Sunscreen {a historical perspective}

I've always thought that sunscreen smells bad, feels bad, and is just generally inconvenient. Since I also know that vitamin D is important for many reasons, and your body synthesizes it from the sun, I generally use the excuse of “getting my vitamin D” for not applying sunscreen as often or as liberally as recommended.

Since sunscreen season is fully upon us, I thought a post (or perhaps a series of posts)
looking at what the evidence has to say about sunscreen would be timely. Today we’ll start with a historical perspective.

In The Five Paradoxes of Vitamin D and the Importance of Sunscreen Protection, Russell Chesney takes time to look at the history and relationship between vitamin D and sunshine. Below is a short summary and review of his journal article published in Clinical Pediatrics.

Rickets, a vitamin D deficiency disorder, first emerged in England around the start of the industrial revolution and reached epidemic proportions by 1650. At first, it was puzzling that rickets was much less prevalent in the tropics and in rural areas, but as the link between vitamin D and rickets and the sources of vitamin D became known, this observation made sense. By 1930, it was well understood that vitamin D deficiency caused rickets and that there were 2 “sources” of vitamin D, a substance found in cod liver oil, and sunshine. Due to the nature of extreme latitudes, the coal in the air above cities to filter the sunlight, and the habits of city dwellers, it made sense that those who lived in cities would receive less sunlight, and therefore be more susceptible to vitamin D deficiency and rickets.

In 1931, The Children’s Bureau strongly advised parents to suntan infants and give them cod liver oil. At this time in history, the value of sunlight exposure was highly stressed, while there was little thought given to potential skin damage. (How far we have swung to the other side, when we now recommend little to no sun exposure for the first 6 months!)

Around 1985 it was observed that skin cancer rates were increasing. With this observation came the real fear of developing skin cancer from exposure to sunlight. Sun exposure recommendations therefore changed, and today the AAP and the American Academy of Dermatology recommend shelter form sun and liberal sunscreen use. However, adhering to these recommendations necessitates vitamin D supplementation by mouth in order to prevent deficiency.

It is interesting to me, but not surprising, that opinions of whether vitamin D should be absorbed from the sun or ingested through diet/supplements are highly influenced by the current opinion concerning the potential harmfulness of the sun.

It’s estimated that a large percentage of the United States is vitamin D deficient, and I’m curious if this could be related to our sun protection behaviors. Also, is there any reason that the sun might be stronger today and consequently require more “protection” from than in the past? Or is this obsession with sun protection just a result of our safety obsessed society? Next week, I hope to address some of these questions.

But enough of me talking, what is your relationship to sunscreen? Do you practically hate it too?

References:
Chesney, RW. The five paradoxes of vitamin D and the importance of sunscreen protection. Clin Pediatr (Phila). 2012 Sep;51(9):819-27. doi: 10.1177/0009922811431161. Epub 2011 Dec 12. http://www.ncbi.nlm.nih.gov/pubmed/22166748. Accessed on 6/3/13.

The weekly dose: xylitol-- a good augment to fluoride?

{About once a week we will examine the evidence pertaining to a health-related matter-- usually something that would be of interest to families with young children.  You should expect a thought out and concise summary of the issue along with several solid references-- there may or may not be a true conclusion.  Sometimes, “more research is needed”  really is the best answer that can be given.  Please leave me a comment if you have thoughts, questions, or another topic idea that you’d like addressed.}

When I was reading and writing about oral hygiene for children under two, I came across an interesting recommendation from the American Academy of Pediatric Dentists regarding maternal oral hygiene. In their recommendations on Infant Oral Health Care, they say that, "Evidence suggests that the use of xylitol chewing gum (at least 2-3 times a day by the mother) has a significant impact on mother-child transmission of MS [mutans Streptococci] and decreasing the child’s caries rate.”  It seems likely to me (or at least biologically plausible) that if chewing xylitol gum can reduce the transmission of bacteria it could also reduce the mother's susceptibility to get cavities herself.  I wanted to see what the evidence had to say about xylitol and gum chewing.

The question I'm interested in today is, is xylitol chewing gum effective at preventing dental cavities?

It turns out that xylitol has been talked about and studied for some time in relation to dental cavities.  The oldest applicable reference on Pubmed is from 1970-- "The effect on rat fissure caries of xylitol and sorbitol."  Despite the fact that study was published 43 years ago, and that there have been multiple published trials in the last decade there is still no firm consensus about xylitol, especially when it comes to the adult population (1).   The American Dental Association published a report on Non-fluoride Caries Preventative agents in 2011 and addressed many different preventative treatments to supplement fluoride use (2).

ADA recommendations (2)

In the report published by the ADA, the panel concluded that the evidence supporting adults chewing xylitol gum was relatively non-existent, and so this recommendation only earned a strength of "expert opinion".  In the figure I attached you can see that the strength of the recommendation for chewing xylitol (or another polyol gum) is actually "stronger" for children. This is because most of the research that has been done surrounding xylitol and chewing gum as an anti-caries agents have focused on children.

When studying xylitol chewing gum it can be difficult to distinguish between the gum and the xylitol, since it is  biologically plausible that gum chewing in itself could reduce the incidence of cavities.  This is because the act of chewing might both increase the rate at which any left over food is removed from the mouth, and increasing salivation(2).  Because of this, it is unfortunate that there has not been a study that compared xylitol gum to other sugar free gums.  This fact significantly contributes to the "weak," or "expert opinion" ratings that you see in the figure for the recommendations to use xylitol gum(2).

