**2.2.5 Table salt**

Chronic intake of excessive amounts of table salt is a possible gastric cancer risk factor (WCRF & AICR, 2007; ADA, 2006a; Key et al., 2004; Béliveau et al., 2007; WHO, 2003, 2005; AICR & WCRF, 2009; Donaldson, 2004). As positive correlation between *Helicobacter pylori* infection and high salt intake has also been noted, it is possible that there is a synergy between the two factors in gastric cancer promotion. Another mechanism of stomach cancer promotion proposed is that high salt intake damages the gastric mucose, increasing the possibility of endogenous mutations, which leads to hypergastrinemia and decrease in number of gastric parietal cells, and thus to cancer promotion (Wang et al., 2009).

Processed foods are the main source of salt in the diet, and in order to reduce cancer risks in adult population, population-level strategy should start by decreasing salt intake among children, adolescents and young adults (Trajković-Pavlović et al., 2010a, 2010b).

#### **2.2.6 Vitamins, minerals and other bioactive molecules**

Micronutrients, such as vitamins and minerals, are essential nutrients in maintaining good health, while other bioactive molecules, such as phytochemicals (substances of plant origin) and zoochemicals (substances of animal origin) are non-essential, but may improve human health (Kaput, 2006). Recommendations for vitamin and mineral intake exist for different population groups (Institute of Medicine, 1998, 2000, 2001), but it is not possible to quantify the need for phytochemicals (Smolin & Grosvenor, 2010).

Many vitamins (e.g vitamin E, vitamin C), minerals (e.g selenium) and phytochemicals (e.g flavonoids) are parts of the antioxidant defense system. Substances with antioxidant properties were seen as promising in lowering risks from chronic diseases and, among them, cancer. In vitro experiments have confirmed that these molecules have antioxidant properties, but the initial hypothesis that antioxidant substances can prevent cancer (or other chronic diseases) in humans has yet to be confirmed (WCRF & AICR, 2007; Mamede et al., 2011).

The impact of calcium and vitamin D on breast and colorectal cancer is being intensively researched during the last ten years, but, up to this point, no definite answers can be given about these relations (Lin et al., 2007; Lappe et al., 2007; Manson et al., 2011).

In the complex pathways of carcinogenesis, there are numerous processes that could be targeted by phytochemicals in order to lower the risk of disease development. The interest

Legumes are known to be beneficial in cardiovascular and type 2 diabetes risk reduction, but there is limited evidence that legumes consumption may reduce the risk of stomach, colorectal, and kidney cancer. Further investigations of these complex relations are still

Effects of nuts and seeds intake on cancer risks are limited and inconclusive (WCRF &

Aflatoxin contamination of fungus-contaminated crops and legumes remains a serious food safety problem, as aflatoxin is known to be a risk for liver cancer (Goldman & Shields, 2003;

Chronic intake of excessive amounts of table salt is a possible gastric cancer risk factor (WCRF & AICR, 2007; ADA, 2006a; Key et al., 2004; Béliveau et al., 2007; WHO, 2003, 2005; AICR & WCRF, 2009; Donaldson, 2004). As positive correlation between *Helicobacter pylori* infection and high salt intake has also been noted, it is possible that there is a synergy between the two factors in gastric cancer promotion. Another mechanism of stomach cancer promotion proposed is that high salt intake damages the gastric mucose, increasing the possibility of endogenous mutations, which leads to hypergastrinemia and decrease in

Processed foods are the main source of salt in the diet, and in order to reduce cancer risks in adult population, population-level strategy should start by decreasing salt intake among

Micronutrients, such as vitamins and minerals, are essential nutrients in maintaining good health, while other bioactive molecules, such as phytochemicals (substances of plant origin) and zoochemicals (substances of animal origin) are non-essential, but may improve human health (Kaput, 2006). Recommendations for vitamin and mineral intake exist for different population groups (Institute of Medicine, 1998, 2000, 2001), but it is not possible to quantify

