Nutrients and Health Benefits of Vegetables

NUTRIENTS AND HEALTH
BENEFITS OF VEGETABLES
Presented by
PELIN B. BELINO, PhD. ,RND
Professor 2
Benguet State University

TOPIC OUTLINE
I. Nutrient Content Vegetables
II. Health Benefits of Vegetables
111. Functional Properties of
Vegetables

Why is it important to eat vegetables?
 Eating vegetables provides health benefits
– people who eat more vegetables and
fruits as part of an overall healthy diet are
likely to have a reduced risk of some
chronic diseases
 Vegetables provide nutrients vital for
health and maintenance of your body

Nutrients
 Most vegetables are naturally low in fat
and calories. None have cholesterol
 Vegetables are important sources of many
nutrients, including potassium, folate (folic
acid), vitamin A, vitamin C, and dietary
fiber

 Diets rich in potassium may help to
maintain healthy blood pressure
 Vegetable sources of potassium include
white beans, tomato products (paste,
sauce, and juice), beet greens, soybeans,
lima beans, spinach, lentils, and kidney
beans, leafy green vegetables

 Dietary fiber from vegetables, as part of an
overall healthy diet, helps reduce blood
cholesterol levels and may lower risk of
heart disease
 Fiber is important for proper bowel
function. It helps reduce constipation and
diverticulosis. Fiber-containing foods such
as vegetables help provide a feeling of
fullness with fewer calories

 Folate (folic acid) helps the body form red
blood cells. Women of childbearing age
who may become pregnant should
consume adequate folate from foods, and
in addition 400 mcg of synthetic folic acid
from fortified foods or supplements
 This reduces the risk of neural tube
defects, spina bifida, and anencephaly
during fetal development

 Vitamin A keeps eyes and skin healthy
and helps to protect against infections
 Vitamin C helps heal cuts and wounds
and keeps teeth and gums healthy
 Vitamin C aids in iron absorption

HEALTH BENEFITS OF
VEGETABLES
 Eating a diet rich in vegetables and fruits
as part of an overall healthy diet may
reduce risk for heart disease, including
heart attack and stroke
 Eating a diet rich in some vegetables and
fruits as part of an overall healthy diet
may protect against certain types of
cancers

HEALTH BENEFITS OF
VEGETABLES
 Diets rich in foods containing fiber, such as
some vegetables and fruits, may reduce the
risk of heart disease, obesity, and type 2
diabetes.
 Eating vegetables and fruits rich in
potassium as part of an overall healthy diet
may lower blood pressure, and may also
reduce the risk of developing kidney stones
and help to decrease bone loss

HEALTH BENEFITS OF
VEGETABLES
 Eating foods such as
vegetables that are
lower in calories per
cup instead of some
other higher-calorie
food may be useful in helping to lower
calorie intake

FUNCTIONAL PROPERTIES
OF VEGETABLES
 Functional foods are foods that provide
physiological benefits beyond that of simply
meeting nutrient needs
 Functional foods are unmodified whole foods
that naturally contain substances that provide a
physiological benefit beyond that provided by
the nutrients they contain
 Some foods are considered functional because
they are good sources of phytochemicals

What are Phytochemicals?
 Phytochemicals refer to the chemicals found
in plants
 Many of these have health-promoting
properties and are associated with
reductions in the risk of cancer and other
degenerative diseases
 Some act as antioxidants, some affect the
activity of enzymes or hormones, others
work by other mechanisms

What are Phytochemicals?
 Many phytochemicals have an anti-
carcinogenic (anti-cancer) action by:
1. Slowing cell proliferation (division) by
interfering with cell cycle
2. Inducing apoptosis (cell suicide)
3. Inhibiting phase 1 enzymes (enzymes that
convert harmless substances into carcinogens)
4. Inducing phase 2 enzymes (enzymes that
can attach carcinogens to molecules that
facilitate speedy excretion

I. FLOWER VEGETABLES
BROCCOLI (Brassica
oleraceae L.
var.italica)
Broccoli is rich in
fiber, provitamin A
carotenoids, and
vitamins C and K

Functional Properties
 Cruciferous vegetables contain
phytochemicals which help create
immune and antioxidant support in the
body by inducing extra protection of the
enzymes involved in detoxifying
carcinogens and flushing them out of the
body
 Broccoli is an important source of Vitamin
K, which helps prevent stomach and colon
cancer

1. Carotenoids (ά-carotene, β-carotene, β-
cryptoxanthin, lutein, zeaxanthin)
 Carotenoids are phytochemicals that have
antioxidant properties
 The intake of carotenoid-containing fruits and
vegetables has been associated with a reduced
risk of certain cancers, cardiovascular disease,
and age-related eye diseases such as cataracts
and macular degeneration
 The antioxidant properties of carotenoids are
believed to be responsible for some of these
effects