Earlier this year, a fascinating 3-year trial was published that looked at the effects of xylitol on the incidence of cavities in adults (1) (Medscape has a pretty good summary here, if you're interested but don't want to read the original).  This study did not look at chewing gum, but instead used xylitol lozenges.  Even though this study doesn't directly relate to my question, I think it is a well designed study (well, at least the study lasted longer than a year and was a randomized controlled trial)  and can contribute to our understanding of xylitol. The authors concluded that in adults, xylitol lozenges have little or no effect on caries.  Although they did see a small reduction in the incidence of cavities in the experimental group, it was not large enough to be significant.  One interesting observation the authors make is that because of the small magnitude of reduction in cavities (~10%), previously published trials could have either missed or magnified this relationship due to unintentional incorporation of bias.

So, where does all this leave us?  After nearly two weeks of thinking off and on about xylitol gum, do I have an answer for my question?  Is chewing xylitol gum an effective measure against dental cavities?  I think I can conclude that there is no strong, evidence-based support for this, but that there is a possibility that chewing (sugar free) gum may mildly help to reduce the incidence of dental cavities.  And, since the gum I buy contains xylitol, I will be chewing xylitol gum.  But, since the recommendations are so weak, I won't be seriously working on changing my gum chewing habits.  (Although, to be honest I'm chewing gum right now, and I think I've chewed a little more than previously since starting the post. ;) )

How about you? What are your gum-chewing habits?


(1) Bader, JD, et al. Results from the Xylitol for Adult Caries Trial (X-ACT). J Am Dent Assoc. 2013 Jan;144(1):21-30. Accessed from http://www.ncbi.nlm.nih.gov/pubmed/23283923 on 4/30/2013.

(2) Rethman, MP, et al. Non-fluoride Caries Preventative Agents: Full report of a systematic review and evidence-based recommendations. ADA Center for Evidence Based Dentistry, 3/24/2011. Accessed from http://ebd.ada.org/contentdocs/clinical_recommendations_non_fluoride_caries_preventive_agents_full_report.pdf on 4/30/2013

The weekly dose: Baby has teeth! (and how shall I care for them?)

{About once a week we will examine the evidence pertaining to a health-related matter-- usually something that would be of interest to families with young children.  You should expect a thought out and concise summary of the issue along with several solid references-- there may or may not be a true conclusion.  Sometimes, “more research is needed”  really is the best answer that can be given.  Please leave me a comment if you have thoughts, questions, or another topic idea that you’d like addressed.}

Last week I spilled the beans that Baby has two little teeth.  They're so cute! (Or at least I think they are.)  Even though it's recommended that you wipe your baby's gums with a wet washcloth from the time he's born, I really haven't been that consistent at caring for his gums, but the advent of actual teeth is certainly motivation enough for me to become consistent and establish a good oral care routine for Baby.

I have a fairly high risk for cavities, or caries, so unfortunately that puts Baby at a high risk too.  Because of this, it's especially important to me to establish good habits for Baby to minimize (hopefully prevent!) cavities both with his baby teeth now, and then later with adult teeth.

It is known that diet plays a huge role in oral health, and that certain feeding habits are strongly associated  with early childhood caries(1), but today, I will be focusing only on the actual oral care routine and not the other factors that may contribute to early childhood caries (ECC).  I just want you to remember and know that simply using the right toothbrush and toothpaste, even if used consistently,  is probably not enough to ward off all early childhood caries.  In technical terms, caries are an infectious disease with a multifaceted etiology (2).

Before we go any further, the question I seek to answer today is, what is the best way to care for a baby's (< 2 years old) teeth?

After a quick Google search, it became evident that there are many different opinions about what is the best way to care for a baby's teeth, the main differences being whether to use a fluoride-containing toothpaste, or "training" toothpaste, and whether to use a baby washcloth, or a baby toothbrush.  To highlight this disparity, the American Dental Association (ADA) recommends against fluoride toothpaste for children under two unless told otherwise by a dentist, while the American Academy of Pediatric Dentistry (AAPD) says a qualified yes for fluoride for children under two(2).

The best resources I found this time where the policy reviews by the AAPD.  Fortunately, the policy reviews are well notated and not based solely on expert opinion.  I tried a few PubMed searches, but was sadly fairly unsuccessful on that front.

In regards to infant oral hygiene, the AAPD's policy is that:

"Toothbrushing should be performed for children by a parent twice daily, using a soft toothbrush of age-appropriate size. In children considered at moderate or high caries risk under the age of 2, a ‘smear’ of fluoridated toothpaste should be used. In all children ages 2 to 5, a ‘pea-size’ amount should be used." (2)

They even included a picture of what a "smear" versus "pea-size" amount of toothpaste is.

It makes me happy to see recommendations that allow for flexibility to be tailored to an individual's needs, since truly, one size rarely fits all. I suppose also that this flexibility could explain the difference between the AAPD's policy and the ADA's policy-- maybe the ADA is assuming a low risk for people reading their webpage(?).

Well, the suggestion to use a smear of fluoride toothpaste is in line with what my dentist recommended when I asked him about it a few weeks ago.  As far as toothbrushes versus baby washcloths go, my dentist suggested the washcloth until baby has more teeth since it's probably a little easier to get into Baby's mouth and actually clean the teeth than it would be with a toothbrush.  Once Baby has molars, if not before, I'll certainly plan on switching over to a baby toothbrush though.  

We can't forget about flossing though! Well, maybe we can since without teeth that touch, there's no need to floss.

Happy toothbrushing!

(1) American Academy of Pediatric Dentistry. (2012). Policy on the Dietary Recommendations for Infants, Children and Adolescents. Reference Manual V 34/No 6. pages 56-58.  
(2) American Academy of Pediatric Dentistry. (2011). Policy on Early Childhood Caries (ECC): Classifications, Consequences, and Preventive Strategies. Reference Manual V 34/No 6. pages 50-52.  
http://www.aapd.org/media/Policies_Guidelines/P_ECCClassifications.pdf.  Accessed 4/11/13.

is the HPV vaccine fundamentally different?

