Archives for posts tagged ‘preventing cancer’
Friday, 30 December 2011
Tuesday, 29 November 2011
Coverage of the decision by the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) to expand its recommendation for the Human Papilloma Virus (HPV) vaccine (Gardasil) to boys and young men aged 11-21 was widespread, appearing on the three network newscasts, and in national newspapers.
Monday, 3 October 2011
A major study is reporting that people who practiced four low-risk behaviors are 63% less likely to die (during the stydy period) than those who kept none of those practices. The researchers found that ALL four of these low-risk behaviors were individually associated with a reduction in death and that the higher number of behaviors practiced, the lower the risk of death. So, what were they?
Tuesday, 19 July 2011
According to a study published in the American Journal of Epidemiology, sedentary behaviors, particularly those that require minimal energy expenditure, may increase the risk of developing chronic diseases including colon cancer and heart disease.
Wednesday, 6 April 2011
Readers of this blog over the last year, have seen many of my posts on the plethora of studies and recommendations about vitamin D. Now there’s some new data I think you’ll be interested in.
Wednesday, 23 March 2011
In two previous blogs (“Thirty percent of breast cancers could be prevented by lifestyle changes” and “Three Healthy Habits Cut Breast Cancer Risk, Study Finds“) I’ve discussed the association between cancer risk and lifestyle choices.
Friday, 28 January 2011
Congrats to the new Surgeon General, for taking an even stronger stand on tobacco in her recent report, “How Tobacco Smoke Causes Disease.: The Los Angeles Times and Orlando Sentinel write that the report has found that “ANY exposure” to tobacco smoke can cause immediate damage to the human body.
“There is NO safe level of exposure to cigarette smoke,” Surgeon General Regina Benjamin said.
“Inhaling even the SMALLEST amount of tobacco smoke can also damage your DNA, which can lead to cancer.”
The report also finds almost NO difference between being a light smoker and a heavy smoker.
“That’s because of the inflammatory processes occur at very, very low doses,” said cardiologist Dr. Stanton Glantz.
The AP notes that the report “is the 30th issued by the nation’s surgeons general to warn the public about tobacco’s risks,” but “is unusual because it devotes more than 700 pages to detail the biology of how cigarette smoke accomplishes its dirty deeds — including the latest genetic findings to help explain why some people become more addicted than others, and why some smokers develop tobacco-caused disease faster than others.”
CNN says that the report “links smoking directly to 13 different cancers including esophagus, trachea, stomach, pancreas, kidney, bladder, cervix and acute myeloid leukemia.”
It also “ties smoking to more than a dozen chronic diseases like stroke, blindness, periodontitis, heart disease, pneumonia; reproductive problems like diminishing fertility; chronic obstructive pulmonary disease (COPD), asthma and other respiratory illnesses.”
The Washington Post “Checkup” blog reports that Matthew L. Myers, president of the Campaign for Tobacco-Free Kids, called the report “a stark reminder of how lethal and addictive smoking truly is.”
Friday, 28 January 2011
You’re likely hearing a fair bit of controversy over the Institute of Medicine’s (IOM’s) new recommendations (RDA) for vitamin D and calcium. I first reported on this in my blog, “Institute of Medicine says megadoses of vitamin D, calcium unnecessary.”
The IOM calls for MORE vitamin D and LESS calcium … but many experts say the vitamin D doses are still not high enough.
The new RDA is:
- 400 IU for infants,
- 600 IU for ages 1 to 70, and
- 800 IU for over 70.
But these RDAs are based ONLY on the amount needed to prevent bone problems, such as rickets, osteomalacia, osteopenia, osteoporosis, and fractures.
Higher amounts of vitamin D are associated with a lower risk of falls, cancer, heart disease, autoimmune disorders, etc. But the RDA is not set higher because the IOM feels there’s not sufficient proof of these benefits.
The experts at Prescriber’s Letter (PL)are telling healthcare professionals, “Recommend 400 IU for infants, 600 IU for kids, and 800 to 2000 IU for adults. The higher adult dose is safe and may provide extra benefits.” I’m with Prescriber’s Letter on this one. I concur with the new guidelines from Osteoporosis Canada recommending 1000 IU/day for adults under age of 50 and 2000 IU/day for adults over 50.
PL goes on to say, “Discourage adults from taking over 4000 IU/day without monitoring. Consider vitamin D testing for people likely to be deficient due to advanced age … dark skin … limited sun … malabsorption … etc.”
