In this four-way crossover study, a plasmakinetic profile of GABA from tomatoes as compared to a gamma-aminobutyric acid (GABA) supplement in healthy young men will be established. In addition, a plasmakinetic profiles of glutamate from a supplement and from tomatoes as well as the effects of glutamate from tomatoes and a supplement on the GABA plasma levels will be determined. This study will therefore provide information about the effect of a food matrix on GABA plasmakinetics.

Inclusion Criteria:

• BMI between 18.5 and 25 kg/m2
• Age is between 18 and 28 years
• Good general health
• Male
• Veins suitable for blood sampling
• Able to speak Dutch

Exclusion Criteria:

• Is currently suffering from a disease including mental disorders
• Has had any gastrointestinal condition/disease within the 3 months prior to the intervention
• Haemoglobin (Hb) level < 8.5 mmol/L
• Has used medication in the two months before and/or during the intervention. Occasional use of NSAIDs or paracetamol (<once a week on average) are is allowed.
• Reported weight loss or weight gain of > 2 kg in the month prior to the intervention
• Use of dietary supplements, 3 weeks before-, or during the intervention.
• Allergic to products that are provided as part of the standardised diet
• Unwilling to consume the products that are part of the standardised diet
• Allergic to tomatoes
• (History of) drug abuse, in this case meaning >1 x per month use of recreational drugs
• Smoking
• Alcohol consumption of >10 standardised glasses per week.
• Not able to refrain from alcohol consumption 2 days before each test day
• Recent or planned blood donation (<3 month prior to first study day or during intervention)
• Personnel of Wageningen University, department of Human Nutrition and Health,
• Currently participating in other research or was participating in another study within 1 month of the intervention or within 3 months if invasive procedures were used.