Many vitamins (e.g vitamin E, vitamin C), minerals (e.g selenium) and phytochemicals (e.g flavonoids) are parts of the antioxidant defense system. Substances with antioxidant properties were seen as promising in lowering risks from chronic diseases and, among them, cancer. In vitro experiments have confirmed that these molecules have antioxidant properties, but the initial hypothesis that antioxidant substances can prevent cancer (or other chronic diseases) in humans has yet to be confirmed (WCRF & AICR, 2007; Mamede et

The impact of calcium and vitamin D on breast and colorectal cancer is being intensively researched during the last ten years, but, up to this point, no definite answers can be given

In the complex pathways of carcinogenesis, there are numerous processes that could be targeted by phytochemicals in order to lower the risk of disease development. The interest

about these relations (Lin et al., 2007; Lappe et al., 2007; Manson et al., 2011).

number of gastric parietal cells, and thus to cancer promotion (Wang et al., 2009).

children, adolescents and young adults (Trajković-Pavlović et al., 2010a, 2010b).

**2.2.6 Vitamins, minerals and other bioactive molecules** 

the need for phytochemicals (Smolin & Grosvenor, 2010).

waited upon (Kolonel et al., 2000; Aune et al., 2009b).

AICR, 2007).

Wogan et al., 2004).

**2.2.5 Table salt** 

al., 2011).

in phytochemicals has grown substantially over the years and it has not lessen, although screening for potential chemopreventive molecules requires a systematic and wide-range approach (Tan et al., 2011; Milner, 2004). In order to reduce the risk of cancer in human population, many experiments studying herbs and spices and their effects on carcinogenesis were conducted on animals. The possibility of using herbs and spices as substitutes for unhealthy food constituents (e.g added sugars, added fat, table salt) can contribute to chemopreventive potential of herbs and spices (Tapsell et al., 2006).

If phytochemicals are added to foods, such foods become functional. Functional foods are foods that provide healthy benefits beyond basic nutrition, when consumed as part of a varied diet on a regular basis, at effective levels (ADA, 2009; Howlett, 2008). According to some authors, health effects of consuming functional foods containing bioactive substances or pharmaceuticals may be as beneficial as consumption of those substances from their natural sources (Howlett, 2008). Other authors claim that chemopreventive properties of fruits and vegetables are a result of synergistic and additive effects of phytochemicals acting together in their natural environment, and therefore, cannot be imitated by functional foods (Tapsell et al., 2006; Liu, 2003; Milner, 2006b).

Global use of dietary supplements containing vitamins, minerals and other bioactive compounds, although already enormous, is still on the rise. Dietary supplements can reduce the risk of deficiencies and promote optimal health, but should not be considered substitutes for a well-balanced, healthy diet (Mason, 2007). Evidence supporting the use of dietary supplements in cancer risk reduction are scarce, so population-based recommendation is to increase the percentage of people who are achieving optimal nutrition without the use of dietary supplements (WCRF & AICR, 2007; Myung et al., 2009). Determination of oxidative stress-based biomarkers should be regarded as "indication" for using antioxidant supplements (Ziech et al., 2010), although this is not financially viable yet.

Mediterranean diet is considered to be protective against cancers, opposite to USA and Northern Europe diet patterns. Adoption of Mediterranean eating pattern in USA and Northern Europe may help cancer risk reduction (Simopoulos, 2001; Verberne et al., 2010).

#### **2.3 Physical activity**

Regular physical activity, besides leading to fitness, provides many health benefits (Warburton et al., 2006; Miles, 2007). Physical activity increases overall well-being, and if regular, improves quality of life, helps body mass maintenance and therefore, reduces cancer risks (WCRF & AICR, 2007; WHO, 2003, 2005, 2008a, 2009b; AICR & WCRF, 2009). Cancer risks in regularly physically active are up to 40.0% lower than among physically inactive (Newton & Galvão, 2008).

