
Phytochemicals
Phytochemicals are only found in plant-based (especially organic) foods, which is why they are often neglected in the modern Western diet. In this article you will learn the most important facts about phytochemicals and what you can do to get enough of them.
Functions
What are phytochemicals? Phytochemicals are formed in the secondary metabolism of plants. They are therefore only found in plants and only in small amounts. Like fibre, they belong to the group of bioactive substances, as the focus is not on their nutritional value but on their health-promoting effect. They achieve a variety of pharmacological effects in our body with health-promoting effects. Depending on the type of phytochemical, they are anticarcinogenic, antimicrobial, antioxidant, antithrombotic, immunomodulating, anti-inflammatory, blood pressure regulating, cholesterol lowering and blood glucose stabilising.
Formation and Occurrence
Phytochemicals are not essential for the plant itself. It forms them as a defence against pests, for protection against UV radiation and evaporation, for growth regulation, as colouring, flavouring and scenting substances or for mechanical strengthening. As a result, organically grown plants contain more phytochemicals than conventionally grown plants. However, most phytochemicals are found in wild plants. The contents also vary according to variety, degree of ripeness, harvesting, growth and storage conditions.
Supply
The general population consumes 1 – 1.5 g/day of phytochemicals. The content is significantly higher in vegetarians. People who live vegan consume the highest amount of plant foods, therefore they have the highest intake of phytochemicals.
Supplements are not recommended because they only contain isolated substances, which can then quickly lead to a toxic dose. Nowadays, the food industry supplements products withphytochemicals, which is by no means risk-free and therefore questionable. A balanced and varied diet is recommended. Or as the saying goes: “Eat the rainbow”.
Examples
These examples serve to help understand the topic, the list is incomplete. What is important to know for everyday life is that some are more available when cooked. Others, however, are sensitive to heat and should therefore be consumed raw. A balance between raw food and cooked food is to be strived for as much as a colourful plate.
Polyphenols
Polyphenols are found in peel & rim layers.
Anthocyanins
Occurrence
- Aubergine
- Aronia
- Grapes
- Sweet cherries
- Blood oranges
- ect.
Effect
- anticarcinogenic
- antioxidant
- antithrombotic
- anti-inflammatory
Flavonoids
Occurrence
- Onions
- Cabbage
- Apples
- green and black tea
Effect
- anticarcinogenic
- antimicrobial
- antioxidant
- antithrombotic
- immunomodulating
Phenolic Acids
Occurrence
- Coffee
- Bran
- Wholemeal cereals
- Potato peel
Effect
- anticarcinogenic
- antimicrobial
- antioxidant
Resveratrol
Occurrence
- Peanut butter
- Grape juice
- Wine
Effect
- anticarcinogenic
- antioxidant
- antithrombotic
- anti-inflammatory
Isoflavonoids
Isoflavonoids are “plant hormones”. Since they are similar to oestrogen, they bind to its receptor. As a result, they inhibit the cell growth and reproduction-promoting effect of the body’s own hormones.
Occurrence
- Peanuts
- Legumes
- Soy products
Effect
- anticarcinogenic
- antioxidant
- indirectly increases binding of oestrogen in the blood
Terpenes
Cartinoids
Cartinoids consist of about 750 different substances, these are divided into carotenes and xanthophylls. In contrast to the xanthophylls, carotenes are oxygen-free.
Carotenes
They can be better absorbed by adding fat, crushing and heating.
Occurrence
- orange
- yellow
- red fruits and vegetables
Effect
- anticarcinogenic
- antioxidant
- immunomodulating
- anti-inflammatory
Xanthophylls
They are destroyed by heating.
Occurrence
- green vegetables
- green leafy vegetables
- maize
Effect
- anticarcinogenic
- antioxidant
- immunomodulating
- anti-inflammatory
Saponins
Saponins act mainly in the intestine.
Occurrence
- Legumes
- Pseudocereals
- Cereals
- Spinach
- Asparagus
- Onion vegetables
Effect
- anticarcinogenic
- antimicrobial
- immunomodulating
- anti-inflammatory
- increases blood pressure
- cholesterol-lowering
Phytosterols
Phytosterols are “plant cholesterol” and they have the opposite effect to cholesterol in the human body. There are 44 different phytosterols.
Occurrence
- Nuts and seeds
- Legumes
- Cereal germs
- Peanut oil
- Olive oil
- fatty plant parts
Effect
- anticarcinogenic
- cholesterol-lowering
Monoterpenes
Monoterpenes are aromatic substances (ethereal oils).
Occurrence
- Oranges
- Grapes
- Apricots
- Raspberries
Effect
- anticarcinogenic
- antimicrobial
- cholesterol-lowering
Nitrogenous Compounds
Sulphides
Sulphides are sulphur- and nitrogen-containing compounds. There are water-soluble and fat-soluble ones.
Occurrence
- Garlic
- Onions
- Chives
- ect.
Effect
- anticarcinogenic
- antimicrobial
- antioxidant
- antithrombotic
- immunomodulating
- anti-inflammatory
- blood pressure regulating
- cholesterol lowering
- digestive
Glucosinolates
Glucosinolates are mustard oil glycosides. They are sensitive to heat, which can lead to a loss in preparation of up to 50 %.
Occurrence
- Mustard
- Radish
- Cruciferous plants
- Horseradish
- Rape
- Papaya
Effect
- anticarcinogenic
- antimicrobial
- antioxidant
- immunomodulating
- cholesterol-lowering
Phytates
Phytic Acid
Phytic acid is a primary plant substance. Since humans do not have enzymes that break down phytate, it is not absorbed. It does, however, limit protein digestibility. Phytate is partially broken down by soaking and sprouting.
Occurrence
- Rim layers of cereals
- Legumes
- Oilseeds
Effect
- anticarcinogenic
- antioxidant
- immunomodulating
- cholesterol-lowering
- Blood sugar lowering
Proteins & Glycoproteins
Protease Inhibitors
Protease inhibitors are amino acid chains that inhibit enzymes in the small intestine. As proteins, they are heat-labile.
Occurrence
- Plant seeds
- Legumes
- Potatoes
Effect
- anticarcinogenic
- antioxidant
- anti-inflammatory
- satiating
Lectins
Lectins are complex proteins and glycoproteins. They are heat-labile.
Occurrence
- Plants (especially in legumes & cereals)
- Animals
- Microorganisms
Effect
- Blood sugar lowering
- possible unlikely intestinal wall damage

