Pairing food chemistry and cancer biology in a laboratory study, scientists at the Johns Hopkins University's Kimmel Cancer Centre tested the potentially harmful effects of foods and flavourings on the DNA of cells.
They found that liquid smoke flavouring, black and green teas and coffee activated the highest levels of a well-known cancer-linked gene called p53.
The p53 gene gets activated when DNA is damaged. Its gene product makes repair proteins that mend DNA. The higher the level of DNA damage, the more activated p53 becomes.
"We don't know much about the foods we eat and how they affect cells in our bodies," says Scott Kern, professor of oncology and pathology at the Johns Hopkins University School of Medicine.
"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."
"We found that Scotch whiskey, which has a smoky flavour and could be a substitute for liquid smoke, had minimal effect on p53 activity in our tests," says Kern.
Liquid smoke, produced from the distilled condensation of natural smoke, is often used to add smoky flavour to sausages, other meats and vegan meat substitutes. It gained popularity when sausage manufacturers switched from natural casings to smoke-blocking artificial casings.
Other flavourings like fish and oyster sauces, tabasco and soy sauces, and black bean sauces showed minimal p53 effects in the tests, as did soybean paste, kim chee, wasabi powder, hickory smoke powders and smoked paprika.