Phytochemicals

Presented by Janice Hermann, PhD, RD/LD

OCES Adult and Older Adult Nutrition Specialist

Phytochemcials and Functional FoodsFoods contain many different nutrients:

CarbohydratesFiber

LipidsProteinsVitaminsMinerals

Phytochemicals and Functional Foods

Plant foods also contain non-nutrient compounds including – phytochemicals

Phytochemicals are compounds in foods that physiological activity in the body

Phytochemicals and Functional Foods

Concept that foods provide health benefits beyond those provided by the major nutrients has developed from numerous epidemiological studies demonstrating a protective effect of plant foods on cancer and heart disease.

Phytochemicals andFunctional Foods

Although current research is discovering the beneficial roles of phytochemicals have in human health.

Only a few of the tens of thousands of phytochemicals have been researched, and there are still many questions and only indefinite answers.

Phytochemicals and Functional FoodsConcept foods provide health benefits beyond

those of nutrients initiated name “functional foods"

Nature’s functional foodsGrains rich in dietary fibersFish rich in omega-3 fatty acidsFruits, vegetables and legumes rich in phytochemicals

and fiberNewest controversies is the development of novel

foods to which phytochemicals have been added to promote health.

Phytochemicals and Functional Foods

Phytochemicals can have profound physiological effects in the body, functioning as:AntioxidantsMimicking hormonesSuppressing the development of diseases

Example Phytochemicals

Carotenoids in deeply pigmented fruits and vegetables (apricots, broccoli, cantaloupe, carrots, pumpkin, spinach, sweet potatoes, tomatoes) act as antioxidants possibly reducing risk of cancer and other diseases.

Curcumin in tumeric may inhibit enzymes that activate carcinogens

Example Phytochemicals

Flavonoids in berries, black tea, celery, citrus fruits green tea, olives, onions, purple grapes, purple grape juice, soy beans and soy products, vegetables, whole wheat, and wine act as antioxidants, scavenge carcinogens, bind to nitrates in the stomach preventing conversion to nitrosamines, and inhibit cell proliferation.

Example PhytochemicalsIndoles in broccoli and other cruciferous

vegetables and mustard greens may trigger production of enzymes that block DNA damage from carcinogens and may inhibit estrogen action.

Isothiocyanates in broccoli and other cruciferous vegetables and mustard greens inhibit enzymes that activate carciongoens, trigger production of enzymes that detoxify carcinogens.

Example PhytochemicalsLignans in flaxseed and whole grains block

estrogen activity in cells.Monoterpenes in citrus fruit peels and oils

may trigger enzyme production to detoxify carcinogens; inhibit cancer promotion and cell proliferation

Organosulfur compounds in chives, garlic, leeks, and onions may speed production of carcinogen destroying enzymes, slow production of carcinogen activating enzymes.

Example PhytochemicalsPhenolic acids in coffee beans, fruits, oats,

potatoes, and soybeans may trigger enzyme production to make carcinogens water soluble facilitating excretion.

Phytic acids in whole grains binds to minerals, preventing free-radical formation.

Phytoestrogens (genistein and daidzein) in soybeans and other legume products mimic estrogen and may inhibit estrogen

Example PhytochemicalsProtease inhibitors in broccoli, potatoes, soy

beans and other legumes may suppress enzyme production in cancer cells, slowing tumor growth, inhibit hormone binding and inhibit malignant changes in cells.

Phytosterols in soybeans and other vegetables may protect against heart disease by inhibiting cholesterol absorption

Example PhytochemicalsSaponins in alfalfa sprouts, green vegetables,

potatoes and tomatoes may interfere with DNA replication, preventing cancer cells from multiplying and stimulate immune response.

Tannins in black-eyed peas, grapes, lentils, red and white wine and tea may inhibit carcinogen activation and cancer promotion and act as antioxidants.

Protecting Against CancerMany phytochemicals from many different

foods seem to protect against cancer by preventing DNA damage.

Soybeans, flaxseed oil, whole grains, fruits, and vegetables are rich sources of phytochemicals, including phytoestrogens. Phytoestrogens weakly mimic or modulate the

effects of estrogen in the body. Phytoestrogens have antioxidant activity and

seem to slow the growth of breast and prostate cancer.

Protecting Against Cancer

Tomatoes appears to protect against esophagus, lung, prostate, and stomach cancers. Lycopene is found in apricots, guava, papaya, pink

grapefruits, watermelon, and it is especially abundant in tomatoes and cooked tomato products.

Lycopene is a powerful antioxidant that appears to inhibit the growth of cancer cells.

Protecting Against Cancer

Soybeans and tomatoes are examples of only two of the many fruits and vegetables attributed with protecting against cancer.

Researchers hypothesize that people may cut their risk of cancers in half by simply consuming the recommended amounts of fruits and vegetables daily.

Protecting Against Heart DiseaseDiets rich in whole grains, vegetables and

fruits also appear to lower risk of heart disease.

These foods provide an abundance of nutrients, fiber, and phytochemicals.

Protecting Against Heart Disease

Flavonoids - large group of phytochemicals that may protect against heart disease.Flavonids found in whole grains, legumes, soy,

vegetables, fruits, herbs, spices, teas, chocolate, nuts, olive oil, and red wines.

