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EDUCATION AND DEBATE: Malcolm Law Plant sterol and stanol margarines and health BMJ 2000; 320: 861-864 [Full text]

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Plant sterols: unproved effects on health

Uffe Ravnskov   (13 April 2000)

THE DEBATE ON CHOLESTEROL LOWERING MARGARINES

Charles van Heyningen   (19 April 2000)

Stanol/Sterol Margarines; Trans fats and Benecol

Eddie Vos   (21 February 2001)

Why medicate the whole population?

Aenid Pettingill   (17 October 2001)

Plant sterols: unproved effects on health 13 April 2000
Uffe Ravnskov, private practitioner; independent researcher Råbygatan 2, S-22361 Lund Sweden Send response to journal: Re: Plant sterols: unproved effects on health	Dr. Law pleads for an introduction of plant sterol and stanol margarines into human food consumption arguing that these sterols lower the serum cholesterol concentration and therefore also the morbidity and mortality of ischaemic heart disease.1 This is wishful thinking only. Before the statin era the same assumption gave rise to a host of trials using dietary manipulations and/or a variety of drugs, but although these trials lowered the cholesterol concentration, neither coronary or total mortality was changed.2 A beneficial effect has been achieved with the statins, but it was independent on the degree of cholesterol lowering; coronary morbidity and mortality was lowered whether cholesterol was lowered only a little or whether it was lowered very much, indicating that the statins have other, more important effects than cholesterol lowering.3 4 Possibly, plant sterols may have beneficial effects also, but before this has been proved in controlled, randomised and double-blind trials it seems prudent to avoid a general usage of an unnatural food with unfavourable effects on the absorption of antioxidant vitamins and the flavour of the food. 1. Law M. Plant sterol and stanol margarines and health. BMJ 2000; 320: 861-4. 2. Ravnskov U. Cholesterol lowering trials in coronary heart disease: frequency of citation and outcome. BMJ 1992; 305: 15-9. 3. West of Scotland Coronary Prevention Study Group. Influence of pravastatin and plasma lipids on clinical events in the West of Scotland Coronary Prevention Study (WOSCOPS). Circulation 1998; 97: 1440-5. 4. Sacks FM, Moyé LA, Davis BR et al. Relationship between plasma LDL concentrations during treatment with pravastatin and recurrent coronary events in the cholesterol and recurrent events trial. Circulation 1998; 97: 1446-52.
THE DEBATE ON CHOLESTEROL LOWERING MARGARINES 19 April 2000
Charles van Heyningen Send response to journal: Re: THE DEBATE ON CHOLESTEROL LOWERING MARGARINES	Law presented a case for the introduction of plant sterol and stanol containing margarines into the food chain for the primary prevention of heart disease (1). There are however a number of concerns about such a policy. Phytosterolaemia, a very rare homozygous recessively inherited defect, is characterised by increased absorption of plant sterols and accelerated atherosclerosis, and it remains to be shown whether heterozygous carriers, found with a greater frequency, are predisposed to accumulate these compounds (2). As has been shown in many other human studies, a recent study on cholesterol reduction by different plant stanol mixtures in postmenopausal women (3) found a four-fold increase in serum campostanol with the use of campostanol ester-rich margarine and a two-fold increase in serum sitostanol with sitostanol ester-rich margarine. The serum cholesterol precursor sterols were similarly increased by +12% to +19% with stanol-ester containing margarine or butter. Although these increases were considered to be meaningless, since other plant sterol levels were decreased, it is possible that in some populations long term increases in blood plant stanol or sterol levels may promote atherosclerosis. Law's paper suggests that people in their fifties would achieve a 0.5 mmol/l reduction in LDL cholesterol when consuming two or more grams of plant sterol or stanol per day and that this would reduce the risk of heart disease by about 25% after two years (1). Such a 0.5 mmol/l reduction in LDL cholesterol is equivalent to a 0.6 mmol/l or 10% reduction in total cholesterol. As a 1.5% coronary risk reduction per 1% total cholesterol fall is regarded as realistic, a 10% cholesterol reduction translates to a 15% reduction in major coronary events. In controlled studies dietary change can reduce total cholesterol by 10 to 15%, but in free-living