Transcript: Why Might Vegetarians Have Less HPV?
Cervical cancer is now considered a sexually transmitted disease, originally suspected as such as it was supposedly found less in nuns and more in prostitutes, but now we have DNA fingerprinting proof that virtually all cervical cancer is caused by a sexually transmitted virus, human papilloma virus, which also causes cancers of the penis, vagina, vulva and throat. HPV is considered a necessary, but not sufficient cause of cancer.
Most young women contract HPV, but most don't get cervical cancer because their immune systems are able to clear out the virus. 70% of women clear the infection within 1 year and more than 90% within 2 years before the virus can cause cancer, unless you're immunocompromised or something.
Well if that's the case, maybe those with particularly strong immune systems might clear the virus even faster. That's what may behind this new study that found vegetarian women appeared to have significantly lower infection rates with HPV, one of many studies reporting that vegetarians have lower risk of HPV infection thought to be because of the presence of more fruits and vegetables in their diet which are rich source of all sorts of good phytonutrients.
So for example if you take a bunch of women with cancer causing strains of HPV infecting their cervix and follow them out and retest at 3 months, and then 9 months while analyzing their diets, what do you find? Higher levels of vegetable consumption may cut the risk of HPV persistence in half, double one's likelihood of clearing this potentially cancer-causing infection. And "higher" levels just meant like 2 or more servings a day.
What do antioxidants in plants have to do with viral diseases? Different antioxidants affect different viruses in different ways, but against HPV don't you know that electrophoretic mobility supershift assays showed "Irrespective of enhanced c-fos expression, c-jun was phosphorylated and became primarily heterodimerized with fra-1, which was also induced after PDTC incubation," I mean duh. I had to read this paper like 5 times, long story short, antioxidants appear to suppress the activation of critical segments of the virus' DNA. Maybe that's why smearing green tea on genital warts—also caused by HPV—has been found so effective in clearing them.
In terms of preventing cervical cancer, through their role as antioxidants, phytonutrients like lutein, found in dark green leafy vegetables, and lycopene, the red pigment in tomatoes, may decrease viral load, thereby decreasing persistence and progression to disease. Whereas the protective associations may be due to their antioxidant properties, they have all sorts of other wonderful effects, so who knows, who cares, bottomline: higher consumption of vegetables may decrease risk of HPV persistence," which may help explain why this 2013 study found vegan woman have significantly lower rates of all female cancers combined, including cancer of the cervix.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Ariel Levitsky.
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