A few weeks ago BabyCenter News posted an article from HealthDay News, Parents' worries about the safety of HPV vaccine on the rise, study says (March 15, 2013).  Years ago I spent a semester studying HPV and its relationship to oral cancer, so I'm naturally a bit interested in the HPV vaccine discussions.

Before I say too much, I want you to know that I am not an expert on vaccines, and am not either recommending, or not recommending that you or your children get the HPV vaccine.  I do think it's interesting to critically think through this article and the recommendations that accompany it. 

According to this article, the safety concerns of parents in regards to the HPV vaccine nearly quadrupled between 2008 and 2010.  HealthDay News doesn't tell us which study actually found this out, merely using using the catch words of "experts" and "study."  I'd be curious to know how the study actually measured these concerns, since there could certainly be room for error here.  Did the concerns really quadruple?

The article also states that, "There are more than 100 strains of HPV....".  It's true that there are many different strains of HPV, but to emphasize this when focusing on the  HPV vaccine seems a little over dramatic since the HPV vaccine is only effective against 4 strains of HPV(1).

But what really jumps out the most to me is that the article states that,

"...the worries [about safety] seem specific to the HPV vaccine. Parents in the study were also asked about two other vaccines recommended for teenagers: the "Tdap" vaccine against tetanus, diphtheria and whooping cough; and the "MCV4" vaccine against bacterial meningitis -- a potentially fatal inflammation around the brain and spinal cord.  Across the study period, less than 1 percent of parents cited safety concerns over those two vaccines."

This makes sense to me-- think about the different modes of transmission.  Tetanus, diphtheria, whooping cough, and meningitis are all highly contagious and can be transmitted in an everyday
setting.  HPV is different.  HPV is a sexually transmitted disease.  I believe that's at least part of the reason why it was reported that just over 17% of parents said that the HPV vaccine was "not necessary." 

The ways of acquiring HPV are directly related to a specific lifestyle, whereas the other diseases can be acquired simply by going to the grocery store or stepping on a rusty nail.  And that is a difference that ought to be considered when thinking about  this vaccine.

No matter how safe a medical intervention is, there will always be associated risks and costs (at least to someone).  In critically thinking about this, we must weigh these risks and benefits.  The article may be right that there are very few risks associated with the vaccine, but we should also be careful to think about the potential benefits since this disease is a result of a lifestyle that is chosen. 

But anyways, just some musing on how the HPV vaccine is a little different ideologically than other vaccines.

What do you think though? Is a different mode of transmission for the disease a big enough difference to put this vaccine in a different sort of category?  Or, does it all just seem the same to you?


(1) CDC. (2012). Human Papillomavirus (HPV) Vaccine. http://www.cdc.gov/vaccinesafety/Vaccines/HPV/index.html. Accessed 3/27/2013

The weekly dose: is vinegar an effective household disinfectant?

{Once a week we will examine the evidence pertaining to a health-related matter-- usually something that would be of interest to families with young children.  You should expect a thought out and concise summary of the issue along with several solid references-- there may or may not be a true conclusion.  Sometimes, “more research is needed”  really is the best answer that can be given.  Please leave me a comment if you have thoughts, questions, or another topic idea that you’d like addressed.}

The question of whether vinegar is an effective household disinfectant is an important question by itself, but it is also closely linked to the question of how important it is to actually have disinfected homes.  But perhaps that’s a question for a different day.

So, the question for this week: is vinegar an effective household disinfectant?

Australia's ABC Health and Wellbeing posted a reasonable article answering the question, "Does vinegar really kill household germs?".  They concluded that it does, but not as well as commercial products.  However, in classic fashion, I wanted to know what the original research had to say about this.

Most of the research that I found centered around disinfecting produce or chicken, but this still seems relevant since they compared the vinegar to other disinfectants, which usually included bleach.

Searching PubMed for "vinegar disinfect*" I came up with 878 results.  Limiting the studies to humans and studies published in the last 5 years reduced that number to 64, but to be honest this probably wasn’t the best search.  One interesting result that did show up was a study about Salmonella on Chicken breasts (1).  This would at least be applicable in the kitchen.  This study found that 0.2 mg/mL thymol (which is found in Thyme oil) plus 2 mg/mL of acetic acid (vinegar) was just as effective in reducing the Salmonella as a chlorine-based washing solution on contaminated chicken breast meat.   However, the huge draw back to this study is that they didn’t compare the acetic acid and thymol mixture to a simple acetic acid solution, so it’s unclear to me how much of a difference the thymol actually makes.

On an unrelated note, Amazon apparently sells thyme oil, but I’m not sure what the actual concentration of thymol inside the thyme oil would be.  I wonder if the thyme oil would make vinegar smell better though.  Hmm.  Maybe I’ll have to try it. 

Changing the search terms to “domestic surfaces disinfect*” seemed to pull up more relevant results.  Unfortunately, most of the results still seemed to center around food.  One study looked at knifes and bell peppers inoculated with Salmonella and e. coli(2).   They compared 3% hydrogen peroxide, 2.5% acetic acid, 70% ethyl alcohol (wine is usually 12-15% ethyl alcohol), and sterile distilled water for decontamination of the bell peppers.   The study concluded that ethyl alcohol and hydrogen peroxide may be effective antimicrobials for in-home decontamination of peppers, and that use of detergent and warm water is effective for decontamination of knifes used during meal preparation.  The authors of this study explain that it is important to pay attention to disinfecting food in the home since it is possible for food outbreaks to occur even in the home.  In 2008 15% of food outbreaks with a known origin came from a home.  This was a good reminder to me, that this really does matter for me in my home. 

