TUESDAY July 8, 2008 (foodconsumer.org) -- Tomatoes could be a suitable carrier for an oral vaccine against Alzheimer's disease, according to a study published in the Biotechnology Letters.

HyunSoon Kim from the Korea Research Institute of Bioscience and Biotechnology (KRIBB) in Korea and colleagues from Digital Biotech Inc. and the Department of Biological Science at Wonkwang University conducted the study.

The researchers reported that mice fed tomatoes with a beta-amyloid protein developed immune response to the foreign protein.

Alzheimer's disease is the most common cause of dementia and it is believed that the accumulation of human beta-amyloid causes the age-related degenerative disease which leads to the death of neurons.

In the study, a vaccine was created to prevent or delay the onset of Alzheimer's by stimulating the immune system to reduce beta-amyloid in the brain.

Tomatoes were used because they can be eaten without cooking, which would otherwise destroy the immune stimulation potential of a foreign protein.

The researchers inserted the beta-amyloid gene into the tomato genome and measured the immune response to the foreign protein in a group of 15 month-old mice.

To test the vaccine, they gave the mice orally the genetically modified tomatoes   plants once a week for three weeks, and then a booster four weeks later and then tested blood sample.

They found a strong immune response, the production of antibodies to the foreign body, was generated after the booster.

The authors conclude: “Although we did not reveal a reduction of existing plaques in the brain of mice challenged with tomato-derived beta-amyloid…this study represents a unique approach in which transgenic plants expressing beta-amyloid protein are used to produce a vaccine.”

The researchers are now working to find strategies to boost the production of protein in the tomato plants.   Fresh tomatoes contain only 0.7 % protein and the level of foreign protein is even lower.