 Beta-carotene is the best known
carotenoid
 The carotenoids lutein and zeaxanthin
are most strongly associated with reduced
risk of macular degeneration - the leading
cause of severe vision loss in people over
age 60. It occurs when the small central
portion of the retina, known as the
macula, deteriorates

2. Glucosinolates (Glucobrassicin)
 The consumption of cruciferous vegetables
has been associated with a reduced risk of
cancer of the lung, stomach, colon and
rectum and also reduced risk of coronary
heart disease
 These effects have been attributed to their
high concentration of glucosinolates

 Glucosinolates convert to
isothiocyanates (contain sulfur) when
vegetables containing them are cut
 Isothiocyanates can reduce poisonous
effects of carcinogens and act by inhibition
of cell proliferation and induction of
apoptosis
 They act against cancer by phase 2 enzyme
induction
 Brocolli and cabbage show the greatest
protection against bladder cancer

a. Sulfur-Contaning Phytochemicals
 Isothiocyanates (sulphoraphane), and
dithiolthiones stimulate the activity of
enzymes that detoxify carcinogens
 It causes cell cycle arrest and apoptosis of
cancer cells
 It is shown to produce D-glucarolactone, a
significant inhibitor of breast cancer
 Isothiocyanates present in broccoli may
help to reduce the carcinogenic effects of
cigarette smoke

Mechanisms to inhibit cancer cells
 Some produce beneficial changes in gene
expression, thus altering levels of key proteins and
enzymes, while others inhibit cell adhesion, spread,
and invasion
 Scientists have shown that the cruciferous
vegetable compound phenethyl isothiocyanate
(PEITC) directly inhibits a tumora€TMs ability to
supply itself with blood. This interruption of
angiogenesis (growth of new blood vessels) is
considered an important cancer-fighting
mechanism

 Sulforaphane is a phytonutrient that
stimulates the formation and function of
'phase II' enzymes. These enzymes have
been identified as being responsible for
processing and removing cancer-causing
substances from cells under experimental
conditions. It is speculated that these
phase II enzymes may be able to perform
this function in the human body

 Sulforaphane induces cancer cells to commit
cellular suicide, while other compounds
particularly 13C (Indole-3-carbinol)
or its condensation product diindolyl-
methane (DIM) interrupt the ability of
cancer cells to reproduce and DIM affected
the expression of large number of genes
that are related to the control of
carcinogenesis, cell survival, and
physiologic behaviors

 The recent finding of a group of
researchers in Johns Hopkins University
School of Medicine has confirmed that in
laboratory tests, sulforaphane killed
Helicobacter pylori, bacteria that cause
stomach ulcers and often fatal stomach
cancers
 They also showed it can kill the bacterium
whether it is inside or outside cells

 The protective effect of these phytochemicals may
arise from their ability to inhibit the carcinogen-
activating phase 1 liver enzymes, while inducing
the carcinogen-detoxifying phase II enzymes
 The critically important phase II enzymes convert
dangerous compounds, such as toxins, hormones,
and xenoestrogens (estrogen-like compounds
from the environment), into less toxic compounds
that can safely be eliminated by the body

b. Indoles (Indole-3-carbinol)
 This is the most important indole in broccoli.
It inhibits the human papilloma virus (HPV),
which can cause uterine cancer
 It also blocks estrogen receptors in breast
cancer cells
 It induces cell cycle arrest and apoptosis of
breast and prostate cancer cells

 The substance indole-3-carbinol (I3C) contained
in broccoli and other cruciferous vegetables was
found in preliminary research that it affected the
metabolism of estrogen in a way that might
protect against breast and other female cancers,
an idea supported by animal and test tube
research
 Scientists demonstrated that I3C interferes with
breast cancer cell proliferation by altering the size
of a protein associated with cellular reproduction.
As a result, cellular division grinds to a halt

I. FLOWER VEGETABLEs
CAULIFLOWER (Brassica oleracea L. var. botrytis L.)

• They act against cancer by phase 2
enzyme induction
a. Sulfur-Contaning Phytochemicals
Isothiocyanates (sulphoraphane),
and dithiolthiones stimulate the
activity of enzymes that detoxify
carcinogens

 Sulphoraphane, an isothiocyanate is
particularly effective at boosting the activity
of enzyme systems that detoxify
carcinogens, and it has been shown to
protect animals from breast cancer
cancer cells