Perez, et al. included a insightful figure (see below) looking at the length of exposure a disinfectant and the corresponding efficacy of the different disinfectants that clearly shows that the length of time the bell pepper was exposed to the disinfectant greatly influenced the efficacy of the disinfectant.  Even though alcohol appears to be the best disinfectant in the shortest amount of time, the authors recognize that many people might not be comfortable with such an elevated concentration of alcohol, and because of this they suggest the use of hydrogen peroxide with an application time of 5 minutes.

Perez et al., Figure 1

So, where does all this leave me? Is vinegar an effective household disinfectant?  It does appear to be effective against Salmonella and e. coli.  Since all the studies I found focused in the kitchen, I’m not comfortable generalizing these conclusions to the bathroom (I’m guessing there’s a different set of organisms in there), but as far as the kitchen goes, vinegar appears to be at least mildly effective.  I’ll probably start using it occasionally.  However, since I’m not interested in using alcohol, as Perez et al. suggested, I think I’ll start disinfecting the kitchen and my produce with hydrogen peroxide-- it smells better than vinegar anyway.

(1) Lu Y, Wu C. 2012. Reductions of Salmonella enterica on chicken breast by thymol, acetic acid, sodium dodecyl sulfate or hydrogen peroxide combinations as compared to chlorine wash. Int J Food Microbiol. 152(1-2):31-4. doi: 10.1016/j.ijfoodmicro. Accessed from: http://www.ncbi.nlm.nih.gov/pubmed/22030209.
(2) Perez KL, Lucia LM, Cisneros-Zevallos L, Castillo A, Taylor TM. 2012. Efficacy of antimicrobials for the disinfection of pathogen contaminated green bell pepper and of consumer cleaning methods for the decontamination of knives.Int J Food Microbiol. 2012 May 1;156(1):76-82. doi: 10.1016/j.ijfoodmicro.2012.03.012. Accessed from: http://www.ncbi.nlm.nih.gov/pubmed/22476008.

wisdom and the limitations of science

In perusing my blogroll I came across two different posts that, when combined with my experience of being a mother, make an interesting illustration for the importance of wisdom when applying and interpreting evidence.

Alice Callahane, at Science of Mom wrote about researching and trying to understand sleep choices for infants.  I'm far from an expert on this subject, but I believe this is a fairly well researched, but highly polarized subject.  In regards to this, she says,

"In the real world, lots of factors determine how different families handle sleep. Infant temperament is one of them. Safety is another. There are also cultural expectations, family dynamics, work schedules, parenting styles, and feeding methods to factor in. Where baby sleeps is a complex parenting decision, one that is exceedingly difficult to study in a quantitative manner. ..I also recognize that this parenting decision – and most of them for that matter – can never be reduced to science and statistics..." (emphasis mine)

I too often fall into this trap of believing that decisions can be reduced to science and statistics. It's easy to read a study and then conclude that this study must necessarily apply to everyone I know.  If the study design was good, and the statistics were also pretty clear, why shouldn't I be able to generalize the results to everyone? I believe there are both extrinsic and intrinsic reasons against being too liberal in my study generalizations.

The intrinsic reason against applying a study too generally is that population-based studies are, just that, population based.  Because of this, they show what is best for the population, and not necessarily for a particular individual.  If I make too many particular conclusions from a population based study I commit the whole to part fallacy, what is true of the whole (population) is not necessarily true for every part (an individual).  Population based studies don't, and can't, look at every factor that effects every person, like in the sleep example above.

The extrinsic reason against over-generalization is closely related to the intrinsic reason, but instead of focusing on the limitations due to the actual science, the extrinsic reason focuses more on your personal experiences and preferences.  

The importance of considering personal experience in decision making was driven home to me when I read a post from Kyte, a friend from high school, where she candidly wrote about some of her experiences of being a new mom. My experience has been very different, but it's not that hers is the "right" experience and mine the "wrong", or vice versa. They're simply different experiences.  And, I'm sure, at least partly because of these different experiences, we'd make different decisions for our families, even if we had the same exact evidence available to us.  That's just the way decision are, even evidence-based ones.

These are some of the reasons I've been thinking about the limitations of science and how this effects evidence-based decisions.  Next time I'm tempted to judge someone for making a different decision than I would have, I'll try a little harder to remember that decisions cannot be reduced to science and statistics and that wisdom dictates that I factor in individual experience.

The weekly dose: are there measurable risks associated with Clorox bleach?

{Once a week we will examine the evidence pertaining to a health-related matter-- usually something that would be of interest to families with young children.  You should expect a thought out and concise summary of the issue along with several solid references-- there may or may not be a true conclusion.  Sometimes, “more research is needed”  really is the best answer that can be given.  Please leave me a comment if you have thoughts, questions, or another topic idea that you’d like addressed.}

After discovering the other week that it really is better to avoid food coloring, I’ve been curious about other “natural” claims that I often run into, but usually ignore.  As a former dental assistant, infection control is something that is close to my heart, so I thought I’d start thinking about cleaning products.

Clorox bleach happens to be my favorite home disinfectant for the bathroom and kitchen-- there’s just something about it that smells so clean, and it does such a good job making sinks look sparkling clean, and making mold and mildew disappear.  Not surprisingly though, the greener/more natural crowd does not look kindly upon Clorox bleach.  A quick google search about “household use of bleach as a disinfectant” brings up quite a range of hits, from an article from Reader’s Digest listing the amazing things you can do with bleach, to an article from National Geographic about natural alternatives to bleach.

