Before letting you read the article from The Conversation, let me state that I disagree with both David Gillespie's AND the reviewers' stances on dietary fats.
Peer review: David Gillespie's Toxic Oil
By Peter Clifton, University of South Australia and Bill Shrapnel
A best-selling book about nutrition has a power to influence the national diet that many health professionals can only dream about. And, if David Gillespie’s success is anything to go by, being a layman author is an advantage.
Freed of the constraints and caveats of scientific precision, the layman can use overstatement and simplistic messages to craft a story that resonates with the man or woman in the street.
In Gillespie’s earlier book Sweet Poison, he took the familiar dietary message to limit sugar intake, greatly elevated its health significance and broadcast it. Although the experts pooh-poohed his science, it could be argued that the whole exercise was positive for public health.
The same cannot be said for Gillespie’s latest book Toxic Oil, which carries the subtitle “Why vegetable oil will kill you and how to save yourself”. Here, the author’s key message is diametrically opposed to that of just about every reputable nutrition authority in the world.
At a time when a consensus has emerged that polyunsaturated fats are the preferred replacement for dietary saturated fats for the prevention of coronary heart disease, Gillespie declares that polyunsaturated fats actually increase coronary risk. And, for good measure, they increase the risk for cancer and macular degeneration too. Saturated animal fat is recommended as a healthier choice.
Despite claiming to be “Australia’s No. 1 Health Crusader”, Gillespie has no qualifications in nutrition or any other health science but argues that, as a lawyer, he knows how to assess evidence.
Over the last four years, there has been a lively debate in the scientific literature about saturated fat and its preferred replacement in the diet. Two meta-analyses of randomised controlled trials with clinical end points have been published as well as a pooled analysis of prospective cohort studies, not to mention the scores of studies of the effects of dietary fats on blood lipids in the literature.
Yet none of this found its way into Toxic Oil. Instead, the author re-visits some of the earliest studies into dietary fats and heart disease and revives the cholesterol controversy that those early studies generated 40 years ago.
The arguments presented are not original. Rather, like so many articles found on the internet, they flow from the familiar script of the cholesterol sceptics – Ancel Keys (an early research in the field) fiddled his figures; saturated fat and cholesterol have nothing to do with heart disease; it’s all been a con; and the truth can now be revealed.
The prevarication continues in the section headed Polyunsaturated fats cause cancer, which is supported by minimal evidence – a non-significant finding in a trial commenced in the 1960s and a single prospective cohort study showing a weak association between polyunsaturated fat consumption and increased risk for breast cancer.
Any reasonable review of the evidence on this topic could not have missed the pooled analysis of prospective cohort studies that showed no link. Somehow, the author of Toxic Oil comes to a conclusion at odds with every leading nutrition and cancer authority in the world.
This book will not appeal to the health professional. There’s almost no referencing and some data are presented in figures without acknowledging the source, so they can’t be checked. In one instance, British data are used to support an argument on the grounds that Australian data are “pretty thin on the ground”. Relevant Australian data are readily available; they just don’t support the argument.
Predictably, the dietary recommendations that flow from all this non-evidence leave a lot to be desired. Gillespie sums up his advice better than we can do:
If you do what I suggest, you will be doing all the wrong things, according to our health authorities. You’ll be eating butter, drinking full-fat milk, chomping through bacon and eggs for breakfast and enjoying a meat pie for lunch.
The message is so over-the-top that it’s hard to believe that anyone would take it seriously. Still, messiahs develop followers and the author’s previous advocacy on sugar probably guarantees him an audience that is at least prepared to listen. But any public good that came from David Gillespie’s earlier work will be undone by this poorly researched and ill-conceived book.
Peter Clifton has previous[ly] done research for edible oil industries but not in the last decade.
Bill Shrapnel Director of Shrapnel Nutrition Consulting and consults to Goodman Fielder, which makes a range of vegetable oil products. One of his clients in the last year was the Heart Foundation of Australia.
This article was originally published at The Conversation.
Read the original article.
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MY SAY
First, it's my opinion that Gillespie is the wrong person to be saying anything about the relative merits of nutritional alternatives. Although I'm knowledgable merely about public health and some of the vagaries of human physiology you may believe I'm totally out of place criticising his position because I'm no nutritionist either. However, I'm having my say and it's in partial agreement with Gillespie's! I noticed that the "peer reviewers" have both been tied to marketing or consulting around food oils and neither is a cardiologist or a metabolic biochemist, who could get down to the nitty gritty of how oil and butter behave in the human body.
