Chew your calories and drink water: Industrial beverages and tooth erosion

Dental erosion is a different problem from dental caries. Dental erosion is defined as the removal of minerals from the tooth structure via chemicals. Dental caries are the result of increased site-specific acidity due to bacterial fermentation of sugars.

Still, both have the same general result, destruction of teeth structure.

Losing teeth probably significantly accelerated death among our Paleolithic ancestors, as it does with modern hunter-gatherers. It is painful and difficult to eat nutritious foods when one has teeth problems, and chronic lack of proper nutrition is the beginning of the end.

The table below, from Ehlen et al. (2008), shows the amount of erosion that occurred when teeth were exposed to beverages for 25 h in vitro. Erosion depth is measured in microns. The third row shows the chance probabilities (i.e., P values) associated with the differences in erosion of enamel and root. These are not particularly enlightening; enamel and root are both significantly eroded.

These results reflect a broader trend. Nearly all industrial beverages cause erosion, even the “healthy” fruit juices. This is due in part, but not entirely, to the acidity of the beverages. Other chemicals contribute to erosion as well. For example, Coke has a lower pH than Gatorade, but the latter causes more erosion of both enamel and root. Still, both pHs are lower than 4.0. The pH of pure water is a neutral 7.0.

Coke is how my name is pronounced, by the way.

This was a study in vitro. Is there evidence of tooth erosion by industrial beverages in people who drink them? Yes, there is quite a lot of evidence, and this evidence dates back many years. You would not guess it by looking at beverage commercials. See, for example, this article.

What about eating the fruits that are used to make the erosion-causing fruit juices? Doesn’t that cause erosion as well? Apparently not, because chewing leads to the release of a powerful protective substance, which is also sometimes exchanged by pairs of people who find each other attractive.

Reference

Leslie A. Ehlen, Teresa A. Marshall, Fang Qian, James S. Wefel, and John J. Warren (2008). Acidic beverages increase the risk of in vitro tooth erosion. Nutrition Research, 28(5), 299–303.

"This is Public Health" is now an iPhone Application!

In March 2011, the Association of Schools of Public Health (ASPH) launched a new This Is Public Health (TIPH) iPhone application. It is available via the Apple itunes store. “This innovative application will allow users to digitally place an image of the TIPH sticker in photographs on their mobile device, so they no longer need to have physical stickers with them everywhere they go in order to participate in the campaign.”

The "This is Public Health" campaign was first piloted during the 2008 National Public Health Week.

The TIPH campaign was developed to achieve the following objectives:

• Increase awareness about public health and the important role public health plays in our daily lives.

• Position Schools of Public Health as innovative/effective leaders in public health outreach and education.

• Engage new audiences, including policymakers and funders, in a dialogue about the importance of supporting public health.

• Attract and inspire the next generation of public health professionals through non-traditional engagement tools.
  

The campaign uses stickers with the slogan "This is Public Health" placed in locations around the world to help reach its goals.

The campaign's website clearly shows the reach of the campaign- over 1,000 public health practice organizations, individuals, and other academic institutions in over 45 countries have joined the campaign. But of course (as always), I'm interested in seeing an evaluation of the campaign. It was unclear to me from the website how they define their target audience. I was not sure if they wanted to "increase awareness" of public health among "participants" of the campaign (i.e., those giving out the stickers) or among the general public (i.e., those seeing the stickers in various locations). I was able to track down an evaluation report from September 2009 (which covered the first year of the project). For purposes of this report, data was collected from program participants (defined as those that requested stickers or the campaign video). Both qualitative and quantitative data was collected via phone interviews, feedback from public health groups and individuals, a review of program data and statistics, and an online survey. Here are some key findings:

• The majority of participants [32.7%] learned about the campaign through the ASPH website.

• Educating the general public about public health, increasing awareness about careers in public health and increasing the understanding of the work of a particular institution were the top three goals of those who executed the campaign locally.

• When asked to rate on a scale of 1-10 how effective the “This Is Public Health” materials were in achieving their campaign goals, nearly a quarter [23.8%] gave the materials a 10, citing them as “very helpful” and over three-quarters of the respondents rated the effectiveness a 7 or higher.

• Simplicity and ease of use were what most campaign participants liked best about the “This Is Public Health” campaign.

• Nearly all respondents [92.1%] said that they were likely to recommend the campaign to colleagues in the public health community with almost 70% saying they were “very likely” to do so.

Interestingly, some areas of mixed review were around the program's website, flickr group (pictures), and interactive google maps. There was some concern that keeping all the program materials online because it excluded those without Internet access. In addition, the adoption of flickr and maps depended on the "tech savviness" of the participants. So seeing that their newest addition is an iPhone application, it will be interesting to see which groups of participants are the earliest adopters of the technology. I look forward to seeing the next evaluation report!

