Friday, 10 May 2013

Tomatoes, Prostate Cancer and Parkinson's Disease

Tomatoes have been in the news on two occasions recently. Researchers at the University of Illinois have discovered that when mice eat both tomato and soybean products their risk of prostate cancer is significantly decreased. Other research performed at the University of Washington has shown that tomatoes and bell peppers appear to reduce the risk of Parkinson's disease.

Prostate Cancer

The University of Illinois experiment involved mice that had been genetically engineered to develop a serious type of prostate cancer. The mice were divided into four groups and received one of the following diets between the ages of four and eighteen weeks.

  1. 10% whole tomato powder
  2. 2% soy germ
  3. Both tomato powder and soy germ
  4. No tomato or soy products
At the end of the project, the percentage of mice that developed prostate cancer were as follows.
  1. Group 1: 61%
  2. Group 2: 66% 
  3. Group 3: 45%
  4. Group 4: 100%
The research team say that in cultures where men eat a lot of soy the rate of prostate cancer is significantly lowered. According to Krystle Zuniga from the University of Illinois, the new study suggests that three or four servings of tomato products every week and one or two servings of soy every day could give men even better protection against prostate cancer.

Parkinson's Disease

Tomatoes may reduce the risk of prostate cancer
and Parkinson's disease.
Photo by mconnors at
In Parkinson's disease brain cells that make dopamine die. As a result the person experiences serious movement problems. Dr. Susan Searles Nielsen and other researchers at the University of Washington asked people with and without Parkinson's disease to complete a questionnaire. The answers showed that the regular consumption of peppers and tomatoes was linked to a reduced incidence of Parkinson's disease in people who didn't smoke. Peppers showed the greatest benefit. Furthermore, the survey showed that the more tomatoes and peppers that were eaten, the lower risk of developing Parkinson's.

Bell peppers and tomatoes belong to the Solanaceae family of plants, which also contains the tobacco plant. It's already known that smokers seem to have a lower rate of Parkinson's disease, but since smoking can create serious health problems it can't be recommended as a method to reduce the risk of Parkinson's. Smokers inhale nicotine. Like the tobacco plant, peppers and tomatoes contain nicotine (in a low concentration), which enters the body of someone who eats these foods.

While researchers have noticed a link between Parkinson's disease reduction and both smoking and ingestion of plants containing nicotine, they haven't shown that nicotine is the helpful factor. The chemical responsible for the benefit could be a different one. It's also possible that the beneficial chemical in peppers and tomatoes is different from the beneficial chemical in inhaled smoke. The good news is that eating peppers and tomatoes appears to reduce the risk of Parkinson's disease, for whatever reason.