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Dietary and Herbal Supplements

What is a dietary supplement?

A diet is a plan or strategy for eating certain foods. Adding anything to your regular diet to improve your health or help you heal is called a dietary supplement. Some examples are:

  • Vitamins

  • Minerals

  • Amino acids

  • Natural hormones

  • Enzymes

Can dietary supplements help people with cancer?

There is no scientific evidence that a person’s diet can cure cancer. But you may get medical nutrition therapy from a registered dietitian as part of your regular healthcare. Your body's nutritional needs can be met by eating a balanced diet.

Some supplements might help decrease cancer risk. But there's no clear evidence for this claim. Many such claims made by manufacturers of some supplements are not scientifically proven. And some supplements might interfere with the safety or effectiveness of certain cancer treatments. Be sure to let your healthcare provider know about any supplements you take (including multivitamins) before starting treatment.

There are also many possible side effects from certain diets and supplements, especially if you take high doses. These include weakness, diarrhea, or kidney problems. Following diets that your healthcare provider or registered dietitian has not approved can be unsafe at any time, but especially during cancer treatment. Talk with your healthcare provider or registered dietitian before making any changes to your regular diet.

What are the different dietary supplements?

Below is a list of some dietary supplements. Always talk with your healthcare provider before taking any of these:

  • Vitamins. These are needed in small quantities for the body to grow and stay strong. They include vitamin A, vitamin D, vitamin C, and vitamin E.

  • Minerals. These are elemental nutrients. They are needed to stay healthy. They include calcium, magnesium, and zinc.

  • Antioxidants. These protect the body’s cells from damage caused by free radicals. Free radicals are by-products of the body’s normal chemical processes.

  • Enzymes. These are proteins made by the body. They start and speed up chemical processes, such as digestion. Some enzymes can be taken as supplements.

  • Amino acids. These are the building blocks of the body’s proteins. Proteins are needed for growth and development. Some amino acids are made by the body. Others, called essential amino acids, come from your diet.

  • Plant extracts. These are sometimes used to help nourish the body. Followers of the principles of Chinese medicine may use them. Traditional Chinese medicine works to restore a balance of energy, body, and spirit for good health. When cancer causes imbalances, people who use Chinese medicine may try herbs, minerals, and plant extracts as treatment.

  • Hormones. These are chemicals made in glands in the body. They affect how organs and tissues work.

  • Herbs. These are plants used in food preparation or for medicinal purposes.

  • Homeopathic products. These are very small doses of natural substances, often herbs, diluted with water or alcohol. Homeopathic medicine is based on the belief that what causes symptoms in a healthy person can cure the same symptoms in someone who is not healthy. These products are used to start healing, not to stop symptoms.

You can find dietary supplements at grocery stores, health food stores, and drug stores. They come in many forms, such as:

  • Pills

  • Capsules

  • Liquids

  • Power bars

  • Cookies

  • Powders

  • Elixirs

Are there any possible problems or complications?

Not all dietary supplements available over the counter are proven to be safe.

Each supplement is different. Most are not scientifically tested. So the side effects are unknown. Many cancer experts advise that you do not use vitamins or other dietary supplements. If you're getting cancer treatment and were already taking dietary supplements before the cancer was diagnosed, be sure to tell your healthcare provider. Some supplements may interfere with your treatment.

Some supplements can increase skin sensitivity. This can be a problem for people getting radiation treatment. Other supplements may increase the risk of bleeding. That can increase complications after surgery. People being treated with chemotherapy may have more side effects depending on what supplements they take. Some supplements can make chemotherapy work less well.

What is an herbal supplement?

Herbal supplements are products made from plants. They are used in treating and managing certain diseases and health problems. Many prescription and over-the-counter medicines are also made from plants. These products contain only purified ingredients. And unlike herbal supplements, they are closely regulated by the FDA. Herbal supplements may contain entire plants or plant parts.

Herbal supplements come in all forms. They may be dried, chopped, powdered, or put in a capsule or liquid. They can be used in various ways, including:

  • Swallowed as pills

  • Brewed as tea

  • Put on the skin as gels

  • Added to bath water

Can herbal supplements help people with cancer?

The practice of using herbal supplements dates back thousands of years. Today, there is a renewal in the use of herbal supplements among Americans. But herbal supplements are not for everyone. In fact, some herbal products may cause problems for people getting cancer treatment. Because they are not subject to close scrutiny by the FDA or other governing agencies, the use of herbal supplements is controversial. Don't take any herbal supplements without first talking with your healthcare provider.

The FDA and herbal supplements

The FDA considers herbal supplements to be foods, not medicines. So these products don't get the same testing, manufacturing, and labeling standards and regulations as medicines.

Don't self-prescribe. Talk with your healthcare provider before taking herbal supplements.

Medical Reviewers:

  • Jessica Gotwals RN BSN MPH
  • Sabrina Felson MD
  • Todd Gersten MD