Insufficient physical activity is considered to be the fourth leading risk factor in overall mortality. WHO holds insufficient physical activity responsible for 6.0% of global deaths (WHO, 2009a). Dropping levels of physical activity worldwide are in part responsible for rising prevalence of NCDs, including cardiovascular diseases, diabetes and cancer (WCRF & AICR, 2007; WHO, 2005, 2009a; Fair & Montgomery, 2009; AICR & WCRF, 2009; Newton & Galvão, 2008; Tucker et al., 2011; Hardman et al., 2011; Wannamethee et al., 2001). Insufficient physical activity accounts for 21.0-25.0% of breast and colon cancer burden (WHO, 2009a, 2010a)

Lifestyle Changes May Prevent Cancer 163

Tobacco is a plant that contains nicotine, various carcinogens and toxins, and it is considered addictive (WHO, 2011d). Around 4000 chemicals have been detected in tobacco smoke, with more than 50 of them identified as carcinogenic (WHO, 2006). Tobacco dependence is classified as a disease under the International Classification of Diseases [ICD-

Tobacco use has grown into a global epidemic. The number of tobacco users is on the rise in middle and low income countries, while in decline in developed countries (Mackay et al., 2006; IARC, 2004; WHO, 2008b). Smoking is the second principal cause of global mortality participating with 8.7% (3.7% DALYs) (WHO, 2008b, 2009a; IARC, 2004). At the same time, smoking is the most modifiable single risk factor for malignant diseases and other NCDs

Smoking causes 71.0% of lung cancer deaths (WHO, 2009a), but it is also a risk for other cancer localizations, like throat, mouth, esophagus, stomach, pancreas, kidney, bladder and cervix (WHO, 1999, 2011d). Not only smokers die of smoking-related lung cancer – 4300 secondhand smokers die from lung cancer every year in USA (IARC, 2004; WHO, 2008b,

Tobacco use, in any form, is unhealthy. Attempts were made to create less toxic versions of tobacco products, but such products were unacceptable by consumers and consequently failed. Although not widely used, in some parts of the world smokeless tobacco represents a

Definitions of smoking and related terms – secondhand tobacco smoke [SHS], environmental tobacco smoke [ETS] or other people's smoke and smoking free area – are given in WHO Framework Convention on Tobacco Control [WHO FCTC] as recommended

WHO FCTC aims to protect public health policy makers from commercial interests, to provide guidance for protection against tobacco smoke, to regulate the contents of tobacco products, to implement rules for labelling, advertising and promotion of tobacco products, to educate people and communicate information about tobacco addiction. Ultimately, the goal is to decrease the number of tobacco users and increase the number of former smokers

There are several aspects of harmful effects of smoking. Dietary nutrient intake and plasma folate level can also be affected by smoking status. Depletion of plasma folate, an antioxidant, together with depletion of other dietary substances, might be a factor in early onset of tobacco-related morbidity and mortality in smokers. Beneficial effects of Mediterranean diet on smokers' health have been documented and they are presumably related to optimal ratio of omega-6 to omega-3 polyunsaturated fatty acids and significant

In conclusion, all tobacco products should be considered harmful and addictive, and strict regulations should be implemented in order to control the tobacco epidemic (WHO, 2011e; IARC, 2008). Public health researchers of the Oxford Vision 2020 Program, underlined not only the societal, but the individual responsibility towards health and healthy lifestyle

significant form of tobacco use (WHO, 2006; IARC, 2004, 2006, 2008).

terms for smoking and secondhand smoke (WHO, 2006, 2011e).

amounts of bioactive molecules (Vardavas et al., 2008, 2011).

**2.4.1 Tobacco use** 

10] (WHO, 1999).

2011e).

(WHO, 2009a; Danaei et al., 2009).

(WHO, 2011e; IARC, 2008).

Physical inactivity is a modifiable lifestyle choice and a cancer risk factor, and it is therefore of great public health significance (WCRF & AICR, 2007; WHO, 2005; AICR & WCRF, 2009; Warburton et al., 2006; Miles, 2007; Newton & Galvão, 2008; Tucker et al., 2011; Hardman, 2001; Wolin et al., 2009), but meeting physical activity recommendations has proven to be as big of a challenge on an individual level, as on the society one.

