Tuesday, January 20, 2015

Vitamin D and Colorectal Cancer?


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!
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.
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.
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.
Overweight
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.
Remove large polyps
Getting polyps 1 centimeter and larger removed may reduce the chance of them becoming cancerous.
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.
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.


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.
Change in bowel habit
Diarrhea, constipation or feeling bowel does not empty.
·    Frequent gas pains 
 Feeling bloated, the sensation of gas, or abdominal cramps are health concerns to discuss with your health care provider. 
Weight loss
Discuss unintentional weight loss with your health care provider.
Tiredness
If you are feeling unusually tired, discuss this with your health care provider.
Vomiting




Resources:


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


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.

At this time, it is NOT recommended that you take more vitamin D to reduce your risk of colon cancer. The only people that should take vitamin D supplements are those who have low vitamin D status. You can find out if you have a vitamin D deficiency or if your vitamin D status is low through a simple blood test. Most physicians are willing do this and many routinely test for vitamin D. Vitamin D lingers in the body and can be toxic at high doses. The recommended amount for adults is 600 IU per day for people 1 to 70 years and 800 IUs after 70 years (Office of Dietary Supplements, Vitamin D). If you do invest in supplements, remember that supplements are not regulated by the Food and Drug Administration in the same way pharmaceuticals are regulated. Also, pay careful attention to the dosage amount.



Symptoms of too much vitamin D (vitamin D toxicity).

Nausea
Vomiting
Loss of appetite
Constipation
Increased blood calcium
Confusion
Heart arrhythmia
Depression
Headaches
Sleepiness
Weakness



Resources:
 Literature Cited

 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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