Therapies using herb and plant extracts

Therapies using herbs and plants can be available as a tea or taken as a tablet, cream or ointment. Some common therapies that use herb and plant extracts include:

  • Aromatherapy, which uses natural oils extracted from plants.
  • Flower remedies, which use the essence of flowers.
  • Homeopathy, which uses plant and mineral extracts diluted many times.
  • Herbal medicines, which use plants or mixtures of plant extracts.

Although plants and herbs are natural, this doesn’t always mean they are safe. Some herbs can interfere with cancer treatments by making them less effective or by increasing side effects.

Always tell your doctor if you are using herb and plant therapies and let your therapist know that you have cancer. Many doctors advise that herbal medicines should be avoided during, and for a few weeks before and after, treatment with chemotherapy or radiotherapy.

About herb and plant extracts

Therapies using herbs and plants are widely available in supermarkets, chemists, health food shops, on the internet, and from nutritionists, herbalists and homeopaths. They are mainly taken by mouth but can also come as oils and creams.

There is no medical evidence to show that flower, plant or herb therapies have any effect on cancer.

A few herb and plant extracts have been shown to be helpful with certain symptoms and side effects. But most have no effect on cancer symptoms or side effects of treatment.


Homeopathy

Homeopathy is used for a number of illnesses. It may be used with conventional treatment to try to improve the quality of life for people with cancer. There is no reliable medical evidence that homeopathy is effective.

Homeopathy is based on the idea that ‘like cures like’. Homeopathic medicines are given that are thought to cause similar symptoms to the illness being treated. Therapists believe that this triggers the body’s natural reaction against the symptoms.

Homeopathic remedies are mostly made of plant and mineral extracts. They come as tablets, liquids or creams, in a very diluted form. Some of the remedies are diluted so much that they have hardly any of the plant or mineral extract left in them.

Some GPs and hospital doctors are trained in homeopathy, and it is sometimes available through the NHS. If you are interested in this type of therapy, you can discuss it with your GP or cancer doctor.

Homeopathy is safe to use alongside conventional cancer treatments because the remedies are extremely diluted. There is no evidence that it causes direct harm.


Aromatherapy

Aromatherapy is the use of natural oils extracted from plants. The oils are thought to be beneficial to your body and mind. They may be used during massage but can also be used in baths and creams, and through diffusers and nasal inhalers.

You don’t always have to remove clothing to have massage or aromatherapy. Having your hand, forearm or head and neck massaged can be very relaxing. There is no medical evidence to show that aromatherapy helps with the symptoms of cancer or side effects of treatment. But many people find it a relaxing and enjoyable experience.

It is important to tell the aromatherapist about any medicines you are taking and give them all your medical details. They use very low-strength oils for people with cancer. But some oils can have physical effects on the body and, for example, may affect blood pressure. Also, some oils can have oestrogen-like effects. You should avoid these oils if you have an oestrogen-dependent cancer, which includes some types of breast cancer.

If you are having any type of cancer treatment, always check with your cancer doctor before you have aromatherapy. Usually it is fine to have aromatherapy and massage during radiotherapy, as long as it is not used on the area being treated.


Flower remedies

Flower remedies use the essence of flowers heated in water. You take the remedy as a liquid. They are considered to be safe and some people feel they help reduce anxiety and help them feel better. But no medical evidence has shown this to be true.

Different types of flower remedies are available. You can buy them from health food shops and some chemists.

Flower remedies are sometimes diluted in alcohol, so people who don’t drink alcohol may choose not to use them.


Herbal remedies

Herbal remedies use plants or mixtures of plant extracts to treat illness and promote health. Practitioners of Chinese medicine also use herbs as part of Traditional Chinese Medicine. Herbs may be boiled in water and drunk as a tea, mixed in an alcohol solution, or be made into tablets, creams or ointments.

Some herb and plant extracts have been researched in clinical trials and have been shown to help with certain symptoms or side effects. Others have been shown to have no effect.

Commonly used remedies include:

  • ginger – used to relieve feelings of sickness (nausea)
  • St John’s Wort – used to treat a low mood and mild to moderate depression.

Although plants and herbs are natural, this doesn’t mean they are safe. Natural substances can have powerful effects and cause side effects. Some conventional treatments are made from plant extracts. So if you choose to take herbal remedies, it is important to use them safely. You need to be aware of any side effects they may cause.

If you take herbal remedies or are interested in them, talk to your cancer doctor or pharmacist. They need to know all the medicines you are taking and whether they are prescribed. This is so they can give you the best possible care.


Taking herbs during cancer treatment

Although we know about some interactions between herbs and cancer treatments, a herbal supplement may have dozens of compounds. All of its active ingredients may not be known. So it is often not possible to know the effects of herbs and possible interactions with other medicines or treatments.

Many doctors advise that herbal remedies should be avoided during, and for a few weeks before and after, treatment with chemotherapy or radiotherapy. Some herbs can interfere with cancer treatments by making them less effective or by increasing side effects. For example:

  • St John’s Wort can reduce the effectiveness of the chemotherapy drug irinotecan.
  • Drinking green tea or taking extract of green tea may make the cancer medicine bortezomib (Velcade®) less effective.
  • Green tea can also increase the side effects caused by the chemotherapy drug irinotecan and by the hormonal therapy tamoxifen.
  • Garlic and evening primrose oil may affect blood clotting and should be avoided before surgery.

Some herbs and dietary supplements can interfere with cancer treatments by making them more toxic or less effective. It is important to check with your cancer doctor or pharmacist if you are planning to use herbal remedies or take supplements during, and for a few weeks before and after, cancer treatment.

The Memorial Sloan Kettering Cancer Center is a reliable website that can give you safety information about individual herbs. If you are seeing a herbalist, check that they are registered with an accredited body.