Flavonoids are strong antioxidants that may help to protect LDL cholesterol against oxidation and reduce blood platelet stickiness, making blood clots less likely.

Protecting Against Heart DiseaseIn addition to flavonoids, fruits and

vegetables are rich in carotenoids.Diets rich in carotenoids is also associated

with a lower risk of heart disease. Two carotenoids that may defend against

heart disease are lutein and lycopene.

Protecting Against Heart DiseasePhytosterols found in soybeans and other

vegetables appear to protect against heart disease.

Phtosterols are similar in structure to cholesterol and inhibit the absorption of cholesterol decreasing blood cholesterol levels.

Phytoestrogens may also protect against heart disease by functioning as antioxidants and lowering blood pressure.

Phytochemicals in PerspectiveBecause foods deliver thousands of

phytochemicals in addition to dozens of nutrients, consumers must be careful in giving credit for particular health benefits to any one compound.

Diets rich in whole grains, legumes, vegetables, and fruits seem to be protective against disease, but identifying the specific foods or components of foods that are responsible is difficult.

Phytochemicals in Perspective

Foods contain many phytochemicals. Broccoli may contain as many as 10,000 different

phytochemicalsEach with the potential to influence some action

in the body.The effect of different phytochemicals in food

may be synergistic.This reinforces the principle of variety.

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Oklahoma Cooperative Extension Service

Functional foods...

from nature

from manufacturers

Functional Foods

Because foods naturally contain thousands of phytochemicals, whole foods, in reality, are functional foods.Cranberries may help protect against urinary tract

infectionsGarlic may help ower blood cholesterol; and

tomatoes may protect against certain types of cancers

Functional Foods

In addition to naturally occurring functional foods, food manufacturers are trying to create functional foods as well – becoming the fastest growing trend in the food supply.Foods may be fortified or enhanced with

nutrients, phytochemicals or herbsSometimes an entirely new food is created

Foods or Drug?

Such functional foods raise the question – is it a food or drug?

In the past, most could agree what was a food and what was a drug.

Functional foods have distorted the distinctions.

Functional foods have characteristics of both foods and drugs, but do not fit clearly into either category.

Foods or Drug?

For example, yogurt contains Lactobacillus and other living bacteria that ferment milk into yogurt.

These microorganisms, called probiotics, alter the gastrointestinal population of microorganisms, which protects the gastrointestinal tract against disorders.

Foods or Drug?

Research is investigating whether probiotics:Help to alleviate diarrhea, inflammatory bowel

disease, and lactose intolerance Enhance immune functionProtect against gastrointestinal cancerLower blood cholesterol

Food or Drug?An example of where food manufactures are

developing products with added phytochemicals is margarine.

Consuming nonhydrogenated margarine sparingly may lower blood cholesterol slightly over several months and falls clearly falls into the category of a food.

Whereas, the drug Lipitor lowers blood cholesterol significantly within weeks and clearly falls into the category of a drug.

Food or Drug?

Consider, margarine enhanced with the phytosterol. Phytosterol is a phytochemcial that is structurally similar to cholesterol, and has been found to lower blood cholesterol levels by inhibiting cholesterol absorption.

Margarine enhanced with phytoserol falls between the categories of a food and drug.

Food or Drug?

Use of functional foods to result in beneficial effects results in a whole new set of diet-planning problems.

Just as drugs, functional foods may need to be consumed several times a day for several months or years to have beneficial effects. Sporadic use may have disappointing results.

Food or Drug?

For example:Margarine with added phytosterols consumed

four times a day for four weeks lowered cholesterol by 8 percent.

But cholesterol lowering drugs lowered cholesterol by 32 percent.

Functional foods may be more useful for prevention and mild disease cases than for intervention and more severe

Cost Differences

There may also be a difference in cost as well. Functional foods such as fruits and vegetables

have no added costsFoods manufactured with added phytochemcials

can be expensive, costing much more than their conventional counterparts

Unanswered QuestionsTo achieve a desired health effect, which is

the better choice: to eat a food designed to affect some body function or simply to adjust the diet?Does it make more sense to use a margarine

enhanced with a phytosterol that decreases cholesterol absorption, to consume foods naturally high in phytosterol or limit the amount of saturated fat in the diet?

Unanswered Questions

One concern is that the food industry moves too fast for science and the FDA to keep up.

Consumers were able to modified foods while research is still being conducted as to the safety and efficacy.

What Should Consumers ThinkDoes it work?

Research is generally lacking and inconclusiveHow much does it contain?

Research is lacking as to what level is effective or dangerous

Is it safe?Functional foods can act like drugs, they contain

ingredients that can alter body functions. Is it healthy?

Adding phytochemcials to a food doesn’t magically make it a healthy choice

What Should Consumers ThinkResearchers have not identified the perfect

combination of nutrients and phytochemciasl for optimal health.

Yet food manufacturers are freely adding various phytochemicals to foods.

What Should Consumers Think

Important to remember foods naturally provide a variety of nutrients and non-nutritive compounds that may be beneficial to health, most of which have yet to be identified or understand.

A well balanced diet, from a variety of foods can in itself provide the variety of nutrients and non-nutrients for health and well-being.