With each question I try to formulate and research, I feel like I find a million more questions that need answering.  There are so many facets to the issue of household use of Clorox bleach, from the chemistry and toxicity of bleach, to the ideas/theories behind our standards of a cleanly home, to the efficacy of natural alternatives.  In short, I feel like I need a background in chemistry to fully understand, and then probably the length of a book to explain.

But, with no further excuse, the question I wish to address today is: are there measurable risks associated with household use of Clorox bleach?

Clorox bleach (from here on I’ll simply call it bleach) contains 5-10% sodium hypochlorite (NaClO) and is extremely basic with a pH value around 12(1)(the pH scale ranges from 0 to 14, with a pH of 7 being neutral).  According to the MSDS, bleach is corrosive, and may cause severe irritation or damage to skin and eyes.  It is also harmful if swallowed(1).  None of this sounds good, but MSDS’s never sound good since they give you a worse-case scenario and, I feel, do not really represent the potential risks from reasonable household use.  To understand what the more realistic risks are I spent time searching PubMed for an appropriate study to read and summarize.

In 2009, Zock, et al., published a study looking at the domestic use of bleach in 10 European countries and allergic sensitization and respiratory symptoms in adults (2).  The authors had a significant number of participants since their study was part of a larger study designed to identify risk factors for asthma and allergies which had 7,263 participants.  The participants were interviewed and asked a variety of questions regarding their household use of bleach.  Other lab tests, including spirometry (to measure lung function) and blood work (to measure certain antibodies to quantify allergies) were performed. The study also collected dust samples from some homes.  The authors then analyzed the collected data to see if there was any association between bleach use, allergies, and respiratory symptoms.

In short, the study concluded that the health effects of bleach are paradoxical.  It appears that bleach use in the home is associated with fewer allergies, but it is also associated with an increase in non-allergic lower respiratory symptoms. 

One observation that the study made was that their results are specific for the use of bleach, and not simply the overall cleanliness of a home.  The authors considered many possible confounders (a third factor which, in this case would independently effect both those who use bleach and those who don’t) and adjusted for a variety of characteristics without observing a difference in the observed associations.  If cleanliness was a confounder and they did not adequately adjust for it their results, any potential associations could be distorted, but this was not the case.

Although I found this to be an interesting study to analyze, after pulling out some notes form a class years ago, I confirmed that these observed associations, although statistically significant were weak to moderate at best.  Because of this, and a few other factors, I don’t feel like this study is strong enough to suggest that bleach actually causes either a decrease in allergies or an increase in respiratory symptoms.  But then again, I really was just looking for good associations.

To properly answer my question though, yes I believe this study showed that there are measurable risks associated with household use of bleach.  However, it gets trickier since this study also showed measurable benefits associated with the use of bleach-- the paradoxical nature of this study.

This study has given me much food for thought in my quest to understand bleach and the possible pros and cons in regularly using it in my home.  Perhaps some of the puzzle is starting to come together. 

But that said, as far as my recommendations go, and what I will be doing in my home, I’m afraid all I have to say is, “more research is needed.” 

(1)The Clorox Company. (2009). Material Safety Sheet: Clorox Regular Bleach.  Retrieved from www.thecloroxcompany.com/downloads/msds/bleach/cloroxregularbleach0809_.pdf.
(2) Zock JP, Plana E, Antó JM, Benke G, Blanc PD, Carosso A, Dahlman-Höglund A, Heinrich J, Jarvis D, Kromhout H, Lillienberg L, Mirabelli MC, Norbäck D, Olivieri M, Ponzio M, Radon K, Soon A, van Sprundel M, Sunyer J, Svanes C, Torén K, Verlato G, Villani S, Kogevinas M. (2009 Oct.). Domestic use of hypochlorite bleach, atopic sensitization,  and respiratory symptoms in adults. J Allergy Clin Immunol.,124(4):731-8.e1. doi: 10.1016/j.jaci.2009.06.007. Epub 2009 Aug 8. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/19665775

stumped

I've been studying household bleach for the past week (plus some), and it's turned out to be more complicated than I had originally thought.  As I imagined, using bleach to disinfect is common practice; however, the "greener" crowd sees bleach as a fairly toxic chemical (in excess and when mixed with certain other common substances it certainly is!) that doesn't really belong in our homes.  I haven't found any conclusive scientific studies that look at household use of bleach, and so I'm still thinking and will hopefully have a more thorough discussion up soon.

One interesting line of thought that I've been entertaining is, how important is it to have our homes disinfected?  Clearly the goal of cleaning a home is different than cleaning a hospital or dental office, and perhaps, just maybe, "clean" but not disinfected is best for a home setting. The Hygiene Hypothesis might support this thought too.  I ran across this over at My Two Hats the other day:

"...digging in the dirt may be healthy is the hygiene hypothesis. This theory, bandied about for a number of years now, states that as our environment gets cleaner and cleaner, the way in which our immune system interacts with the environment changes. Because the immune system isn’t challenged in the same way, it may not develop in the same way. The theory suggests that kids who have far fewer exposures to microbes may have higher risk of some diseases, such as asthma and eczema. Of course, this is still a “theory”, and we must approach it with a balanced perspective."

 This is not the first time I've come across this line of thought, and it mostly makes sense to me, but again, I haven't fully looked into it either.

What are your thoughts about using bleach in your home?  What is important to you to disinfect? The bathroom? Kitchen sink?

Handwashing, a continuation

Since I’ve been studying triclosan and hand soaps for the past week (The weekly dose: are antimicrobial hand washes beneficial?), you could say handwashing has been weighing heavily on my mind.  Again, nothing new and crazy here, but just some reflections from everything that I’ve read.