As I’ve told you before (Vitamin D Supplementation and Cancer Prevention): I check a vitamin D level as part of my annual exam. I do this on all adolescents and adults. If the vitamin D level is below 30, I suggest supplementing with vitamin D and rechecking.”
I give my patients two options:
- OTC vitamin D, 2000 IU per day, and recheck the level in 4-6 months, or
- Prescription vitamin D, 50,000 IU per week for 12 weeks and then recheck the level.
PL recommends, “Aim for a serum 25-hydroxyvitamin D level above 20 ng/mL for bone health … but below 60 ng/mL until more is known about the long-term safety of higher levels.” In my practice, we’re aiming for levels of 30 to 50 ng/mL.
The new RDA for elemental calcium is:
- 1300 mg for adolescents,
- 1000 mg for women up to 50 and men up to 70, and
- 1200 mg for older adults.
PL says, “Advise people not to get carried away with calcium supplements. Recommend not going over 2000 mg/day from food AND supplements for adults over 50. Too much calcium FROM SUPPLEMENTS might increase the risk of kidney stones and POSSIBLY heart attacks.
You can read more in my blog, “Can Calcium Supplements Cause Heart Attacks?”
Friday, 28 January 2011
In a front-page article, the New York Times says, “The very high levels of vitamin D and calcium that are often recommended by doctors and testing laboratories – and can be achieved only by taking supplements – are unnecessary and could be harmful, an expert committee says” in a low-awaited report.
The “group said most people have adequate amounts of vitamin D in their blood supplied by their diets and natural sources like sunshine.” Dr. Clifford J. Rosen, “a member of the panel and an osteoporosis expert at the Maine Medical Center Research Institute,” said, “For most people, taking extra calcium and vitamin D supplements is not indicated.”
The AP reports, “Long-awaited new dietary guidelines say there’s no proof that megadoses prevent cancer or other ailments – sure to frustrate backers of the so-called sunshine vitamin.”
This “decision by the prestigious Institute of Medicine, the health arm of the National Academy of Sciences, could put some brakes on the nation’s vitamin D craze, warning that super-high levels could be risky.”
Notably, “a National Cancer Institute study last summer was the latest to report no cancer protection from vitamin D and the possibility of an increased risk of pancreatic cancer in people with the very highest D levels. Super-high doses – above 10,000 IUs a day – are known to cause kidney damage, and the report sets 4,000 IUs as an upper daily limit – but not the amount people should strive for.”
According to a report in the Wall Street Journal, the committee members disagreed with previous findings that Americans and Canadians do not consume sufficient vitamin D, and instead suggested that a blood level of 20 nanograms/ml was adequate.
This suggestion contradicts groups such as the Endocrine Society and the International Osteoporsis Foundation, which have recommended 30 ng/ml for good bone health — and is what I recommend for my patients.
Meanwhile, the NIH has begun to recruit participants for a large study that will compare the impact on health of vitamin D and omega-3 fatty acids derived from fish oil.
USA Today reports, ”According to the report, children and adults younger than 71 need no more than 600 international units (IUs) of vitamin D a day and should consume 700 to 1,300 milligrams of calcium a day, depending on their age.”
Indeed, the “committee was surprised to see that most Americans are meeting their needs for both of the nutrients, except for adolescent girls who may not be getting enough calcium and some elderly people who don’t get enough of either, says Catharine Ross, professor of nutrition at Pennsylvania State University and chairwoman of the panel that prepared the report.”
Still, Time points out, ”Those 71 years or older … may need more vitamin D, up to 800 IU a day, to combat deteriorating bone,” the group said.
Due to “the lack of sufficient data to date, advice on vitamin D up to this point was not considered as a recommended dietary allowance, which is based on stronger scientific evidence, but rather an adequate intake suggestion, and stood at anywhere from 200 IU to 400 IU for adults.”
Notably, the “new recommendations are based on data from more than 1,000 studies, most of which included trials in which volunteers were randomly assigned to receive either vitamin or calcium supplements or a placebo, after which their health outcomes were compared to one another.”
The Washington Post “The Checkup” blog says, ”The United States and Canada asked the Institute of Medicine, which is part of the National Academy of Sciences, to update the official vitamin D recommendations for the first time since 1997.”
You read more about my application of this report in my blog, “My Take on the new Vitamin D and Calcium Recommendations.”