II. ROOTS ANDTUBERS
CARROTS (Daucus carota L.)

1. Terpenol
 Terpenol gives carrot flavor to carrots
 It causes cell cycle arrest in cancer cells
2. Carotenoids- Beta-carotene
 Beta-carotene's anti-inflammatory effects
may reduce the severity of conditions like
asthma, osteoarthritis, and rheumatoid
arthritis, which all involve inflammation

 Large scale studies have shown low blood
levels of carotenoids correspond with
greater cancer risk
 Researchers have found that carotenoids
can inhibit the growth of certain types of
breast cancer cells, skin cancer cells, lung
cancer and stomach cancer (Kiani)

 Although epidemiological studies have
shown reduced lung cancer incidence
among those with high plasma serum
levels of beta-carotene, some large
intervention studies showed an increased
incidence of lung cancer among smokers
taking beta-carotene supplements

Beta-carotene is shown to be:
• a weak antioxidant, but strong against
singlet oxygen
• boost the activity of natural killer (NK)
immune cells
• stimulate DNA repair enzymes
• give better cornea protection against
UV light than lycopene

3. Soluble Fiber
 This may reduce the risk of coronary heart
disease (CHD)
 It also reduces both cholesterol and
triglyceride levels

II. ROOTS AND TUBERS
RADISH (Raphanus sativus L.)
RADISH (Raphanus sativus L.)

1. Isothiocyanates
 Isothiocyanates are responsible for the hotness of
horseradish, radish and mustard
 Sulphoraphane, an isothiocyanate is particularly
effective at boosting the activity of enzyme
systems that detoxify carcinogens, and it has
been shown to protect animals from breast
cancer
cancer cells

2. Carotenoids-Beta- carotene
 Radish leaves are rich in carotenoids,
particularly beta-carotene
 Researchers have found that carotenoids in
dark green leafy vegetables can inhibit the
growth of certain types of breast cancer cells,
skin cancer cells, lung cancer and stomach
cancer

II. ROOTS ANDTUBERS
SUGAR BEETS/BEETROOT
(Beta vulgaris)

1. Betaine (Trimethylglycine)
 Betaine is found in beets
 It is capable of removing pro-
atherosclerotic protein homocysteine from
the body
●An elevated plasma level of homocysteine
has long been known as an independent
predictor of cardiovascular disease

III. FRUIT VEGETABLES
BELL (SWEET) PEPPER
(Capsicum annuum L.)

1. P- Coumaric Acid (Para-Coumeric
Acid)
 Para-Coumeric Acid is high in red and green
bell peppers
 It is a flavonoid precursor
 It is an antioxidant for the colon mucosa.
This binds with nitric acid and its
derivatives before they combine with
protein amines to form nitrosamine

2. Chlorogenic Acid
 Chlorogenic acid is very high in tomatoes
and bell peppers
 It is most frequently an ester of caffeic
acid. Caffeic acid reduces mutagenicity of
polycyclic aromatic hydrocarbons
 It has an antioxidant activity. Caffeic acid
can regenerate oxidized Vitamin E

3. Beta-carotene (in red bell peppers)
 Beta-carotene’s anti-inflammatory effects
may reduce the severity of conditions like
asthma, osteoarthritis, and rheumatoid
arthritis, which involve inflammation

TOMATOES
(Lycopersicon esculentum Mill.)

1. Carotenoids- Lycopene
 Lycopene, the carotenoid that gives
tomatoes their red color, is a potent
scavenger of oxygen radicals
 Studies have shown that the processing of
tomatoes and of tomato products, such as
sauces, soups and juices, increases the
bioavailability of lycopene. The bioavailability
from tomato paste is nearly four times
greater than from fresh tomatoes
 Lycopene accounts for nearly half the total
carotenoids in the blood serum

Lycopene
 It is a powerful antioxidant which reduces damage
to DNA and proteins
 It gives better skin protection against UV light
than beta-carotene
 It is concentrated in the skin, testes, adrenal and
prostate where it protects against cancer
 It can reduce LDL cholesterol levels
 It suppresses insulin-like growth factor (IGF-I)
that stimulates tumor growth

 Several studies have linked the consumption of
tomatoes and tomato products with a decreased
risk of these diseases:
1. Lung, bladder, cervix, skin, breast , prostate and
colorectal cancers because of their anti-oxidant
and anti-proliferative properties
2. Cardiovascular disease, because they may inhibit
cholesterol synthesis and enhance LDL (bad
cholesterol) degradation

