BBC Radio 4 this morning had a brief item about margarine. The item focused on the fact that margarine manufacturers can trumpet the presence of ‘heart-healthy’ omega-3 fats on the label. Professor Jack Winkler, Professor of Nutrition Policy at London Metropolitan University made the claim that such labelling is misleading. It seems that margarine manufacturers are putting ‘cheap’ plant-based omega-3 fats (I assume alpha linolenic acid) and kinda passing them off as fish oils. Professor Winkler appeared to claim that fish-derived omega-3 fats have proven cardiovascular benefits that do not extend to plant-derived omega-3. What he wants is for food manufacturers to be able to make claims about the omega-3 content of their products, but only if they contain actual marine omega-3. Seems fine to me.
But why stop there? Why not look and see what evidence there is for the other nutritional attributes of this ‘food’?
The major constituents of margarine are ‘vegetable’ oils, obtained from foods such as sunflower seeds, rapeseed or soya beans. These oils are usually extracted using the application of pressure and heat, and maybe the use of solvents too. This processing can damage the fats and impart some unhealthy properties on them. The oil obtained by this process is then treated with sodium hydroxide to ‘neutralise’ certain fats in the oil that are unstable and may cause spoilage. After this, the oil is then bleached, filtered and steam-treated to produce what is essentially a colourless, flavourless liquid.
To convert this into margarine, this oil is subjected to chemical processes such as interesterifcation or hydrogenation. Interestification involves the use of high temperature and pressure, along with enzymes or acids, to ‘harden’ the oil. In hydrogenation, hydrogen is bubbled through the oil at high temperature. The ‘partially-hydrogenated’ fats so produced can be tainted with trans fats that are strongly linked with heart disease. As a result, manufacturers now use interesterification as their preferred processing method. However, question marks remain regarding the health effects of these fats [1] – a situation that is essentially the same as the one when partially hydrogenated fats were introduced into the food supply and lauded as a healthy step forward.
After this, hydrogenation or interesterification, the solidified fat is generally blended with other fats, which can be of vegetable or animal origin. And then the product needs to be both coloured and flavoured. Then, what are known as ’emulsifying agents’ are added to prevent the product from separating out. And finally, the end result is extruded into a plastic tub.
While margarine is passed off as something generally healthy, it is (in my view) a highly-processed, chemicalised food that does not really deserve the title of ‘food’ at all. It was originally sold to us on the basis that it is low in heart-stopping’ saturated fat, and therefore a healthy alternative to butter. However, hard as one looks, there is really no good evidence that saturated fat causes heart disease.
Oh, and then we have margarine’s cholesterol-reducing properties. Except that taking dietary steps to reduce cholesterol does not appear to have broad benefits for health.
And even if cholesterol-lowering did have apparently miraculous health benefits, does that mean that something that reduced cholesterol must be healthy. If a known poison was found to reduce cholesterol, would that somehow make it ‘healthy’? What is critically important is not the impact of a food (or anything else) on cholesterol levels, but it’s impact on health.
So, what does the science show in this regard?
One study in the scientific literature which examined the association between butter and margarine consumption and risk of heart disease in men [2]. This study found that butter consumption was not associated with heart disease risk. In other words, those men eating more butter were not at increased risk of suffering from heart disease. On the other hand, margarine consumption was associated with an increased risk of heart disease: in the long term, for each teaspoon of margarine consumed each day, risk of heart disease was found to be raised by 10 per cent.
In another study [3], this one in women, long-term margarine consumption was associated with a 67 per cent increased risk of heart disease. These studies are old, but I’m not able to find any newer ones. Some say these studies reflect what we know about trans fats, but now we have interesterified fats, there’s no cause for concern. However, as I pointed out above, the health effects of these fats are essentially unknown. In my opinion, we really are not in a position to declare these fats as healthy. They may not even be safe.
It appears as though there is no good evidence that margarine is healthier than butter. In fact, the evidence suggests butter is the preferred choice (it also tastes better, of course). The marketing of margarine to the masses seems distinctly unscientific and misleading to me, whatever the source of omega-3 fats it may contain.
References:
1. Karupaiah T, et al. Effects of stereospecific positioning of fatty acids in triacylglycerol structures in native and randomized fats: a review of their nutritional implications. Nutrition & Metabolism 2007;4:16
2. Gillman MW, et al. Margarine intake and subsequent coronary heart disease in men. Epidemiology. 1997;8(2):144-149
3. Willett WC, et al. Intake of trans fatty acids and risk of coronary heart disease among women. Lancet. 1993;341(8845):581-5
I heard this broadcast live, too, John.
Prof Winkler began the interview by referring to the ability of manufacturers to trumpet the properties of omega-3 and omega-6 within the product as being beneficial to health. Flora, the most prominent of brands, for example, has a current TV advertising campaign(*) which associates Flora with heart health and with reference to a ‘unique blend of omega-6 and omega-3’.
What I found notable during the course of the interview was no further comment was made on the topic of omega-6. The relatively short discourse was exclusively about omega-3.
So far as I understand matters (please correct me if I am wrong) the omega-6 is essentially intrinsic to the product being comparatively plentiful in the preferred component vegetable oils that go into the ‘recipe’. Presumably one can influence the amount of these EFAs (essential fatty acids) to an extent in the product according to the choices of source oils in the mix. However, I derived from Prof Winkler more of a sense of ‘fortification’ with omega-3 fats and the distinct impression that fortification with plant derived omega-3 is inferior to fortification with marine derived omega-3. I hope to major in ‘scepticism’ soon, and en route I wonder why must manufacturers feel it expedient to fortify margarine products?
