Researchers at John Hopkins Kimmel Cancer Center(2) have found a compound in saliva, which along with common proteins in blood and muscle may protect human cells from toxins in tea, coffee and liquid smoke flavoring. The article cited in Food and Chemical Toxicology(1) journal, suggest that humans can naturally launch multiple defenses against plant chemicals called pyrogallol like polyphenols or PLPs found in tea, coffee, and liquid smoke flavoring. The presence of these natural defenses in people explains why PLPs are not crippling cells and causing illness, as expected from their widespread use.
Johns Hopkins Investigator Scot Kern, M.D., and his colleagues showed that PLPs found in everyday food and flavorings could do significant damage, by breaking strands of DNA. At some stage the damage caused by these toxins (PLPs) were found to be 20 times more than that of chemotherapy drugs, which are used for cancer patients. Baffled by these developments, researcher thought to find out why there was no further damage and how these cells are fighting them back. Kern said, “If these chemicals are so widespread–they’re in flavorings, tea, coffee–and they damage DNA to such a high degree,” adding further, “we thought there must be defense mechanisms that protect us on a daily basis from plants we choose to eat.”
An enzyme in saliva called alpha-amylase, along with the blood protein albumin and muscle cell protein myoglobin, together protected cells from DNA breakage by tea, coffee and isolated PLPs. Researchers measured DNA damage by looking onto the activity levels of p53 gene. A gene that helps in repairing damaged DNA. “It was quite easy to uncover a few of these protective substances against the tested cancer therapeutic drugs, which suggests there may be many more layers of defenses against toxins,” said Kern, the Kovler Professor of Oncology and Pathology at the Johns Hopkins University School of Medicine.
It was also found that the saliva enzyme and the proteins did not protect against the chemotherapeutic drugs, which can also damage DNA. This clarifies the fact that, defenses against PLPs may have evolved against a response to natural plant compounds, which is a part of human diet for a long time. Surprisingly, cells did not seem to need these protector proteins after a period of exposure to the toxins. Kern further explains, “After about two weeks we found it difficult to get the cells to be damaged by the same chemicals, even if they were damaged by the chemicals weeks earlier.” He further adds, “They seem to have some innate ability to respond to the damage or sense it and somehow protect themselves against it, even in the absence of albumin, muscle proteins or saliva components.” “It made us wonder, do people who eat the same PLP-containing diet day after day develop a natural cellular protection to the toxins,” Kern asked, “so that, as has been said before, what doesn’t kill us makes us stronger?”
Researchers are planning further, to study how albumin, myoglobin and salivary alpha-amylase protect against PLPs and their possible innate defenses against the chemicals. Kern also plans an alternative study, to find how these natural defenses were compromised in some people causing cancers or other illnesses. Finding of the research also speculates that a morning cup of coffee might be less harmful if enjoyed with a protective myoglobin from a meat (chicken, bacon, etc…). Also eating smoked meat might be less toxic if they are enough to make you salivate. But researchers say that these ideas are just speculation.
1) Scott E. Kern, M. Zulfiquer Hossain, Kalpesh Patel, , 2014. Salivary α-amylase, serum albumin, and myoglobin protect against DNA-damaging activities of ingested dietary agents in vitro. Food and Chemical Toxicology, Volume 70, Pages 114–119.
2) Hopkinsmedicine.org. 2014. Compounds in Saliva and Common Body Proteins May Fend Off DNA-Damaging Chemicals in Tea, Coffee and Liquid Smoke.[Accessed 23 June 14].