Tomato Bioactive Components and Modes
of Action
• Tomatoes contain many bioactive components,
including those that act as antioxidants, such
as the vitamins C and E, and many
carotenoids
• Lycopene is the most efficient carotenoid at
scavenging singlet oxygen and reactive
oxygen species
• The antioxidant effect of lycopene is
potentially beneficial in disease prevention for
both CVD and prostate cancer

 In regard to CVD, lycopene and tomatoes
could possibly reduce the disease
development by reducing inflammation,
inhibiting cholesterol synthesis, or
improving immune function
 The proposed mechanism of action of
lycopene in prostate cancer prevention
includes inhibition of proliferation, anti-
androgen and antigrowth factor effects

Research conducted showed that the lycopene
supplemented group had less cancer at the
surgical margins and in extraprostatic tissues,
smaller tumors, and an 18% reduction in
prostate specific antigen (PSA) levels,
whereas the control group’s PSA levels increased
by 14%
 Lycopene treatment was also found to increase
expression of connexin 43 in cancerous prostate
tissue. Connexin 43 is a recognized tumor
suppressor gene, which can increase gap junction
communication and therefore suppress overgrowth
of cells

2. Chlorogenic Acid
 Chlorogenic acid is very high in tomatoes
and bell peppers
 It has an antioxidant activity

SQUASH (Cucurbita maxima)
SQUASH (Cucurbita maxima)

 Beta-carotene is an antioxidant which can
help reduce oxidative damage done by free
radicals in the body
 Antioxidant vitamins may prevent or protect
against cancer, cardiovascular disease,
asthma, pulmonary function problems,
diabetes and weight loss
 They may also protect eyesight, help protect
the brain, and promote gastrointestinal health

BITTERMELON
BITTERMELON (MOMORDITA charantia L)

1. Charantin
 Bitter melon, also known as balsam pear, is a
tropical vegetable has been used extensively in folk
medicine as a remedy for diabetes
 The blood sugar lowering action of the fresh juice
or extract of the unripe fruit has been clearly
established in both experimental and clinical
studies
 Bitter melon is composed of several compounds
with confirmed anti-diabetic properties
 Charantin, extracted by alcohol, is a
hypoglycaemic agent

2. Polypeptide-P or p-insulin
 The fruit of bitter melon contains several
compounds that contribute to its success:
saponins, proteins, and a polypeptide called “p-
insulin”
 Momordica contains an insulin-like polypeptide,
polypeptide-P, which lowers blood sugar levels
when injected subcutaneously into type 1 diabetic
patients
 The oral administration of 50-60 ml of the juice
has shown good results in clinical trials

p-insulin
 Some scientists suggest that this botanical
may help inhibit the absorption of
sugar into cells without driving insulin
levels to unstable levels (Raman, 1996)
 Furthermore, its juice was shown in one
study to enhance glucose tolerance in 73%
of the participants evaluated

Toxic Effects
Excessively high doses of bitter melon juice can
cause abdominal pain and diarrhea
 Small children or anyone with hypoglycemia
should not take bitter melon, since this herb could
theoretically trigger or worsen low blood sugar, or
hypoglycemia
 Furthermore, diabetics taking hypoglycemic drugs
or insulin should use bitter melon with caution, as
it may potentiate the effectiveness of the drugs,
leading to severe hypoglycemia

IV. LEAFY VEGETABLES
CABBAGE
(Brassica oleracea L. var. capitata L)

 Glucosinolates convert to isothiocyanates
(contain sulfur) and indoles (contain no sulfur)
when vegetables containing them are cut
 They are high in cruciferous vegetables,
particularly cauliflower and cabbage and to a
lesser extent in broccoli
 They act against cancer by phase 2 enzyme
induction. Brocolli and cabbage show the
greatest protection against bladder cancer

 Glucosinolates may prevent cancer by
acting as metabolic detoxicants to
facilitate alteration and excretion of cell
carcinogens
 Glucosinolate-derived indole compounds
are inducers of liver and intestinal
enzymes that reduced tumor formation
in rats

a. Sulfur-Contaning
Phytochemicals
 Isothiocyanates (sulphoraphane),
and dithiolthiones, all contain sulfur
in their structure
 These classes stimulate the activity
of enzymes that detoxify carcinogens

b. Indoles (Indole-3-carbinol).
 It inhibits the human papilloma virus
(HPV), which can cause uterine cancer
 It also blocks estrogen receptors in breast
cancer cells
 It induces cell cycle arrest and apoptosis
of breast and prostate cancer cells

2. Soluble Fiber
 May reduce the risk of coronary heart
disease (CHD) and reduce both
cholesterol and triglyceride levels
Anti-nutrients
 Isothiocyanates are goitrogenic in
animals and people if consumed in
sufficient quantities

RED CABBAGE
(Brassica oleracea L. var. capitata L.)