Friday, 19 November 2010
Most doctors (81 percent) fall short when it comes to comparing what they do for colon cancer screening with what they should be doing. And, we docs fall off both sides of the balance beam, either ordering tests too frequently or too seldom. Here are the details from HealthDay News:
Only one in five doctors in the United States follows all the recommended colon cancer screening guidelines, a new report finds. Some 40 percent of doctors follow guidelines for some tests, while the remaining 40 percent don’t follow guidelines for any colon cancer screens, the researchers said.
“There’s more work to be done to understand how to improve colorectal cancer screening,” concluded lead researcher Robin Yabroff, an epidemiologist at the U.S. National Cancer Institute.
Most doctors also don’t adhere to guideline recommendations about when people should start screening and how often they should be screened, she added. The report is published in the online edition of the Journal of General Internal Medicine.
In the study, the researchers looked at the recommendations for various tests to find colon cancer, including colonoscopy, flexible sigmoidoscopy, fecal occult blood test (stool-based testing) and double-contrast barium enema.
For the study, Yabroff’s team questioned almost 1,300 doctors who participated in a National Cancer Institute survey. The researchers compared the survey answers against expert guidelines for the various screening tests.
They found that while most doctors correctly recommended beginning screening for adults at average risk for colon cancer at age 50, and correctly recommended how often screening was needed, only 19 percent followed the guidelines for the different types of tests they recommended.
Doctors who followed screening guidelines tended to be younger and board-certified, Yabroff’s group noted.
In addition, they were more likely to use electronic medical records and take patient preferences into account. They were also likely to be influenced by the clinical evidence behind the screening guidelines, the researchers found.
Moreover, many doctors either overused or underused certain tests, Yabroff’s team found. For example, colonoscopy was the test many doctors recommended more frequently than the guidelines called for.
Colonoscopy is the most expensive screening test and the most commonly recommended, the researchers found. They note that overuse of screening can result in unnecessary follow-up testing and an increased risk of complications.
On the other hand, some doctors recommended starting colon cancer screening in patients older than age 50, or at intervals that are less frequent than guidelines recommend. Underuse of screening can result in fewer cancers being found at an early stage when they are more likely to respond to treatment, Yabroff’s group says.
Commenting on the study, Dr. Durado Brooks, director of colorectal cancer at the American Cancer Society, said that “the good news is that most of these physicians do recommend colorectal cancer screening. The concern is how inexact their recommendations are.”
Brooks noted that the knowledge gap around the guidelines is occurring mostly in older doctors. They often continue to practice as they have since they were trained and aren’t keeping up with the latest recommendations, he said.
“We need to figure out how to disseminate that information effectively to people once they have been out in practice,” he said. But as the number of doctors using electronic health records increases, adherence to guidelines will also increase, Brooks believes.
Patients also have a role to play in cancer screening, Brooks said.
- First, they should be aware of the need for screening and
- Second, they should know which tests are available, when screening should start, and how often it’s needed, he said.
“As much as we can get people to take responsibility for their personal health and the health of their family members, the greater the likelihood that care can be given appropriately,” Brooks said.
What the Experts Recommend on Colon Cancer Screening
Here are the American Cancer Society’s current guidelines on checking for colorectal cancer and polyps (often precursors to cancer). Starting at age 50, men and women should follow one of these testing schedules:
To detect both polyps and cancer (preferred) :
- A flexible sigmoidoscopy every five years or a colonoscopy every 10 years (sigmoidoscopy examines the lower part of the colon, colonoscopy is more extensive)
- double-contrast barium enema once every five years
- or CT (“virtual”) colonoscopy once every five years
To primarily detect a cancer:
- Fecal occult blood test (gFOBT) or fecal immunochemical test (FIT) every year
- Stool DNA test (SDNA), interval as yet uncertain
Some people may require a different screening schedule due to personal or family history; the cancer society recommends that you talk with your doctor to determine which schedule is best for you.
For more information on colon cancer, visit the U.S. National Cancer Institute here.
Friday, 12 November 2010
An easy-to-remember formula for good health (0, 5, 10, 30, 150) is proposed in a wonderful editorial in American Family Physician titled “Preventive Health: Time for Change.” The author suggests this formula to physicians to “help patients achieve healthy lifestyle goals”:
- 0 = no cigarettes or tobacco products
- 5 = five servings of fruits and vegetables per day
- 10 = ten minutes of silence, relaxation, prayer, or meditation per day
- 30 = keep your BMI (body mass index) below 30
- 150 = number of minutes of exercise per week (e.g., brisk walking or equivalent)
The editorial is penned y Colin Kopes-Kerr, MD, from the Santa Rosa Family Medicine Residency in Santa Rosa, California:
It is time to make a decision. Which will be our health promotion strategy—primary prevention or secondary prevention?
