Naturally occurring toxins can be present in some edible plants. Phytochemicals produce biological activity and some can cause toxicity in high amounts or long-term use. Toxic compounds include haemagglutinins in legumes like soybeans, goitrogens in cruciferous vegetables, and cyanogens in foods like cassava. Lathyrogens in foods like chickpeas can cause skeletal issues. Cooking methods like soaking and boiling can reduce toxicity from compounds in foods like soybeans and cassava. Consuming a variety of whole plant foods as part of a balanced diet can help prevent risks from naturally occurring toxins in some edible plants.

1. TOXICITY FROM
NATURALLY
OCCURRING TOXINS IN
PLANT FOODS
Ms. RABIA SHABBIR
NUTRITIONAL PSYCHOLOGIST

2. CONTENTS
• Phytochemicals
• Accidental toxicity
• Toxic compounds in edible plants
• Other toxic compounds
• Mechanism by which anti-nutritional compounds
exert their effects
• Prevention & detoxification
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3. PHYTOCHEMICALS
• Phytochemical is a broad term meaning plant (phyto) chemical
referring to a wide variety of compounds that occur naturally
in plants. (Yancui Huang, 2016)
• Some phytochemicals produce activity in biological systems,
including humans; hence, the term ‘bioactive phytochemicals.
• Phytochemicals are non-nutritive components present in
a plant-based diet (‘phyto’ is from the Greek word meaning
plant) that exert protective or disease-preventing effects.
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5. POTENTIAL RISK OF PHYTOCHEMICALS
ASSOCIATED WITH HIGH DOSAGE &
LONG-TERM USE
• epidemiological research suggests that phyto-chemicals may be
effective in treating various diseases owing to their antioxidant
and anti-inflammatory activities.
• consumption of certain phyto-chemicals may cause some acute
and chronic toxic effects and may even cause the development
of cancer.
• It is obvious that the number of phyto-nutrients taken, the
individual’s age and gender, and the conditions, as well as
exposure levels, are important in the occurrence of potential
risks.
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6. Contd…
• The daily consumption of specific phytonutrients
may easily reach high levels when high doses of
related compounds containing dietary supplements
are taken simultaneously.
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7. Out of 300,000 plants species found in the world, almost 700
have been declared as serious and hazardous, even causing
death.
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8. LIST OF THE PLANTS DECLARED AS
POISONOUS WORLDWIDE
PLANTS NAMES POTENTIAL RISK FACTORS
Lily of the valley Consuming its toxic compounds — called
cardiac glycosides — can send people to
the hospital with symptoms like dizziness,
vomiting, rashes, and diarrhea.
Castor oil plant Just one seed can kill a child, as the toxic
protein ricin can cause severe dehydration
from vomiting and diarrhea.
Rhubarb Eating too much will shut down the
kidneys, occasionally proving fatal.
Foxglove Can cause heart failure when taken in
excess
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9. Wisteria vomiting or diarrhea.
Lilies Eating just a small amount can lead to
acute kidney failure or death.
dieffenbachia Even brushing against it can cause burning
or itching.
Daffodil Ingesting too much could cause vomiting,
diarrhea, convulsions, tremors, and cardiac
arrhythmia.
Oleandar Symptoms of poisoning include
drowsiness, slowed heart rate, and
shaking.
Water hemlock attacks the nervous system
English yew The alkaloids throughout the yew can
cause convulsions, paralysis, and, in
extreme cases, heart failure.
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10. Wild arum Cause poisoning among the children
who eat its toxic fruits
Deadly nightshade Cause poisoning among the children who
eat its toxic fruits
Wild bryony Cause poisoning among the children who
eat its toxic fruits
Raw cashew nuts Irritation & swelling of skin
Ackee apple Its unripe fruit causes sores in mouth,
vomiting, drowsiness, convulsions and
even coma.
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11. PLANTS- A SOURCE OF MINERALS
Plants are considered as rich sources of minerals. But
anyone of the naturally occurring chemical component
(intrinsic ones) above a threshold have been proven
hazardous or even fatal to the consumers.
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12. COMMON MINERALS WITH THEIR
HAZARDOUS EFFECTS DUE TO EXCESS
IN DIET
Elements Sources Toxic effects
Aluminum Citrus fruits, stone fruits,
cooking utensils
GIT irritation, rickets
Arsenic Sea foods Nausea, vomiting, diarrhea,
burning of mouth and
throat, severe abdominal
cramps
Copper Drinking water, cooking
utensils, some permitted
colors, preservatives
Wilson’s disease (a genetic
disease in which excessive
copper builds up in body)
Iron Liver, kidney, heart,
legumes, shellfish
Hemochromatosis, liver
enlargement, skin
pigmentation, cardiac
failure, DM
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13. Lead Drinking water, food
containers, cigarette,
smoking, vehicle, exhaust,
bones
Abdominal colic,
encephalopathy,
myelopathy, peripheral
neuropathy, anemia
Phosphorous Milk, dairy products, meat,
grains, poultry
Jaw erosion
Sodium Common salt, several foods Nausea, vomiting,
hypertension, edema
Tin Widely distributed in foods,
tin cans
Vomiting
zinc Wheat germ, bran, oysters,
drinking water
Irritability, stiffness, pains
in muscles of back and
neck, loss of appetite,
nausea, vomiting, diarrhea
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14. TOXIC COMPOUNDS IN EDIBLE
PLANTS
There are several toxic compounds present in plants,
that are toxic not for the plants themselves, but for the
consumer, including humans and animals.