The Harvard Health Letter(1) reminded me that the amount of time I take to wash my hands matters.  This letter said that washing your hands for 15 seconds, which is about the time it takes to sing “Happy Birthday” (really?! I would have guessed that took longer than 15 seconds...), reduces bacterial counts by about 90%, but if you spend 30 seconds washing your hands the bacterial counts drop close to 99.9%.

Perhaps one way to make sure you spend a long enough time washing your hands would be to recite a memory verse-- or post one next to your sink and wok on memorizing it.  If you wash your hands 10 times a day, for 30 seconds each, that would be 5 minutes.  Could we more purposefully use this time than just letting our minds wander?

In some ways, this next fact doesn’t fit with what the Harvard Health letter stated at all.  I’m not quite sure how to perfectly harmonize these statements, but, I don’t think this fact annuls the importance of taking your time when you wash your hands. 

The double-blind study that compared soap uses in inner-city households found that about one-third of participants had higher microbial counts on their hands after washing them then before washing their hands(2).  When I first read this in the abstract, I thought I didn’t understand what the authors were looking at, or misunderstanding what they were actually saying.  But yes, they did find that sometimes microbial counts go up after washing your hands.  The authors accounted this to increased skin shedding during washing, which is caused by the mechanical friction of rubbing your hands together.  However, even though they measured this increase, it would be wrong to conclude that washing your hands is of not use.  This study followed the participants for one year, and there were significant reductions in all microbial counts after a year.  This indicated that sustained and consistent hand hygiene practices do significantly reduce microbial counts over time, even if a single wash doesn’t make a huge difference.  This is a fascinating study with some interesting discussion if you want a good read...

A good take away would be to wash consistently and thoroughly, dry gently, and remember to use moisturizer to avoid skin flaking/extreme dryness. 

I know this isn’t anything mind-blowing, but I find it interesting to examine common practices to see if there’s actual evidence to back it up.  And yes, I believe there is evidence to support the importance of hand washing. 

(1) The Handiwork of Good Health. Harvard Health Letter. 2007 Jan;32(3):1-3. http://www.ncbi.nlm.nih.gov/pubmed/17323497.  Accessed 1/28/2013.
(2) Larson E, Aiello A, Lee LV, Della-Latta P, Gomez-Duarte C, Lin S. Short- and long-term effects of handwashing with antimicrobial or plain soap in the community.  J Community Health. 2003 Apr;28(2):139-50. http://www.ncbi.nlm.nih.gov/pubmed/12705315. Accessed 1/30/13.

The weekly dose: are antimicrobial hand washes beneficial?

{Once a week we will examine the evidence pertaining to a health-related matter-- usually something that would be of interest to families with young children.  You should expect a thought out and concise summary of the issue along with several solid references-- there may or may not be a true conclusion.  Sometimes, “more research is needed”  really is the best answer that can be given.  Please leave me a comment if you have thoughts, questions, or another topic idea that you’d like addressed.}

It seems lately everyone has been ill with something or other, and as you know, I was no exception.  The common (and simple!) anecdote to not spreading illness, that we have all been taught since we were small, of washing our hands, is still one of the best ways to avoid spreading illness.  With flu season in full swing, it seems appropriate to examine what we wash our hands with.  Hopefully I’m not beating a dead horse here, but here’s the promised discussion about triclosan and hand soap.

The question I would like to answer is: in the home (or another community, non-healthcare setting) is it beneficial to use an antibacterial soap containing triclosan?

It is estimated that in America, about half of the commercially available hand soaps contain an antibacterial additive(1).  Most of the time this additive is Triclosan.  According to Wikipedia, Triclosan has been used since the early 1970’s, and is a chemically synthesized antimicrobial.  The FDA states that Triclosan is not known to be hazardous to humans, however there are some new studies that raise potential concerns so the FDA is now reevaluating the use of Triclosan in consumer products (2). 

Triclosan is often used in healthcare facilities, and because of this, many studies look at this application.  I would like to point out though, that the needs of a household are much different than the needs of a healthcare facility, and therefor the decision on whether to use antimicrobial soap in one setting will not necessarily transfer to another setting.  According to one study(3), the primary purpose of handwashing in the community, or home, is to prevent or reduce the acquisition of “transient organisms” which have a potential to cause disease. This can be contrasted to a healthcare setting where handwashing is designed to minimize the organisms naturally found on a provider’s hands, as well as to prevent cross contamination during patient care.  It is also important to note that the products available to the consumer contain a much lower concentration of antimicrobial than products that are available in a health care setting, and so the efficacy of the soaps will differ. 

After looking at some miscellaneous articles about Triclosan on the web, I went to PubMed (http://www.ncbi.nlm.nih.gov/pubmed) and searched “triclosan hand soap” which resulted in 58 hits with publication dates from August 1975 through May 2012.  At least 18 of these hits were highly relevant, based on the title alone.

Historically, there hasn’t been much research concerning the effects antimicrobial soap in a community setting (3).  One double blind study in 2003 compared the use of triclosan (0.2%) handwash soap to plain handwash soap in 238 inner city households.   The effects of handwashing after a year were significant, regardless of whether plain soap or antimicrobial soap was used, however there was not a significant difference between the two types of soap.  Because there was no definitive evidence in favor of triclosan soap, the authors suggest against using antibicorbial soap as general household soap.

One meta-analysis (a review-type article where they synthesis results from many published studies) did find that antimicrobial soap produced statistically significant reductions when compared with plain soap (4).  However, I only have access to this abstract, and so don’t know whether they looked at hospitals or communities, and what concentrations of antimicrobials they considered.  Since the abstract says they also considered chlorhexidine gluconate, iodophor, and povidone I’m guessing that they were not specifically considering household, or community use.