1. Glucosinolates
a. Isothiocyanates (sulphoraphane), and
dithiolthiones
•Sulphoraphane, an isothiocyanate is particularly
effective at boosting the activity of enzyme systems
that detoxify carcinogens, and it has been shown to
protect animals from breast cancer
•It causes cell cycle arrest and apoptosis of cancer
cells. Sulphoraphane is a strong inducer of the phase
II enzymes responsible for anticarcinogenic activities
•It shown to produce D-glucarolactone, a significant
inhibitor of breast cancer

2. Flavonoids ( Anthocyanin)
 Purple cabbage and other purple-or red-
pigmented cole crops contain various
anthocyanins
 One of the most important types of
flavonoids is the anthocyanin, which are
pigments that give blue and red colors to
blueberries, raspberries, and red cabbage

2. Flavonoids ( Anthocyanin)
 These compounds are strong antioxidants
and have anticancer properties and protect
against cardiovascular disease by inhibiting
the oxidation of LDL cholesterol and
affecting platelet function
 Flavonoids scavenge free radicals by
forming a stable radical that can react with
another flavonoid radical to produce two-
nonradicals

 The phytochemical called anthocyanidins
can neutralize free radical damages to the
collagen matrix of cells and tissues that can
induce glaucoma, peptic ulcers, varicose
veins, hemorrhoids, cataracts, heart
disease and cancer
 Anthocyanins can improve the wholeness
of support structures in the veins and the
entire vascular system

These are some benefits of flavonoids:
bolsters cellular antioxidant defenses
may contribute to maintenance of brain
function
may contribute to maintenance of heart
health
neutralizes free radicals
may contribute to maintenance of urinary
tract health

LEAF AMARANTH
(Amaranthus viridis L.)

1. Chlorophyll
 Chrorophyll is the most abundant pigment in
plants
 It is the principal light-absorbing pigment in
photosynthesis
 It forms tight molecular complexes with
some carcinogens: aflatoxin-B1,
polyaromatic hydrocarbons (tobacco smoke)
and heterocyclic amines (cooked meat)

Anti-nutrients
 Their moderately high content of oxalic acid
inhibits the absorption of calcium and zinc, and
also means that they should be avoided or
eaten in moderation by people with kidney
disorders, gout, or rheumatoid arthritis
 Reheating cooked amaranth greens is often
discouraged, particularly for consumption by
small children, as the nitrates in the leaves can
be converted to nitrites, similarly to spinach

IV. LEAFY VEGETABLESHORESERADISH
(Moringa oleifera Lam)

1. Isothiocyanates
 Isothiocyanates are responsible for the
hotness of horseradish, radish and mustard
2. Chlorophyll
polyaromatic hydrocarbons (tobacco
smoke) and heterocyclic amines (cooked
meat)

3. Carotenoids- Beta-carotene, Lutein
and Xanthin
•Lutein and zeaxanthin constitute about
half of all carotenoids in the retina. Lutein
and zeaxanthin are the only carotenoids in
the macula of the eye
•This is found to protect the eye from
macular degeneration and cataracts
It is also shown to protect against colon
cancer

4. Flavonoids- Quercetin and
Kaempferol
 In various epidemiological studies and
clinical trials, consumption of quercetin
have been associated with a reduced risk
of heart disease and improved
cardiovascular health
 Quercetin and resveratrol provide
important synergistic benefits for the
heart

LEAF MUSTARD (Brassica juncea L.)

 Dark green leafy vegetables include
spinach, kale, romaine lettuce, leaf
lettuce, mustard greens, collard greens,
chicory and Swiss chard are excellent
sources of fiber, folate and a wide range
of carotenoids which seem to help
prevent cancer by acting as antioxidant

1. Isothiocyanates
2. Chlorophyll
• forms tight molecular complexes with
polyaromatic hydrocarbons (tobacco
smoke) and heterocyclic amines (cooked
meat)

SPINACH (Spinacia oleracea L.)