Concerning human metabolism and it's links to modern diet and obesity I always refer back to the original diet our conspecific ancestors evolved to consume back in the mists of time. Now I'm neither a fan of the recent invention "The Paleo Diet", nor of cutting out ALL modern processed foodstuffs, but I do believe that we are getting the balance of nutrients wrong for most people and that we simply don't move enough now to justify the number of calories we consume.
It may be a hackneyed reference, but look at what those ancestors of ours were restricted to eating: mostly lean meat with a smattering of saturated fat, seasonal helpings of Vitamin C, fibre and folate-rich fruits, berries, roots and tender leaves and then a little later we all started to get some whole grains, as a fore runner of more modern breads, flat breads and pasta. On this mixture, I believe our ancestors started to thrive and increased their intelligence and lifespan while human metabolism stayed the same.
Obesity only occurred when individuals or small groups declared themselves socially "above" their fellows and thus ceased their share of hunting, gathering or tilling the soil and instead became more sedentary, ate more than their fair share and discovered tasty and intoxicating substances for their own pleasure. They tipped the balance in their own bodily metabolism and swam against the tide of increasing longevity. I also think it's important to make the point that human evolution did NOT at that stage "choose" particular genes to survive that were "obesogenic". Although some scientists seem to claim that many modern children have "inherited" obese tendencies from their parents, I'm pretty confident those tendencies are purely socio-environmental.
On a biological backdrop our genome as humans forces us to seek caloric content in foodstuffs that is energy-economic for our total organism. This biology is the same biology we all share and our inner workings respond to anything we put in our mouths with the objective of extracting maximum energy at minimal cost. This way we are drawn to energy-rich simple, tasty sugars and comforting, warm, slippery fats. Our socially primitive brains find energy-dense inputs pleasurable because they are linked to ancient survival mechanisms FOR THE GENES.
When we substitute mono- and polyunsaturated fats for the saturated ones in meats (and Westerners ADD them more often than substituting!), we are telling our metabolism to expend less energy in breaking chemical bonds, but we still get that warm, comforting sensation that satisfies the appetitve, primitive brain. I've forgotten a lot of biochemistry, so I can't recall the specifics here, but if we expend less energy on vegetable oils, what happens to the extra? Or am I right in assuming that we use that metabolic energy to either lose a little weight or digest something extra we consumed from the sugar/fibre categories? Anyway, we have to use it or lose it!
Besides consuming less energy in the digestive/physiological area it IS possible that we are engaging metabolic pathways that are not so advantageous to our survival. Again, I'm not seeking evidence to say that polyunsaturates might give you cancer, but they may do something that's not good for overall metabolism and ultimately affect us adversely when consumption goes over a certain threshhold. It is physically and ethically impossible to do a study of sufficient length and size to study the fine details of metabolism in humans in order to test what happens with different balances of saturated vs other fats in the diet from infancy.
Therefore, I'd like to see nutritionists, food scientists and food technologists go back to their mates in the biochemistry and molecular biology labs and get them to set up some working models of metabolic stages. Then there might be less emphasis on marketing whatever manufacturers can produce cheaply and more on growing the right mixture of foodstuffs to suit our genes. Perhaps as a result there would be less employment for some of those technology guys and more for farmers and grocers!
My leaning towards the political economy of health provokes thoughts of greater fairness if we could shift profits from food manufacturing to food-growing, nutritional quality-control on agricultural products and considering local and wider ecology when transporting food from its production locality to the markets. We need to value the farmer, food-harvesters and handlers more than the production-line workers who add value for bosses rather than value for their consumers' metabolism. Can we have inverse food pricing? Should we pay for food by calorie-content so it costs the consumer a fortune for a hot chocolate and almost nothing for a capsicum? Then we pay the capsicum farmer per kilo what we used to pay the cocoa baron??
I'd better watch out for @RedScareBot!
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Australian & New Zealand Nutrient Reference Guidelines: http://www.nrv.gov.au/resources/appendix1.htm
For an erudite explanation of fats in the diet: http://www.nrv.gov.au/nutrients/fat.htm
This contains some statements that rather startled me, vis:
"Saturated fatty acids have both physiological and structural functions. They can be synthesised by the body so are not required in the diet.";
and:
"The monounsaturates are also synthesised by the body and are thus not required in the diet."
These sound like "survival" statements rather than anything related to what humans need day to day in order to perform their daily activities, but what do I know? I must inquire. Surely we are not meant to survive solely on polyunsaturates?? How did the current human metabolic "machine" evolve on those saturated fats?
This was an interesting read on a related topic, and only appeared January 2013 as well:
http://www.cjr.org/cover_story/survival_of_the_wrongest.php