Traditionally, the only one available to us was secondary prevention. Medicine consisted of a one-on-one physician-patient relationship, and taking care of patients meant minimizing the impact of any diseases the patient had. We did not have the time or tools to do anything else. More recently, we have been able to reduce a patient’s mortality by 20 to 30 percent by treating heart disease with a statin or beta blocker. These two medications have had the most dramatic effects in secondary prevention.
But now, the way we practice medicine has changed. We have a real choice to make. According to recent literature, primary prevention appears to work better than any other strategy in medicine. So why do some physicians not implement primary prevention? Despite the literature, maybe physicians are not getting the news. We need to keep repeating the message to physicians and patients that primary prevention is simple and effective. Next, we need to take a look at our own behavior as physicians and determine if it makes sense in the context of primary prevention.
There are 10 major studies on the effects of primary prevention.(1–15) These studies demonstrate very large correlations between specific healthy lifestyle behaviors and decreases in major chronic diseases (e.g., diabetes mellitus, heart disease, stroke, cancer) and all-cause mortality.
Although these studies offer a complex array of data to sift through, the elements of a healthy lifestyle are clear: not smoking, regular exercise, healthy diet, healthy body weight, and reduced stress.
Although exercise guidelines vary, I ascribe to the U.S. Department of Health and Human Services’ Physical Activity Guidelines for Americans, which recommends at least 150 minutes of brisk walking or the equivalent per week.(16) For the diet criterion, the Atherosclerosis Risk in Communities study illustrates that merely consuming five servings of fruits and vegetables per day is associated with the same benefits as consumption of a Mediterranean-style diet.(11) A standard of five servings of fruits and vegetables is much easier to remember and adhere to.
There is strong support for at least one weight-related variable in a healthy lifestyle. This may include body weight, body mass index (BMI), waist circumference, or waist:hip ratio. The INTERHEART study showed waist:hip ratio to be the most predictive of cardiovascular disease.(6) However, unlike BMI calculation, measurement of weight:hip ratio has not yet become standard in U.S. practices. I use BMI as the metric, and a value less than 30 kg per m2 as the cutoff between a healthy and unhealthy lifestyle. The goal is to move away from this outer limit toward a more ideal parameter, such as less than 25 kg per m2.
The final variable of a healthy lifestyle, which has strong support from the INTERHEART study, is stress reduction.(7) The INTERHEART study offers useful suggestions for measuring stress—perception of severe stress at home or at work, financial stress, or major life events.(7)
The minimal lifestyle intervention that would be beneficial is not defined. However, 15 to 20 minutes of silence, relaxation, or meditation appears to be a common interval.(17) To be more inclusive of patients, I set the criterion to an even less restrictive amount, about 10 minutes per day.(17) This is enough time to produce a change in biorhythms and is achievable for most patients.
Information alone does not lead to behavior change, however. Motivational interviewing or brief negotiation is a new framework that can close the gap between knowledge of available lifestyle interventions and changing behaviors. The framework has already been proven markedly effective for tobacco, drug, and alcohol addiction.(18) Few physicians have received the training necessary to implement motivational interviewing or brief negotiation. Resources for learning about these skills include the Kaiser Permanente Medical Group Web site and the book Motivational Interviewing in Health Care: Helping Patients Change Behavior.(18)
In terms of health, we can have it all. We have the requisite tools to convert knowledge into healthy behaviors. This newfound power to reduce diabetes, heart disease, stroke, cancer, and all-cause mortality with primary prevention strategies should impel us to change how we counsel patients. Research is needed to explore why some physicians are not making this change.
Address correspondence to Colin Kopes-Kerr, MD, at firstname.lastname@example.org. Reprints are not available from the author.
Author disclosure: Nothing to disclose.