In 2007 a systematic review was published which examined the efficacy of products containing triclosan in a community setting (5).  The authors concluded that soaps containing triclosan at concentrations commonly used (0.1%-0.45% wt/vol) were no more effective than plain soap at preventing infectious illness symptoms and reducing bacterial levels on the hands.  The authors also noted that it is possible that triclosan contributes to the development of antibiotic-resistant bacteria. 

There are other studies suggesting that there are several harmful risks associated with triclosan, even at the low levels found in consumer products.  These risks range from being harmful to the environment and aquatic organisms (6), to weakening muscles (8), to developing antibiotic resistant bacteria. However, I haven’t taken the time to fully examine these, or other potential risks.

So, in the home is it beneficial to use an antibacterial soap containing triclosan? No, I believe the research shows there are no benefits to be gained by using a triclosan antibacterial soap in the home, and therefore, my family will continue to avoid buying these products.

(1)The Handiwork of Good Health. Harvard Health Letter. 2007 Jan;32(3):1-3.  http://www.ncbi.nlm.nih.gov/pubmed/17323497.  Accessed 1/28/2013.
(2) FDA: For Consumers. Triclosan: What Consumers Should Know. Aug. 29, 2012.  http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm205999.htm.  Accessed 1/29/2013.
(3) Larson E, Aiello A, Lee LV, Della-Latta P, Gomez-Duarte C, Lin S. Short- and long-term effects of handwashing with antimicrobial or plain soap in the community.  J Community Health. 2003 Apr;28(2):139-50. http://www.ncbi.nlm.nih.gov/pubmed/12705315. Accessed 1/30/13.
(4) Montville R, Schaffner DW. A meta-analysis of the published literature on the effectiveness of antimicrobial soaps. J Food Prot. 2011 Nov;74(11):1875-82. doi: 10.4315/0362-028X.JFP-11-122. http://www.ncbi.nlm.nih.gov/pubmed/22054188.  Accessed 1/30/13.
(5) Aiello AE, Larson EL, Levy SB. Consumer antibacterial soaps: effective or just risky? Clin Infect Dis. 2007 Sep 1;45 Suppl 2:S137-47. http://www.ncbi.nlm.nih.gov/pubmed/17683018.  Accessed 1/30/13. 
(6) Bedoux G, Roig B, Thomas O, Dupont V, Le Bot B. Occurrence and toxicity of antimicrobial triclosan and by-products in the environment. Environ Sci Pollut Res Int. 2012 May;19(4):1044-65. doi: 10.1007/s11356-011-0632-z. Epub 2011 Nov 5. http://www.ncbi.nlm.nih.gov/pubmed/17683018. Accessed 1/30/2013. 
(7) Fritsch EB, Connon RE, Werner I, Davies RE, Beggel S, Feng W, Pessah IN. Triclosan Impairs Swimming Behavior and Alters Expression of Excitation-Contraction Coupling Proteins in Fathead Minnow (Pimephales promelas). Environ Sci Technol. 2013 Jan 28. [Epub ahead of print].  http://www.ncbi.nlm.nih.gov/pubmed/23305567.  Accessed 1/30/2013.

Why do medical recommendations constantly change?

At least monthly it seems like there is “new research” or “new guidelines” that are published and tell the reader that what was previously thought is now considered wrong.  Butter is bad, but margarine is better--5 years later, no, margarine is bad, butter might be better.   Or, running is better than walking, wait no, walking is usually better than running This flip-flopping can make decisions annoying at best and impossible at worst; I know it drives my mom nuts.  However, I think this flip-flopping is just the nature of research and goes along with living an evidence-based life. Here are some reasons that I believe contribute to this flip-flopping.

A big part of having an “evidence-based” attitude is making the best possible decision for a given situation using the best available evidence.  When considering why it’s ok that recommendations change, it’s important to remember that decisions (and thus recommendations) are based on what’s available at that particular time.  Because of this, as new research becomes available, the recommendations ought to change to reflect new knowledge.

Even if there is no new research available, another reason for recommendations to change is if the originally available research has been reexamined and has been found lacking.  No human is infallible, and scientists certainly aren’t excluded from this characteristic! There could be statistical mistakes, or even underlying study design mistakes that could significantly change a border-line conclusion.

One more reason for the apparent flip-flop nature that I’d like to highlight is the news media and their love of sensationalism.  It’s much more exciting to say something like, “sunscreen causes Rickets,” than “preliminary research suggests a correlation between prolonged sunscreen use and vitamin D deficiencies” (fictional example).  Obviously, if I were trying to attract attention I would chose the first headline, but as a consumer I should realize that the news article probably doesn’t give me the whole picture.

Despite these difficulties in having an “evidence-based” approach to life, I truly think it is worth the extra effort to think through decisions, and then to periodically rethink the same decisions, even if that means changing your position.  It has taken me years to realize that it’s not a bad thing to change my mind, sometimes there’s new information available, or sometimes the situation could have changed.  And sometimes, I hate to admit it, just sometimes, I was actually wrong in the first place.

The weekly dose: Is there a real harm to food dye?

{Once a week we examine the evidence pertaining to a health-related matter-- usually something that would be of interest to families with young children.  (However, the subject could be anything that piques my interest.) You should expect a thought out and concise summary of the issue along with several solid references-- there may or may not be a true conclusion.  Sometimes, “more research is needed”  really is the best answer that can be given.}

Several weeks ago I was browsing my Facebook feed and noticed someone posted an article about the dangers of food dyes, and how my friend was consequently going to return the fruit snacks they had just bought.  Mentally I filed this issue in the “non-scientific hippie” folder, but was curious as to why food dyes were being portrayed in such a bad light.  I mean, I didn’t imagine that they’d be nutritious, but I didn’t really expect them to be deleterious either.  After some digging, I was surprised to find that there is quite a history to this issue.

