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Table 2 Systematic reviews of clinical trials of hypericum and garlic preparations

From: Systematic reviews of complementary therapies – an annotated bibliography. Part 2: Herbal medicine

Author Indication Intervention Comparisons Studies 1/2/3/ Results Author's Conclusion
Year      4/5   
St John's wort ( Hypericum perforatum )
Gaster depression hypericum placebo and 8 RCT p/y/p/ 4 placebo-controlled trials with Data suggest that hypericum is
2000 [20]    antidepressants   y/n positive results, in 4 trials superior to placebo, insuffcient
       standard antidepr. tended to be evidence re equivalence with
       slightly better antidepressants
Williams depression hypericum placebo and 14 RCT y/y/n/ Treatment response: RR 1.9 Data suggest that hypericum is
2000 &   (and other antidepressants   y/y (95%C11.2–2.8) vs. placebo and superior to placebo, insuffcient
Mulrow 98   drugs)     1.2 (1.0–1.4) vs. antidepressants evidence re equivalence with
[21, 22]        antidepressants
Kim 99 [23] depression hypericum placebo and 6 RCT p/y/y/ Treatment response: RR 1.48 Hypericum more effective than
    antidepressants   y/y (95%C11.03–1.92) vs. placebo placebo and similarly effective as
       and 0.98 (0.67–1.28) vs. low dose antidepressants; quality
       antidepressants problems
Stevinson depression hypericum placebo and 6 RCT y/y/y/ Only trials published after Linde Data confirm findings of earlier
99 [24]    antidepressants   y/n 96; trials show effects better trials, but still insuff. evidence to
       than placebo/similar to assess equivalence with
       antidepressants antidepressants
Linde 98 & depression hypericum placebo and 27 RCT y/y/y/ Treatment response: RR 2.47 Hypericum more effective than
96 [25, 26]    antidepressants   y/y (95%C11.69–3.61) vs. placebo placebo. Inadequate evidence to
       and 1.01 (0.87–1.16) vs. assess equivalence with
       antidepressants antidepressants
Volz 97 depression hypericum placebo and 15 p/p/n/ Most placebo-controlled trials A therapy with hypericum of mild
[27]    antidepressants RCT/CCT n/n positive; similarly effective as and moderate depression can be
       (not adequately dosed) attempted. Further studies needed
Ernst 95 depression hypericum placebo and 11 RCT y/y/y/ Most of 8 placebo-controlled Hypericum is superior to placebo
[28]    antidepressants   y/n trials positive. 3 trials against and seems equally effective as
       standard medication with similar standard medication
Volz 2000 mild to hypericum fluoxetine 17+9 n/y/n/ No direct comparison of Response rates are similar;
[29] mod.    CCT y/n hypericum and fluoxetine findings difficult to interpret
  depression      available. Mean depression because of the indirect comparison
       score (HAMD) reduction in  
       hypericum trials 53%, in  
       fluoxetine trials 55%  
Friede 98 anxiety in hypericum placebo, 8 RCT ?/y/y/ Trials collectively show reduction Hypericum is effective for
[30] depressed   amitriptyline   y/n of anxiety symptoms over depressed patients with anxiety
  p.      placebo. Only 1 trial vs  
Garlic ( Allium sativum )
Lawrence cardiovasc. garlic mainly placebo; 45 RCT y/y/y/ 37 trials consistently show small Insufficient data to draw conclusion
2000 [31] risk factors   no & other   y/y short-term effects over placebo regarding clinical cardiovascular
    treatment    for cholesterol reduction. No outcomes. Garlic preparations may
       consistent effects on blood have small, positive, short-term
       pressure, promising effects re effects on lipids
       platelet aggregation and  
       fibrionolytic activity  
Stevinson hyperchol- garlic placebo 13 RCT y/y/y/ Pooled total cholesterol Available data suggest that garlic is
2000 [32] esterolemia     y/y reduction over placebo 0.41 superior to placebo. The size of the
       (95% Cl -0.66 to -0.15) mmol/l; effect is modest. The use of garlic
       when analysis restricted to high for hyperchol. is therefore of
       quality trials 0.11 (-0.30 to 0.08) questionable value
Silagy 94 & cholesterol garlic placebo 16 RCT y/p/y/ Pooled cholesterol reduction Meta-analysis suggests positive
Neil 96 lowering     y/y over placebo 0.65 (95% Cl 0.53– effects but reviewers are sceptic
[33, 34]       0.76) mmol/l (low quality; own replication
Warshafsky cholesterol garlic placebo 5 RCT p/y/y/ Pooled cholesterol reduction Available evidence supports the
93 [35] lowering     y/y over placebo 0.59 (95%Cl 0.44– use of garlic as one modality to
       0.74) mmol/l decrease cholesterol levels
Silagy 94 lowering dried garlic placebo, other 8 RCT y/p/y/ Pooled reduction over placebo: Garlic maybe of some clinical use
[36] blood (Kwai) treatment   y/y SBP 7.7 (95% Cl 4.3–11.0), DBP in subjects with mild hypertension.
  press.      5.0 (2.9–7.1) mm Hg Further research needed
Kleijnen 91 cardiovasc. garlic placebo 18 p/p/y/ Most studies with shortcomings. No clear conclusion drawn
[37] risk factors supplements   RCT/CCT y/n The majority of trials with pos.  
       results but inconsistent effect  
Kleijnen 89 cardiovasc. garlic & unclear 10 RCT, y/p/n/ All trials with severe Inadequate evidence to justify
[38] risk factors onions   8 CCT y/n shortcomings. Fresh garlic with supplementation, further research
       beneficial effcts, onions and needed
       commercially available  
       supplements yielded  
       contradictory results  
Jepson 97 lower limb garlic placebo 1 RCT y/y/y/ Walking distance not Insufficient evidence
[39] atheroscler.     y/- significantly different between  
  1. legend see table 1