Can Food Really Be Medicine?

Patricia B. Brevard, PhD, RD, FADA

Department of Health Sciences

James Madison University

Nutrition and Disease Prevention:

Can Specific Nutrients Help to Prevent Cancer and Other

Chronic Diseases?

Preview of Presentation:

• Nutrient content of foods• Prevalence and causes of dz• Other chem found in fd• Vit/min/antiox and how they prevent dz• AHA prevention diet, CA prevention diet• Fds most likely to be used as preventive

mechanisms: Top Ten Food Lists• CA, CVD < risk with good nutr

Essential Nutrients Found in Foods(Required for Good Health)

Macronutrients(energy nutrients)ProteinsCarbohydratesFats

Vitamins8 B vitamins (thiamineniacin, riboflavin, folic acid,Vitamin B 12, Vitamin B6, pantothenic acid, biotin)Vitamin CVitamins A, D, E, K

Water

MineralsCa, Fe, Mg, Mn, Se, Na, K, V, Bo, I, S, Cl,P, Cr, Cu, F, Mo, Zn

The Ten Leading Causes of Death in the United States

Heart diseaseCancersStrokes

Chronic lung diseasesAccidentsDiabetes mellitusPneumonia and influenzaAlzheimer’s diseaseKidney diseasesBlood infections

Diet relatedAlcohol relatedOther causes

Key:

Deaths per 100,000 population

Free Radicals Cause Many Diseases, Antioxidants Quench Free Radicals

(cont’d)

The Actions of Free Radicals and Antioxidants (cont’d)

Phytochemicals and Antioxidants

• Important chemicals found in foods• Not currently known if they are required• Play an important role in prevention of dz• May be up to 10,000 in a single food• Over 600 currently identified• Like nutrients, also found in foods• Many different methods of identifying, many

foods not yet tested for their content• Numbers currently reported not yet complete

Immune system:

• Cells and chemicals synthesized in the blood, tissues (antibodies, white blood cells, etc.)

• Designed to destroy anything detected as “not self”, any foreign substance that can harm the body

• Lines of defense: skin, tears, GI tract, blood, tissues, cells, and chemicals

• A healthy immune system helps resist disease

What is MI?

• Initial damage to blood vessel walls, chemical or physical stress may contribute to damage

• Begins as fatty streak, then develops into fibrous plaque, fat, cholesterol deposited

• Platelets in blood aggregate, clot forms, plaque occludes arteries

• Blood flow to part of body is restricted• Extent of damage determined by location of plaque • Oxidized LDL and elevated serum LDL are key factors• Elevated HC and CRP also increase risk• All are related to nutrients and phytochemicals• What you eat at each feeding may be critical in causing

or preventing platelet aggregation and MI occurrence

What is CA?

• Loss of control of division mechanism of cells• Lack of differentiation of cells• Many surface constituents lost on cell• Cell fools IS into thinking it’s “self”• Different set of rules, different surface enzymes,

charges, antibodies• Often DNA damage begins the process of

carcinogenesis or development of cancer

Metastasis…spreading

• Normal cells know their boundaries, divide as genetically programmed, die as programmed

• CA cells “immortal”, don’t have time clock telling when to die

• CA cells metastasize: break off and grow in another part of the body, spread, still maintain cell characteristics where originated, ie, colon type metastasized cells growing in liver, breast type cells growing in lung, etc.

Figure 18-6Page 637

Carcinogen Initiation PromotionTumorformation

Normal cells Initiators begin theprocess of changingthe DNA in some ofthe cells.

Promoters enhancethe development ofabnormal cells.

Benign Normal cells

Malignant Normal cells

Cancerous (malignant) tumor releases cells into the bloodstream (metastasis)

Noncancerous (benign) tumor

Tumor Formation

For the best heart attack and cancer fighter, visit your local produce center and look for different colors!

©2003 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

In-text Figure Page 619

Vegetables rich in fiber, phytochemicals, and the antioxidant nutrients (beta-carotene, vitamin C, and vitamin E) help to protect against chronic diseases.

Nutrition recommendations change as science changes…

new research every day, but we don’t change recommendations

based on one study

BE CAREFUL!!

Hundreds of studies show diets high in beta-carotene...

….decrease risk of cancer.

Case study: Beta-carotene

But how did we really know it was the beta-carotene?

We Didn’t!!!

Common Carotenoids

• beta-carotene*• alpha-carotene• cryptoxanthin*• lycopene• lutein• zeaxanthin• neoxanthin

• canthaxanthin• violaxanthin• phytoluene• phytoene• astaxanthin• *indicates VA activity

Controversial clinical trials:

• CARET Study, NEJM 1996;Omen et al

• Physician’s Health Study, NEJM 1996, Hennekens et al.

