conventional advice.

 

PUBLIC HEALTH MESSAGES:

The fearsome warnings about dietary cholesterol and saturated fats, imbedded in public health messages, has led to the widespread avoidance of  natural healthy dietary choices like butter, eggs, animal fats and tropical oils, and to the  increased consumption of the officially recommended alternatives, like poly-unsaturated fats and carbohydrate laden choices, camouflaged by “low fat” or “fat free” labelling.

The American Heart Association (AHA) and the United States Department of Agriculture (USDA) have promoted their anti-fat and anti-cholesterol policy for several decades,  successfully influencing bio-medical models  worldwide to echo their dietary dogma.

Their public portrayal of the “heart healthy” diet, as symbolized by the traditional Food Pyramid, involves the vilification of saturated fats, and the preferential  promotion of food choices high in poly-unsaturated fats and carbohydrates.

According to the Food Pyramid protocol, the foods to be avoided, or eaten “sparingly” are those allocated to the “top shelf “of the Pyramid, containing animal fats and tropical oils. (3)

 

NEW FINDINGS:

 

According to the BMJ report, new research has revealed that the purported  “heart healthy” fats may not be so healthy after all, and that the much maligned fats, derived from animals and tropical oils, may be the healthier choice.

In a review of clinical data from the Sydney Diet Heart Study (1966 – 1973), previously unavailable and recently released, a 74% increase in the risk of death from heart disease was observed in men who reduced their intake of saturated fats and increased their intake of omega-6 rich poly-unsaturated fats.

In the study, men in the control group were given no dietary advice, while those in the intervention group were instructed to replace dietary saturated fat with  omega 6 linoleic acid from safflower oil and poly-unsaturated margarine.

By so doing, the men in the intervention group increased their risk of death from all causes, coronary heart disease and cardiovascular disease, without any evidence of benefit from omega 6 poly-unsaturated fats.

In 2010 researchers led by Dr. C. E. Ramsden assessed the previously acclaimed health benefits of omega 6 fats and found insufficient evidence to support the conventional wisdom of replacing dietary saturated fats with poly-unsaturated fats. (4).

These same researchers, in their recent review of emergent data (previously hidden ) from the Sydney Diet Heart Study,  confirmed their earlier findings, and stated that these findings “ could have important implications for worldwide dietary advice to substitute omega 6 linoleic acid, and poly-unsaturated fats in general, for saturated fatty acids.” (5).

 

HEART HEALTHY FATS:

The AHA promotes the preferential dietary intake of poly-unsaturated fats as it’s “heart healthy” alternative to saturated fats, on the grounds that saturated fats raise serum cholesterol levels and LDL levels, considered by the AHA to be risk factors for heart disease.

This advice ignores the fact that saturated fats actually raise HDL cholesterol,  and improve total cholesterol / HDL-C ratios with cardio-protective benefits, and that raised LDL levels are irrelevant without making a distinction between the harmless buoyant LDL (pattern A – non atherogenic) and small dense LDL particle numbers (pattern B – pro-atherogenic). (6).

Saturated fats also reduce serum levels of pro-atherogenic lipoprotein Lp(a), thereby conferring their cardio-protective properties to arteries. (7) (8) (9).

National Health bodies in Ireland, including the Irish Heart Foundation (IHF) and The Irish Nutrition & Dietetic Institute (INDI)  continue to promote the “low fat “ message without making the vital distinction between unhealthy, partially hydrogenated fats, high in pro-inflammatory omega 6, and heart-healthy saturated fats and health sustaining omega-3 fats.

Their website advice is to “follow the Food Pyramid and limit choices from the top shelf “, and to “choose low fat spreads instead of butter, to eat lean meat and to cut off visible fat from meat”. (10) (11).

This dietary advice, in line with AHA and USDA recommendations, will lead to the inevitable reductions of dietary fat required for the optimal absorption of essential fat-soluble vitamins, like vitamin D, A, K and E .

Furthermore, reductions in dietary saturated fat, in accordance with AHA policy,  have been shown to adversely affect the cardio-protective sub populations HDL2, thereby increasing the potential for cardiovascular disease. (12)

The conventional dietary warnings about saturated fats have been repeatedly voiced by leading HSE dieticians, and several high profile clinicians, through public media policy statements or in patient prescriptions, and efforts to challenge these perceptions and prescriptions have been either ignored or unsupported by the public and medical media.

Vindication for these fats, as important inclusions in a healthy diet, should now be given recognition, and the necessary revisions to national  dietary advice be made as a matter of urgency.

Once again, Ireland has an opportunity to take a lead, as it did in revisions of anti-tobacco policy, and to publicly reverse it’s current anti-fat policy.

The HFSS (high fat, salt, sugar) slogan is misleading and counter-productive, and should be replaced by slogans that make a clear distinction between saturated fats and unsaturated fats, and between the ubiquitous inflammatory omega 6 rich vegetable oils present in processed foods and spreads, and the heart healthy anti-inflammatory omega 3 fats.

The recent decisions by the IMB to terminate the reimbursement of heart healthy omega 3 nutrients (Omacor) for deserving patients is likely to compromise their dietary intake of omega 3 fish oils, and tilt their omega 3 / omega 6 balance in favour of the latter, thereby increasing the potential for inflammatory disorders of the heart, lungs and central nervous system.

The low fat message has failed the test of time, and recently recovered clinical data has reinforced, not only,  the heart healthy benefits of dietary saturated fats, but also the importance of revising current dietary advice, which is contradicted, not only by the emergent evidence, but by half a century of clinical evidence that has either been hidden or ignored.

 

Dr. Neville Wilson. The Leinster Clinic. Maynooth, IRELAND.

 

REFERENCES:

 

  1. BMJ 5 Feb, 2013.
  2. www.heart.org / HEARTORG /Diet.
  3. www.usda.gov
  4. B J Nutr 2010; 104: 1586-6000
  5. BMJ 2013; 346: e8707, Ramsden, C E.
  6. JAMA 1998; 260: 1917- 1921
  7. Athero, Thromb & Vasc Biol 1998, 18: 441-449. Ginsberg
  8. Athero Thromb & Vasc Biol 24(2004), p  498 – 503.
  9. Athero, Thromb & Vasc Biol 24(2004), p 498 – 503.
  10. www.irishheart.ie
  11. www.indi.ie
  12. May Clin Proc 2003,78:1331-1336.

 

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