The question that I wish to answer: Do the risks associated with synthetic food dyes warrant the removal of foods containing these dyes from a family’s diet?

As background information, the FDA regulates all color additives (1), and has for some time.  In 1966 the FDA restricted the use of many color additives due to adverse health risks, and has continued to limit the allowed color additives since then (2).  Today, there are 9 synthetic dyes that are approved for use (2, 3). However, there is concern that these 9 approved dyes are also associated with adverse health risks.

The Center for Science in the Public Interest (CSPI) published a 58 page report in 2010 summarizing many of the risks associated with synthesized food dyes (3).  In this report, Kobylewski and Jacobson examined published studies pertaining to the carcinogenicty, genotoxicity (ability to cause mutations or damage chromosomes), and neurotoxicity of these 9 food dyes.  Although some of the studies they reviewed were imperfect and lacking in one way or another, I believe it is still highly concerning the amount of evidence that suggests food dyes are associated with serious health risks. Some of these adverse risks include, tumors in multiple locations, various cancers, and an allergic-like hypersensitivity (3).   After reading the report, I agree with the conclusion Kobylewski and Jacobson reached-- that synthesized food dyes do not belong in our food since they posses no nutritive value, and are likely detrimental to our health.

To examine what else had been published, I searched PubMed (http://www.ncbi.nlm.nih.gov/pubmed) using the search terms “food dye*” which resulted in 254 hits.  Since most of the studies Kobylewski and Jacobson referenced were either animal studies or in vitro studies (Latin for, “in glass”, these are studies that typically look only at a cell or molecule, but not the entire organism) I was interested primarily if anyone had studied the affects of food dye in a human population.  After applying a species filter of “humans” to my search, I had 61 hits-- a manageable number to look through.  After reading the titles, I narrowed the studies down to 26 articles that appeared relevant to my question.  The publication dates ranged from September, 1974 to July, 2012; apparently the safety of synthetic food dyes is not a new area of research.  Admittedly, I didn’t read through all 26 articles, but most of them were studies related to treating ADHD, and it appeared as if they were all ending up with similar conclusions.  In summary, ADHD is complicated, and we should not expect changing a child’s diet to act as a panacea, but, the elimination of artificial food dyes likely does reduce ADHD symptoms.

In 1970 Dr. Benjamin Feingold found that when artificial food additives and dyes were eliminated from the diets of hyperactive children, the symptoms of hyperactivity were reduced.  However, follow up studies during the next 20 years were less than convincing.  Because of this, interest in the effects of food additives on hyperactive children waned.  Recently though, there has been more research and public interest regarding this association.  Because of these circumstances, in 2009 the British government requested that food manufacturers remove most artificial food dyes from their products (4).  It is sadly ironic that food companies that produce food for both Britain and the US use natural or no colorings there, but continue to use artificial dyes in America (3).

In one study, the authors point out that even though controlled studies usually suggest the elimination of artificial food dyes to reduce ADHD symptoms, this is really a recommendation that should apply to the diets of the entire pediatric population (5).  Konikowska et al., (6) state that although the cause of ADHD is unknown, many studies show that nutrition is a large factor in the development of symptoms.  Although I have not read anything that suggests that artificial food dyes cause ADHD, this study again points out that many studies have shown a positive impact of the elimination of food products containing synthetic food additives on the behavior of children with ADHD (6).

So, what does this mean for my family?  For us, this means that I now consciously avoid buying products that contain synthetic food dyes, even if this means paying a little bit more for a dye-free alternative.  Previously when I read food labels I’d generally ignore the food dye information.  We don’t eat a lot of processed foods, so I didn’t anticipate this being difficult.  However, we do eat a decent amount of whole-grain breakfast cereal, and I discovered that Life Cereal has several food dyes in it (although Kix and Rice Krispies do not).  This is sad news since Life often goes on good sales and my husband enjoys it.   That said, I don’t believe food dye will single handedly give us cancer or otherwise kill us, so we intend to be level headed and still enjoy food when others offered to us-- even if it does contain food dyes. 


(1) FDA. For Industry: Color Additives. 2011. http://www.fda.gov/ForIndustry/ColorAdditives/default.htm. Accessed 1/16/13.
(2) FDA. For Industry: Color Additives Status List.  2009 (updated 2011).   http://www.fda.gov/ForIndustry/ColorAdditives/ColorAdditiveInventories/ucm106626.htm.  Accessed 1/9/13. 
(3) Kobylewski, S, and Jacobson, MF. Food Dyes, A Rainbow of Risks.  2010. Center for Science in the Public Interest. http://www.cspinet.org/fooddyes/.  Accessed 1/9/13.
(4) Kanarek, RB.  Artificial food dyes and attention deficit hyperactivity disorder. Nutr Rev. 2011 Jul;69(7):385-91. doi: 10.1111/j.1753-4887.2011.00385.x. Epub 2011 Jun 30. http://www.ncbi.nlm.nih.gov/pubmed/21729092.  Accessed 1/17/2013.
(5) Hurt, EA, Arnold, LE, and Lofthouse, N. Dietary and nutritional treatments for attention-deficit/hyperactivity disorder: current research support and recommendations for practitioners.  Curr Psychiatry Rep. 2011 Oct;13(5):323-32. doi: 10.1007/s11920-011-0217-z.  http://www.ncbi.nlm.nih.gov/pubmed/21779824. Accessed 1/17/2013.
(6) Konikowska, K, Regulska-Ilow B, and Rózańska D. The influence of components of diet on the symptoms of ADHD in children. Rocz Panstw Zakl Hig. 2012;63(2):127-34. http://www.ncbi.nlm.nih.gov/pubmed/22928358.  Accessed 1/17/2013.