Nutrition in Cancer Prevention

Guidelines for Cancer Prevention

1.Choose a diet rich in a variety of plant-based foods.2.Eat plenty of vegetables and fruits.3.Maintain a healthy weight and be physically active.4.Drink alcohol only in moderation, if at all.5.Select foods low in fat and salt.6.Prepare and store food safely.

And always remember . . . Do not use tobacco in any form.

From American Institute for Cancer Research: Simple steps to prevent cancer, Washington, DC, 2000, AICR. 14

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

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 effectWomen who spent an average 3.8 hours per

week in physical activities had lower risk of colon and reproductive cancers

Obesity

Obesity is a Risk Factor for several cancers:

Breast (among postmenopausal women)

Colon

Endometrium

Esophagus

Gallbladder

Pancreas

Kidney

and 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;

High fiber diets also tend to be lower in meat, fat, and refined carbohydrates;

Fruits and Vegetables

Fruits and vegetables found to be associated with lower risk in 128 of 156 dietary studies

Good sources of antioxidants (vitamins C, E, selenium, carotenoids, flavonoids)

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

Plant based foods may prevent cancer by

Inhibiting hormone-dependent steps in tumor formation and protecting genetic material from carcinogenic agents

Suppressing free radical productionServing as bulking agents to dilute

carcinogens and decrease gastrointestinal transit time

Stimulators of physiologically active and anti-cancer enzymes

Mobley C. Nutrition and cancer prevention. In McCallum and Polisena, The Clinical Guide to Oncology Nutrition. Oncology Nutrition Dietetic Practice Group, 2000.

Preserved Meats and Cancer Risk

Some studies link eating large amounts of preserved meat to increased risk of colorectal and stomach cancers

Nitrites on preserved meat 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

Cooked Meat and Cancer Risk

Frying, broiling, and grilling meats at high temperatures creates chemicals that might increase cancer risk (cause cancer in animals)

Use techniques such as braising, steaming, poaching, stewing and microwaving

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

Food Safety and Cancer

Choose in-season, locally grown produceRinse fruits and vegetables and remove

outer leaves before eatingUse proper food storage to prevent growth

of fungal carcinogensMarinate protein foods to decrease cooking

timeUse cooking methods to avoid contact of

foods and food drippings with flames

Mobley C. Nutrition and cancer prevention. 2000

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

Eat a variety of healthful foods, with an emphasis on plant sources.

Eat five or more servings of a variety of vegetables and fruits each day.

Include vegetables and fruits at every meal and for snacks.

Eat a variety of vegetables and fruits.

American Cancer Society Guide to Nutrition and Activity

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

Limit French fries, snack chips, and other fried vegetable products.

Limit consumption of refined carbohydrates, including pastries, sweetened cereals, soft drinks, and sugars.

Choose 100% juice if you drink fruit or vegetable juices.

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.

American Cancer Society Guide to Nutrition and Activity

Choose foods that help maintain a healthful weight.When you eat away from home, choose food low in

fat, calories, and sugar and avoid large portions.Eat smaller portions of high-calorie foods. Be

aware that “low fat” or “fat free” does not mean “low calorie”.

Prefer vegetables and fruits instead of calorie-dense foods such as French fries, cheeseburgers, pizza, ice cream, doughnuts, and other sweets.

American Cancer Society Guide to Nutrition and Activity

Lifestyle Change to Prevent Cancer

Increase your physical activity

Eat more vegetables and fruit

Limit intake of red meats

Avoid obesity

Avoid excess alcohol

Avoid all forms of tobacco

Source: American Cancer Society, accessed 2005

Recommendations for Cancer Survivors

Limit total fat intake to 15-20% of total calories. Monounsaturated fats are preferred.

Aim for 10-12 daily servings of a variety of whole vegetables and fruits.

Consume 4-6 servings of whole grains daily.Eliminate or severely restrict alcohol intake.Exercise moderately (30 minute daily walk,

for example).Maintain desirable body weight.

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, and others

Overweight increases risk of cancer recurrence and decreases survival

Physical activity is inversely associated with cancer

AICR’s New American Plate