A Pop Health Book Review of "The Immortal Life of Henrietta Lacks"

This book is not brand new; it has been out for about a year. However, it continues to pick up momentum and be read by book clubs across the country. Therefore, after it was recommended to me by my mother-in-law, I thought it would be perfect for a Pop Health Book Review.

As someone who works in public health, I collaborate with our University's Institutional Review Board (IRB) on a daily basis to ensure the safety of our research (for the good of our research team, funder, and participants). And even though I know and understand the importance of the collaboration, it can still feel like a burden to address and document each question that is asked by our IRB (I know many of you would agree!) I see the students I work with roll their eyes and sigh when they have to take the IRB and HIPAA trainings. HIPAA stands for Health Insurance Portability and Accountability Act of 1996 Privacy and Security Rules. The students say, "Yeah...we already know this stuff".

However, this book takes what you "already know" and puts a face on it. It reminds you that it wasn't long ago that people (especially vulnerable people) were experimented on and/or used for research without their consent. Often with sad and deadly outcomes.

Rebecca Skloot, an award-winning science writer, takes the reader on her personal journey (lasting over a decade) to learn about the woman behind HeLa cells. The woman's name was Henrietta Lacks. The original cells were taken from her cervix shortly after she was diagnosed with cancer and before her death. HeLa cells have been vital for many scientific advances, including the development of the polio vaccine.

Henrietta's story, pieced together through more than a thousand hours of interviews conducted by Rebecca, touches on the most essential and controversial aspects of public health and research:

1. Treatment/Research on Vulnerable Populations:

• Henrietta Lacks was a poor Southern tobacco farmer, seeking medical care from Johns Hopkins "colored" ward in the early 1950s. A sample of her tumor was taken and given to researchers without her consent. She was treated with radiation without a discussion about the side effects. Henrietta had no idea the radiation would cause her to be infertile. The hospital convinced her husband David to agree to an autopsy (after he already refused) by saying that the exam "could help his children one day". The autopsy results were later given to a writer who published all the details in his book.

• It is no wonder that the IRB now requires specific training and attention to address research that focuses on vulnerable populations. These include pregnant women, fetuses, neonates, prisoners, children, and other special classes of individuals such as minorities and those that are mentally ill.

• It is no wonder that it can be incredibly difficult to recruit members of these vulnerable groups to participate in research, even today! Henrietta's family spoke of their fears of being snatched off the streets around Johns Hopkins by doctors wanting to experiment on them. Rebecca found research that tales of "night doctors" had filled black oral history since the 1800s. These doctors would kidnap black people for research.

2. Ethical Issues

• This book examines the ethical issues of sharing human tissue. Consent to share human tissue (e.g., those you have "discarded"after a blood test or biopsy), is not the same as consenting to participate in research. Often consent is not required.

• But do researchers and doctors have an ethical responsibility to disclose to the patient if (1) their cells/tissues are unique and valuable in some way, (2) the researcher or doctor has a financial interest in their tissue, (3) the patient's tissue will be used in any way that is contrary to their beliefs?

3. Informed Consent

• Times have certainly changed since 1951 when Henrietta Lacks was subjected to tests and procedures without giving informed consent. Unfortunately, it took about 50 years to get there. Her husband and children were still left in the dark regarding the purpose of blood tests in the years after her death. Scientists wanted to map their genes. The family thought they were being tested for cancer. They waited years for results that never came.

• Most of Henrietta's family only completed school until their early-mid teenage years. Even when the doctors explained parts of procedures, it was not at a level or in a way that was familiar to them.

• This book emphasizes the importance of being "informed" in the consent process. If the participants don't understand, their verbal or written consent means nothing.

All of these important issues are discussed with beautiful storytelling by Henrietta's family and Rebecca's careful research. It is a must read, especially for my fellow science and public health friends out there.

You'll find yourself cheering for Henrietta's daughter Deborah and her siblings, who have all endured more than their share of suffering. And probably most important, you'll find yourself making a pact to never sigh when it is time to complete the annual IRB training.

Health markers varying inexplicably? Do some detective work with HCE

John was overweight, out of shape, and experiencing fatigue. What did he do? He removed foods rich in refined carbohydrates and sugars from his diet. He also ditched industrial seed oils and started exercising. He used HealthCorrelator for Excel (HCE) to keep track of several health-related numbers over time (see figure below).

Over the period of time covered in the dataset, health markers steadily improved. For example, John’s HDL cholesterol went from a little under 40 mg/dl to just under 70; see chart below, one of many generated by HCE.

However, John’s blood pressure varied strangely during that time, as you can see on the chart below showing the variation of systolic blood pressure (SBP) against time. What could have been the reason for that? Salt intake is an unlikely culprit, as we’ve seen before.

