In Brief
A tomato a day keeps death away (for some people)
Children eating tomatoes had a significantly lower mortality rate than children who did not, in a prospective study of nearly 29 000 Sudanese children under 5 years of age. The Harvard School of Public Health team conducting the study visited the homes of the children on 4 occasions at 6-monthly intervals. Children reported by their mothers on 3 of these occasions to have eaten tomatoes had an 83% reduction in mortality compared with children not reported to have eaten tomatoes. Tomatoes also showed a dose-related reduction in diarrhoea-related deaths. Adjusting for confounding factors, including vitamin A intake, only slightly weakened the link with tomato consumption. What is important, said Dr Fawzi, who headed the study team, is not so much the magnitude of the mortality reduction the 3891% confidence interval was quite large but that a dietary approach, in this case tomato consumption, can have an extremely important impact on mortality and morbidity in children. He believes the effect of the tomatoes could be due, among other things, to their high content in immunostimulatory antioxidants. The study was published in the October 2000 issue of the Journal of Nutrition. 
A fly that vaccinates the host it feeds on
A US research team headed by David Sacks of the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, reported last November in Science what could become a revolutionary approach to vaccination against vector-borne infections. They found that exposing mice to the bites of uninfected sandflies protected them against leishmaniasis, a disease that can be as disfiguring and disabling as leprosy, and that can only be transmitted to humans by sandflies. Something still unidentified in sandfly saliva seems to produce a delayed-type hypersensitivity response that prevents Leishmania parasites from causing disease, the researchers postulate. When that something is identified, it may, they believe, become the basis for a vaccine against leishmaniasis, and a similar approach might be used to vaccinate against other diseases carried by insect vectors, including malaria.
Laugh to your hearts content!
People who dont laugh a lot may be at greater risk of heart disease than those who do, according to a US study by cardiologists at the University of Maryland Medical Center in Baltimore, Maryland. The study, presented at the American Heart Association meeting in New Orleans last November, found that among an otherwise matched sample of 300 people responding to a questionnaire about their laughing habits, the 150 participants with a history of heart disease were 40% less likely to laugh at a variety of situations described in the questionnaire than the 150 with no history of heart disease. Who gets the last laugh on the issue is anyones guess.