- Stampfer MJ, Hu FB, Manson JE, et al. Primary prevention of coronary heart disease in women through diet and lifestyle. N Engl J Med. 2000;343(1):16–22. View here
- Hu FB, Manson JE, Stampfer MJ, et al. Diet, lifestyle, and the risk of type 2 diabetes mellitus in women. N Engl J Med. 2001;345(11):790–797. View here
- Forman JP, Stampfer MJ, Curhan GC. Diet and lifestyle risk factors associated with incident hypertension in women. JAMA. 2009;302(4):401–411. View here
- Knowler WC, Barrett-Connor E, Fowler SE, et al.; Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393–403. View here
- Knoops KT, de Groot LC, Kromhout D, et al. Mediterranean diet, lifestyle factors, and 10-year mortality in elderly European men and women: the HALE project. JAMA. 2004;292(12):1433–1439. View here
- Yusuf S, Hawken S, Ounpuu S, et al.; INTERHEART Study Investigators. Effect of potentially modifiable risk factors associated with myocardial infraction in 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364(9438):937–952. View here
- Rosengren A, Hawken S, Ounpuu S, et al.; INTERHEART Investigators. Association of psychosocial risk factors with risk of acute myocardial infarction in 11119 cases and 13648 controls from 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364(9438):953–962. View here
- Chiuve SE, McCullough ML, Sacks FM, et al. Healthy lifestyle factors in the primary prevention of coronary heart disease among men: benefits among users and nonusers of lipid-lowering and antihypertensive medications. Circulation. 2006;114(2):160–167. View here
- Chiuve SE, Rexrode KM, Spiegelman D, et al. Primary prevention of stroke by healthy lifestyle. Circulation. 2008;118(9):947–954. View here
- Kurth T, Moore SC, Gaziano JM, et al. Healthy lifestyle and the risk of stroke in women. Arch Intern Med. 2006;166(13):1403–1409. View here
- King DE, Mainous AG III, Geesey ME. Turning back the clock: adopting a healthy lifestyle in middle age. Am J Med. 2007;120(7):598–603. View here
- Khaw KT, Wareham N, Bingham S, et al. Combined impact of health behaviours and mortality in men and women: the EPIC-Norfolk prospective population study [published correction appears in PLoS Med. 2008;5(3):e70]. PLoS Med. 2008;5(1):e12. View here
- Ford ES, Bergmann MM, Kröger J, et al. Healthy living is the best revenge: findings from the European Prospective Investigation into Cancer and nutrition–Potsdam study. Arch Intern Med. 2009;169(15):1355–1362. View here
- Lee CD, Sui X, Blair SN. Combined effects of cardiorespiratory fitness, not smoking, and normal waist girth on morbidity and mortality in men. Arch Intern Med. 2009;169(22):2096–2101. View here
- Djoussé L, Driver JA, Gaziano JM. Relation between modifiable lifestyle factors and lifetime risk of heart failure. JAMA. 2009;302(4):394–400. View here
- U.S. Department of Health and Human Services. 2008 physical activity guidelines for Americans. View here.
- Dialogue Partner. View here
- Rollnick S, Miller WR, Butler CC. Motivational Interviewing in Health Care: Helping Patients Change Behavior. New York, NY: Guilford Press; 2008. View here
Friday, 12 November 2010
There’s been a lot of debate about mammograms for breast cancer screening, but an even more important health promotion exercise would be for women to everything they can to prevent breast cancer. And now experts are reporting that women can do three things to dramatically reduce their risk of getting breast cancer — especially if they have a strong family history of breast cancer:
- Exercise (20 minutes of heart-rate raising exercise at least five times a week),
- Maintain a healthy weight (BMI of 18.5 to under 25), and
- Watch alcohol intake (fewer than seven drinks per week).
Here are the details in a report from HealthDay News:
Women who maintain certain “breast-healthy” habits can lower their risk of breast cancer, even if a close relative has had the disease, a new study finds.
Engaging in regular physical activity, maintaining a healthy weight and drinking alcohol in moderation, if at all, was shown in a large study to help protect against breast cancer in postmenopausal women, the researchers said.
“Whether or not you have a family history, the risk of breast cancer was lower for women engaged in these three sets of behavior compared to women who were not,” said study leader Dr. Robert Gramling, associate professor of family medicine at the University of Rochester Medical Center in New York. The study was published in the journal Breast Cancer Research.
Gramling wanted to look at the effects of lifestyle habits on breast cancer risk because he suspects some women with a family history may believe their risk is out of their control.
He analyzed data on U.S. women aged 50 to 79 from the Women’s Health Initiative study starting in 1993. During 5.4 years of follow-up, 1,997 women were diagnosed with invasive breast cancer.
Gramling excluded women with a personal history of breast cancer or with a family history of early-onset cancer (diagnosed before age 45), then observed the impact of the healthy habits.
