The study will determine how baby lettuce leaves influence the antioxidant levels in human blood.
Volunteers will take part in one of two blind trials in which they will be given fresh or bagged baby lettuce leaves (Lactuca sativa) of the green cos variety. Blood samples will then be taken and analysed at the University of Southampton's School of Biological Sciences.
Project leader Professor Gail Taylor said: "Lettuce is often considered as a leaf of little nutritional value and there is limited understanding of health-giving properties it might have. This study will provide direct evidence of whether lettuce does improve antioxidant status."
Dr Graham Clarkson from Vitacress added: "We are keen to see proof that eating our freshly prepared and bagged leaves is as good as cutting them from your garden."