The complexity of cancer - physical activity interactions should be assessed on gene level, too. Thune & Furberg (Thune & Furberg, 2001) believe that "genetic predisposition to be physically active, combined with the knowledge that cancer is a genetic localized disease, warrants studies in general population and high-risk groups alike".

Physical activity is divided into inactivity, insufficient activity and sufficient activity. Sufficient activity is subdivided into "meeting current recommendations" (moderate physical activity) and "highly active" (WHO, 2007b, 2009a, 2009b, 2010a).

"Meeting current recommendations" is possible by 2.5 hours of moderate physical activity, or 1 hour of vigorous physical activity per week. Both are equivalent with 600 metabolic equivalents [MET] per week. Highly active individuals' energy expenditure is equivalent to 1600 MET per week. Metabolic equivalent is the ratio of energy consumption during a specific physical activity to energy consumption while sitting and resting. One MET is defined as the resting metabolic rate obtained during quiet sitting and is set by convention to 3.5 ml O2/kg/min or 1 kcal/kg/h (WHO, 2010a). Physical activities are classified according to energy needed for their performance, using MET as a reference value. On a population level, moderate physical activity should be set as a goal for health benefits and cancer risk reduction. Indivividuals and population groups that are already moderately active, should be encouraged to become highly active.

In the "Global Recommendations on Physical Activity and Health" (WHO, 2010a), WHO aims to establish dose-response relationship between physical activity and the consequent health benefits, as well as to identify the frequency, duration, intensity, type and total amount of physical activity needed for health benefits, such as cancer or other NCDs risk reduction (WHO, 2007b, 2009b, 2010a). Currently, it is believed that diabetes, heart diseases and cancer risks, including breast and colon cancer risks, can be reduced among people who are 18 or older by 150 minutes of moderate intensity aerobic activity the least, or 60 minutes of vigorous activity weekly. At least 60 minutes of moderate to vigorous physical activity can reduce NCDs risks in 5-17 year-olds (WHO, 2009a, 2009b). For added health benefits, introduction of physical activity, with the amount, frequency, duration and intensity being gradually increased, is recommended for inactive adults, older adults and those limited in activity by their disease (WHO, 2010a).

Public health goals set by new physical activity recommendations include achieving and maintaining optimal health (WCRF & AICR, 2007; WHO, 2003, 2005, 2007, 2008a, 2009a, 2009b, 2010a; Wolin et al., 2009).

#### **2.4 Tobacco, alcohol use and everyday drinks**

Although alcoholic beverages and everyday drinks are considered foods, together with tobacco use, their consumption may pose a health risk. On the other hand, safe drinking water is not a health risk, but a prerequisite for optimal health.

#### **2.4.1 Tobacco use**

162 Cancer Prevention – From Mechanisms to Translational Benefits

Physical inactivity is a modifiable lifestyle choice and a cancer risk factor, and it is therefore of great public health significance (WCRF & AICR, 2007; WHO, 2005; AICR & WCRF, 2009; Warburton et al., 2006; Miles, 2007; Newton & Galvão, 2008; Tucker et al., 2011; Hardman, 2001; Wolin et al., 2009), but meeting physical activity recommendations has proven to be as

The complexity of cancer - physical activity interactions should be assessed on gene level, too. Thune & Furberg (Thune & Furberg, 2001) believe that "genetic predisposition to be physically active, combined with the knowledge that cancer is a genetic localized disease,

Physical activity is divided into inactivity, insufficient activity and sufficient activity. Sufficient activity is subdivided into "meeting current recommendations" (moderate

"Meeting current recommendations" is possible by 2.5 hours of moderate physical activity, or 1 hour of vigorous physical activity per week. Both are equivalent with 600 metabolic equivalents [MET] per week. Highly active individuals' energy expenditure is equivalent to 1600 MET per week. Metabolic equivalent is the ratio of energy consumption during a specific physical activity to energy consumption while sitting and resting. One MET is defined as the resting metabolic rate obtained during quiet sitting and is set by convention to 3.5 ml O2/kg/min or 1 kcal/kg/h (WHO, 2010a). Physical activities are classified according to energy needed for their performance, using MET as a reference value. On a population level, moderate physical activity should be set as a goal for health benefits and cancer risk reduction. Indivividuals and population groups that are already moderately

