Table 4

Acceptability of treatment (chocolate or capsules)

Dark chocolate groups:

Capsule groups:

Mean (SD)

P-value^a

70% cocoa, 50 g daily

tomato extract (15 mg lycopene) or placebo, 1 capsule daily

Ease of taking supplements^b

50% found it hard to eat 50 g dark chocolate daily for 8 weeks

100% found it easy to take one capsule daily for 8 weeks

Chocolate groups: 2.4 (1.3)

Capsule groups: 1.3 (0.5)

p < 0.0001

Acceptability^c

20% found it unacceptable

100% acceptable

Chocolate groups: 1.9 (1.0)

Capsule groups: 1.3 (0.5)

p < 0.0001

Reason for unacceptability

Unpalatable, too rich, encountered side-effects, such as constipation and headache

N/A

Withdrawals

unpalatable (n = 2)

gastrointestinal upset (n = 1); illness unrelated to study (n = 1)

Willingness to continue with treatment after trial^d

73% would continue with daily dark chocolate;

100% would continue with capsules;

Average dark chocolate consumption increased after the trial compared to baseline: mean increase = 44 ± 194 g/week

80% intended adding more tomatoes to diet;

35% would rather eat tomatoes than take a capsule

Willingness to pay for supplements^d

73% would be willing to spend ~A$1.25 for 50 g dark chocolate per day

66% would be willing to spend ~A$1 per capsule per day

^aP-values are calculated by student t-test,

^b Ease was assessed using a 5-point Likert scale with 1 = very easy, 2 = easy, 3 = sometimes easy, sometimes hard, 4 = hard, 5 = very hard;

^c Acceptability was assessed using a 4 = point Likert scale with 1 = very acceptable, 2 = acceptable, 3 = unacceptable, 4 = very unacceptable

^dWillingness for long-term treatment was estimated by bivariate questions (yes/no)

Ried et al. BMC Complementary and Alternative Medicine 2009 9:22   doi:10.1186/1472-6882-9-22