Professor H Kiesewetter, Director of The Institute of Transfusion Medicine and Immunohaemotology, University Hospital, Charit_ of the Humboldt University, Berlin.
lowering effects are described for garlic powder products that are standardised according to Allicin. An anti-atherosclerotic action is stated in the monograph for garlic in Europe. The aim of this randomised, placebo-controlled double-blind study is to demonstrate that 54 months therapy with garlic-powder tablets has an effect on plaque formation in both carotid branches and both femoral arteries. An intermediate aim, without breaking research codes is to review any effects after 18 months' therapy.
The enrolment phase was completed on 31st October 1993. A total of 280 persons were enrolled. The main study parameter (plaque volume determination) was measured every 18 months. The following were determined every 6 months: medical history, clinical examination, blood pressure, peripheral Doppler pressures, as well as plasma viscosity, platelet aggregation, cholesterol, triglycerides and blood sugar. An intermediate medical history was taken every 3 months, at which time side effects, arterial blood pressures and heart rate were registered, tablets handed out and compliance recorded. The patients received 900 mg LI-114 (900 mg garlic powder produced by Lichtwer Pharma GmbH), standardised to 1.3% alliin (equivalent to 0.6% allicin) or identically prepared placebo tablets.
The test subjects were participants in a large-scale epidemiological study, the so-called Aachen study. The total population consisted of 2841 participants, 1709 men and 1112 women (average age = 52 years). A total of 612 persons from this pool of patients and 60 other people, who were reached by word of mouth were given a B-scan examination for plaques in the carotid branches and femoral arteries on the basis of relevant atherosclerotic risk factors. This group of at risk individuals included 227 women and 445 men. Their average age was 60 years (women 61, men 59). Their mean height was 157 cm (women 145, men 163). Their mean weight was 67kg (women 65, men 72).
No plaques were diagnosed in 313 persons, one or more plaques in 359, 280 persons with plaques were enrolled in the study. A total of 79 patients were not recruited despite their having plaques. The reasons for this included 31 who declined to participate in the study, exclusion criterion fulfilled by 30 patients, severe primary disease: 2 were not keen to participate in studies as a matter of principle: 3 for various other reasons and 13 were not interested, had already died or were felt to be too old.
A total of 174 subjects were included in the intermediate analysis of the total population in November 1994, having been treated for 18 months. The 174 study participants included 51 women and 123 men. Their average age was 59 years (women 61, men 58). Their mean height was 172 cm (women 163, men 175). Their mean weight was 76 kg (women 65, men 81).
Of the 174 study participants, 16.9% were adipose, 3.1% had diabetes mellitus, 17.7% hypertension, 4% hyperuricaemia and 32.6% hypercholesterolaemia. 12.6% were active smokers, 13% ex-smokers. In the base-line examination, 55% had plaques with volumes of up to 30 mm2 (mean 15.7 mm2), 31% plaques of between 30 and 60 mm2 (mean 41.2 mm2) and 14% plaques of over 60 mm2 (mean 102.2 mm2). After the 18 months of treatment, 58% of the total population had plaques of less than 30 mm2 (mean 40.4 mm2) and 11% plaques with volumes of over 60 mm2 (mean 88 mm2). This reveals a trend towards a reduction in plaque volumes in the total population.
Since the determination of plaque volumes is a valid parameter, as confirmed by the literature, the anti-atherosclerotic effect can be described as clinically relevant. An important effect inhibiting the progression of plaque growth may be that garlic reduces platelet aggregation. The importance of platelet aggregation in the pathogenesis of atherosclerosis is recognised, as is that of hypercholesterolaemia. Clinical effects of garlic in coronary heart disease and in smokers' leg have also been described. Thus our preliminary results indicate a significant reduction in plaque growth amongst the total population. Clearly we shall have to wait a further 36 months before the full implications of this study may be presented.
Professor Beltz concluding remarks summarised the opinion of all those who presented data at this International Symposium. At the present time garlic powder tablets that can produce a guaranteed yeild of the active agent allicin represent the best scientifically rigorous natural compound for the prevention of stroke and reduction of several major cardiovascular risk factors.
Exhibiting a number of well defined actions that mimic several pharmaceutical preparations, but without the side effects and a clear financial benefit in many countries, garlic powder tablets have now been studied in many countries across a wide spectrum of clinical and pharmacological activity. Powerful meta-analysis confirm significant benefits in terms of cholesterol and blood pressure reduction, which are supported by elegant pharmacological studies that have confirmed several mechanisms of action. Further work is in progress to continue to strengthen the arguements for supplementing garlic powder tablets, such as Kwai for, both prophylactic and clinical use in cardiovascular care.