Tuesday, 16 February 2016

21. Clinical evidence for cancer prevention through diet




    
     Findings from an Italian study published this month in the American Journal of Nutrition has demonstrated a clear link between the amount of phytochemical-rich polyphenols we eat and mortality from breast, pancreatic, throat, prostate and skin cancers. Phytochemicals are plant compounds, which give vegetables and fruit their pleasing colour, taste and aroma.
     Over 12 years, the joint Italian/Spanish/USA study assessed intake in 807 men and women by measuring their total urinary polyphenol, which could have come from numerous phytochemical-rich polyphenol food sources including tomatoes, tea, broccoli, herbs and spices or even Chianti wine. It showed that those with the highest polyphenol levels had the lowest death rate from cancer and heart disease.
   

Clinical evidence for a dietary benefit after cancer

     Other studies published by the British Journal of Medical Practitioners have shown that the anti-cancer effects of phytochemicals in these polyphenols do not stop after a diagnosis of cancer when combined with other healthy lifestyle habits such as regular exercise.
     Breast cancer survivors eating polyphenol fruit, vegetables, soy and green tea were found to have lower relapse rates.
     Individuals with skin cancer, who had a high intake of leafy green vegetables and broccoli, had lower rates of new cancer formation, while a polyphenol rich diet has been linked to a slower rate of PSA progression among men with indolent prostate cancer.
     A Shanghai Breast Cancer Survival Study has shown a dramatic drop in relapse and death for breast, chronic leukaemia and prostate cancer sufferers with high intake of polyphenols.  Cancer cells have to go through a series of biochemical pathways in order to grow faster, invade adjacent organs and metastasise.
     Laboratory experiments using cancer and normal cells in petri dishes show that some foods can directly inhibit these pathways.  Polyphenols have a direct ant-cancer mechanism of action via inflammation cellular modulation and signalling events involved in growth, invasion and metastasis. 
     I strongly recommend reading the BJMP article below. Essential reading, it not only gives a summary of the recent studies but also provides a comprehensive list of phytochemicals with notable food rich sources in a variety of fruits, vegetables, grains, pulses and nuts.

Further Reading

British Journal of Medical Practitioners : Phytochemicals in Polyphenols and cancer prevention
Stuart's Kitchen : Recipes for healthy seasonal Mediterranean Diet produce.