nutritional preventing of cancer

Nutritional Preventing of Cancer

Dr A Norouzy

Associate Professor in Nutrition

Mashhad Medical School

About one third of all cancers can be prevented

European Code Against Cancer: 5th ed1) Do not smoke; if you smoke, stop doing so. If you fail to stop, do not smoke in the

presence of non-smokers.

2) Avoid Obesity.

3) Undertake some brisk, physical activity every day.

4) Increase your daily intake and variety of vegetables and fruits: eat at least five servings daily. Limit your intake of foods containing fats from animal sources.

5) If you drink alcohol, whether beer, wine or spirits, moderate your consumption to two drinks per day if you are a man or one drink per day if you are a woman.

6) Care must be taken to avoid excessive sun exposure. It is specifically important to protect children and adolescents. For individuals who have a tendency to burn in the sun, active protective measures must be taken throughout life.

7) Apply strictly regulations aimed at preventing any exposure to known cancer-causing substances. Follow all health and safety instructions on substances which may cause cancer. Follow advice of national radiation protection offices.

http://www.cancercode.eu /

Food, nutrition and physical activity and the prevention of cancer

• Be as lean as possible - maintain body weight within normal range

• Be physically active every day

• Limit consumption of energy-dense foods and sugary drinks

• Eat mostly foods of plant origin

• Limit consumption of:

– Red meat

– Processed meats

– Alcohol

– salt

• Avoid mouldy cereals or pulses

• Avoid dietary supplements for cancer prevention

• Breastfeed children for at least six monthshttp://www.dietandcancerreport.org/cancer_resource_center/downloads/Second_Expert_Report_full.pdf

Cancerchemoprevention

Nutrition in Cancer Prevention

• Because carcinogenesis occurs over years,

most data linking diet and cancer is

epidemiological (case control, cohort, or

cross-sectional studies)

• It is estimated that one third of the cancer

deaths each year in the US can be attributed

to nutrition and other lifestyle factors (not

including smoking)

Nutrition in the Etiology of

Cancer• Complex relationship

• Dietary carcinogens: naturally occurring

and added in food preparation and

preservation

• Inhibitors of carcinogenesis: antioxidants,

phytochemicals

• Enhancers of carcinogenesis

• Latency period between initiation and

promotion

Energy Intake, Body Weight,

Obesity, and Physical Activity

• Energy restriction inhibits cancer and

extends life span in animals

• Positive associations between overweight

and cancers of the breast, endometrium,

kidney, colon, prostate

• Overweight increases risk of cancer

recurrence and decreases survival

• Physical activity is inversely associated

with cancer

Nutrition and Cancer Etiology

• Fat

• Protein

• Soy and phytoestrogens

• Carbohydrates: fiber, sugars, and glycemic

index

• Fruits and vegetables

• Nonnutritive sweeteners

Nutrition and Cancer Etiology• Alcohol

• Coffee and tea

• Methods of food preparation and preservation

• Cancer chemoprevention

• Cancer prevention recommendations: nutrition

and physical activity

• Nutrition and physical activity

recommendations for cancer survivors

Color Code System of

Vegetables and Fruits

Color Phytochemical Vegetables and Fruits

Red Lycopene Tomatoes and tomato products, pink grapefruit, watermelon

Red/purple Anthocyanins, polyphenols

Berries, grapes, red wine, prunes

Orange α-, β-carotene Carrots, mangoes, pumpkin

Orange/yellow β-cryptoxanthin, flavonoids

Cantaloupe, peaches, oranges, papaya, nectarines

Yellow/green Lutein, zeaxanthin Spinach, avocado, honeydew, collard and turnip greens

Green Sulforaphanes, indoles Cabbage, broccoli, Brussels sprouts, cauliflower

White/green Allyl sulphides Leeks, onion, garlic, chives

Data from Heber D: Vegetables, fruits and phytoestrogens in the prevention of diseases, F Postgrad Med 50:145, 2004.