• ATBC Study, NEJM 1996

• Chinese Study, AJCN 1995, Blot et al.

Increased CA risk in smokers

• stronger effect if > 20 cigarettes/d

• stronger effect if EtOH around 1 drink/d

• smoking + drinking lowers serum beta-carotene

• smokers should avoid supplements, especially high doses

Nutrients function metabolically at optimal physiological doses...

…in proper combinations.

American Heart Association’s Eating Plan for Healthy Americans (Oct 2000)

• Eat a variety of fruits and vegetables, 5+ svgs/d

• Eat a variety of grains, include whole grains, 6+ svgs/d, include fat-free and low-fat milk products, fish, legumes (beans), skinless poultry, lean meats

• Choose fats and oils with 2 grams or less saturated fat/T, ie. liquid and tub margarines, canola oil, olive oil

• Balance the number of calories you eat with the number you use daily. (To find that number, multiply the number of pounds you weigh now by 15 calories. This represents the average number of calories used in one day if you're moderately active. If you get very little exercise, multiply your weight by 13 instead of 15. Less-active people burn fewer calories.)

Maintain a physical activity level to keep you fit and match the number of calories you eat: salk or do other activities at least 30 minutes most days; to lose weight, do enough activity to use up more calories than you eat daily

Limit intake of foods high in calories/low in nutrition, ie. soft drinks, candy, foods with a lot of sugar

Limit foods high in saturated fat, trans fat and/or cholesterol, such as full-fat milk products, fatty meats, tropical oils, partially hydrogenated vegetable oils and egg yolks; choose foods low in saturated fat, trans fat and cholesterol

Eat less than 6 grams of salt (sodium chloride) per day (2,400 milligrams of sodium)

Have no more than one alcoholic drink per day if you're a woman and no more than two if you're a man; with one drink defined as no more than 1/2 ounce of pure alcohol, ie 12 oz. beer, 4 oz. wine, 1-1/2 oz. 80-proof spirits, or 1 oz. 100-proof spirits

Cancer Guidelines July 1997

World Cancer Research Fund

American Institute for Cancer Research

Other observer groups: Internat’l Agency for Res. on CA

FAO of UNWHO, NCI, NIH

CA Prevention Guidelines• 1. Variety: consume varied diet based primarily on plant foods with a

wide variety of vegetables and fruits, pulses (legumes)• 2. Maintaining Weight: keep BMI in range of 18.5 – 25, avoid

underweight or overweight; limit weight gain during adulthood to less than 5 kg (11 #)

• 3. Maintain Physical Activity via an active lifestyle throughout life, take and hour’s brisk walk or other exercise daily, exercise vigorously for a total of at least 1 hr/wk

• 4. Year-round consume 7%+ of total energy from fruits and vegetables, eat 15 - 30 oz or 5 + servings daily of a variety of fruits and veggies

• 5. Other plants: eat variety of starchy plants, minimally processed, 45-60% of kcals from starches, <10% from sugars, eat 20-30 oz or 7+ svgs/d of cereals, grains, pulses, roots, tubers, plantains

• 6. Consumption of EtOH is not recommended; excessive consumption is discouraged, if it is used, restrict to < 5% total energy men and 2.5% for women which is the equivalent of 2/d for M and 1/d for F

7. If eaten at all, red meat should provide < 10% of kcals or less than 3 oz/d, preferable to choose fish, poultry, or meat from non-domesticated animals in place of red meat

8. Total fats and oils should provide 15% to 30% of total energy, limit fatty foods, esp those of animal origin, use modest amounts of appropriate veggie oils

9. Salt from all sources should amount to < 6 g/d or .25 oz for adults, limit salted foods, limit use of cooking oil and table salt, season foods with herbs and spices

10. Store perishable foods to minimize fungal contamination, do not eat food with liability to contamination with mycotoxins

11. Preservation: freeze or chill foods not consumed right away, use refrigeration or other appropriate methods to preserve perishable food as purchased and at home

12. Monitor enforcement of safety limits of food additives, pesticides, and their residues; when carefully monitored, residues of additives are not present in food and drink at levels known to be harmful; unregulated or improper use can be a health hazard, esp in developing countries

13. Do not eat charred meats, avoid burning meat juices, cook meats at low temperatures; consume these only occasionally: meat and fish grilled or broiled in direct flame, cured and smoked meats

14. Dietary patterns should be consistent with reducing cancer risk without use of dietary supplements, supplements are probably unnecessary, and possibly unhelpful, for reducing cancer risk

15. Discourage production, promotion, use of tobacco in any form, do not smoke or chew tobacco, it is especially dangerous combined with alcohol

Changes AICR Conference 2003

• “Double action”: either too much or too little of some nutrients/chemicals may cause cancer, they protect if adequate, but increase risk if too low or too high

• EtOH less than 1 drink/d or < 15 g/d• Many specific foods appear to have protective

chemicals, but may work in combination with other foods/chemicals

• Phytochemicals and nutrients may interact to protect if adequate, or harm if too high or too low

• Varied diet with lots of different foods will insure that you get all of the chemicals/nutrients in proper combinations

The Antioxidant Theory of Disease Prevention

©2003 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

Phytochemicals in many foods may help prevent diseases

In-text Figure Page 467

Functional foods provide us with many health benefits.

