Effect of Food Taste in Cancer Forming and Progression; Viewpoint From Persian Medicine.

Dear Editor,

Cancer prevention and treatment is one of the worldwide research priorities. Ancient medicine like Greek, Egyptian, Indian, Chinese and Persian medicine (PM) is a good source for research in intricate field of medicine.

According to PM, risk of cancer or being susceptible to it, depends on various factors such as sleep pattern, physical activity, digestive system function, stresses due to personal or social conditions, previous infections, chronic irritation, and inflammation (1, 2).

Persian physicians, in more than thousand years ago, had been emphasized the importance of lifestyle on the cancer development and progression. They believed that avoiding from less and late night sleep, mental and emotional excitement such as fear, anger and strenuous exercise can protect patient from progression of cancer (1, 2).

Nowadays the influences of some factors were proved and well known (3, 4). Thus, paying attention to other factors which are ignored without sufficient notice is extremely essential and taste of foods is one of them.

The type of diet is one of the important factors in prevention for susceptible people and treatment of patient. Persian physicians believed that taste of foods is a significant sign in identification of material effect. Bitter, salty, sour and spicy tastes, in persistent intake, are stimulating factors for cancer progression as a result of liver dysfunction and cancerous material production (1, 2).

In the other hand the collective influence of multiple factors is notable. For example, the effects of persistent intake of bitter, sour, salty and spicy tastes are higher in people with excessive anger, poor sleep or constipation disease (1, 2).

Recent studies indicate that salty or spicy diet was directly associated with risk of gastric and colorectal cancer in prospective population studies. Consumption of salted meat, pickled and preserved vegetables, are also positively associated with these cancers (5-7). Also a strong adverse effect of total salt intake and salt-rich foods on the risk of stomach cancer has been detected in comprehensive meta-analysis of longitudinal studies in the general population. Epidemiological, clinical and experimental evidence were shown that reduction in population salt intake decreased the rate of gastric cancer (8).

According to the PM, these tastes not only are effective in digestive cancer but also can influence the other site of body like breast, uterine, skin and other parts (1, 2).

In the other hand, PM recommended tasteless food for cancer patient such as vegetable without taste like cucurbit, barley soup, chicken, goat and lamb meat, fresh fish, fresh milk, wheat bread and sweet almond oil. patients also be avoided from foods such as brassica oleracea (Cabbage, Cauliflower, Kohlrabi) in row form, Solanum melongena (eggplant), Lens culinaris (Lentil), processed meat, salty, sour and spicy taste such as crude onions and garlic, old cheese, salting meat and pepper (1, 2).

Although such recent studies expressed that some of these foods like brassica oleracea have anticancer effect in vitro (9, 10) but according to PM viewpoints, in some conditions, these foods can stimulate tumor progression in cancer patients. Thus more in vivo and clinical studies are needed for nutritional advices.