VOLUME 8 NUMBER 4 • NOVEMBER 2011
175
SA JOURNAL OF DIABETES & VASCULAR DISEASE
REPORT
Controversies at ESC 2011: Dietary approaches for lipid assessment
A
t this year’s Congress of the European
Society of Cardiology (ESC), 27–31
August in Paris, France, experts debated a
number of controversial issues. A key ses-
sion was the debate on dietary approaches
for lipid assessment, chaired by Prof Rory
Collins, Oxford, UK and Dr Mikael Rabaeus,
Clarens-Montreux, Switzerland.
From:
Br J Prim Care Nursing
2011, published online.
S Afr J Diabetes Vasc Dis
2011;
8
: 175–177.
Building on his argument, Prof Bruckert
showed that there is overwhelming evi-
dence from population studies, clinical out-
comes trials and genetic studies to confirm
the cardiovascular benefits of a long-term
10% reduction in LDL cholesterol.
3,4
In a
meta-analysis of 58 dietary and drug trials
involving nearly 15 000 subjects, long-term
reduction in LDL cholesterol of 1.8 mmol/l
(
∼
70 mg/dl) reduced the risk of ischaemic
heart disease by about 60%.
3
Therefore, by
extrapolation, he implied that lowering of
LDL cholesterol levels by
∼
10% with dietary
plant sterol supplementation is likely to be
useful in preventing CVD.
In the second part of his presentation,
Prof Bruckert focused on issues relating to
the risk versus benefit of plant sterol supple-
mentation. He emphasised that the safety
dossiers for phytosterol-supplemented
products have been extensively reviewed by
numerous regulatory agencies, including the
US Food and Drug Administration. Over-
viewing the data, he concluded that there
was no consistent evidence of accumulation
of plant sterols in tissues, oestrogenic effects
or effects on the gut morphology or physiol-
ogy. Instead, the data suggested that dietary
phytosterol supplementation may be associ-
ated with possible anti-atherogenic effects,
based on three key lines of evidence.
• First, recent studies in large numbers of
patients using appropriate adjustment
of confounders showed no associa-
tion between increased plasma levels of
plant sterols and risk for ischaemic heart
disease.
5-7
For example, in the Longitudi-
nal Aging Study Amsterdam, high plasma
levels of sitosterol, a marker of plant
sterols, were associated with a markedly
reduced risk for coronary heart disease
(CHD), suggesting that plant sterols might
have protective anti-atherogenic effects.
6
• Second, extensive experimental data
consistently showed beneficial effects on
stabilisation or regression of atheroscle-
rosis.
8
• Third, a systematic meta-analysis includ-
ing data from 17 studies in 11 182
subjects did not indicate an association
between serum levels of plant sterols and
increased risk of CVD.
9
In summing up his case, Prof Bruckert
emphasised that phytosterol-supplemented
foods have been recognised as effective and
safe in almost all countries.
Dr Oliver Weingärtner, University Hospi-
tal of Saarland, Homburg at Saar, Germany
argued the case against the motion. He sug-
gested the need for caution in extrapolating
that lowering of LDL cholesterol with dietary
plant sterol supplementation translates to
reduction in CVD risk. To highlight his point,
he referred to the ILLUMINATE trial with the
cholesteryl ester transfer protein inhibitor
torcetrapib.
10
Although effective in raising
high-density lipoprotein cholesterol and low-
ering LDL cholesterol, torcetrapib was also
associated with an increase in risk for major
cardiovascular events. Additional research
suggested that this adverse effect was most
likely attributable to off-target pharmaco-
logical effects on the adrenals, resulting in
hyperaldosteronism and hypertension.
11
In a key point, Dr Weingärtner highlighted
the fact that while the human body has very
efficient means of eliminating sterols in a
normal diet, plant sterol supplementation
has been shown to more than double serum
sterol levels. The biological signi cance of
this effect has been the subject of much
debate.
Dr Weingärtner overviewed data from
two studies. In one small study, dietary sup-
plementation with plant sterols increased
plasma sterol levels and sterol concentra-
tions in aortic valve tissue in patients with
aortic stenosis.
12
Another study showed that
common genetic variants at the ATP-binding
cassette hemitransporter ABCG8 and ABO
blood group, gene loci were associated with
increased sterol levels and coronary artery
disease risk.
13
However, these data are not
definitive as these variants were also asso-
ciated with elevated cholesterol levels. In
his rebuttal, Prof Bruckert highlighted the
need to consider the weight of evidence as
a whole to avoid over-reacting to the results
of individual studies. There are also meth-
odological issues; in the case of animal stud-
ies it is important that the effects of plant
sterols are compared against a standardised
level of cholesterol intake.
Dr Weingärtner suggested that dietary
plant sterol supplementation may be associ-
ated with impairment of endothelial func-
tion, based on experimental evidence in
apolipoprotein E-deficient mice. This study
Is food supplementation with
plant sterols useful to prevent
cardiovascular disease?
Prof Eric Bruckert, Institute of Endocrinol-
ogy and Prevention of Cardiovascular Dis-
ease, Pitié-Salpêtrière Hospital, Paris, France
argued the case for this motion. The effect
of individual dietary changes on cardiovas-
cular disease (CVD) risk is difficult to evalu-
ate in short-term (< 5 years) clinical studies.
Therefore evidence to support dietary rec-
ommendations is based on a more complex
approach.
Extensive data show that consump-
tion of plant sterols (1–2 g/day)
*
has been
consistently associated with reduction in
plasma concentrations of low-density lipo-
protein (LDL) cholesterol by
∼
10%. This
was recently reaffirmed by a meta-analysis
of 84 randomised, controlled studies in
6 805 patients.
1
Indeed, recent dyslipidaemia
guidelines by the ESC and European Athero-
sclerosis Society recommend inclusion of
foods supplemented with phytosterols (1–2
g/day) in individuals with elevated total LDL
cholesterol for whom total cardiovascular
risk assessment does not justify the use of
pharmacotherapy.
2
* According to the European Food Safety Authority dossier, the
efficacy of phytosterol supplementation is proven with a daily
dosage in the range of 1.5–2.4 g.
