Tea and other plant-based foods may have damaging effects to
human DNA, potentially causing cancer

Scientists at the Johns Hopkins Kimmel Cancer Center have found that coffee, tea and other plant-based foods may have damaging effects to human DNA, potentially causing certain types of cancer.

The study was published online on February 8 in the Food and Chemical Toxicology Journal.

Using a test developed by Dr. Scott Kern, a professor of oncology and pathology at the John Hopkins University School of Medicine, researchers were able to expose human tissue to the tested substances in amounts which would be found in a normal diet. In addition to coffee, black tea and green tea, researchers also found that certain common food additives such as liquid smoke also caused damage to human DNA. When exposed to active chemicals found in these foods, scientists saw potential cancer activity increasing as much as 30 times normal.

The research was conducted by measuring levels of a gene known as p53 which is a well-known cancer linked protein that in humans. P53 is a gene protector which rises when DNA is damaged.

Speaking of the study's findings, Dr. Kern remarked:

"We don't know much about the foods we eat and how they affect the cells in our bodies."

"But, it's clear that plants contain many compounds that are meant to deter humans and animals from eating them, like cellulose in stems and bitter tasting tannins in leaves and beans we use to make teas and coffees, and their impact needs to be assessed," added Kern.

DNA damaging compounds found to be present in coffee, teas and liquid smoke are also present in other products such as bread crust, cigarette smoke, cocoa powder, hair dye and roasted malt.

The study did however show good news for Scotch drinkers. Because of its somewhat smoky flavor, the researchers included Scotch in their study.

"We found that Scotch whiskey, which has a smoky flavor and could be a substitute for liquid smoke, had minimal effect on P. 53 activity in our tests, reported Kern.