As it turns out, John knew that heart rate could influence blood pressure somewhat, and he also knew that his doctor’s office measured his heart rate regularly. So he got the data from his doctor's office. When he entered heart rate as a column into HCE, the reason for his blood pressure swings became clear, as you can see on the figure below.

On the left part of the figure above are the correlations between SBP and each of the other health-related variables John measured, which HCE lists in order of strength. Heart rate shows up at the top, with a high 0.946 correlation with SBP. On the right part of the figure is the chart of SBP against heart rate.

As you can see, John's heart rate, measured at the doctor's office, varied from 61 to 90 bpm. Given that, John decided to measure his resting heart rate. John’s resting heart rate, measured after waking up using a simple wrist watch, was 61 bpm.

Mystery solved! John’s blood pressure fluctuations were benign, and caused by fluctuations in heart rate.

If John's SBP had been greater than 140, which did not happen, this could be seen as an unusual example of irregular white coat hypertension.

If you are interested, this YouTube video clip discusses in more detail the case above, from HCE’s use perspective. It shows how the heart rate column was added to the dataset in HCE, how the software generated correlations and graphs, and how they were interpreted.

Reference

Kock, N. (2010). HealthCorrelator for Excel 1.0 User Manual. Laredo, Texas: ScriptWarp Systems.

The Role of Social Media in Emergency Preparedness and Recovery

Last month I attended a presentation about a research study which evaluated the content of State-level emergency preparedness websites. The reviewers were looking for the presence of essential components such as clear contact information and links to federal emergency preparedness resources. I raised my hand and asked, "Are you evaluating these websites/organizations for a social media presence?" I used the example of the most recent Philadelphia "emergency" I encountered, 15 inches of snow. I did not go onto the city's emergency management website for information. I follow NBCPhiladelphia and SEPTA (the city's mass transit system) on Twitter. So I looked at my phone to find out what offices were closed and which buses/trains were running or cancelled. As always the key question remains, how does your target population get their information? What systems will still be working in an emergency (e.g., what if you lose electricity or internet?)

Since last Friday, we have all been watching the sad and heartwrenching images from the earthquake and tsunami in Japan. And you may wonder, with so much of the country affected, how will people make contact with their loved ones and how will the government get critical information out quickly? This morning, Mashable ran an article called, "Social Media Plays Vital Role in Reconnecting Japan Quake Victims with Loved Ones". While the earthquake knocked out electricity, the internet remained largely intact. The US Embassy in Tokyo is trying to take advantage of this fact and is encouraging Americans in Japan to contact their loved ones via text message and social media (i.e., Facebook and Twitter). Facebook and Twitter analytics from the day of earthquake show incredibly high usage.

A recent post on the Federal Emergency Management Agency (FEMA) blog discusses how social media is being considered as a key element in emergency preparedness. FEMA administrator Craig Fugate discusses a January 2011 planning meeting in which he met with the founder of Craigslist and editors from Wired, Twitter, Apple, and Facebook. He reports that they discussed:

• "The need to provide information to the public as data feeds, because they are a key member of our emergency management team"
• "The importance of referring to people impacted by a disaster as survivors and utilizing them as a resource"
• "The importance of providing good customer service"
• "How [emergency managers], need to stop trying to have the public fit into our way of doing things and receiving information, but that we should fit the way the public gets, receives and seeks out information"

It is great to hear that emergency managers are identifying social media as a powerful tool and planning how best to take advantage of it during an emergency.

Other online resources for making connections after a tragedy include:

Google Person Finder : This google service is used in the aftermath of such tragedies and allows users to click, "I am looking for someone" or "I have information about someone".

Red Cross Family Links: The purpose of this website is to help people get connected after being separated by disaster or conflict. Currently, there are links for Japan, Bosnia, Kosovo, Nepal, Iraq, and Somalia.

We share an ancestor who probably lived no more than 640 years ago

This post has been revised and re-published. The original comments are preserved below. Typically this is done with posts that attract many visits at the time they are published, and whose topics become particularly relevant or need to be re-addressed at a later date.

The China Study II: Fruit consumption and mortality

I ran several analyses on the effects of fruit consumption on mortality on the China Study II dataset using WarpPLS. For other China Study analyses, many using WarpPLS as well as HCE, click here.

The results are pretty clear – fruit consumption has no significant effect on mortality.

The bar charts figure below shows what seems to be a slight downward trend in mortality, in the 35-69 and 70-79 age ranges, apparently due to fruit consumption.

As it turns out, that slight trend may be due to something else: in the China Study II dataset, fruit consumption is positively associated with both animal protein and fat consumption. And, as we have seen from previous analyses (e.g., this one), the latter two seem to be protective.

So, if you like to eat fruit, maybe you should also make sure that you eat animal protein and fat as well.