In the "Global Recommendations on Physical Activity and Health" (WHO, 2010a), WHO aims to establish dose-response relationship between physical activity and the consequent health benefits, as well as to identify the frequency, duration, intensity, type and total amount of physical activity needed for health benefits, such as cancer or other NCDs risk reduction (WHO, 2007b, 2009b, 2010a). Currently, it is believed that diabetes, heart diseases and cancer risks, including breast and colon cancer risks, can be reduced among people who are 18 or older by 150 minutes of moderate intensity aerobic activity the least, or 60 minutes of vigorous activity weekly. At least 60 minutes of moderate to vigorous physical activity can reduce NCDs risks in 5-17 year-olds (WHO, 2009a, 2009b). For added health benefits, introduction of physical activity, with the amount, frequency, duration and intensity being gradually increased, is recommended for inactive adults, older adults and those limited in

Public health goals set by new physical activity recommendations include achieving and maintaining optimal health (WCRF & AICR, 2007; WHO, 2003, 2005, 2007, 2008a, 2009a,

Although alcoholic beverages and everyday drinks are considered foods, together with tobacco use, their consumption may pose a health risk. On the other hand, safe drinking

big of a challenge on an individual level, as on the society one.

warrants studies in general population and high-risk groups alike".

active, should be encouraged to become highly active.

activity by their disease (WHO, 2010a).

**2.4 Tobacco, alcohol use and everyday drinks** 

water is not a health risk, but a prerequisite for optimal health.

2009b, 2010a; Wolin et al., 2009).

physical activity) and "highly active" (WHO, 2007b, 2009a, 2009b, 2010a).

Tobacco is a plant that contains nicotine, various carcinogens and toxins, and it is considered addictive (WHO, 2011d). Around 4000 chemicals have been detected in tobacco smoke, with more than 50 of them identified as carcinogenic (WHO, 2006). Tobacco dependence is classified as a disease under the International Classification of Diseases [ICD-10] (WHO, 1999).

Tobacco use has grown into a global epidemic. The number of tobacco users is on the rise in middle and low income countries, while in decline in developed countries (Mackay et al., 2006; IARC, 2004; WHO, 2008b). Smoking is the second principal cause of global mortality participating with 8.7% (3.7% DALYs) (WHO, 2008b, 2009a; IARC, 2004). At the same time, smoking is the most modifiable single risk factor for malignant diseases and other NCDs (WHO, 2009a; Danaei et al., 2009).

Smoking causes 71.0% of lung cancer deaths (WHO, 2009a), but it is also a risk for other cancer localizations, like throat, mouth, esophagus, stomach, pancreas, kidney, bladder and cervix (WHO, 1999, 2011d). Not only smokers die of smoking-related lung cancer – 4300 secondhand smokers die from lung cancer every year in USA (IARC, 2004; WHO, 2008b, 2011e).

Tobacco use, in any form, is unhealthy. Attempts were made to create less toxic versions of tobacco products, but such products were unacceptable by consumers and consequently failed. Although not widely used, in some parts of the world smokeless tobacco represents a significant form of tobacco use (WHO, 2006; IARC, 2004, 2006, 2008).

Definitions of smoking and related terms – secondhand tobacco smoke [SHS], environmental tobacco smoke [ETS] or other people's smoke and smoking free area – are given in WHO Framework Convention on Tobacco Control [WHO FCTC] as recommended terms for smoking and secondhand smoke (WHO, 2006, 2011e).

WHO FCTC aims to protect public health policy makers from commercial interests, to provide guidance for protection against tobacco smoke, to regulate the contents of tobacco products, to implement rules for labelling, advertising and promotion of tobacco products, to educate people and communicate information about tobacco addiction. Ultimately, the goal is to decrease the number of tobacco users and increase the number of former smokers (WHO, 2011e; IARC, 2008).