Excluding those with an early-onset family history makes sense, because a stronger genetic (versus environmental) component is thought to play a role in early-onset, experts say.
Following all three habits reduced the risk of breast cancer for women with and without a late-onset family history. “For women who had a family history and adhered to all these behaviors, about six of every 1,000 women got breast cancer over a year’s time,” he said.
In comparison, about seven of every 1,000 women developed breast cancer each year if they had a late-onset family history and followed none of the behaviors.
Among women without a family history who followed all three habits, about 3.5 of every 1,000 were diagnosed with breast cancer annually, compared to about 4.6 per 1,000 per year for those without a family history who followed none of the habits.
For his study, Gramling considered regular physical activity to be 20 minutes of heart-rate raising exercise at least five times a week. Moderate alcohol intake was defined as fewer than seven drinks a week. A healthy body weight was defined in the standard way, having a body mass index, or BMI, of 18.5 to under 25.
Gramling hopes his research will reverse the thinking of women whose mother or sister had breast cancer who sometimes believe they are doomed to develop the disease, too.
The findings echo what other experts have known, said Dr. Susan Gapstur, vice president of the epidemiology research program at the American Cancer Society, who reviewed the study findings.
“The results of this study show that both women with a family history [late-onset] and without will benefit from maintaining a healthy weight and exercising, and consuming lower amounts of alcohol, limiting their alcohol consumption,” she said.
The American Cancer Society guidelines for reducing breast cancer risk include limiting alcohol to no more than a drink a day, maintaining a healthy weight and engaging in 45 to 60 minutes of “intentional physical activity” five or more days a week.
The risk reduction effects found in the Gramling study may actually increase if women follow the more intense exercise guidelines of the ACS, Gapstur said.
To learn more about breast cancer risk factors, visit the American Cancer Society web site here.
Friday, 20 August 2010
Readers of this blog are well aware than many (if not most) Americans have insufficient to deficient levels of vitamin D. Other than prescribing oral vitamin D or vitamin D-containing foods, we doctors were left with prescribing a little sunshine. But, we know that exposing your skin to unprotected UVA or UVB light can increase your risk of skin cancer. And, there has been controversy about exactly how much sunlight one might need to avoid vitamin D supplements. Now, I may have an answer for you.
But, first a few basics. Vitamin D is essential for bone mineralization and may have a wide variety of other health benefits. Here are just a few I’ve blogged about:
- Vitamin D Supplementation and Cancer Prevention
- Vitamin D helps fend off flu and asthma attacks
- Increasing vitamin D levels may cut heart disease risk
- Vitamin D Supplementation Helps Prevent Falls in Older Adults
- Vitamin D Linked to Lower Heart Risk
- Can Vitamin D Ease Fibromyalgia Pain?
- In Lab Tests Vitamin D Shrinks Breast Cancer Cells
- Vitamin D May Lower Colon Cancer Risk
- Daily Calcium Plus Vitamin D Supplements May Reduce Fracture Risk
- Low levels of vitamin D may be linked to greater asthma severity
- Heart patients lacking vitamin D more likely to be depressed
- More reasons to consider having your vitamin D level checked – you may think better and have less arthritis
- Vitamin D tests soar as deficiency, diseases linked
Experts disagree on the serum vitamin D level necessary to maintain health. Some recommend concentrations above 30 ng/mL and consider the range between 20 and 30 ng/mL insufficient and concentrations lower than 20 ng/mL deficient. In our area, most experts are recommending level of 50 ng/mL (and, indeed, we are supplementing to this level).
By this reckoning, many, perhaps most, Americans are vitamin D insufficient or deficient.
Because it is difficult to obtain enough vitamin D from food intake, oral supplements and sunlight have been recommended for individuals with low serum D levels.
The suggested dose for supplements is 400 to 1000 IU/day.
It has also been suggested that a few minutes of sunlight each day to the face, neck, hands, and arms are all that is necessary to restore vitamin D sufficiency, but the amount of sunlight required for photoconversion of 7-dehydrocholesterol to pre–vitamin D varies considerably depending on a person’s age, Fitzpatrick sun-reactive skin type, geographic location, and season.
The six Fitzpatrick skin types classify sensitivity to ultraviolet light; skin type I is fair skin that always burns, never tans; type III is darker white skin that burns and tans; type V is brown skin that rarely burns, tans easily.
