I held a Q & A session on my Instagram and have only had a chance now to write up some of the posts (#friyay). I thought this was such an interesting question:
“Hi there! I just saw that your research is on HPV. Interesting timing for me because a friend was just saying this morning that HPV can be prevented with proper nutrition. I was only able to do a quick Google search and could not find any credible sources discussing this. I was wondering if you could comment on any link between nutrition and HPV? Or perhaps you could point me to some studies on this topic?”
My first response to this was er… no. Sure, nutrition does play a part in maintaining a healthy immune system, but unless there’s a specific compound in food that’s been found to have high antiviral activity, I doubt that eating healthily alone prevents infection by human papillomavirus (HPV). But instead of completely writing it off, I thought I’d do a little digging around on the interwebs. But first, a little background…
Background on HPV
Only a handful of the approximately 200 types of HPV cause cancer – that is cervical, anal and oropharyngeal cancers. The rest normally cause warts, also known as papillomas or they have no effect. HPV is responsible for causing cancer in more than half a million people a year worldwide. So infection by high-risk HPV types that cause cancer is extremely common and is easily transmitted to skin cells that are susceptible to infection by direct physical contact. However, only a small proportion of these infections will progress to cancer and most people are able to clear the infection. It’s not known why some infections are benign and others cause cancer, but we think it might have to do with small variations in the genes of these common viruses.
Moving on to the crux of the matter…
Could eating a healthy diet really prevent infection by HPV?
A study suggested that increasing dietary intake of lutein/zeaxanthin (found in kale, basil, lettuce and broccoli), β-cryptoxanthin (found in orange rind, papaya, egg yolk, butter and apples) and vitamin C (peppers, guava, kale, kiwi, broccoli and strawberries) appear to be associated with reduced risk of persistence of type-specific HPV infection. Persistence of HPV is a strong determinant of risk of cervical cancer. Eating papaya, a major source of dietary carotenoids was also associated with reduced risk of persistent infection. Another study also indicated that antioxidant vitamins (mainly α-carotene, β-carotene, and vitamins E and C) might be beneficial in reducing the risk of invasive cervical cancer.
The science behind the claim
In recent years you might have heard about something called free radicals if you paid attention to those wrinkle-blasting moisturiser commercials.
Free radicals are created by oxidation in the body during normal metabolic processes or even in the fight against bacteria and viruses. Simply put, they’re basic molecules with an electron missing that causes it to be unstable. In an effort to stabilise itself, they steal an electron from other chemical structures in the body. These chemical structures that have had an electron stolen become free radical themselves, thus starting a whole chain reaction that might disrupt a living cell. This is the basis behind ageing, hence the claims behind anti-wrinkle creams being able to mop up free radicals!
What do free radicals and fruit salads have to do with cervical cancer?
Antioxidant vitamins found in healthy foods may prevent free-radical damage to DNA as they are able to neutralise these free radicals and enhance the immune system [1, 5], linking back to my initial thoughts on this subject.
The bottom line, I’m still not overly convinced that eating your veggies will prevent infection by HPV because there aren’t specific antiviral compounds in fruit and vegetables that will clear the virus (or definitely not in high enough concentrations). What it will do, however, is help in maintaining a healthy immune system that may assist your body to clear the infection. Persistence of HPV is necessary for cancer to develop. HPV infection is however completely preventable if you are vaccinated before exposure. Want to know about vaccination? Leave me a comment 🙂
1. McCullough, M. L. & Giovannucci, E. L. Diet and cancer prevention. Oncogene 23, 6349–6364, 10.1038/sj.onc.12077161207716 (2004).
2. Stebbing, J. & Hart, C. A. Antioxidants and cancer. Lancet Oncol 12, 996, 10.1016/S1470-2045(11)70282-0S1470-2045(11)70282-0 (2011).