Milk thistle: uses and benefits

This traditional herbal medicine can support liver health.

🕒 2 min read

Milk thistle (Silybum marianum) has been used as a herbal medicine for at least 2,000 years, and is especially popular for supporting liver health. The remedy is derived from the seeds of a thistle, the leaves of which are splattered with prominent white splashes.

Classified as a traditional herbal medicine in the UK, milk thistle is now licensed to relieve the symptoms associated with occasional over-indulgence of drink and food, such as indigestion and upset stomach.

How does it work?

Milk thistle seeds contain a mix of antioxidants, known collectively as silymarin. These antioxidants help to protect cells from damaging free radicals (unstable oxygen-containing molecules) and, in the case of liver cells, may help to protect them from the poisonous effects of toxins, including excess alcohol.

It appears to work by maintaining or increasing levels of the liver's own protective antioxidant, glutathione. It may also have an effect on liver cell membranes to stop toxins from entering, and may stimulate liver cell regeneration.

What can it help?

Liver health

Research suggests that milk thistle can improve liver function. Eight clinical trials involving people with raised enzyme levels due to non-alcoholic fatty liver disease found that silymarin reduced these levels more than placebo.

Further data from 19 clinical trials that studied the effects of milk thistle in treating alcoholic liver disease also found that silymarin lowered the level of one liver enzyme. Survival rates were significantly higher in those taking milk thistle extracts, too, both overall and when taking liver-related mortality into account.

Type 2 diabetes

Milk thistle extracts may improve glucose control in people with type 2 diabetes. A study showed that taking 140mg of silymarin three times a day for 45 days significantly improved fasting blood glucose levels (by 11 per cent) and insulin resistance, while lowering blood triglyceride levels (by 23 per cent). Total and LDL-cholesterol levels fell by more than seven per cent, while 'good' HDL-cholesterol increased.

How much should I take?

Milk thistle is taken at a dose equivalent to 108mg of silymarin (from 193mg to 261mg dry extract). This can be taken once or twice a day, preferably between meals.