How seed oils increase Breast Cancer risk

By September 12, 2012Vegetable Oils

The science has definitively demonstrated that the dominant fats in margarine increase our risk of developing breast cancer. But that science has been comprehensively ignored by the Health Authorities. Is their obsession with pushing margarine for heart health clouding their vision?

Breast cancer is the most common cancer in Australian women. One in nine women will develop the disease in their lifetime.

We are getting very good at detecting and treating the cancer (88 per cent of new cases survive five years or more). But there are no signs of any reduction in the numbers of women developing the disease in the first place. In the last 30 years the incidence has increased dramatically.

An Australian woman in 2012 was almost 50% more likely to develop breast cancer than her mother was in 1982. If the woman lived in the ACT, was white and is affluent, her risk is even higher.

Forty new cases will be diagnosed today. Forty women will discover they have breast cancer today that thought they were well yesterday. And tomorrow another 40 will join the list. And another 40 the day after that. Even more disturbingly three of those women every day will be under 40.

Despite its enormous impact, we know almost nothing about what causes the disease. The best the experts can tell us so far is what many would regard as the bleedin’ obvious – that we are more at risk if we are female, have relatives that have had the disease (or other cancers) or have previously had the disease (or other cancers) ourselves.

There is nothing in the official advice about the risks associated with polyunsaturated fat consumption. But researchers have known that there is a strong link between high polyunsaturated fat, seed oils (man-made oils extracted from grains and seeds such as canola, sunflower, grape-seed, corn and ricebran) and cancer for more than 40 years.

The Veterans Trial, completed in 1971, was conducted with a population of 846 Californian military veterans randomly assigned to two different kitchens. One kitchen replaced all animal-fat products with corn oil for the eight-year duration of the study. The other kitchen kept on serving a normal high-animal-fat diet.

The purpose of the trial was to determine whether animal fat caused heart disease, but it drew a blank on that front. Heart-disease-related events were slightly less than expected in both groups, and not significantly different from each other. But the researchers noticed something of far more concern. There was the dramatic difference in cancer deaths between the two groups. The incidence of fatal cancers in the corn-oil group was nearly double that of the normal-diet group by the end of the trial.

Ethical approval for more trials on humans was in short supply after that study saw the light of day. But rat studies performed in the 1970s and 1980s consistently noted that mammary (breast) cancer was formed more often in rats fed corn oil (high in polyunsaturated fats) than in those fed coconut oil (high in saturated fats). And a truly disturbing study published in 1997 showed that feeding the rat equivalent of a breastfeeding mother a diet high in polyunsaturated fat (43 per cent corn oil) doubled the rate of mammary cancer in her daughters, caused cancers to appear among them earlier and caused earlier onset of puberty.

In 1996, Swedish researchers decided it was time for a human study to provide some hard data on breast cancer. Scientists from the Karolinska Institute recruited 63,870 women aged 40–76 and monitored their diet and the occurrence of breast cancer for an average of 4.2 years. The dietary questionnaires used in the study enabled the researchers to determine exactly how much saturated, monounsaturated and polyunsaturated fat the women were consuming.

They found no association between the total fat or saturated-fat (the dominant fat in animal fats) intake and a woman’s risk of developing breast cancer. Monounsaturated-fat (the dominant fat in Olive Oil) consumption reduced the risk of breast cancer by 20 per cent but polyunsaturated-fat consumption did exactly the opposite. Just as the rat studies had predicted, the women consuming the most polyunsaturated fat were 20 per cent more likely to develop breast cancer than the women consuming the least.

Since that study, further human studies have found significant associations between dietary polyunsaturated fat consumption (in particular the omega-6 fats which dominate seed oils) and the risk of developing breast cancer. A review of the studies conducted by the Université Joseph Fourier (Grenoble, France) concludes “there are several recent and concordant studies that strongly suggest that dietary omega-6 [polyunsaturated fats] … increase the risk of breast cancers.”

Meanwhile the Australian Heart Foundation is busily telling ‘Mums’ that they should be replacing butter with margarine. They are doing this because for the last 30 years they have been telling people that plant fats reduce the risk of heart disease. Unfortunately there is no evidence that this is true. Indeed it is likely that the omega-6 fats in margarine significantly increase the risk of heart disease and death. Even more unfortunately the margarine they want all our mums to eat is made from the very oils the French review concluded “increase the risk of breast cancer.”

This evidence is compelling. It demands critical discussion. It demands widespread publication. And it demands public warnings. But none of this is happening. The folks charged with safeguarding our safety are asleep at the wheel (I’m being generous). And the folks with a buck to make from selling us seed oils appear to be running the show.

We are not talking about a rare disease afflicting tropical fish. Breast cancer is a blight upon the community. There is not one person who will not be personally affected by the tragedy of this very modern epidemic. Our mothers, sisters and daughters (and even very occasionally our men folk) deserve better. Somebody wake the watchdogs – please. And while you wait for them to stir, stop eating seed oils.

