|
|
| Phytochemicals |
|
Phytochemicals are
nonnutritive plant chemicals that contain protective,
disease-preventing compounds. More than 900 different
phytochemicals have been identified as components of
food, and many more phytochemicals continue to be
discovered today. It is estimated that there may be more
than 100 different phytochemicals in just one serving of
vegetables (6). |
|
As early as 1980, the National Cancer
Institute Chemoprevention Program of the Division of
Cancer Prevention and Control began evaluating
phytochemicals for safety, efficacy, and applicability
for preventing and treating diseases. Researchers have
long known that there are phytochemicals present for
protection in plants, but it has only been recently that
they are being recommended for protection against human
disease. |
| |
| Most Commonly Studied
Phytochemicals |
|
Food |
Phytochemical(s) |
|
Allium vegetables
(garlic, onions, chives,
leeks) |
Allyl sulfides |
|
Cruciferous vegetables
(broccoli,
cauliflower,
cabbage, Brussels
sprouts,
kale, turnips, bok choy,
kohlrabi) |
Indoles/glucosinolates
Sulfaforaphane
Isothiocyanates/thiocyanates
Thiols |
|
Solanaceous vegetables
(tomatoes, peppers) |
Lycopene |
|
Umbelliferous vegetables
(carrots, celery,
cilantro,
parsley, parsnips) |
Carotenoids
Phthalides
Polyacetylenes |
|
Compositae plants (artichoke) |
Silymarin |
|
Citrus fruits
(oranges, lemons,
grapefruit)
Glucarates |
Monoterpenes
(limonene)
Carotenoids |
|
Other fruits (grapes, berries,
cherries,
apples, cantaloupe,
watermelon, pomegranate) |
Ellagic acid
Phenols
Flavonoids (quercetin) |
|
Beans, grains, seeds
(soybeans, oats,
barley, brown
rice, whole wheat, flax
seed)
Protease inhibitors |
Flavonoids (isoflavones)
Phytic
acid
Saponins |
|
Herbs, spices (ginger, mint,
rosemary,
thyme, oregano,
sage, basil, tumeric,
caraway,
fennel) |
Gingerols
Flavonoids
Monoterpenes (limonene) |
|
Licorice root
Green tea
Polyphenols |
Glycyrrhizin Catechins | |
|
There are also
hundreds more phytochemicals existing and in need of
discovery! |
|
|
How are they
beneficial? |
|
Although phytochemicals are not yet
classified as nutrients, substances necessary
for sustaining life, they have been identified as
containing properties for aiding in disease prevention.
Phytochemicals are associated with the prevention and/or
treatment of at least four of the leading causes of
death in the United States -- cancer, diabetes,
cardiovascular disease, and hypertension (7). They are
involved in many processes including ones that help
prevent cell damage, prevent cancer cell replication,
and decrease cholesterol levels. |
|
Specifically, the economic cost of
cancer to society was estimated to be about $104 billion
in 1997 (8). With health-care costs being a major issue
today, it would be cost effective to continue the
research needed to help promote the awareness and
consumption of phytochemicals as a prevention strategy
for the public. |
|
|
|
Can I
just take a pill containing these substances? |
|
Americans spend approximately $2-2.5
billion a year on vitamin/mineral supplements (9). It
should be expected that extracted phytochemicals will
be, if not already, available for consumer purchasing.
Consumption of supplements containing phytochemicals
will only provide selected components in a
concentrated form, not the diversity of
compounds that occur naturally in foods (10). It is
important to continue the effort to encourage increased
fruit, vegetable, and grain consumption to acquire the
benefits of phytochemicals versus simply ingesting a
pill containing these substances. Researchers continue
to investigate the interactions of phytochemicals
naturally present in food. It would be difficult to
extract phytochemicals from plants for supplement use
before understanding the synergistic effect of all
phytochemicals present. |
|
|
|
Are
there any negative effects? |
|
Individual phytochemicals are being
evaluated for their safety and effectiveness in regard
to disease prevention. Although most studies support
positive outcomes, there are a few studies involving
animals that show possible detrimental effects. These
studies involve animals and specific extracted
phytochemicals in high dosages. The safety of consuming
large amounts of fruits, vegetables, and grains is not
presently a concern. The research question being asked
is: "Should one increase the intake of a particular
plant food containing phytochemicals, and how much
should they increase it?" Obviously, like any other
newly discovered chemical, there is a need for further
investigation for potential health benefits and possible
health risks. Optimal levels of phytochemicals have yet
to be determined. In addition, requirements during
disease states may differ from requirements for
prevention of heart disease and cancer. Individual
recommendations in terms of requirements for different
genders, age groups, body types, and so forth also need
further study. |
|
|
|
How
can I incorporate more phytochemicals into my diet? |
|
First, it is important for Americans to
become aware of their lack of consumption of fruits,
vegetables, and grains. The average American consumes
only one serving of vege-tables and one serving of fruit
each day (11). In one survey, one in every nine
Americans ate no fruit or vegetable on the day they were
interviewed (12).
Increasing the consumption of plant
products in one's diet should not be difficult or time
consuming. There are plenty of simple strategies for
increasing dietary fruits, vegetables, and grains,
including the suggestions below: |
 |
Keep fruits and vegetables (fresh, frozen, and
canned) stocked and in sight. |
|
Reach for juice instead of coffee or soda. |
|
Add chopped fruit to cereal, yogurt, pancakes,
muffins, or even a milkshake. |
|
Snack on fresh chopped carrots, celery, broccoli,
cauliflower, and peppers (purchase at a salad bar to
save time). |
|
Add fresh greens, carrots, celery, parsley,
tomatoes, and/or beans to your soups. |
|
Store dried fruit (apricots, dates, raisins, and
more) for a quick snack at home or work. | |
| There
are also several other easy methods for increasing
fruits, vegetables, and grains in your lifestyle. Why
not challenge yourself and create one of your own? Good
Luck! |
|
|
|
Conclusion |
|
It was once stated that our health is a
"gift" -- a largely controllable gift (13). We can
control this gift through lifestyle choices of our own.
These choices include the foods we choose to eat.
Research has demonstrated the
tremendous potential of phytochemicals in regard to
prevention and treatment of disease. Now, it is the
responsibility of not only health-care professionals,
but also individuals to begin the conscientious effort
of improving their diet. Even though phytochemicals are
readily available in today's food supply, it is highly
possible that future foods may undergo bioengineering or
fortification to enhance naturally occurring
phytochemical concentrations. This would make it even
easier to incorporate phytochemicals in the diet.
The research involving phytochemicals
is promising, but with any newly discovered chemical, it
is recommended that further studies be conducted. This
fact sheet was designed to introduce the discovery and
importance of phytochemicals. It is in no way intended
to replace your health-care provider's recommendations.
As with any health recommendation, it is advisable to
check with your physician before adapting any lifestyle
changes. | |
| | | |
