Cancer is a preventable disease that requires major lifestyle changes

Abstract

This year, more than 1 million Americans and more than 10 million people worldwide are expected to be diagnosed with cancer, a disease commonly believed to be preventable. Only 5-10% of all cancer cases can be attributed to genetic defects, whereas the remaining 90-95% have their roots in the environment and lifestyle. The lifestyle factors include cigarette smoking, diet (fried foods, red meat), alcohol, sun exposure, environmental pollutants, infections, stress, obesity, and physical inactivity. The evidence indicates that of all cancer-related deaths, almost 25-30% are due to tobacco, as many as 30-35% are linked to diet, about 15-20% are due to infections, and the remaining percentage are due to other factors like radiation, stress, physical activity, environmental pollutants etc. Therefore, cancer prevention requires smoking cessation, increased ingestion of fruits and vegetables, moderate use of alcohol, caloric restriction, exercise, avoidance of direct exposure to sunlight, minimal meat consumption, use of whole grains, use of vaccinations, and regular check-ups. In this review, we present evidence that inflammation is the link between the agents/factors that cause cancer and the agents that prevent it. In addition, we provide evidence that cancer is a preventable disease that requires major lifestyle changes.

Fig. 1

The role of genes and environment in the development of cancer. A The percentage contribution of genetic and environmental factors to cancer. The contribution of genetic factors and environmental factors towards cancer risk is 5–10% and 90–95% respectively. B Family risk ratios for selected cancers. The numbers represent familial risk ratios, defined as the risk to a given type of relative of an affected individual divided by the population prevalence. The data shown here is taken from a study conducted in Utah to determine the frequency of cancer in the first-degree relatives (parents + siblings + offspring). The familial risk ratios were assessed as the ratio of the observed number of cancer cases among the first degree relatives divided by the expected number derived from the control relatives, based on the years of birth (cohort) of the case relatives. In essence, this provides an age-adjusted risk ratio to first-degree relatives of cases compared with the general population. C Percentage contribution of each environmental factor. The percentages represented here indicate the attributable-fraction of cancer deaths due to the specified environmental risk factor.

Fig. 2

Genes associated with risk of different cancers.

Fig. 3

Cancers that have been linked to alcohol and smoking. Percentages represent the cancer mortality attributable to alcohol and smoking in men and women as reported by Irigaray et al. (see 13).

Fig. 4

Cancer deaths (%) linked to diet as reported by Willett (see 35).

Fig. 5

Various cancers that have been linked to obesity. In the USA overweight and obesity could account for 14% of all deaths from cancer in men and 20% of those in women (see 51).

Fig. 6

Various cancers that have been linked to infection. The estimated total of infection attributable cancer in the year 2002 is 17.8% of the global cancer burden. The infectious agents associated with each type of cancer is shown in the bracket. HPV Human papilloma virus, HTLV human T-cell leukemia virus, HIV human immunodeficiency virus, EBV Epstein–Barr virus (see 57).

Fig. 7

Various cancers that have been linked to environmental carcinogens. The carcinogens linked to each cancer is shown inside bracket. (see 64).

Fig. 8

Fruits, vegetables, spices, condiments and cereals with potential to prevent cancer. Fruits include 1 apple, 2 apricot, 3 banana, 4 blackberry, 5 cherry, 6 citrus fruits, 7 dessert date, 8 durian, 9 grapes, 10 guava, 11 Indian gooseberry, 12 mango, 13 malay apple, 14 mangosteen, 15 pineapple, 16 pomegranate. Vegetables include 1 artichok, 2 avocado, 3 brussels sprout, 4 broccoli, 5 cabbage, 6 cauliflower, 7 carrot, 8 daikon 9 kohlrabi, 10 onion, 11 tomato, 12 turnip, 13 ulluco, 14 water cress, 15 okra, 16 potato, 17 fiddle head, 18 radicchio, 19 komatsuna, 20 salt bush, 21 winter squash, 22 zucchini, 23 lettuce, 24 spinach. Spices and condiments include 1 turmeric, 2 cardamom, 3 coriander, 4 black pepper, 5 clove, 6 fennel, 7 rosemary, 8 sesame seed, 9 mustard, 10 licorice, 11 garlic, 12 ginger, 13 parsley, 14 cinnamon, 15 curry leaves, 16 kalonji, 17 fenugreek, 18 camphor, 19 pecan, 20 star anise, 21 flax seed, 22 black mustard, 23 pistachio, 24 walnut, 25 peanut, 26 cashew nut. Cereals include 1 rice, 2 wheat, 3 oats, 4 rye, 5 barley, 6 maize, 7 jowar, 8 pearl millet, 9 proso millet, 10 foxtail millet, 11 little millet, 12 barnyard millet, 13 kidney bean, 14 soybean, 15 mung bean, 16 black bean, 17 pigeon pea, 18 green pea, 19 scarlet runner bean, 20 black beluga, 21 brown spanish pardina, 22 green, 23 green (eston), 24 ivory white, 25 multicolored blend, 26 petite crimson, 27 petite golden, 28 red chief.

Fig. 9

Phytochemicals derived from fruits, vegetables, spices, condiments and cereals with potential to prevent cancer. 1 diosgenin, 2 glycyrrhizin, 3 glycyrrhetinic acid, 4 18-β-glycyrrhetinic acid, 5 oleandrin, 6 oleanolic acid, 7 betulinic acid, 8 lupeol, 9 guggulsterone, 10 celastrol, 11 ursolic acid, 12 acetyl-11-keto-β-boswellic acid, 13 1’-actoxychavicol acetate, 14 α-lipoic acid 15 yakuchinone A, 16 yakuchinone B, 17 curcumin, 18 gingerol, 19 resveratrol, 20 piceatannol 21 genistein, 22 capsaicin, 23 dibenzoylmethane, 24 piperine, 25 kahweol, 26 indiruibin-3’-monoxime, 27 caffeic acid phenethyl ester, 28 emodin, 29 eugenol, 30 linalol, 31 quinic acid, 32 garcinol, 33 sesamin, 34 theaflavin-3,3’-digallate, 35 sanguinarine, 36 silymarin, 37 mangostin, 38 mangiferin, 39 butein, 40 berberine, 41 glabridin, 42 myricetin, 43 carnosol, 44 β-lapachone, 45 evodiamine, 46 wogonin, 47 apigenin, 48 (-)-epigatechin, 49 tanshinones IIA, 50 tanshinones I, 51 (-)-epicatechin gallate, 52 epigallocatechin gallate, 53 carnosol, 54 zerumbone, 55 sulforaphane, 56 phytic acid, 57 allicin, 58 benzyl isothiocyanate, 59 baicalin, 60 ascorbic acid, 61 anethole, 62 indole 3-carbinol, 63 phenyl isothiocyanate, 64 thymoquinone, 65 plumbagin, 66 γ-tocotrienol, 67 lutein, 68 β-cryptoxanthine, 69 β-carotene, 70 lycopene, 71 α-tocoperol.

Fig. 10

Carcinogens activate and chemopreventive agents suppress NF-κB activation, a major mediator of inflammation.