subjects less than half this reduction is achieved. Hence it is likely that cholesterol lowering margarine, when used by the general population, will achieve only an average 5% reduction in total cholesterol with a large variability due to differences in compliance and genetic heterogeneity. A review (4) of cholesterol lowering margarines following the marketing of two such products in the USA, concludes that the long term effect of these products on mortality and morbidity from coronary artery disease is currently unknown, and that the benefits of cholesterol lowering may be offset by increased plasma plant sterol concentrations and reduced plasma antioxidants such as beta-carotene (2). The American Heart Association is also cautious (5): Alice Lichtenstein warns that no studies have shown prophylactic effects and that these additional ways of lowering cholesterol have small effects and should not give people a false sense of security. Basic diet and lifestyle changes, as has been recommended for years, rather than one easy change, is advised. In conclusion, I believe that there is not yet a good evidence base for recommending the widespread use in the general population of cholesterol lowering margarines in the prevention of coronary heart disease. Charles van Heyningen Consultant Chemical Pathologist University Hospital Aintree References: (1) Law M.R. Plant sterol and stanol margarines and health. BMJ 2000, 320, 861-864. (2) Thompson G. R. Plant lipids that lower serum cholesterol. Eur. Heart J. 1999, 20, 1527-1529. (3) Gylling H, Miettinen TA, Cholesterol reduction by different plant stanol mixtures and with variable fat intake. Metabolism 1999, 48(5), 575 -580. (4) The Medical Letter 1999, 41(1055), 56-58. (5) Larkin M, Functional foods nibble away at serum cholesterol concentrations. Lancet 2000, 355, 555.
Stanol/Sterol Margarines; Trans fats and Benecol 21 February 2001
Eddie Vos, Independent researcher Sutton Qc Send response to journal: Re: Stanol/Sterol Margarines; Trans fats and Benecol	Law (1) makes the case for benefits of LDL-cholesterol lowering sterol/stanol margarines and he mentions Benecol as an example of a stanol (hydrogenated phytosterol probably linoleic esterified) spiked margarine. The U.K. Benecol website gives no data about the trans or any other fatty acid content of their margarine but data from its U.S. counterpart site suggests that the recommended 2 tablespoons per day also provide about 2g (omega-3 and omega-6 derived) trans fats. Two grams of trans fats is the daily maximum suggested by the International Society for the Study of Fatty Acids and Lipids (ISSFAL; April 1999: http://www.issfal.org.uk/adequateintakes.htm ). ISSFAL goes further: "Therefore, the Working Group does not recommend trans-FA to be in the food supply as a result of hydrogenation of unsaturated fatty acids .." It is well established that trans fats have deleterious effects on blood lipids, on insulin resistance, and probably on heart-disease risk by preferentially eliminating omega-3 fatty acids. Therefore, the over-all benefits of trans fat containing sterol/stanol margarines must be questioned, regardless their hypothesized benefit of LDL-lowering. Apart from the obviously deleterious trans fats, the amount of omega- 6 linoleic in margarines like Benecol may well be near the upper limit of 6.6 grams suggested by ISSFAL. The ingestion of high omega-6 products that are simultaneously low in omega-3 and/or high in trans fats may well underlie heart and other chronic diseases. Therefore, compulsory Trans, omega-3 and omega-6 package labeling (like those soon coming to Canada) would give consumers the much needed information about possibly beneficial and deleterious ingredients in their fat and oil products. Eddie Vos ( http://www.health-heart.org) Sutton Qc Canada (1) Law M, Plant sterol and stanol margarines and health. BMJ 2000; 320:861-864.
Why medicate the whole population? 17 October 2001
Aenid Pettingill Send response to journal: Re: Why medicate the whole population?	I found the section on plant sterols very interesting and it seems they do work to reduce cholesterol. My question is - why medicate the whole population when not everyone has a cholesterol problem? Especially children? And it seems these sterols do reduce carotene which I find a worry. Aren't these antioxidants a defence against cancer? If people want sterols then they should be made available in tablet form - I am very much against medicating the whole population for the benefit of a few. Keep our food and our medication separate!