Silybum marianum L. (Family Asteraceae)
Hepatic.
It is surprising to many that thistles are members of the daisy family (Asteraceae). Asteraceae all have groups (inflorescences) of many small flowers forming a flower head that looks like a single flower.
Their are many species of thistle and to the untrained eye a lot of them look more or less all the same. The distinguishing features of the milk thistle are its milky sap (which one can see coming out of the leaves when they are broken) and the white markings on its leaves (see the photo below). Hence the name. It is also called Saint Mary’s thistle: in popular legend the white leaf markings are supposed to represent the virgin Mary’s milk.
Milk thistle is an upright herb which when adult may be anything from 30 cm to 2 m tall. The stem is grooved and sometimes bears fine cotton-like hairs. Like most thistles the leaves are spiny. The red-purple inflorescences are 4 to 12 cm and in flower in the three summer months. The flower head is surrounded by spiny bracts (modified leaves).
Milk thistle is native to Mediterranean Europe, Iran and Afghanistan, although it has been widely introduced to other areas of the world.
It is found most readily on disturbed ground such as the edges of fields, on fallow or pasture land, near rubble deposits, on waste ground and such like.
The parts of the plant most used for medicine are the seeds, but all of the above ground parts may be used for similar purposes.
While I am wary of speaking in terms of single active constituents (I am more interested in the total effect of the whole plant), many of milk thistle’s properties have been attributed to its silymarin content.
Vital Qualities in Traditional Medicine
In traditional Chinese medicine (TCM) milk thistle is considered a cooling bitter herb that affects the liver, clearing heat and relieving toxicity. As bitterness is associated with a Drying nature and toxicity with Damp, one can conclude that milk thistle has Cooling, Drying properties. Milk thistles bitterness is however mild, which suggests a harmonising effect and a gradual, restorative action, especially on the liver. Nevertheless, it can have dramatic effects as has been demonstrated in its protection against acute death cap mushroom poisoning.
When To Use It
- Liver disorders.
- Scarcity of breast milk.
Milk thistle is antioxidant, hepatoprotective, restorative to the liver, choleretic (it stimulates bile secretion from the liver) and galactogogue (stimulates breast milk production). Its primary use is for liver and gall bladder disorders often as adjuvant treatment: abnormal liver function, hepatitis, cirrhosis, gallstones (prevention of formation), alcoholism, fatty liver, non-alcoholic liver disease, diabetes secondary to cirrhosis, exposure to liver toxins (e.g. death cap mushroom poisoning), chemotherapy, drug abuse, oral contraceptive use. It can also be tried for scarcity of breast milk in lactating mothers.
When and How to Harvest
Milk thistle seeds are harvested in the autumn when the flowers dry out and the thistle head is covered in whispy hairs. Harvest them on a warm dry day after any dew has evaporated. These hairs come from the ends of the seeds, which are brown, beige or grey in colour. Wearing thick gloves cut off the thistle heads with pruning shears, leaving a few centimetres of stalk on the head. Dry them by putting them in the oven at 70ºC for 5 hours or until the flower parts crumble easily between your fingers. When they are dry put them into a hessian bag, shake it vigorously and press it between your fingers to loosen the seeds from the thistle heads. Then they may be poured from the bag into a sealable jar for conservation. If you do this outside in a breeze, the chaff will blow away while the seeds will go into the jar!
The flowers and leaves are best harvested just after flowering. make sure you wear protective gloves to protect your hands from the spines.
Easy Household Use
Authority sources recommend between 4 and 15 g per day [1, 2]. They are referring to the dried seed as most sources do. We can only make an assumption that the same dosage range holds true for the above ground parts of the plant.
Split into 3 doses (the normal way of taking herbs) that is a minimum dose of about 1.3 g (or a third of a teaspoon) and a maximum of 5 g (1 teaspoon) taken 3 times a day. This can be taken as a decoction (hard parts like seeds) or infusion (softer parts like leaves and flowers).
For an average dose of a decoction use 10 g of dried seeds in 600 mL of water. Let it boil down to 500 mL, then strain. This is the quantity needed for one day. Drink 3 cups a day.
For an infusion bring 500 mL of water to the boil, turn off the heat, add 10 g of dried leaf or flower and let steep for 15 minutes before straining.
Or make a tincture using 200 g of dried seeds in 1 L of vodka or white wine / apple vinegar. Clearly alcoholic tinctures are not appropriate when there is serious liver damage or alcoholism. An alternative is to make your tincture using vinegar or vegetable glycerine. Take a dessertspoonful in water three times a day. 1 L will last you a month.
If using fresh plant parts, double the above weights of the plant parts used.
Silymarin absorption is enhanced when taken with lecithin. A simple way of achieving this is to eat the yolk of a boiled egg, or lecithin may be bought as a food supplement.
When Not to Use It
Milk thistle may lower your blood sugar so if you are on antidiabetic medication wou will need to consult your doctor before taking it and monitor your blood sugar regularly while taking it.
[1] Principles and Practice of Phytotherapy by Kerry Bone and Simon Mills,Churchill Livingstone, 2013.
[2] European Commission E, as reported in Medical Herbalism by David Hoffmann, Healing Arts Press, 2003.
Mediterranean Healing Herbs 