If I chose to spread margarine on my toast it would be as an alternative to butter. Butter in general, and the grass fed Anchor brand, are not especially rich sources of either omega-6 of omega-3 fats but the traces present are roughly in balance. The balance of omega 6 & 3 fats in margarines varies considerably between brands but the balance is usually tipped significantly to comparative abundance of omega-6. 100g of Flora Original contains 26g omega-6 and 3.5g of omega-3, (the omega-3 here presumably largely of the plant derived short chain variety) and equating to a ratio of 7.43:1. So far as I can tell 6:1 is about as good as it gets in any brand and many will be 10:1 or worse. It is hard to be sure from packaging because unless the packaging references a health claim there is no legal obligation to include EFAs in the obligatory nutrition box. As things stand it is possible to declare say 2.5g of omega-3 per 100g of product but make no similar declaration of the omega-6. My scepticism here, largely founded upon the chapter ‘Oil Crisis’ from your own book, ‘The True You Diet’, along with propositions from other authors (Sears, Parker, and others) is that folks are possibly getting more omega-6 than is good for them. Might that be one reason it is considered expedient to fortify the product?
The Food Standards Agency will happily direct people away from saturated fat and, in common with commercial messages, contribute to continued migration from butter to margarine. The FSA does so knowing full well the ramifications drawn to our attention by Professor Jack Winkler and the co-signatories to the petition.
On 19/3/2009 an FSA Scientific Officer answered a query by email, “Agency research has shown that consumption of the short chain omega 3 fatty acids does not appear to have the same benefits on cardiovascular disease as the long chain omega 3 fatty acids found in fish. Although shorter chain omega 3 fatty acids, found in vegetable oils, can be converted to longer chain versions by the body, this process appears to be limited.”
I can see that fish oils may be important to us. Riverine and coastal habitats would have been important as humans migrated from the Rift Valley. But the richest sources of long chain omega-3 oils are from cold water fish. The puzzling thing is to wonder if habitats further back in human ancestry provided equally abundant sources of long chain omega-3 oils. If they didn’t, then perhaps recognition of their importance now may also provoke further speculation that their importance to us may be in part as mitigation for some other aspect of dietary change with otherwise negative impact.
(*) The ad is under investigation awaiting adjudication by the Advertising Standards Authority.
Dr. Uffe Ravnskov has contributed a three part article titled: “Saturated Fat is Good for You” to Dr. Duane Graveline, MD, MPH’s website.
What Spacedoc has to say about Statins is also worth reading.
Andreas Eenfeldt has been waging war with Unilever in Sweden with some success and now in Sweden saturated fat sales are rising and obesity rates in middle class children are falling.
Dr Dalhqvist has a good set of links to Swedish low carb higher fat websites that are worth following using google translate.
The margerine manufacturers lie in other ways too. Here in the USA, they also claim “zero trans fat.” But if you read the ingredients, you will see “partially hydrogenated _____ oil.” A loophole in the labeling laws allow them to claim “zero” if there is less than 0.5 g per serving. The trick is to list a small enough serving that it comes in at less than 0.5 g. One margerine ad claims “now we know better.” Yeah right.
Tom Naughton, producer of the Fat Head movie recently posted about margerine. He contrasted the process for making margerine with the process for making butter. I’ll stick to butter, thank you. He also links to some margerine ads I remember as a kid. It really isn’t nice to fool mother nature and we are paying for it with our health.
http://www.fathead-movie.com/index.php/2009/09/21/margarine-and-mother-nature/
I thought you would be interested in my article on omega-3s in Prevention Magazine: http://health.msn.com/nutrition/articlepage.aspx?cp-documentid=100245164
Margarine is one of the big problems of modern society. By the time the oils have been processed they are like nothing found in nature. They should be avoided at all costs!!!
If you read up on the much advertised omegas used in infant formula and much other processed food -with implicit claims of benefit to infant brain development – you’ll find that the “vegetables” that produce these fats are genetically modified marine algae and soil fungi. I found the Martek Biosciences website illuminating (and to me, terrifying as the possibility of sensitisation to these “food” sources seems not to have been independently investigated, and logically there is a possibility of cross reactivity to say freshwater algae….). Algae, as we know, are the scum you will see after water has been left standing…Most people wouldn’t want to buy or eat fungal or algal oils, much less feed them to babies, which might be why our Food Standards authority kindly amended labelling laws to allow these to be called simply “vegetable oils”, where previously the source of fats in infant formula had to be declared. And as with other GM sourced food, this does not have to be declared either.. As one infant formula company advertised for years, “What you feed them now, matters forever.” Is that why there’s so little research about the intergenerational effects?
Reminds me of case of a premium brand of ‘organic’ milk being promoted for its higher omega 3 content, when the different with ‘normal’ milk was so minimal that if people took an extra mouthful of normal milk they’d get the same additional omega 3.
The common thread seems to be an inability of the responsible authorities to create and enforce appropriate labelling regulations, allowing these marketers to dupe consumers.
Hi Dr Briffa,
Bit late on this one but interesterified margarine is a little suspect too. If my boots were yellow I might use it as polish…. (they’re not)
Peter
http://www.nutritionandmetabolism.com/content/4/1/3
http://www.nutritionandmetabolism.com/content/4/1/10
http://www.nutritionandmetabolism.com/content/4/1/13
http://www.nutritionandmetabolism.com/content/4/1/16