New study asks ‘Does lettuce have health giving properties?’
Scientists from the University of Southampton, in collaboration with Vitacress Salads, are undertaking a trial to assess the health benefits of eating ‘supermarket bagged’ lettuce.
Previous studies involving other vegetables and fruit have shown a number of plant compounds to have properties that aid prevention of certain diseases. By acting as antioxidants, these compounds have shown, or been proposed to show, benefits in preventing certain forms of cancer, in reducing cholesterol levels, helping to prevent age-related eye diseases and in prevention of diabetes.
However, very little information is available for lettuce, while consumption of bagged salads has increased significantly in recent years. Vitacress Salads, near Andover, for example, often produces one and a half million bags of salad for the UK market each week.
The purpose of the study is to determine how the ingestion of ‘fresh from the field’ and ‘supermarket bagged’ baby lettuce leaves influence the levels of total antioxidants in human blood and how these nutrients decline in time. The project also aims to identify the individual antioxidant phytonutrients (the nutrients found in plants) which compose the total antioxidant content absorbed by humans, pin-pointing which plant chemicals are important.
Volunteers will take part in one of two blind trials (where they will not know which treatment group they are in), in which they will be given fresh or bagged baby lettuce leaves (Lactuca sativa) of the green cos variety for breakfast. Blood samples will then be taken over several hours and analysed at the University of Southampton’s School of Biological Sciences, to assess the impact of lettuce eating.
Project leader, Professor Gail Taylor of the University of Southampton, comments: “Many of us are now aware that eating green vegetables such a broccoli and leaves like watercress may be good for us, but 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 in a large group of volunteers. We really will know whether eating lettuce is good for us.”
Dr Graham Clarkson from Vitacress adds: “We at Vitacress are passionate about the health giving properties of our salads, from watercress and wild roquette down to the not so humble lettuce. We are particularly keen to see proof that eating our freshly prepared and bagged leaves is just as good as cutting them from your own garden.”
This research is funded by the Biotechnology and Biological Sciences Research Council and Vitacress Salads. The study will be undertaken by PhD student Gaia Biggi.