Investigators in a new study employed the FastRT computational tool to predict the length of daily exposure required to obtain the sunlight equivalent of 400 and 1000 IU oral vitamin D supplementation.
At noon in Miami, someone with Fitzpatrick skin type III would require 6 minutes to synthesize 1000 IU of vitamin D in the summer and 15 minutes in the winter.
Someone with skin type V would need 15 and 29 minutes, respectively.
At noon in the summer in Boston, necessary exposure times approximate those in Miami, but in winter, it would take about 1 hour for type III skin and 2 hours for type V skin to synthesize 1000 IU of D.
After 2 PM in the winter in Boston, it is impossible for even someone with Fitzpatrick type I skin to receive enough sun to equal even 400 IU of vitamin D.
About this study, Craig A. Elmets, MD, writes, “These findings raise serious questions about the recommendation that a ‘little bit’ of outdoor sun exposure is sufficient to maintain adequate vitamin D levels.
“Moreover, predictions of the time required to achieve adequate vitamin D photosynthesis are probably underestimates, because it is unlikely that people would walk around Boston for an hour or two in the winter with face, neck, and arms exposed.
“These findings corroborate another study that casts doubt on sun exposure as a way to prevent vitamin D deficiency.”
The bottom line is that it looks like oral vitamin D supplements are going to end up being shown to be the safest and most effective to gain adequate vitamin D levels.
Friday, 6 August 2010
CNN/Health.com reported, “Millions of Americans already take fish oil to keep their hearts healthy and to treat ailments ranging from arthritis to depression.”
Now a new study appearing in Cancer Epidemiology, Biomarkers & Prevention suggests that fish oil “supplements may also help women lower their risk of breast cancer.”
In fact, “postmenopausal women between the ages of 50 and 76 who took fish oil were … less likely to develop certain types of breast cancer than women who didn’t,” researchers at the Fred Hutchinson Cancer Research Center found.
However, consider this information very preliminary. My friends at the Natural Medicines Comprehensive database say this:
You can read more about the study here.
You can also read my blog on how to take the right kind and amount of fish oil here.
Sunday, 25 April 2010
Fish oil (omega-3 fatty acids) have been shown effective in treating high levels of triglycerides and in preventing primary and secondary cardiovascular disease. Now comes a new study showing that the fatty acid found in fish oil (EPA) has shown promise in the prevention of colorectal cancer in patients with familial adenomatous polyposis. The study was a randomized study. Although the study was performed in patients with a genetic predisposition to colorectal cancer, the benefits might also extend to non-inherited, or sporadic, colon cancer. Here are the details from MedPage:
An omega-3 polyunsaturated fatty acid significantly reduced both the number and size of rectal polyps in patients with familial adenomatous polyposis, a randomized trial found.
Six months of treatment with the free fatty acid formulation of eicosapentaenoic acid (EPA) led to a decrease in mean number of polyps from 4.13 at baseline to 3.61, a 12.4% decrease, according to Nicholas J. West, MBBS, of St. Mark’s Hospital in London, and colleagues.
In contrast, six months of placebo treatment resulted in an increase from 4.50 polyps at baseline to 5.05, which represented a 9.7% increase, the researchers reported online in Gut.
Familial adenomatous polyposis is an autosomal dominant disorder in which affected individuals are predisposed to colorectal cancer, and prophylactic removal of the colon is recommended.
In younger patients, the procedure generally undertaken is colectomy with ileorectal anastomosis, but the remnant of rectal tissue remains susceptible, so patients must undergo routine endoscopic surveillance.
In the past, patients also were given chemoprevention with cyclo-oxygenase (COX)-2 inhibitors, but the recognition that these drugs have cardiovascular toxicity limits their long-term use today.
Strong preclinical evidence suggests that certain polyunsaturated fatty acids are active against colorectal cancer, but typical fish oil supplements are associated with adverse effects such as dyspepsia.
So a new, enteric-coated, free fatty acid formulation which is released and absorbed primarily in the small intestine was used to evaluate the potential efficacy of EPA for prevention of colorectal cancer in post-colectomy patients.
A total of 55 adult patients with familial polyposis were randomized to receive 2 g EPA per day or placebo.
After six months the difference between the change in polyp number between the EPA and placebo groups was −1.06 (95% CI −1.78 to −0.35, P=0.005), with an overall decrease of 22.4% (95% CI 5.1 to 39.6%, P=0.012).
