This week the wheels of the internet churned with news
headlines about vitamin D and colorectal cancer. I clicked links, read articles and
soon discovered that the flurry of interest stemmed from a single research
study published in the January 2015 edition of the journal Gut. I went to PubMed and found the article there. I read the
abstract and tried to access the article. Since the research was funded in-part
by the National Institute of Health, I hoped to be able to access the
publication (NIH funded research must be published as open-access). However,
journals/publishers have the right to initially restrict access to their
subscribers (mostly universities, medical and research institutions) for
limited periods of time. This article is embargoed. I tried but cannot access
it. What I can access is a press release and the scientific abstract. The press release likely was written by someone in the communications or
marketing division at Harvard Medical School's Dana-Farber Cancer Institute where the research was conducted. The scientific abstract is a very brief summary of the article written by the researchers and is part of the research publication. The
abstract is available at the journal’s website for free and is available on
PubMed.gov.
Based on what I read, most of the journalists who covered
the story rehashed/regurgitated the press release. Here is the original
press release from January 15, 2015: Fana-Farber Cancer Institute-Newsroom-News-Releases/Vitamin-D-protects-against-colorectal-cancer-by-boosting-the-immune-system.
The following are examples of links to news articles that
covered the “story.” Some are better than others. Some let you know that they
are talking about a press release but most do not.
 |
| A sunny day at Ocean Beach in San Diego, CA (January 2015) |
Here is a link to the abstract at PubMed.gov.
I look forward to reading the article and will share my comments with you once I have
some (Song et al., 2015).
Colorectal Cancer in the United States
Colorectal cancer impacts men and women without discrimination. In 2011, 135,260 men and women were diagnosed with colorectal cancer in the United States (CDC-Colorectal Cancer Statistics).Factors that Influence Risk of Colorectal Cancer
You cannot control
some risk factors.
Age
|
The risk for colorectal cancer
increases with age. Most cases are
diagnosed in people 50 years or older. BUT, colorectal cancer develops in
younger people too. If you are concerned about your intestinal health
and/or risk, talk to your doctor. Be persistent. You know your body best. Be your own advocate!
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Health history – your family’s and your own
|
Your family – If you have a first degree relative
who had colorectal cancer, your risk increases.
Your own health – If you have
inflammatory bowel disease you have a greater risk of developing colorectal
cancer.
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Your genes (DNA)
|
Some
changes to your genes increase your risk.
|
You can control some
risk factors.
Drinking alcohol
|
Drinking 3 or more alcoholic
beverages a day increases the risk of colorectal cancer as well as the risk
of developing noncancerous (benign) colon tumors.
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Smoking cigarettes
|
Smoking cigarettes increases the risk of developing colorectal cancer (as
well as other types of cancer) and increases the risk of dying from cancer.
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Overweight
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Being overweight or obese increases the risk of
developing colorectal cancer.
|
Factors that may
reduce your risk.
Regular physical activity
|
A physically active lifestyle is
associated with a lower incidence of colorectal cancer.
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Remove large polyps
|
Getting polyps 1 centimeter and larger removed may reduce the chance of
them becoming cancerous.
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Aspirin
|
Under the
direction and supervision of a qualified health care professional, taking aspirin
daily for 5 years was associated with lower incidence of colorectal cancer.
There are serious side effects of
long-term aspirin use. NEVER take aspirin daily unless directed by your
health care provider.
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Combined hormone replacement therapy (women)
|
Under the direction and guidance of a qualified health care professional,
some postmenopausal women at high risk for colorectal cancer may benefit from
combined hormone replacement therapy that combines estrogen and progestin. This type of therapy has been effective at
reducing the risk of colorectal cancer, however, it may increase the risk of
breast cancer, heart disease, and the formation of blood clots.
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Signs and symptoms of
colon cancer and intestinal problems.
Blood in stool
|
Blood can be bright red in color
or it can be very dark.
You know yourself and what is
normal for you. If something changes, talk to your health care provider.
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Change in bowel habit
|
Diarrhea, constipation or feeling bowel does not empty.
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· Frequent gas pains
|
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Weight loss
|
Discuss unintentional weight loss with your health care provider.
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Tiredness
|
If you are
feeling unusually tired, discuss this with your health care provider.
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Vomiting
|
Resources:
- National Cancer Institute:/Cancer Topics, Prevention - Colorectal
- Dana-Farber Cancer Institute: Adult-Care, Treatment and Support - Colon-Cancer
What about Diet?
Choosing fresh fruits and vegetables, whole grains,
fiber-rich foods, limiting red and processed meats, selecting moderate portion
sizes, and limiting alcohol intake promotes health. These are choices that can
reduce your risk of developing colorectal cancer. Combine these choices with
achieving and maintain a healthy body weight and engaging in regular physical
activity to impact many of the factors you can control when it comes to your
risk for colorectal cancer.
Resources
- Academy of Nutrition and Dietetics: Cancer
- National Cancer Institute:/Cancer Topics, Prevention - Colorectal
Why the Interest in Vitamin D?
Epidemiological studies suggest that people with low vitamin D
levels have an increased risk of developing colorectal cancer (Klampfer, 2014). Researchers want to understand why this is –
how vitamin D influences the risk of colorectal cancer. Vitamin D works inside cells to affect
the way genes are expressed. It is thought that when there is
not enough vitamin D, cells may proliferate too much (unregulated) and not die
as they should. Immune cells use and need vitamin D. When the body lacks
vitamin D, it may not adequately launch the right immune response or it may not
be robust enough. This may include an immune response to deal with tumors (Klampfer, 2014; Song et al., 2015)
Researchers are also investigating whether or not supplementing
recently diagnosed colorectal cancer patients with regular (400 IU) or high (4000 IU) vitamin D in addition to their cancer therapy regimen
improves outcomes. To my knowledge, results from this study are not yet
available, although the on-the-ball publicity team at the Dana-Farber Cancer
Institute did post a press release on January 12, 2015 that Kimmie Ng, MD, MPH
presented research at the 2015 American Society of Cancer Oncology
Gastrointestinal Cancers Symposium (Dana-Farber: Newsroom "New study shows high vitamin D levels increases survival of patients with metastatic colorectal cancer"). I look forward to reading the actual research study when the paper is published.
Final Thoughts
I continue to be shocked and dismayed by the reporting of
science and health news based on press releases. It only functions to confuse,
mislead, and drive consumers towards decisions not yet supported by science and
medicine. I think it is dangerous, irresponsible, and contributes to confusion
and misunderstanding about what we do and do not know about nutrition, science,
health, and medicine.
Symptoms of too much
vitamin D (vitamin D toxicity).
Nausea
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Vomiting
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Loss
of appetite
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Constipation
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Increased
blood calcium
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Confusion
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Heart
arrhythmia
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Depression
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Headaches
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Sleepiness
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Weakness
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Resources:
- Office of Dietary Supplements: Fact Sheet - Vitamin D for Health Professionals
- National Cancer Institute: Treatments and Alternative Medicine, Herbs and Vitamins and Minerals
Klampfer, L. (2014). Vitamin D and colon
cancer. World J Gastrointest Oncol, 6(11),
430-437. doi: 10.4251/wjgo.v6.i11.430
Song,
M., Nishihara, R., Wang, M., Chan, A. T., Qian, Z. R., Inamura, K., . . .
Ogino, S. (2015). Plasma 25-hydroxyvitamin D and colorectal cancer risk
according to tumour immunity status. Gut.
doi: 10.1136/gutjnl-2014-308852
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