Fat

• High intake of total and saturated fat is associated with increased risk of breast, colon, lung and prostate cancers

• High fat diets are associated with obesity, which is linked with cancer of the colon, rectum, esophagus, gall bladder, breast, endometrium, pancreas, and kidney

• Omega 6 may reduce risk of breast cancer

• Low fat diet (<20% fat) may reduce risk of recurrence of breast cancer

Energy Intake and Physical

Activity

• Total energy intake is strongly associated

with breast cancer in postmenopausal

women

• Physical activity may have a protective

effect

• Women who spent an average 1.5 hours per

week in physical activities had lower risk of

colon, reproductive cancers

Obesity is a Risk Factor for:

• Breast cancer (among postmenopausal women)

• Colon

• Endometrium

• Esophagus

• Gallbladder

• Pancreas

• Kidney

• Is also a risk factor for cancer recurrence

Protein

• Difficult to isolate effects of protein, since ↑

protein diets are ↑ in fat and ↓ in fiber

• Low protein diets seem to reduce the risk of

cancer, while risk is increased by very high

protein intakes

• Increased meat intake is associated with

increased risk of colon cancer and advanced

prostate cancer

Fiber

• Observational studies and case control studies indicate that fiber-rich diets are associated with a protective effect in colon cancer

• Higher intakes of vegetables were inversely associated with colon cancer risk in one study

• But high fiber diets also tend to be lower in meat, fat, and refined carbohydrates

Carbohydrate and Glycemic Index

• High glycemic-index diet associated with

increased risk of cancers including ovarian,

endometrial, breast, colorectal, pancreas,

and lung

• Limit processed foods and refined sugars

and emphasize whole grains and low GI

foods

Fruits and Vegetables

• Fruits and vegetables found to be associated

with lower risk in 128 of 156 dietary studies

• Increased consumption of fruits and

vegetables is associated with lower risk of

cancers of the oral cavity, esophagus,

stomach, colon, rectum, and bladder

• Evidence less strong for hormone-related

cancers such as breast and prostate cancer

Cancer Chemoprevention Studies

• ß-carotene supplementation in Finnish smokers was associated with a 16% higher incidence of lung cancer

• Heavy alcohol intake seemed to enhance negative effects

• However, diet studies suggest that high fruit and vegetable consumption, particularly carotenoids, tomatoes, and tomato-based products may reduce risk of lung cancer

Calcium and Cancer Risk

• Several studies suggest that foods high in calcium may reduce the risk for colorectal cancer and that calcium supplements may reduce the formation of colorectal polyps

• However, there is evidence that high calcium intake, especially supplements, is associated with increased risk of prostate cancer

• Bottom line: get calcium through food sources

Preserved Meats and Cancer Risk

• Some studies link eating large amounts of

preserved meat to increased risk of

colorectal and stomach cancers

• May or may not be due to nitrites

• Nitrites can be converted in the stomach to

carcinogenic nitrosamines, which may

increase the risk of stomach cancer

• Vegetables and fruit retard the conversion

of nitrites to nitrosamines

Alcohol

• Alcohol associated with carcinogenesis in

cancers of the mouth, pharynx, larynx,

esophagus, lung, colon, rectum, liver and

breast (USDHHS, 2000)

• Appears to act synergistically with tobacco

• Malnutrition associated with alcoholism

may also be implicated

Coffee and Tea

• Coffee has been investigated as a possible risk factor for a variety of cancers, but does not appear to be associated with increased cancer

• Regular drinking of green tea and other sources of polyphenols may reduce the risk of stomach cancer

• Consumption of very hot drinks may increase the risk of esophageal cancer

Artificial Sweeteners

• Under public pressure, saccharine returned

to the market; it was reviewed and taken off

the list of potential carcinogens in 2000

• Aspartame: no evidence implicating it in

increased cancer risk

Artifical Sweeteners

Five artificial sweeteners on the market:

• Acesulfame-K

• Aspartame

• Neotame

• Saccharine

• Sucralose

Hyperinsulinemia and Cancer

• Increased body mass index may promote

hyperinsulinemia and metabolic syndrome

• Insulin resistance/hyperinsulinemia, higher

estrogen levels, and insulin-like growth

factor I may act synergistically to promote

tumor growth, particularly mammary

tumors.

