The purpose of this study was to measure potential mood, cognition and blood pressure effects of theobromine and caffeine in healthy women

Background Previous research has shown that naturally occurring chocolate ingredients theobromine and caffeine have positive effects on mood.

Objectives: To assess mood and cognition in adult subjects after the consumption of capsules filled with 1. placebo, 2. theobromine alone, 3. caffeine alone or, 4. theobromine and caffeine combined together.

Study design: Double-blind, placebo-controlled, randomized, cross-over design, with a 1 week washout period in between.

During the 4 weeks intervention period, once a week one of the 4 types of test products were consumed with 250ml of water in a randomized order;

1. placebo capsules
2. theobromine capsules (700 mg),
3. caffeine capsules (120 mg),
4. mix of theobromine (700 mg) and caffeine (120 mg). Twenty-four healthy female subjects (and 4 reserve subjects) were recruited for a four week intervention period in total with every week a 4 hrs measurement day and one of the interventions.

Primary parameters: mood (via a Bond-Lader/ caffeine visual analogue questionnaire), cognition (Digit Symbol substitution) Secondary parameters: blood pressure

Inclusion Criteria:

• Female
• Age at start of study 18 till 70 years
• Body Mass Index (BMI) between 20 and 30 kg/m2 inclusive
• Reported alcohol consumption for females < 21
• Willing to refrain from caffeine and theobromine for 24 hours
• Apparently healthy: no reported current or previous metabolic diseases, chronic gastrointestinal disorders, cardiovascular or psychiatric disease which might effect study measurements assessed by Research physician
• willing to consume animal foods products (gelatine).
• Consumes caffeine (7 cups of either tea, cola or coffee per week minimum)
• Having a general practitioner (GP)

Exclusion Criteria:

• Being an Unilever employee
• Blood pressure above 160/90 mmHg at screening and irregular heart rate
• Using or planning to use any medically prescribed diet or weight-loss diet
• Reported intense sporting activities > 10 h/w
• Subjects who undergoing medical treatment that may interfere with the study outcome.
• Reported weight change ± 10% during a period of 6 months prior to the study
• Reported intolerance or allergy for one of test products or standardized meal
• The habit of smoking during the past half year, drug use during the past half year or using nicotine containing medicines during the past month
• Reported lactating (or lactating < 6 weeks ago), pregnant (or pregnant < 3 months ago) or wish to become pregnant during the study
• Not able to perform the computer tasks assessed during screening
• Reported participation in night shift work during the study period