There are several aspects of harmful effects of smoking. Dietary nutrient intake and plasma folate level can also be affected by smoking status. Depletion of plasma folate, an antioxidant, together with depletion of other dietary substances, might be a factor in early onset of tobacco-related morbidity and mortality in smokers. Beneficial effects of Mediterranean diet on smokers' health have been documented and they are presumably related to optimal ratio of omega-6 to omega-3 polyunsaturated fatty acids and significant amounts of bioactive molecules (Vardavas et al., 2008, 2011).

In conclusion, all tobacco products should be considered harmful and addictive, and strict regulations should be implemented in order to control the tobacco epidemic (WHO, 2011e; IARC, 2008). Public health researchers of the Oxford Vision 2020 Program, underlined not only the societal, but the individual responsibility towards health and healthy lifestyle

Lifestyle Changes May Prevent Cancer 165

The WHO Global Strategy to Reduce the Harmful Use of Alcohol (WHO, 2010b) aims to raise awareness of health, social and economic aspects of alcohol abuse, and the relationship between alcohol and disease development. It points to the importance of effective stakeholders involvement in preventing harmful effects of alcohol. It also aims to provide

USDA recommendations for alcohol intake not linked to increase of cancer risks are 28 g of alcohol per day for healthy adult men, and half of that amount for healthy women (USDA & U.S. Department of Health and Human Services, 2011). The European Code Against Cancer recommends up to 20 or 30 g/day of alcohol for healthy men and, again, half of that amount for healthy women (Boyle et al., 2003). AICR made recommendations simple by advising 2 standard drinks for healthy men and 1 standard drink for healthy women (WCRF & AICR,

Tobacco and alcohol use are major risk factors for malignancies of different localizations, but mainly of the gastrointestinal tract (Testino & Borro, 2010; Pelucchi et al., 2008; Seitz & Cho, 2009) and the two also act in synergy increasing the cancer risk. Tobacco smoking combined with alcohol use increase the tissue levels of acetaldehyde, while alcohol helps in activation of different procarcinogens in tobacco smoke by induction of cytochrome-P450-2E1 dependent microsomal biotransformation system in mucose cells of the upper digestive tract and liver (IARC, 2004; Testino and Borro, 2010; Seitz & Cho, 2009). Pancreatic cancer risk is 4.3-fold higher in people who smoke more than 20 cigarettes per day and drink more than 21 standard drinks per week, than in non-smoking people who drink less than 7

Coffee and tea drinking is a widespread habit. Both coffee and tea contain many bioactive substances (antioxidants, phenols) with in vitro anticarcinogenic characteristics (Ferruzzi, 2010). Consumption of 3 cups of coffee per day (equivalent to 300 mg of caffeine) is

It is still not known whether coffee consumption increases the risk of any type of cancer. Evidence concerning the link between coffee and esophageal and pancreatic cancer are inconsistent and difficult to interpret, due to the confounding effects of tobacco and alcohol

Laboratory experiments and animal testing showed chemoprotective activity of tea polyphenols, but there are not enough evidence to confirm the same in human population

Soft drinks consumption shows an increase of 5.0% per year, that is an increase from 467 to 552 billion litres from 2004 to 2007 (Zenith International, 2005, 2008). Cola drinks and carbonated soft drinks reportedly accounted for 42.0% of 467 billion litres of soft drinks consumed within one year, in contrast to fruit juices, nectars and fruit drinks which

support for national efforts to reduce the overall effects of alcohol abuse.

standard drinks per week (Talamini et al., 2010).

considered to be moderate (Tverdal et al., 2011).

use (WCRF & AICR, 2007; Ferruzzi, 2010).

(WCRF & AICR, 2007; Lambert & Yang, 2003).

accounted for 8.0% in 2004 (Zenith International, 2005).

**2.4.3 Coffee and tea use** 

**2.4.4 Soft drinks** 

2007).

choices. Being aware of the health risks related to tobacco use is not merely enough – motivational campaigns should be designed in order to cut down smoking prevalence by 8.0 to 10.0% per year, and achieve the resulting prevalence of less than 10.0% in all social groups (Yach et al., 2005).