In addition, the sum of polyp diameters decreased by 12.6% in the EPA group and increased by 17.2% in the placebo group — an overall difference of 29.8% in polyp size (95% CI 3.6 to 56.1, P=0.027).
Video endoscopy determined that EPA treatment was associated with a modest improvement in the global rectal polyp burden (+0.09), compared to overall worsening with placebo (−0.34). The difference was statistically significant (P=0.011).
There also was a mean 2.6-fold increase in rectal mucosal EPA levels associated with the active treatment.
Two patients in the placebo group withdrew because of abdominal pain, nausea, and rash, while one patient in the EPA group withdrew because of nausea and epigastric discomfort.
The most common adverse event in both groups was diarrhea, which may reflect a post-colectomy lack of physiologic control of fecal water, the investigators suggested.
Nausea was reported by nine patients receiving EPA and by three receiving placebo.
Patients reported no bleeding episodes, and there were no serious adverse events attributable to the treatment.
The antineoplastic activity demonstrated in the study “is almost certainly a combination of regression of existing adenomas and prevention of de novo tumor growth,” the researchers concluded.
Comparison of these findings with those from previous studies of chemoprevention in familial polyposis with the COX-2 inhibitor celecoxib found that the magnitude of effect was “remarkably similar.”
The authors said the data also suggest a role for EPA in chemoprevention of sporadic colorectal neoplasia.
The mechanisms by which EPA inhibits neoplastic activity remain uncertain, although both COX-dependent and COX-independent mechanisms of action have been described, including antioxidant effects and alteration of T cell and colonocyte membrane ‘lipid raft’ functions.
Aside from antineoplastic activity, omega-3 polyunsaturated fatty acids have beneficial cardiovascular and antiplatelet properties.
“Therefore, it is possible that EPA [free fatty acid] treatment may combine [colorectal cancer] chemopreventative efficacy with cardiovascular benefits, which is a particularly attractive therapeutic strategy for middle-to-old age populations relevant to secondary prevention of sporadic colorectal neoplasia,” the investigators asserted.
Sunday, 7 March 2010
I’ve posted a number of blogs about the fact that vitamin D deficiency or insufficiency (low levels of serum vitamin D) is associated with a number of types of cancer, as well as diabetes and asthma, but now new research also shows that vitamin D can kill human cancer cells. The results of this new research fall far short of an immediate cancer cure, but they are encouraging, medical professionals say in a report from ABC News.
JoEllen Welsh, a researcher with the State University of New York at Albany, has studied the effects of vitamin D for 25 years. Part of her research involves taking human breast cancer cells and treating them with a potent form of vitamin D.
She reports that within a few days, half the cancer cells shriveled up and died. Welsh said the vitamin has the same effect as a drug used for breast cancer treatment.
“What happens is that vitamin D enters the cells and triggers the cell death process,” she told “Good Morning America.” “It’s similar to what we see when we treat cells with Tamoxifen,” a drug used to treat breast cancer.
The vitamin’s effects were even more dramatic on breast cancer cells injected into mice.
After several weeks of treatment, the cancer tumors in the mice shrank by an average of more than 50 percent. Some tumors disappeared.
Similar results have been achieved on colon and prostate cancer tumors in mice.
My sense is that, at least for now, you should NOT read too much into these laboratory studies as positive effects in a petri dish or in rats may not necessarily mean similar results in humans.
In addition, it’s also easier to treat cancer in mice than in people.
Nevertheless, it’s another reason either to consider either (1) having an inexpensive vitamin D level drawn during your next medical check up — so as to see if you levels are adequate or not, or (2) taking an inexpensive vitamin D supplement on a daily basis.
Here are some of my other blogs on vitamin D:
- Vitamin D May Lower Colon Cancer RiskVitamin D May Lower Colon Cancer Risk
- Heart patients lacking vitamin D more likely to be depressed
- Vitamin D deficiency in kids is getting more attention
- Study suggests 70 percent of children, young adults do not get enough vitamin D
- More reasons to consider having your vitamin D level checked – you may think better and have less arthritis
- Specific vitamins and a supplement (B vitamins, vitamin D, and calcium) may lower risk of stroke, blindness, and cancer
- Vitamin D tests soar as deficiency, diseases linked
- Lack of vitamin D raises death risk
- Vitamin D Recommendations for Teens May Be Too Low
- Vitamin D may protect against heart attack
- Low Vitamin D Levels Associated with Artery Disease
Wednesday, 5 August 2009