Main toxic compounds in edible plants include:
• Haemagglutinins
• Goitrogens
• Cyanogens
• Lathyrogens
• Allergens
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15. 1. Haemagglutinins
• Proteinaceous compounds
• Present in several legumes such as
soybeans, kidney beans, mung beans,
chick pea, lentil, some cereals.
• Can cause poor food utilization and
impair the individual growth
• Also found on the surface of influenza
viruses
• It has got four types (A,B,C,D)
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16. SOYBEANS
• Contain antitryptic factor (trypsin
inhibitor) that is responsible for
poor digestibility of soybeans.
• This is the reason these beans are
detoxified through soaking,
germination, steaming and
fermenting.
FAVA BEANS
• Also called as broad beans/horse
beans/Windsor beans
• Cause FAVISM-hemolytic
anemia, hemoglobinuria,
jaundice, high fever.
• May cause death in children
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17. 2. GOITROGENS
• Also known as glucosinolates/thioglucosides
• Found in commonly used veges of Cruciferae
family, especially of genus Brassica (such as
kale, cabbage, turnip and radish)
• disrupt the production of thyroid hormones by
interfering with iodine uptake in the thyroid
gland.
• Can cause goiter in humans as well as animals
feeding on these food sources, thus, also termed
as goitrogens.
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18. 3. CYANOGENS
• Also referred to as cyanogenic glycosides
• Present in peas, beans, pulses, fruit kernels and
cassava
• Cause hydrocyanide poisoning (HCN)-nausea,
fever, rashes, headache, insomnia, increased thirst,
weakness, lethargy, weakness, joint and muscle
aches, hypotension.
• ACUTE TOXICITY-convulsions, paralysis,
cessation of respiration.
• CHRONIC TOXICITY- tropical atoxic
neuropathy, endemic goiter.
• Adequate soaking and thorough cooking of these
beans prevent the release of HCN.
• In northern areas, people save the apricots and eat
their kernels in winter, thus, incidences of apricot
toxicity have been reported.
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19. 4. LATHYROGENS
• These are the NITRITES found in
chickling vetch and chick peas
• Responsible for skeletal deformities and
damage to NS causing neurolathyrism
which is a toxic myelopathy caused by
ingestion of the Lathyrus sativus
grasspea.
• Its most commonly grown in India,
Algeria
• When consumed as supplement in
overall balanced diet, its beneficial.
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20. OTHER TOXIC COMPOUNDS
•Solanaceae
family
•Contains
solanine &
chaconine
•Can cause
vomiting,
abdominal
cramps if 8kg
are consumed at
one time !!!
•Pungent, biting taste.
•Contain alkaloid
capsaicin & methyl
vanillyl nonenamide that
can produce burning
sensation in mouth, skin
redness on contact,
swollen tongue and lips.
•It is a diaphoretic-
increases sweating
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21. OXALIC ACID
•Present in spinach, almonds, cashew nuts,
tomatoes, sesame seeds, tea
•Excessive consumption can cause pains,
failure of the blood to clot, even death
•Interferes with absorption of calcium
•Kidney damage by formation of insoluble
calcium oxalate
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23. TWO DISTINCT MECHANISMS
1. Some naturally occurring
chemical compounds exert their
harmful effects by binding or
destroying particular nutrients
present in food, thereby,
decreasing their availability.
e.g. dietary fibers of plants bind
with proteins, mineral and
vitamins, thus, decreasing their
availability in body.
Similarly, oxalates bind with
calcium and decreases its
absorption.
2. The other mechanism is by
decreasing the absorption or
utilization of one nutrient or
the other in food.
e.g. enzyme inhibitor such as
trypsin inhibitor causes the
poor utilization of proteins by
decreasing their digestion.
Similarly, some plant tannins can
bind to digestive system
enzymes thereby inhibiting
their functions.
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24. PREVENTION & DETOXIFICATION
• When you plant your garden and buy your indoor plants, make
sure you place potentially poisonous or dangerous plants in
areas that are out of children’s reach.
• Make sure you know the plants you are putting in your garden.
• Do not leave out packs of seeds.
• When you spray pesticides on your plants, remember to wash
your hands
• Keep all fertilizers and pesticides in their original containers.
• Well-planned plant-based diets can support healthy living at
every age and life-stage. Include a wide variety of healthy
whole foods to ensure your diet is balanced and sustainable.
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