Transcript Can Food Really Be Medicine?

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:
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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)
Water
Proteins
Carbohydrates
Fats
Minerals
Ca, Fe, Mg, Mn, Se,
Na, K, V, Bo, I, S, Cl,
P, Cr, Cu, F, Mo, Zn
Vitamins
8 B vitamins (thiamine
niacin, riboflavin, folic acid,
Vitamin B 12, Vitamin B6,
pantothenic acid, biotin)
Vitamin C
Vitamins A, D, E, K
The Ten Leading Causes of Death
in the United States
Heart disease
Cancers
Strokes
Chronic lung diseases
Accidents
Diabetes mellitus
Pneumonia and influenza
Alzheimer’s disease
Kidney diseases
Blood infections
Key:
Diet related
Alcohol related
Other causes
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
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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?
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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.
Benign
Tumor Formation
Carcinogen
Normal cells
Figure 18-6
Page 637
Initiation
Promotion
Tumor
formation
Noncancerous (benign) tumor
Malignant
Normal cells
Normal cells
Initiators begin the
Promoters enhance
process of changing the development of
the DNA in some of abnormal cells.
the cells.
Cancerous (malignant) tumor
releases cells into the
bloodstream (metastasis)
©2003 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
For the best heart attack and cancer fighter,
visit your local produce center and look for different colors!
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!!
Case study: Beta-carotene
Hundreds of studies show
diets high in beta-carotene...
….decrease risk of cancer.
But how did we really know it
was the beta-carotene?
We Didn’t!!!
Common Carotenoids
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beta-carotene*
alpha-carotene
cryptoxanthin*
lycopene
lutein
zeaxanthin
neoxanthin
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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 betacarotene
• 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 fatfree 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 fullfat 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 UN
WHO, 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
©2003 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
The Antioxidant Theory of Disease Prevention
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
Broccoli and broccoli sprouts contain an abundance of the
cancer-fighting phytochemical sulforaphane.
The phytochemical resveratrol found in grapes (and nuts)
protects against cancer by inhibiting cell growth and against
heart disease by limiting clot formation and inflammation.
The flavonoids in cocoa and chocolate defend
against oxidation and reduce the tendency of
blood to clot.
An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)
An apple a day—rich in flavonoids—may protect against
lung cancer.
The ellagic acid of strawberries may inhibit certain types of
cancer.
Tomatoes, with their abundant lycopene, may defend against
cancer by protecting DNA from oxidative damage.
Spinach and other colorful vegetables contain
the carotenoids lutein and zeaxanthin, which
help protect the eyes against macular
degeneration.
An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)
The phytoestrogens of soybeans seem to starve cancer
cells and inhibit tumor growth; the phytosterols may
lower blood cholesterol and protect cardiac arteries.
The monoterpenes of citrus fruits (and cherries) may
inhibit cancer growth.
Flaxseed, the richest source of lignans,
may prevent the spread of cancer.
An Array of Phytochemicals in a Variety of Fruits and Vegetables (cont’d)
Garlic, with its abundant organosulfur compounds, may
lower blood cholesterol and protect against stomach
cancer. Chives, leeks, and onions also contain these compounds.
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.
Cruciferous vegetables, such as cauliflower, broccoli,
brussels sprouts, cabbage, horseradish, and
mustard greens contain nutrients and the
phytochemicals indoles and isothiocyanates
that may inhibit cancer development.
Black-eyed peas, grapes, lentils, red and white wine, tea
contain 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.
Maintain a healthy
weight. be physically
active. Don’t smoke.
Milk, Yogurt &
Cheese Group
• Eat low-fat or fatfree milk products.
Fats, Oils • Limit salt to < 6 grams.
& Sweets • 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.
Figure 18-7
Page 641
Meat, Poultry,
Fish, Dry Beans,
• Eat < 4 eggs per week.
Eggs & Nuts Group
• Eat red meat sparingly.
• Eat fish frequently.
• Eat nuts and legumes often.
Vegetable Group
• Eat vegetables
in abundance.
Fruit Group
• Eat fruit in abundance.
Bread, Cereal, Rice & Pasta Group
• Eat whole-grain breads,
cereals, rice, and pastas
instead of refined products.
Food Guide Pyramid for Disease Prevention
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. proaggregation 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 best
medicine
you’ll ever
take!