Functional foods: the case for closer evaluation
BMJ 2007; 334 doi: https://doi.org/10.1136/bmj.39196.666377.BE (Published 17 May 2007) Cite this as: BMJ 2007;334:1037
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Dr. Thompson argues that a lower dose of statins may very well be
compensated by the addition of plant sterols or stanols to the daily diet.
We do agree that the data of several randomised clinical trials indicate
that with an optimal dosing regimen plant sterols or stanols have additive
effects to statin therapy on LDL cholesterol lowering [1;2]. However, in
daily practice it is shown that people are not consuming the recommended
plant sterol or stanol dosages [3]. Adherence to both the drug treatment
regimen and the plant sterol or stanol recommendations will then be
suboptimal in the real life case of ‘compensation’. The eventual
additional effects of plant sterols or stanols on LDL cholesterol are not
studied yet, but it is very likely that they are insufficient.
1. Blair SN, Capuzzi DM, Gottlieb SO, Nguyen T, Morgan JM, Cater NB.
Incremental reduction of serum total cholesterol and low-density
lipoprotein cholesterol with the addition of plant stanol ester-
containing spread to statin therapy. Am J Cardiol 2000;86:46-52.
2. Katan MB, Grundy SM, Jones P, Law M, Miettinen T, Paoletti R et
al. Efficacy and safety of plant stanols and sterols in the management of
blood cholesterol levels. Mayo Clin Proceedings 2003;78:965-78.
3. Wolfs M, de Jong N, Ocke MC, Verhagen H, Monique Verschuren WM.
Effectiveness of customary use of phytosterol/-stanol enriched margarines
on blood cholesterol lowering. Food Chem Toxicol 2006;44:1682-8.
Competing interests:
None declared
Competing interests: No competing interests
Rapid Resonses to:
ANAYSIS:
Nynke de Jong, Olaf H Klungel, Hans Verhagen, Marion CJ Wolfs, Marga C
Ocke, and Hubert GM Leufkens.
Functional foods: the case for closer evaluation.
BMJ 2007; 34:1037-1039.
De Jong and colleagues call for closer evaluation of "functional
foods" after their introduction to the market and their exposure to a
broad public. In my opinion this is an issue of uttermost importance. As
pointed out by de Jong, very little is known about long-term effects, drug-
interference and - most important - safety issues of functional foods in
disease prevention. Even the best studied of these foods "sterol
enriched foods" are still controversially debated in the scientific
community and concerns had been raised about possible atherogenic effects
of plant sterols (1). With an increasing body of evidence that plant
sterols themselves might be involved in atherosclerosis food
supplementation with plant sterols should be carefully evaluated (2, 3,
4). This can only be achieved by prospective studies that evaluate not
only the effects of cholesterol reduction, but also relevant clinical
endpoints such as vascular events. As long as results of such trails are
pending recommendation of functional foods supplemented with plant sterols
to reduce serum cholesterol concentrations will be a matter of
controversial debate.
In view of this the authors have rightly observed that a similar procedure
(as followed for drugs) be followed for "functional foods" which are being
consumed by unsuspecting people in large numbers.
1. Patel MD, Thompson PD. Phytosterols and vascular disease.
Atherosclerosis 2006; 186:12-19.
2. Thiery J, Ceglarek U, Fiedler GM, Leichtle A, Baumann S, Teupser D,
Lang O, Baumert J, Meisinger C. Elevated campesterol serum levels--a
significant predictor of incident myocardial infarction: results of the
population-based MONICA/KORA follow-up study 1994-2005. Circulation 2006,
supplement II, Vol 114, No 18, II-884, A 4099.
3. Weingartner O, Sudhop T, Kanig J, von Bergmann K, Schafers HJ, Laufs
U, Bahm M. Relation of serum plant sterol levels to tissue concentrations--effects of diet and family history. Circulation 2006, supplement II,
Vol. 114, No 18, II-114, A 676.
4. Weingärtner O, Lütjohann D, Weisshoff N, List F, Böhm M, Laufs U.
Differential effects of plant sterols compared to ezetimibe on
atherogenesis in apoE -/- mice. J Am Coll Cardiol. 2007; 49(9) Suppl. A:
336.
Oliver Weingartner M.D.
Universitatsklinikum des Saarlandes
Klinik fur Innere Medizin III
Abteilung fur Kardiologie, Angiologie und internistische Intensivmedizin
Kirrberger Strasse
Gebaude 40,
66421 Homburg,
Germany
Email: oweingartner@aol.com
Competing interests:
None declared
Competing interests: No competing interests
I wish to take issue with the statement by de Jong et al that "a
lower dose of statin can never be compensated for by the intake of
functional foods" i.e. plant sterols or stanols. It is well accepted that
doubling the dose of any given statin will decrease low density
lipoprotein (LDL) cholesterol by an additional 6% whereas the addition of
plant sterols or stanols 2g daily as esters has been shown to decrease LDL
cholesterol by an additional 7-11% [1]. Hence, contrary to to the
assertion by de Jong et al, a lower dose of statin can be more than
compensated for by the addition of plant sterols or stanols, preferably
the latter for the reasons given in their article.
1. Thompson GR. Additive effects of plant sterol and stanol esters to
statin therapy. Am J Cardiol, 2005;96(Suppl):37D-39D.
