COPING WITH CARCINOGENS IN FOOD
Carcinogens are chemicals that alter the DNA in the cells of the body, sometimes causing irreversible damage, or mutations, that can lead to cancer. Mankind has always been exposed to various carcinogens naturally present in food and drink, and such exposures also include significant amounts of polycyclic aromatic hydrocarbons (PAHs) and other carcinogens that arise from grilling or heating foods to high temperatures. A smaller contribution to the overall exposure of the population to carcinogens can be ascribed to air pollution and man made chemicals.
However, food and drink is not only a source of substances that increase the risk of cancer, but our diet also contains important protective agents. Scientists think that about a quarter of colon cancers and 15% of breast cancers in northern Europe could be prevented if people ate a traditional Mediterranean diet, because of the presence of such protective chemicals in olive oil, red wine, fresh fruit and vegetables. But it is very difficult to identify these protective agents exactly, because people have such varied lifestyles and tumours take a long time to develop. A Specific Targeted Research Project is taking a new approach, measuring DNA damage directly in people's cells from the oral cavity and blood, rather than monitoring the incidence of cancer after an extended period of time. The goal is to determine the role of dietary PAHs in causing such damage, as well as to study the protective effects from natural substances. The research should generate a novel approach for testing the anti-cancer properties of 'functional' foods.
The project Dietary Exposures to Polycyclic Aromatic Hydrocarbons and DNA Damage (DIEPHY) involves seven research groups, and combines expertise in the fields of toxicology, molecular biology, chemistry, genetics, and epidemiology. A major challenge is relating results from studies of cultured cells and experimental animals to effects in humans. While scientists have found that PAHs cause specific lesions in DNA, the use of such damage as a biomarker of exposure has to be validated, and any relevance to human cancer further investigated.
WOMEN AND DIETS
The DIEPHY project will study women living in Poland, Serbia and Italy, populations with widely differing diets and lifestyles. In general, women are more dietary conscious than men, and consequently are more capable of accurately reporting what they have eaten. They are also less likely to smoke - PAHs from cigarettes could mask any effect of PAHs present in food. Samples of mouth and white blood cells will be taken from female non-smokers and tested for DNA damage caused by PAHs. Results will be related to a detailed analysis of their genetic disposition, diet and other lifestyle factors. In addition, the presence in blood of antioxidants, like vitamin E, as well as the presence of substances in urine that come from transformation of PAHs in the body will be determined.
The research teams will also study exposed individuals in the Danube valley in Serbia, where the petrochemical industry was bombed in 1999. Pollution of soil and water by PAHs was extreme throughout this area, and locally grown food and fish from the Danube became contaminated.
Previous work within the group showed that arsenic, rather than directly affecting DNA, probably causes cancer by ruining the cellular mechanisms by which DNA damages are repaired. This could exacerbate the effects of other carcinogenic substances like PAHs. The project will establish if people exposed to drinking water with high levels of arsenic are more susceptible to DNA damage caused by PAHs in grilled food.
GREEN TEA AND RASPBERRIES
Finally, the scientists will test natural chemicals purported to offer protection against cancer. Supplements, such as ellagic acid found in red berries, or epicatechins from green tea, will be fed to volunteers, and subsequently their cells tested for reduction of DNA damage caused by PAHs in grilled food. The human studies will be backed up with experiments with PAHs in mice to discover how well various protective chemicals work.
If the studies successfully link a reduction in DNA damage caused by dietary PAHs to protection by specific substances, the biomarkers employed could test the anti-cancer potential of functional foods, a development with strong commercial promise.
List of Partners
- Nofer Institute of Occupational Medicine (Poland)
- Stockholm University (Sweden)
- Karolinska Institute (Sweden)
- Czech Academy of Science (Czech Republic)
- University of Tuscia (Italy)
- Biochemisches Institut für Umweltcarcinogene (Germany)
- Institut za nuklearne nauke "VINCA" (Serbia)
- Full title:
- Dietary exposures to polycyclic aromatic hydrocarbons and DNA damage
- Contract n°:
- Project co-ordinator:
- Jolanta Gromadzinska, Nofer Institute, firstname.lastname@example.org
- EC Scientific Officer:
- Ebba Barany, email@example.com
- EU contribution:
- € 1.5M
- Specific Targeted Research Project