An Array of Phytochemicals in a Variety of Fruits and Vegetables

The phytochemical resveratrol found in grapes (and nuts)protects against cancer by inhibiting cell growth and againstheart disease by limiting clot formation and inflammation.

The flavonoids in cocoa and chocolate defendagainst oxidation and reduce the tendency ofblood to clot.

Broccoli and broccoli sprouts contain an abundance of thecancer-fighting phytochemical sulforaphane.

An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)

Tomatoes, with their abundant lycopene, may defend against cancer by protecting DNA from oxidative damage.

The ellagic acid of strawberries may inhibit certain types ofcancer.

An apple a day—rich in flavonoids—may protect against lung cancer.

Spinach and other colorful vegetables containthe carotenoids lutein and zeaxanthin, whichhelp protect the eyes against maculardegeneration.

An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)

The monoterpenes of citrus fruits (and cherries) mayinhibit cancer growth.

Flaxseed, the richest source of lignans,may prevent the spread of cancer.

The phytoestrogens of soybeans seem to starve cancercells and inhibit tumor growth; the phytosterols maylower blood cholesterol and protect cardiac arteries.

An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)

The flavonoids in black tea may protect against heart disease, whereas those in green tea may defend against cancer.

Blueberries, a rich source of flavonoids,improve memory in animals.

Garlic, with its abundant organosulfur compounds, may lower blood cholesterol and protect against stomachcancer. Chives, leeks, and onions also contain these compounds.

Cruciferous vegetables, such as cauliflower, broccoli, brussels sprouts, cabbage, horseradish, and mustard greens contain nutrients and the phytochemicals indoles and isothiocyanatesthat may inhibit cancer development.

Black-eyed peas, grapes, lentils, red and white wine, teacontain antioxidants which inhibit cancer promotion.

Green vegetables, tomatoes, potatoes, alfalfa sprouts,and other sprouts contain saponins which inhibit cancer Growth and stimulate the immune system.

Figure 18-7Page 641

Food Guide Pyramid for Disease Prevention

Maintain a healthy weight. be physically active. Don’t smoke.

Fats, Oils & Sweets

• Limit salt to < 6 grams.• Reduce energy-rich foods high in sat. fat & sugar.• Use unsaturated fats instead of sat. or trans fats.• Drink alcohol in moderation, if at all.

• Eat < 4 eggs per week.• Eat red meat sparingly.• Eat fish frequently.• Eat nuts and legumes often.

• Eat fruit in abundance.

• Eat whole-grain breads, cereals, rice, and pastas instead of refined products.

• Eat low-fat or fat- free milk products.

• Eat vegetables in abundance.

Milk, Yogurt &Cheese Group

Vegetable Group

Meat, Poultry,Fish, Dry Beans,Eggs & Nuts Group

Fruit Group

Bread, Cereal, Rice & Pasta Group

Many“Top 10”/“Power Food” Lists (cancer, CHD, disease prevention)

…eat often but don’t overdo it! These are not magic foods!

• Red/blue berries (grapes, blueberries, strawberries, cranberries, blackberries, etc)

• Soy foods• Beans (pinto, garbanzo, lentils,

kidney)• Oats and grains (oatmeal,

whole grain breads & cereals)• Stanols/sterols (Take Control,

Benecol)• Nuts (almonds, cashews,

pecans, walnuts, peanuts, hazelnuts)

• Garlic, onions• Red wine (2 glasses/d max)• Green and black teas

• Tomatoes, oranges• Salmon and fish in general• Spinach, green leafy veggies

in general• Olives, olive oil• Sweet potatoes• Lowfat milk• Apples• Fruits and veggies in general• Flaxseed• Hot chocolate/chocolate/cocoa• Cruciferous veggies: broccoli,

Brussels sprouts, cauliflower, cabbage, kale, kohlrabi

• Total calcium intake

It’s All About Balance!

• Antioxidant load vs. pro-oxidant load

• Anti-aggregation factors vs. pro-aggregation factors

• Factors that ↓ LDL and ↑ HDL vs. factors that ↑ LDL and ↓ HDL

• Your diet provides all of these, it’s up to you to get the right balance!

Healthy Foods: the bestmedicineyou’ll evertake!