Good night, low-fat diet


Omega-6 margarine spread might just kill you

The old fear of natural saturated fat (such as butter) has been on its way out for a long time. Repeated reviews of science have in recent years not shown any evidence that eating butter is anything but healthy. In Sweden (where I live) lots of people have understood this and sales of skim milk, low-fat margarine and other low-fat products have plummeted.

Here is another nail in the coffin for the fat-phobia and the low-fat hysteria. A review of previously unpublished (hidden) numbers from an older study shows that today’s margarines may not only be unnecessary. They may be directly harmful to the heart.

A disaster

The study involved nearly 500 men with heart disease. Half of them were randomly assigned to increase polyunsaturated omega-6-fat intake, including in the form of margarine (similar to Promise light spread* in the US), and were advised to reduce saturated fat (such as butter). The other half was left alone and allowed to continue eating as before.

When the study was stopped after three years there were significantly more deaths in the group that consumed omega-6-rich margarine. The risk of dying during the study was elevated by a whopping 62%. Those who escaped counseling on margarine clearly lived longer.

Now it’s revealed that the risk of death from heart disease also was significantly elevated, by as much as 74%(!), in the group that was given margarine.

Good night, fat phobia

When you add this previously hidden disastrous result to all other studies that have been done, there isn’t the slightest evidence that omega-6-rich margarine is good for your heart. On the contrary: The numbers are very close to (p=0.06) showing a statistically significant harmful effect from this margarine. A probable increased risk of dying from heart disease as a result of consuming margarine instead of butter.

Adults can of course avoid buying the junk. But not all get to choose. Where I live potentially heart damaging omega-6-rich margarine is the only alternative allowed in many day care centers and schools, citing official fat-fearing dietary advice.

Time to wake up, official dietary guideline authorities?


From the British Medical Journal

*/ Promise light spread contains 1900 mg of omega-6 and only 300 mg of omega-3 per serving.


  1. mezzo
    You can only stay away from that stuff if you make all your own food. Sick people and old people get the worst deal here: they are the ones who would need the best possible nutrition and they usually get the worst there is. Anyone who depends on instiution food gets a rough deal.
  2. Kurt Lao
    In here, those things are served in hospitals and health care centers. Talk about misguided health practices.
  3. Rick Brown
    I totally agree with mezzo and Kurt Lao!
  4. David M Driscoll
    An interesting range of commets on this study from the science media centre, especially re how much faith you can put in 5 extra deaths, or trans fat levels. As one author stated, an interesting piece of the puzzle, I think you are overstating its importance somewhat though?
  5. "Time to wake up, official dietary guideline authorities?"

    No, it's time for the "authorities" to realize that they know less than nothing about nutrition, and have no legitimate business dealing with it in any way.

    When government gets involved in nutrition, we get things like the Danish "fat tax" or the US "healthy whole grains" fiasco.

  6. Janknitz
    "Adults can of course avoid buying the junk."

    In the US, adults are constantly told that various "spreads" like Promise are "heart healthy"--not only shouted from every form if media advertising, but from health care providers, chain restaurants touting "healthy fare" and even Consumer Reports and AARP health publications. Kaiser Permanente health publications on diabetic and heart healthy diets still tell patients that margarine should replace butter.

    Most adults don't know better than that and continue to avoid "artery clogging" butter and animal fats in favor of Omega 6 laden spreads. It's going to take more than this article to turn this ship around.

  7. Wade Henderson
    Gosh, if one wasn't careful, one might get the impression that the alternative Ornish, McDougall, China Study, type-low fat dietary advice suggests using either more margarine, or increased Omega 6 in plalce of saturated fat foods.

    On the contrary, they'd be telling followers to entirely avoid all margerine and butter.

    BTW, the study indicates that the group was told to hold the saturated fat to 10% while "increasing" the omega 6 fats to 15%.
    Suggesting the group was actually increasing overall fats, not lowering them as one might expect on the more agressive low fat dietary plans.
    While I have not looked it up, I think I can safely say that both Ornish and McDougall and that crowd would suggest zero use of margerine.

    Also, this study was conducted from 1966 to 1973. What is published today is only a reanalysis of the orginal data.

  8. "...previously unpublished (hidden) numbers..."

    Hidden's a bit much. The original researchers cooperated with this review of their original data. Pity they hadn't done this look at the data first time around...

  9. Peter Clifton has responded to Ramsden's et al. previous meta-analysis as well this new paper:

    "The most important determinant of event reductions was the length of the intervention; and the studies using ALA-rich oil were much longer in duration than the LA-only studies. If only participants who had been on the diet for 1 year or more in the Minnesota experiment were to be assessed, then the ratio of total coronary events was fifty-four in the treatment group and fifty-eight in the control group."

    "Trans-fatty acids may also play a role – the experimental polyunsaturated fat diet which incorporated soft margarines containing trans-fats would have increased trans-fat intake as was the case in both the Sydney study and the Minnesota study"

    "Although dismissed by the authors trans fats are likely to be responsible for the lack of benefit. The margarine would have contained at least 20% trans fatty acids and if the participants were eating 25g/day of margarine then they would be consuming 5g of trans which might represent about 2% of calories. From the Nurses Health study this could reduce heart disease by 40-50% which would almost completely remove the apparent increased risk from the N6 margarines. The more margarine eaten the greater the risk. The test margarine would have mostly supplanted butter rather than other margarines. The fall in total cholesterol seen not only reflects a fall in LDL cholesterol but also a trans induced fall in HDL cholesterol."

    Here is another response to the reanalysis of the Sydney Diet Heart Study:

    ”Participants in the intervention group consumed “Miracle” Margarine, a product based on safflower oil. Hydrogenation of safflower oil itself creates a grainy product low in linoleic acid, so high-linoleic safflower oil margarine products were created by blending liquid safflower oil with another hydrogenated oil stock (3). Miracle Margarine used in the original study was either low in linoleic acid (due to hydrogenation of the safflower oil itself) or the oil was blended with another commercially hydrogenated fat to create a plastic margarine product. An investigation by Bernfeld, Homburger, & Kelley, published in 1962, indicated that the fatty acid composition of most margarines of the time were about 50-60% 18:1 monounsaturated fats (including oleic and trans isomers) and about 20-30% 18:2 linoleic acid, even in those products having high-PUFA claims on the label (4). None of the 22 margarines studied had a majority of fatty acids coming from PUFA. Another report from the same time period indicates that commercially produced hydrogenated fats, like those added to safflower oil to make margarine, were generally composed of about 25-40% trans fats (5). Fatty acid composition of margarines in the 1960s investigation were not comparable to liquid vegetable oil, despite package claims. The only reference supporting the healthful content of Miracle Margarine is a very general press release from the company who made the product (6). It is probable that Miracle Margarine had significant trans fatty acid content.”

  10. Olivia Nilsson
    Just found this article about diet sodas... - not in the least surprised about it being so bad for one! I have been on the LCHF diet for over 9 months and my diabetes is under control, and I am off medication (Metformin). Have lost a bit of weight, but will take the advice given in another article on this page about cutting down on nuts, etc...
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