1. Carotenoids- Beta-carotene, Lutein and
Zeaxanthin
 Lutein is in highest concentrations in spinach,
watercress and parsely
 Lutein and zeaxanthin constitute about half of
all carotenoids in the retina. Lutein and
zeaxanthin are the only carotenoids in the
macula of the eye
 This is found to protect the eye from macular
degeneration and cataracts
 It is also shown to protect against colon cancer

2. Chlorophyll
plants
photosynthesis
 It forms tight molecular complexes with some
carcinogens: aflatoxin-B1, polyaromatic
hydrocarbons (tobacco smoke) and heterocyclic
amines (cooked meat)

WATERCRESS Nasturtium officinale R.
Br. (Rorippa nasturtium aqauticum L.
Hayek)

1. Phenethyl Isothiocyanate (PEITC)
 Phenethyl isothiocyanate gives bitter taste to
watercress
 It inhibits tumorigenesis by polycyclic aromatic
hydrocarbons
 It induces apoptosis by caspase-8 activation
 It is found to be particularly good against
nitrosamines in tobacco smoke (nitric oxide +
nicotine → nitrosamine, main carcinogen of
tobacco smoke)

 Watercress is also known to work against
other types of cancer
 The majority of cancers are caused by the
ingestion/inhalation of potentially
carcinogenic compounds which result in
genetic disruption of cells, causing them to
become cancerous

 Certain compounds only become
carcinogenic if activated by enzymatic
reactions within tissue. This metabolic
pathway is often referred to as a phase 1
induction. Free radicals are often
produced which in turn initiate phase 2 –
a reaction with tissue DNA which can
result in uncontrolled replication / tumor
development

 PEITC has been shown to inhibit phase 1
enzyme activation
 Effectively it stops potential carcinogens
becoming carcinogenic
 Watercress is one of the richest sources
of dietary PEITC

There are further metabolic pathways
implicated in modulating tumor
development
 The most relevant in this instance is the
ability of certain compounds to cause the
selective death of cancerous tissue –
known as apoptosis

2. Carotenoid- Lutein and Zeaxanthin
 Lutein is in highest concentrations in spinach,
watercress and parsely
 Lutein and zeaxanthin constitute about half of
all carotenoids in the retina
 Lutein and zeaxanthin are the only carotenoids
in the macula of the eye. This is found to
protect the eye from macular degeneration and
cataracts
 It is also shown to protect against colon cancer

3. Chlorophyll
plants
photosynthesis
some carcinogens: aflatoxin-B1, polyaromatic
hydrocarbons (tobacco smoke) and
heterocyclic amines (cooked meat)

IV. STEMS AND SHOOTS
ASPARAGUS (Asparagus officinalis L.)

1. Rutin
 Rutin is in asparagus, buckwheat and
citrus fruits
 This is found to strengthen capillary walls
 Rutin is also with proven protective
properties against radiation as well as
anti-hemorrhagic effects

2. Anthocyanins
 Anthocyanins, which give this variety its
purplish color, offer protective properties
for the cardiovascular system
 Their levels increase as the color
deepens, as does the amount of rutin.
 It also acts as a precursor of B-group
vitamins

3. Saponins
 The saponins contained in green
asparagus give it its diuretic effect and its
high fiber content
 It is diuretic because of an acidic
substance called asparagine

4. Antioxidants
 Asparagus gives important antioxidants
like glutathione (other major
antioxidants are vitamins A, C, and E,
selenium, melatonin, beta carotene,
zinc, and pycnogenol)

 Antioxidants prevent heart disease, lower
cancer risk, help keep bones strong,
protect vision and immune system, and
improve mental function. More importantly,
they keep the skin young
 Green asparagus is distinguished by its
high levels of the antioxidant vitamins A
and C

CELERY
(Apium graveolens L. var. dulce Perr.)

1. 3-n-Butyl Phthalide
 Research is showing that the early use of celery
as a medicine was not unfounded
 3-n-butyl phthalide, one of the components that
gives celery its characteristic smell and taste, is
especially potent as an anti-tumor agent
 Along with the compound sedanolide, an
aromatic ingredient also found in celery, 3-n-
butyl phthalide significantly reduces the
incidence of tumors in laboratory animals

 Other studies suggest that this and other
phthalides may also help reduce high
cholesterol
 Even though it's high in sodium (as
vegetables do), celery is also proving to be
effective at lowering blood pressure
because 3-n-butyl phthalide has been
demonstrated to relax the smooth muscles
that line blood vessels

 Carotenoids neutralize free radicals
which may damage cells
 This also bolsters cellular antioxidant
defenses
 Some studies have shown that beta-
carotene may be an effective ally
against prostate cancer

3. Dietary Fiber- Insoluble Fiber
 Insoluble fiber contributes to
maintenance of a healthy digestive tract
 It also lowers the risk of colon and
breast cancer

RHUBARB (Rheum rhaponticum L.)