Food Safety and Cancer

• Naturally occurring carcinogens (aflatoxins

in peanuts, safrol in plant oils, tannins in

grains and grapes, benzopyrene formed by

smoking meat and fish)

• Pesticides

AICR Diet and Health Guidelines

for Cancer Prevention

• Choose a diet rich in a variety of plant-

based foods

• Eat plenty of vegetables and fruits.

• Maintain a healthy weight and be physically

active.

• Drink alcohol only in moderation, if at all.

• Select foods low in fat and salt.

• Prepare and store food safely.

American Cancer Society Guide to

Nutrition and Activity

• Choose whole grains in preference to processed

(refined) grains and sugars.

• Choose whole grain rice, bread, pasta, and cereals.

• Limit consumption of refined carbohydrates,

including pastries, sweetened cereals, soft drinks,

and sugars.

American Cancer Society Guide to

Nutrition and Activity

• Limit consumption of red meats, especially those high in fat and processed.

• Choose fish, poultry, or beans as an alternative to beef, pork, and lamb.

• When you eat meat, select lean cuts and smaller portions.

• Prepare meat by baking, broiling, or poaching, rather than by frying or charbroiling.

Lifestyle Changes to Reduce Breast

Cancer Risk

• Reducing alcohol consumption

• Breastfeeding

• Avoiding obesity

• Being physically active

Source: American Cancer Society, accessed 2021 Oct

Lifestyle Change to Prevent Colon

Cancer

• Increase your physical activity

• Eat more vegetables and fruit

• Limit intake of red meats

• Avoid obesity

• Avoid excess alcoholSource: American Cancer Society, accessed Oct 2021

Lifestyle Changes to Prevent Oral

and Esophageal Cancers

• Avoid all forms of tobacco

• Restrict alcohol consumption

• Avoid obesity

Lifestyle Changes to Prevent

Pancreatic Cancer• Avoid tobacco use

• Maintain a healthful weight

• Remain physically active

• Eat five or more servings of vegetables and fruits each day


Prostate Cancer

• Limit intake of animal products, especially

red meat and high-fat dairy products

• Eat five or more servings of vegetables and

fruits each day


Stomach Cancer

• Eat at least five servings of vegetables and

fruits daily.

• Stomach cancer rates are falling due to

reduced infection with h. pylori

At Present, There Are No Nutritional

Risk Factors for

• Brain Cancer

• Leukemias

• Ovarian cancer

Source: American Cancer Society, accessed Oct 2021

Diet Recommendations for

Cancer Survivors

• A “cured” cancer pt is at increased risk for other primary cancers in the same organ or other organs

• General dietary guidelines are also appropriate for recovering cancer pts

• Dietary regimens should a) avoid stimulating growth and spread of remaining tumor cells and b) provide maximum prevention against new primary tumors

Nixon DW. Nutrition during cancer recovery. The American Dietetic Association,

2015.

Diet, Nutrition, Physical Activity and Cancer: a Global Perspective

dietandcancerreport.org

• A brief overview of the

Third Expert Report


• The Third Expert Report builds on the groundbreaking

achievements of the First and Second Expert Reports.

• History of the expert reports

wcrf.org/about-the-report

2018


• Cancer causes one in six deaths worldwide

• 21.7 million cases and 13 million death by 2030

• 32.6 million cancer survivors in 2012

• 30 to 50% of all cancers are preventable

• The rising burden of cancer

Data from Parkin et al., Pisani et al., GLOBOCAN 2012, IARC

20050

2

4

6

8

10

Tota

l cancer

death

s

(mill

ions)

20152030

Low- and middle income countries

High-income countries

Source: The global burden of

disease: 2004 update (WHO, 2008)

wcrf.org/cancertrends


• Diet, nutrition, physical activity and the cancer process

Potential impact of diet, nutrition, physical activity and height in increasing susceptibility to cancer

wcrf.org/cancer-process


• Recommendations – an overall package

wcrf.org/cancer-prevention-recommendations

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nutritional preventing of cancer

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