From Our Archives: Advocacy
September 14, 2011
Cancer Imaging Gets Sophisticated
September 14, 2011 – Susan R. Peck, PhD
Sleep Problems Impair Childhood Cancer Survivors
September 14, 2011 – Taylor Walker
Vitamin D and Folate May Reduce Colon Cancer Risk
September 14, 2011 – Lena Huang
From Our Archives: Supplements
September 14, 2011
From Our Archives: Imaging
September 16, 2011
Flaxseed Doesn't Help With Hot Flashes
September 14, 2011 – Kathy LaTour
Safety in Numbers
September 14, 2011 – Jane Hill
Previvors Need Expert Guidance, Close Surveillance
September 14, 2011 – Dawn Dorsey
Should You “Just Do It?”
September 14, 2011 – Marc Silver
Checking Out a Charity
September 14, 2011 – Marc Silver
Understanding Clinical Trials
September 14, 2011
Don’t Believe Everything You Read on Supplement Labels
September 14, 2011 – Laura Beil
Tell What You’re Taking
September 14, 2011 – Laura Beil
Searching for a Cancer Coach?
September 14, 2011 – Jennifer M. Gangloff
What Caused Your Cancer?
September 14, 2011 – Staff Reports
Açaí Berry’s Effect on Cancer in Question
September 14, 2011 – Jason Roberson
Remaining Faithful
September 14, 2011 – Cheryl L. Rice
Pipeline
September 14, 2011 – Lindsay Ray
Supplement Research in Cancer Lacking
September 14, 2011 – Barrie Cassileth, PhD
Managing Cancer-Related Diarrhea
September 14, 2011 – Katy Human
Comments from Readers
September 14, 2011
The Meaning of Stem Cells
September 14, 2011 – Debu Tripathy, MD
San Antonio Breast Cancer Symposium
September 14, 2011 – Lindsay Ray
Q & A: Patients Want Coordinated Care
September 14, 2011 – Len Lichtenfeld, MD
A Survivorship Resource Map
September 14, 2011 – Elizabeth Whittington
Critical Care: A New Nurse Faces Death, Life, and Everything in Between
September 14, 2011 – Kathy LaTour
Breast Cancer Drug Scores Win in Prevention
September 14, 2011 – Elizabeth Whittington
Ford Led Discussion on Breast Cancer
September 14, 2011 – Lindsay Ray
Another State Gets Chemo Parity
September 14, 2011 – Taylor Walker
How to Manage Family Dynamics During Cancer
September 14, 2011 – Jane Hill
Coordinating Care After Cancer
September 14, 2011 – Dawn Dorsey
Do You Need a Cancer Coach?
September 14, 2011 – Jennifer M. Gangloff
Choosing an Imaging Test
September 14, 2011 – Charlotte Huff
Advocates Make Cancer Their Mission
September 14, 2011 – Marc Silver
Unlocking the Mystery of Cancer Stem Cells
September 14, 2011 – Elaine Schattner, MD
Supplements During Cancer: Help or Hype?
September 14, 2011 – Laura Beil
From Our Archives: Advocacy
September 14, 2011
Cancer Imaging Gets Sophisticated
September 14, 2011 – Susan R. Peck, PhD
Sleep Problems Impair Childhood Cancer Survivors
September 14, 2011 – Taylor Walker
Vitamin D and Folate May Reduce Colon Cancer Risk
September 14, 2011 – Lena Huang
From Our Archives: Supplements
September 14, 2011
From Our Archives: Imaging
September 16, 2011
Flaxseed Doesn't Help With Hot Flashes
September 14, 2011 – Kathy LaTour
Safety in Numbers
September 14, 2011 – Jane Hill
Previvors Need Expert Guidance, Close Surveillance
September 14, 2011 – Dawn Dorsey
Should You “Just Do It?”
September 14, 2011 – Marc Silver
Checking Out a Charity
September 14, 2011 – Marc Silver
Understanding Clinical Trials
September 14, 2011
Don’t Believe Everything You Read on Supplement Labels
September 14, 2011 – Laura Beil
Tell What You’re Taking
September 14, 2011 – Laura Beil
Searching for a Cancer Coach?
September 14, 2011 – Jennifer M. Gangloff
What Caused Your Cancer?
September 14, 2011 – Staff Reports
Açaí Berry’s Effect on Cancer in Question
September 14, 2011 – Jason Roberson
Remaining Faithful
September 14, 2011 – Cheryl L. Rice
Pipeline
September 14, 2011 – Lindsay Ray
Currently Viewing
Supplement Research in Cancer Lacking
September 14, 2011 – Barrie Cassileth, PhD
Comments from Readers
September 14, 2011
The Meaning of Stem Cells
September 14, 2011 – Debu Tripathy, MD
San Antonio Breast Cancer Symposium
September 14, 2011 – Lindsay Ray
Q & A: Patients Want Coordinated Care
September 14, 2011 – Len Lichtenfeld, MD
A Survivorship Resource Map
September 14, 2011 – Elizabeth Whittington
Critical Care: A New Nurse Faces Death, Life, and Everything in Between
September 14, 2011 – Kathy LaTour
Breast Cancer Drug Scores Win in Prevention
September 14, 2011 – Elizabeth Whittington
Ford Led Discussion on Breast Cancer
September 14, 2011 – Lindsay Ray
Another State Gets Chemo Parity
September 14, 2011 – Taylor Walker
How to Manage Family Dynamics During Cancer
September 14, 2011 – Jane Hill
Coordinating Care After Cancer
September 14, 2011 – Dawn Dorsey
Do You Need a Cancer Coach?
September 14, 2011 – Jennifer M. Gangloff
Choosing an Imaging Test
September 14, 2011 – Charlotte Huff
Advocates Make Cancer Their Mission
September 14, 2011 – Marc Silver
Unlocking the Mystery of Cancer Stem Cells
September 14, 2011 – Elaine Schattner, MD
Supplements During Cancer: Help or Hype?
September 14, 2011 – Laura Beil