1. Resveratrol
 Resveratrol, trans-3,5,4'-
trihydroxystilbene, has been found in
various plants, including grapes,
berries, peanuts and Rheum spp. incl.
Rhubarb

 Besides cardioprotective effects, resveratrol
exhibits anticancer properties, by its ability to
suppress proliferation of a wide variety of
tumor cells, including lymphoid and myeloid
cancers; multiple myeloma; cancer of the
breast, prostate, stomach, colon, pancreas,
and thyroid; melanoma; head and neck
squamous cell carcinoma; ovarian carcinoma;
and cervical carcinoma

Resveratrol induces apoptosis
 Apoptosis is a mode of cell death that
differs from necrosis
 Apoptosis is characterized by
initiation of cell death from the
outside of the cell, necrosis is a death
mechanism initiated from inside the
cell, primarily from the mitochondria

Figure 1 . Various proposed mechanisms of
apoptosis of tumor cells by resveratrol.

Figure 2. Effect of resveratrol on signaling
proteins involved in apoptosis

 Resveratrol holds great potential in the prevention
and therapy of a wide variety of tumors
 Resveratrol has antiproliferative effects through
induction of apoptosis in cell lines of various origin
such as leukemias and breast, prostate, colon,
pancreas, and head and neck carcinomas
 Most, but not all, studies indicate that resveratrol
does not induce apoptosis in normal cells

 Resveratrol has potential for treating
diseases other than cancer and
cardiovascular ailments
 Howitz et al. found evidence in yeast that
resveratrol mimics calorie restriction and
thus extends the lifespan by 70%

Anti-nutrients and Toxic
Effects in Rhubarb
 The leaves contain high
concentrations of oxalic acid
 Oxalic acid can lock up certain
minerals (especially calcium) in the
body, leading to nutritional deficiency
 Cooking the plant will reduce the
concentration of oxalic acid

Anti-nutrients and Toxic
Effects
 People with a tendency to
rheumatism, arthritis, gout, kidney
stones or hyperacidity should take
especial caution if including this
plant in their diet since it can
aggravate their condition

VI. SEEDS, LEGUMES
KIDNEY BEANS,/SNAP BEANS
(Phaseolus vulgaricus L.)

1. Phytosterols ( Beta-sitosterol,
stimasterol, and campesterol)
 Beta-sitosterol has similar structure to
cholesterol.
 It is the plant equivalent of animal
cholesterol
 It decreases cholesterol absorption from
the GI tract

1. Phytosterols ( Beta-sitosterol,
stimasterol, and campesterol)
 It also reduces cholesterol manufacture by
the liver
 It slows cancer cell growth (cholesterol is
needed for cell membrane)
 Inhibition of epithelial cell division may
reduce atherosclerosis

VI. SEEDS, LEGUMES
SOYBEANS (Glycine max (L) Merr.

1. Saponins ( Soyasaponins,
soyasapogenols)
 Saponin binds bile acids and cholesterol in
the GI tract to reduce absorption
 It is toxic to tumor cells
 Found to be effective against colon cancer
 It is also an antioxidant

2. Phytoestrogens ( isoflavones such as
genistein, biochanin A and daidzein
 Besides scavenging free radicals, some
phenolic compounds, often referred to as
phytoestrogens, appear to interrupt cancer
development and affect health by
interfering with the action of the hormone
estrogen

 Phytoestrogens include isoflavones (also a
flavonoid) and lignins. These compounds
are structurally modified by the microflora
in the intestines to form compounds that
are similar to estrogen
 They are suspected of blocking estrogen
function by tying up estrogen receptors on
cells

 Isoflavones are heterocyclic phenols structurally
similar to the estrogenic steroids. Because they
are weak estrogens, isoflavones may act as
antiestrogens by competing with the more
potent, naturally-occurring endogenous
estrogens (e.g., 17b-estradiol) for binding to the
estrogen receptor
 This may explain why populations that consume
significant amounts of soy have reduced risk of
estrogen-dependent cancer

 Isoflavones, the best known of which is
genistein, are found in soybeans and are
believed to affect hormone-related cancers,
including breast and prostate cancer
 They are also hypothesized to decrease hot
flashes and other symptoms of menopause

 Genistein is also found to inhibit tyrosine
kinases involved in tumorigenesis
 It elevates HDL cholesterol and lowers
LDL cholesterol
 It is a potent antioxidant against
superoxide and hydrogen peroxide
 It helps in the prevention of bone
resorption (osteoporosis) in post-
menopausal women

3. Inositol phosphates ( phytate, inositol,
pentaphosphate)
 Bind metal ions and prevent them from generating
free radicals and protect against cancer
 Phytic acid binds minerals, especially calcium and
iron. Mineral chelation may reduce free radicals
 The iron-binding effect slows cancer growth
because cancer cells need iron for growth and
reduces cardiovascular disease
 This also reduces starch digestion thus lowers blood
glucose