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Join the discussion 10 Comments

  • Deb Hurn says:

    thanks so much for bringing all this to our attention. I am very relieved to know there are things I can do to improve general health and prospects.

  • Once again, you cherry pick the bits you want from a study and ignore the ‘inconvenient’ information. The summary of the paper says “The optimal dietary fat profile
    includes a low intake of both saturated and omega-6
    fatty acids” and later “A moderate intake of plant and marine
    omega-3 in the context of the traditional
    Mediterranean diet (low in saturated and omega-6
    fatty acids but high in plant monounsaturated fat)
    appears to be the best approach to reduce the risk of
    both cardiovascular diseases and cancers, in particular
    breast cancer.”

    Just as in your ‘analysis’ on macular degeneration – your cherry picking of evidence misrepresents the science. Why?

  • Cassie says:

    David M Driscoll, the author just recommends “stop eating seed oils”, which is certainly the advice I get from reading the whole of the human research articles, especially the conclusions.

    The Swedish study appears to recommend olive oil (5:1 monounsaturated to polyunsaturated ratio) and also states “Saturated fat was not associated with the risk of breast cancer.”

    The other recent study to which you refer says “The amounts of omega-6 in most Western
    foods are so high that it could be difficult to obtain an
    intake of omega-6 lower than 4% of energy], which
    would probably be the optimal level.” So, in other words, you will have a low intake of omega-6 if you stop eating seed oils. It recommends the Mediterranean Diet… again olive oil.

    What is wrong with David wanting to spread the word on this research. I’m certainly phasing out all oils other than olive at our place!

  • Cassie, the author actively recommends increasing saturated fat intake – so if we assume that the studies quoted here and in the macular degeneration study are of a high enough quality to quote as evidence, the question must be asked why? How is it not cherry picking , just because the topic of this post doesn’t discuss that?

    Have you actually read all of the human research articles re omega 6/seed oils, read other people’s summaries or just followed links from articles suggesting that they are bad. Wider reading on the topic should instill a degree of uncertainty methinks, as summarised in this study (It could be said that most data regarding the effects of dietary omega-6 PUFAs on cancers are observational [25-30] and do not demonstrate cause-effect relationship. Only randomized trials can demonstrate causality.)”

    Also “The high average
    intake of omega-6 PUFAs in Western countries [53,54]
    may explain the persistently high rate of CVD complications
    and the increased incidence of certain cancers,
    including breast cancer.”
    The word ‘may’ is used, yet typically the caution that scientists show when presenting data that isn’t conclusive isn’t adopted by David when retelling stories!

    It is also worth noting that the original title of this blog was that they CAUSE cancer (only changed after two people on Facebook suggested that it was too strong – peer review of sorts?), but is typical of the black and white view that David has on many topics (eg diabetes epidemic is entirely put down to over-consumption of sugar).

  • fitforhealth says:

    Good morning Mr Driscoll,

    As a regular reader of this blog, I see that you tend to disagree with Mr Gillespie on these matters.

    Why not write a proper book outlining your own interpretation of the science?

    I want to know what you eat and why you eat it.

    It is nice to hear a man write a book for once. Most of the dietary advice books that have ever been written on nutrition in Australia are written by female dietitians who usually parrot each other.

    Where are all the male dietitians out there?

    I see that female dietitians have a clear bias in their food recommendations, all gearing towards eating more oestrogenic foods to tame hot flushes.

    However, this is not relevant to men at all. This is the reason why we have all these “eat more soy and linseed” rubbish floating around in almost every book or magazine article written by a female dietitian. One size fits all right?

    Instead of yapping away on your soapbox, why not write something meaningful to help your fellow man?

    Something that does not revolve around eating more soy and linseed.

    It’s about time that the Australian male dietitians step up. The female dietitians who have been the most vocal in the nutrition sphere have failed miserably to help the public.

  • David M. Driscoll, mistaking the abstract for the data when reading a paper is the worst form of cherry-picking.
    A researcher can detect a correlation (and another find the same effect in animals, and yet another decipher the mechanism in cell cultures), but the paper may well be published with a misleading abstract and the usual politically safe recommendations (because otherwise he may never get another grant).
    It’s the tables and figures that tell you what’s really happened.

    by now you would have read the news from the Sydney Diet Heart Study

    How many more premature deaths since 1973, and when will people learn?
    Benefits from linoleic acid stop above 4% calories, omega 3 is optimal at 1-2%, that leaves 94-95% of calories to come from other sources – minus protein, 80% – of which saturated and monounsaturated fats are the most health-neutral and stable, together with glucose from non-grain plants and butyrate from digestion of some (but not all) plant fibres.

  • Thanks this info is really useful for me because my wife is going breast cancer treatment and i know about the cause of her breast cancer is here…Thanks really you are doing great job!
    breast firming

  • Doctor Tom says:

    This was written nearly 20 years ago:

  • […] From Margarine significantly increases your risk of developing Breast Cancer: […]

  • Doktor Fill says:

    Gilllespie is a “corporate lawyer,” not a doctor, medical professional or biochemist. His word is of less value than avocado wolfe.

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