Supplement Research in Cancer Lacking

Nutritional supplement research is unsatisfactory. 

BY Barrie Cassileth, PhD
PUBLISHED September 14, 2011

The extraordinary prevalence of dietary supplements spans television ads, books and the Internet, plus the recommendations of well-meaning friends and colleagues. The relentless promotion and claims of profit-seeking marketers contribute to supplement appeal. Cancer patients and survivors are routinely encouraged to consider or try such products, and the great majority do both.

Cancer patients who use dietary supplements must contend with multiple clinically important issues, including the dangers of hiding supplement use from physicians and the opposite—bringing bags of supplement bottles to their oncologists for discussion and guidance—as well as needing control to do whatever possible to improve their health.

The motivation to use supplements is entirely understandable, but the heart of the problem is the lack of good guidance. Available data are inconsistent, contradictory, limited, confusing and often inadequate.

Nutritional supplement research began with epidemiologic diet studies showing statistical associations between nutrients and cancer prevention. Researchers then looked at individual nutrients contained in the good diets. However, selecting a single nutrient from the many in a vegetable, for example, and administering it as a medication, is not a viable follow-up. It is unlikely that a single ingredient by itself produces a benefit. Instead, it is likely that interactions among several, if not all, elements produced the benefits seen in diet studies, but not when studied as an isolated element or two.

The famous study of beta-carotene and people at high risk for lung cancer was based on diet questionnaire results showing that smokers who consumed beta-carotene-rich foods had a reduced risk of lung cancer. But that does not imply that a high dose of a single synthetic derivative will achieve the same cancer preventive advantage. In fact, a subsequent beta-carotene study using a synthetic derivative showed the opposite. The isolated derivative of beta-carotene-rich foods caused more, not fewer, deaths in people at high risk for lung cancer, so the study was halted. 

Further, the context of all diet studies must be considered. The beta-carotene study, for example, involved people with a history of smoking or asbestos exposure. It is unlikely that any one vitamin or nutrient could offset the damage that smoking inflicts.

Supplement studies often contradict one another because researchers use different forms of the same nutrient. Vitamin E, for example, is not one chemical substance; there are actually eight forms. One, alpha-tocopherol, has been studied often in cancer. There are also many forms of vitamin D. Moreover, it is uncertain whether the various forms work synergistically. Only future research using complex vitamins can answer this question.

Many claims are based on false, insufficient or poor-quality evidence, heightening the dangers of their use during cancer treatment. There is a very real possibility that antioxidants may interfere with radiation therapy and some chemotherapeutic agents. What patients may gain by taking supplements in short-term feelings of well-being, they may lose in reduced long-term treatment effectiveness. After enduring the difficulties of cancer treatment, it is best to avoid the possibility of minimizing its effectiveness.

Don’t ascribe too much promise to single nutrients. Have realistic expectations, based on the best science available. Get your vitamins from food.

Barrie R. Cassileth, PhD, is chief of Integrative Medicine Service at Memorial Sloan-Kettering Cancer Center in New York City and a member of CURE’s advisory board. Donald Garrity, RD, is an Integrative Medicine Service nutritionist at Memorial Sloan-Kettering.

Be the first to discuss this article on CURE's forum. >>
Talk about this article with other patients, caregivers, and advocates in the General Discussions CURE discussion group.

Related Articles

1
×

Sign In

Not a member? Sign up now!
×

Sign Up

Are you a member? Please Log In