Competing interests:
None declared
Competing interests: No competing interests
risk of 'functional foods' from deaths from excess vitamins is clearly
not the issue. To my knowledge no deaths have ever been recorded from food
fortification with any essential nutrient including those mentioned,
vitamins A (retinol), D (cholecalciferol) and E (tocopherol).
Comparing nutrients with drugs also misses the point since there are
no drug deficiency diseases, only nutrient deficiency diseases with each
of the >40 recognized essential nutrients having a plethora of agreed or
debated deficiency conditions.
The case in point is particularly India where about $0.50/year of food
fortification, i.e. functional foods, can restore known
gross
deficiency that causes extreme homocysteine levels in 24 year olds in
New Delhi(1) that resemble levels that were once measured in over 90 year
olds in Framingham or in elderly home-bound patients in Rotterdam. That
level of 22µM is about 3 times the level of homocysteine where coronary
heart disease is not normally found. The fortification of foods is a cheap
effective way to restore known deficiencies that do cause disease.
To propose that nutrients should be evaluated like drugs forgets the
simple fact that one patient dies every 5 minutes in an American hospital from prescription drugs [JAMA
1998] as opposed to none from nutrient enriched functional foods.
Let's put our effort where it should lie: first, urgently introduce fortified foods, especially in India, to head off what threatens to become one of the largest epidemics of heart and deficiency disease the world has seen and, second, reduce the deaths from prescription drugs that post-fortification
may just be less needed. Fear mongering about nutrients therefore may increase deaths from both causes. vos{at}health-heart.org
1. Misra et al Hyperhomocysteinemia,
and low intakes of folic acid and vitamin B12 in urban North India.Eur J Nutr. 2002 Apr;41(2):68-77.
Competing interests:
None declared
Competing interests: No competing interests
Whenever a new drug is released to the market, a Phase VI research is
carried to study the effects that have not been observed on the small
samples tested before the release in to the market. Some drugs ( Cox 2
inhibitors for instance ) have been withdrawn after reported adverse
effects. Similar is the case with even supplements of some Vitamins and
anti-oxidants ( Vitamin A, Vitamiin D, Vitamin E where increased incidence
of death was noted in clinical trials conducted to test their anti-oxidant
efficacy even though the cause of death was not clear ).
Most of the routinely available "Functional Foods" in the market can as
well be called as "Drugs" based on their composition. In some cases
(Supplements for the body builders for instance) the composition makes
distinction between "Drugs" and "Functional Foods" less clear.
In view of this the authors have rightly observed that a similar procedure
( as followed for Drugs) be followed for the "Functional Foods" which are
being consumed by unsuspecting people in large numbers.
Competing interests:
None declared
Competing interests: No competing interests
Functional Foods: Already a feature of every-day practice
Sales of functional foods or neutraceuticals account for billions of
dollars annually worldwide. A number of recent articles in the BMJ have
highlighted the case for scrutiny of this sector.1,2,3 I feel there are
benefits and also dangers to the use of functional foods. I feel this
sector requires scrutiny of marketing practices and monitoring of the long
-term effects and possible interactions of ingestion of these substances.
In my own daily practice I am regularly encountering patients on
various supplements and fortified foods. I now make a point of being
thorough and asking about drug allergies, prescription medications, over-
the-counter medications, illicit drug use and also about any dietary
supplements they are taking.
A rapid response to the recent articles stated that functional foods
can replace dietary deficiencies.4 They hence can be beneficial and we as
doctors have been treating dietary deficiencies for years by prescribing
iron, thiamine, Vitamin B12 and others. These are given to those with a
clinical need and also have the benefit of years of monitoring and
stringent production procedures. Functional foods by contrast are not
prescribed by doctors and the patients are not reviewed for adverse
effects.
My limited experience would suggest that it is not those who are
deficient in nutrients who are taking functional foods. I do agree with
Mr Vos that in the right subject groups functional foods replacing
nutrients can assist in disease prevention.
I would like to close by raising a number of points.
1. Functional foods are in common usage and as clinicians we need to ask
about them.
2. Marketing of these substances is aimed at a certain profitable sector
of the market, which may not correspond to the sector which may gain
benefit from these substances.
3. There are undoubted benefits to replacing nutritional deficiencies, but
is an unregulated functional food market the way to do this. Would it not
be better to have these foods manufactured to high standards and monitored
over many years, along the lines of the pharmaceutical industry. Should
we not be supportive of attempts by the European Union and FDA to apply
controls to this sector.
4. The ingestion of functional foods may have unexpected effects.
References:
1. de Jong N, Verhagen H, Wolfs MCJ, Ocke MC, Klungel OH, Leufkens HGM.
Functional foods: the case for closer evaluation. BMJ 2007; 334: 1037-
1039.
2. Lang T. Functional foods: Their long term impact and marketing needs
to be monitored. BMJ 2007; 334: 1015-1016.
3. Katan MB. Health claims for functional foods. BMJ 2004; 328: 180-
181.
4. Vos E. Re: Drugs or Functional Foods? eBMJ 2007; Rapid Responses.
www.bmj.com/cgi/eletters/334/7602/1037
Competing interests:
None declared
Competing interests: No competing interests