4. Protease Inhibitors
 Bind to trypsin and chymotrypsin; decrease
growth of cancer cells; inhibit malignant
changes in cells; inhibit hormone binding;
may aid DNA repair which can slow cancer
cell division and help return a cell to its
normal state; prevent tumors from
releasing proteases that destroy
neighboring cells

5. Resveratrol
 Resveratrol is a plant protective phytoalexin
produced by grapes, mulberries, peanuts and soy
beans.
 This compound occurs in two conformational forms
– cis and trans-resveratrol. Trans-resveratrol is the
preferred functional form
 Trans-resveratrol is thought to improve heart
health in a number of ways:
•Laboratory experiments in vitro and studies in
animals have shown that trans-resveratrol can
stop blood platelets from sticking together
(platelet aggregation)

•In one study, scientists investigated the effects of
resveratrol on aggregation of platelets isolated
from healthy male volunteers
•Trans-resveratrol significantly inhibited the
sticking together of blood platelets
• Researchers also induced platelet aggregation in
rabbits with high cholesterol and found that when
trans-resveratrol was given to the rabbits, the
platelets did not stick together
◘ Since sticky platelets are tied to increased risk of
heart attack, stroke and blood clots throughout
the body, this is a significant finding in regards to
life-threatening risk factor

 Another of trans-resveratrol’s interesting
cardiovascular implications is its ability to
enhance angiogenesis, the development of new
blood vessels, in order to help feed the heart
during periods of oxygen deprivation (ischemia)
 The formation of new blood vessels caused by
trans-resveratrol restores the blood supply to the
ischemic area, preventing heart cell death and
abnormal changes to the heart

 In addition to being a powerful antioxidant, trans-
resveratrol acts like a molecular master key,
“opening” or up regulating important genes and
functionally related sequences of DNA or
“families” of genes that directly control both the
lifespan and metabolic efficiency
 Trans-resveratrol also stimulates the production of
ATP in the mitochondria of muscles

 As a key regulatory molecule, trans-
resveratrol improves cellular energy
production and up regulates the expression
of many different genes, leading to
metabolic homeostasis as a prerequisite for
a long and healthy life

6. Fatty Acids- Polyunsaturated fatty
acids and Omega-3 fatty acids- Alpha-
Linolenic Acid (ALA)
 This may contribute to maintenance of
mental and visual functions

7. Soy protein
 Soy protein may have lipid-lowering,
antiatherogenic, antioxidant, anticarcinogenic and
antiosteoporotic activities. May reduce risk of
Coronary Heart Diseases (CHD)
 Soy may also benefit bone health.
A clinical study involving postmenopausal women
conducted at the University of Illinois (Erdman and
Potter, 1997) found that 40 grams isolated soy
protein per day (containing 90 mg total isoflavones)
significantly increased (approximately 2%) both
bone mineral content and density in the lumbar

Mechanism of Action
 Diets rich in soy protein have been found to reduce
serum levels of total cholesterol, LDL-cholesterol,
triglycerides and apolipoprotein B (apo B)
 The mechanism of the lipid-lowering activity of soy
protein is unclear
 There are a few possible explanations. Soy protein
is much richer in L-arginine than is animal protein,
which is richer in L-lysine
 Some animal studies indicate that dietary
increases in L-arginine are accompanied by
decreases in cholesterol levels

Mechanism of Action
 The soy isoflavones may also contribute to the lipid-
lowering activity of soy protein as well as its
antiatherogenic activity
 Most soy protein products contain the isoflavones
genistin, daidzin and glycitin, which have weak estrogenic
effects and also may have antiestrogenic activity. Oral
estrogens have been shown to decrease total cholesterol
and LDL-cholesterol
 The soy isoflavones may have similar actions.
Interestingly, a few studies have shown that when the
isoflavones are removed from the soy protein, the protein
itself has little hypocholesterolemic activity

Mechanism of Action
 There are also other substances associated
with soy protein, including saponins,
trypsin inhibitor and bioactive peptides,
which may also contribute to the lipid-
lowering activity of soy protein. The soy
isoflavones are antioxidants, and their
antioxidant activity may contribute to the
possible anti-atherogenic effect of soy
protein.

Mechanism of Action
 The antioxidant, anticarcinogenic and
antiosteoporotic activities of soy protein are
probably due, in large part, to the soy isoflavones
 Soy protein has been found to reduce intestinal
mucosa polyamine levels in rats, which may be
another anticarcinogenic mechanism.
 Also, a bioactive peptide has recently been
isolated from soybeans and has been found to
have potent antimitotic activity

Nutrients and Health Benefits of Vegetables

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