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Supplements: Myths and Realities

Supplements: Myths and Realitiesby Beth Leibson

This is the second article in a 2-part 2012 update on the use of complementary alternative medicine for cancer. Part I can be found here.

In a fairy tale world, an apple can kill you and a sip of water can make you live forever. Supplements have the reputation of being equally powerful in our world. It’s as easy as swallowing Vitamin A, B-12, and Cod liver oil.

While supplements can be very helpful for cancer patients and survivors, it is important to be careful. There are a lot of myths surrounding supplements, especially for cancer patients and survivors. Here we debunk some of them:

MYTH: Supplements can prevent cancer in the first place.

False. In general, the American Institute for Cancer Research doesn’t recommend supplements for cancer prevention, says Alice Bender, MS, RD, Nutrition Communications Manager at the institute. “No specific nutrient will help for everyone and some can be detrimental,” she explains.

Supplements can upset the balance of nutrients in the body, notes the institute. For instance, while it has been thought that beta carotene might reduce cancer risk, it can actually increase the risk of lung cancer for smokers.

Some people can benefit from vitamin supplements, explains Bender. “People over age 50 may need B-12, people living in northern climates may need vitamin D, the elderly may need calcium,” she adds. “But in general, the American Institute for Cancer Research feels that the overall diet is more important than the individual components in preventing cancer.”

MYTH: Oncologists don’t care if you’re taking supplements.

False. “I want to know any supplements any patients are taking if they’re going for any complementary medicine,” says Beth Baughman DuPree, MD, FACS, a breast surgeon with Southampton, PA-based Holy Redeemer Health System.

Sometimes multiple medicines or supplements interact with each other and create pain or danger for the patient. And some Eastern modalities can affect the efficacy of Western treatments. It is best to talk with your doctor about any supplements you are taking or considering taking, to be sure they are a good fit for your situation.

MYTH: Cancer occurs because the body's immune system fails to detect cancerous cells and get rid of them before they cause harm. For this reason, cancer patients must boost immunity to beat their disease.

Tricky, but false. This myth is interesting because it has a grain of truth to it, says Suzanne Dixon, MPH, MS, RD a dietician and epidemiologist. It is true that the immune system fails to detect cancerous cells in some solid tumors, such as breast, colon, lung, and prostate cancers, she adds. Boosting immunity may be beneficial for patients with these tumors.

“However, boosting immunity across the board for all cancer patients is NOT a good idea,” says Dixon, because some other tumors occur within the immune system. These cancers result because the immune cells themselves become cancerous. These cancers, including leukemia and lymphoma, are sometimes called "liquid" or hematalogic (blood) tumors. “In these cases, boosting the immune system may cause more harm than good,” Dixon adds. It could ‘rev up’ or ‘turn on’ production of those same immune system cells that are causing the cancer. “Not a good idea!” Dixon explains.

In the end, supplements can help cancer patients manage the symptoms of treatment, enhance their energy, and improve their quality of life. But it is important to take the right ones, in the proper amounts, and at the appropriate times.

MYTH: If one vitamin is good, more is better.

False. More is not necessarily better. “I can probably name 50 things that are good for people with cancer,” says Sarah Cimperman, ND, a board-certified doctor of naturopathic medicine in private practice in New York City. But that doesn’t mean that each one is meant for every individual patient.

“I’ve had patients come in here taking 20 different supplements,” Dr. Cimperman explains. While each of these supplements offers benefits, she says, mixing all of them can be very hard on the liver. “You need someone to pick strategically.”

It is important to look at the whole person and match the supplement to the particular patient, says Dr. Cimperman.

“For instance, green tea can be very helpful for people who have or want to prevent cancer,” she explains. “It is also helpful for other conditions, especially ones that involve swelling, such as diabetes.” So it may be a good match for a patient struggling with both cancer and diabetes. Green tea is fairly benign, says Dr. Cimperman, and so it is often a safe bet.

But not always. “People with anxiety can be sensitive to the caffeine in green tea,” for instance, says Dr. Cimperman. And anyone who tends toward anxiety is sure to experience it during cancer treatment.

MYTH: If a supplement is natural, it’s good (and safe).

False. Many supplements are natural, which means they come from a plant, mushroom, bacteria, or other substance found in nature, says Dixon. While natural supplements can be both beneficial and safe, they are not necessarily so.

“Many plants which are natural, and even have edible parts, also can be toxic,” says Dixon. “Apples are delicious, but their seeds contain cyanide-type substances referred to as cyanogenic glycosides. The same is true for peaches, cherries, plums, and apricots. The fruit is edible, but the pits and even the leaves of these plants can be toxic.”

Similarly, many mushrooms are edible and can even be used medicinally – but others are highly toxic and can cause liver failure and death if eaten, Dixon explains.

Also, bear in mind that not many herbal products are standardized, says K. Simon Yeung, PharmD, MBA, Lac, research pharmacist, acupuncturist, and clinical coordinator for the Integrative Medicine Service at Memorial Sloan-Kettering Cancer Center. So you cannot be certain they are in the correct dosage, Dr Yeung explains; too little of a given supplement could be ineffective while too much could be dangerous. The Sloan-Kettering website offers plenty of information on supplements at their website.

MYTH: It’s been used for thousands of years, so it must be good.

False. “Many substances which have a long history of use in native or indigenous medicine systems have potential benefits,” says Dixon. “However, not all products that have a long history of use offer health benefits or are safe.” The obvious example is tobacco. Archaeological evidence suggests it has been used medicinally since at least 1000 BCE, notes Dixon. But today, “we know that regular tobacco use is damaging to health, increasing the risk of lung and other cancers.”

There are any number of other remedies that have been used for decades if not centuries – but are now considered to be unsafe. These include chaparral (for colds, inflammation, and cancer but can cause liver and kidney damage), comfrey (treats conditions ranging from painful menstrual periods to cancer, but can cause liver damage and possibly cancer), and blue cohosh (has been used to induce labor but can cause stroke, heart attack, and shock). There are many other examples, notes Dixon. Before you start taking supplements, be sure to get up-to-date information on safety and efficacy.

MYTH: The FDA wouldn’t let the manufacturer claim something that’s not true.

False. The Food and Drug Administration (FDA) regulates dietary supplements under a different set of regulations than food or drugs (prescription and over-the-counter), according to the FDA website.

The supplement manufacturer is responsible for ensuring that supplements are safe. Generally, they don’t need to register their products with the FDA before producing or selling them. The FDA is responsible for taking action against an unsafe supplement after it reaches the market. “The FDA doesn’t take action until someone complains,” says Dr. Yeung.

By which point, it may well have been purchased – and used. Hopefully not by you.

Supplements can provide many benefits to cancer patients and survivors. They can help manage the symptoms of treatment, enhance their energy, and improve their quality of life. Just be careful to pick and choose carefully – consult an expert.


Beth Leibson lives and writes in New York City. She is author of I’m Too Young to Have Breast Cancer (LifeLine Press, 2004).