Category: Uncategorized (Page 5 of 5)

In her lecture ‘Using Activity Trackers in Research Studies’ Dr. Kelly Evenson discussed the brief history of tracking devices in physical activity studies and the potential of these devices to aid in public health surveillance of physical activity.

Personal activity trackers are a relatively new phenomenon, gaining much popularity with brands like Nike and Garmin offering commercial products for individuals to keep track of their health behaviors. There are currently over 400 activity trackers on the market and devices like Fitbit have been used to track physical activity in over 140 research studies worldwide. The advantages of using such devices in research studies include the fact that they are low-cost, passive, and low-burden ways to assess physical activity levels.

In order to be confident in the results gained from studies using activity trackers, we must first assess their reliability and validity. Dr. Evenson and her research team completed a systematic review on the topic to determine the reliability and validity of these devices in five specific measures: steps, distance, physical activity, energy expenditure, and sleep. The results of this work indicated that trackers are relatively accurate at capturing the number of steps taken, but less accurate at estimating energy expenditure and sleep. In addition, the authors indicate that more studies are needed in order to determine the validity of trackers to provide accurate information on distance and overall physical activity. Luckily, Dr. Evenson shared that since this review was undertaken, there have been a multitude of new studies using these devices so her group is beginning to plan another review of the literature to assess these topics and update their conclusions.

With the popularity of these devices and the increasing amount of research being conducted on their accuracy, it is only logical to wonder if activity trackers could have a role in public health surveillance of physical activity on a national level. Currently, physical activity at this level is assessed by survey and sometimes accelerometry in nationwide surveillance systems. Dr. Evenson and her colleagues performed a study to assess the agreement between Fitbit data and that from the Behavioral Risk Factor Surveillance System and unfortunately at this time, there was no correlation between the two.

In closing her discussion, Dr. Evenson mentioned a few pieces of advice for different audiences regarding use of activity trackers. For individuals, she recommends making sure to wear the device in the same position every day, enter and update personal characteristics (i.e. height, weight, and age), and make sure the device is set to receive updates so its algorithms remain accurate. For researchers, Dr. Evenson urged more studies focused on assessing reliability and validity of these instruments and making sure that they are tested for such in both free-living and lab-based conditions. Finally, she recommends that device manufacturers publicize information about updates to their software (apps), allow users to have access to data in smaller time intervals, and that they establish standards for rigor in what they measure.

A popular media article from www.msn.com recently caught my eye. The headline that drew me in was, “The One Food That Can Make Your Bones 20 Percent Stronger (It’s Not Dairy).” I was shocked by such a dramatic claim (20% stronger bones!!) and clicked on the article to read further. It turns out the article was referencing a research study done in male mice on a specific type of bone loss due to radiation exposure. I found a handful of claims from the article to be misrepresentative of the information from the original research paper. Most of the issues with the claims from the media article stem from the important fact that the findings of animal studies are not directly translatable to humans. It may be insulting to your intelligence to say that mice are very different from humans. While animal research is vital to science, a major weakness is the lack of direct relatability to humans. Additionally, the title of the media article may confuse consumers by undercutting the vital role that adequate calcium plays in bone health.

The study compared an antioxidant cocktail, dihydrolipoic acid (DHLA), ibuprofen, and prunes. They found that mice on the prune diet exposed to radiation maintained levels of bone-related gene expression comparable to the control mice. In a second experiment comparing a control, DHLA, and prunes, the bone volume mice on the prune diet was preserved following a radiation treatment.

Among the inaccurate claims from the popular media article was the assertion that eating prunes makes “your” bones 20 percent stronger. The glaring issue with this statement is that just because and effect was seen in mice does not mean that same type of effect will be detected in humans. Additionally, even if the effect was seen in humans, it may not occur at the same magnitude (i.e. maybe x amount of prunes per day can help to make radiation damaged bones 5% stronger).

The mice in the prune group of the experiment were fed a diet that consisted of 25% prunes by weight. Often in animal studies researchers will use large doses of the independent variable they are studying to see an effect. This is not a bad thing, it can save time and money by showing the researcher if a topic is worth studying in greater detail. However, it is important to keep in mind what a high proportion of the experimental diet was prunes when interpreting the results.

The popular media article contained a recommendation for the public to eat 4-5 prunes per day for bone strengthening benefits. While prunes are a healthy food and provide many important nutrients, the findings from this particular study in no way support a specific recommendation for humans. The protective effect of prunes in the mice was specific to bone loss from radiation, which is mainly applicable to astronauts, cancer patients undergoing radiation, radiation workers, and victims of nuclear accidents. The public is largely not at risk for bone loss due to radiation exposure.

Another inaccurate claim from the article was that prunes have an “unknown superpower” to help bones. There is a large body of research surrounding prunes and bone health. Researchers have been aware of the beneficial effects prunes have on bones for years.

A more honest (but perhaps not as eye-catching) headline for this media article would be: One study finds a diet high in prunes to benefit the bone integrity of male mice exposed to radiation. This revised headline emphasizes that these are results from ONE study (which should never be accepted as truth- we need repetition for validation), the study was done in male animals (mice, not humans), and informs the reader of the specific type of bone loss that the experiment found prunes to prevent (radiation-induced bone loss).

Study source:

Schreurs, A-s; Shirazi-fard, Y; Shahnazari, MAuthor; Alwood, J S; Truong, T A; et al. Dried plum diet protects from bone loss caused by ionizing radiation. Scientific Reports (Nature Publisher Group); London6 (Feb 2016): 21343.

Popular media article:

https://www.msn.com/en-us/health/nutrition/the-one-food-that-can-make-your-bones-20-percent-stronger-it%E2%80%99s-not-dairy/ar-AAsuIb6?ocid=iehp

Physical inactivity is a plague affecting the entire world today, not just the United States. The World Health Organization (WHO) recognizes this crisis and is committed to leading the world in a treatment plan.  In a webinar, conducted by the ISBNPA and ISPAH, two international societies for physical activity and health, Dr. Fiona Bull (WHO) described their detailed plan of how to combat physical inactivity in the world called the Global Action Plan on Physical Activity (GAPPA).

The ultimate goal of GAPPA is to decrease insufficient physical activity (PA) by 10% relative to each country involved. The four thematic objectives in this plan are to create active societies, environments, people, and systems. The core part (Part 3) of the plan outlined how specific actions fit into each of these objectives. For example, an active environment is achieved by improving urban design, improving safety, and fast-tracking those methods through necessary political channels. The final part of the plan is the practical application of the theoretical ideas. While this section is currently under development, it will link GAPPA to the already established Global Physical Activity Toolkit in the hopes of providing countries with tangible resources to accomplish each objective.

During the second half of this webinar, Dr. Charlie Foster (ISPAH President) and Dr. Jo Salmon (ISBNPA Past-President) facilitated a discussion to address weaknesses or confusing areas of GAPPA. One topic that came up repeatedly was how countries begin to take action and how to evaluate their progress when each country has a different starting point. Dr. Bull emphasized a portion of the plan that discusses “best buys,” or successful interventions the WHO deemed most cost effective in their analysis. By far, the two best strategies were mass media efforts and physician-based care from primary care professionals. Another interesting point that came up during the discussion was the question of how to set the PA goals for each country in 2030. On the one hand, should it be “bigger and bolder” than the goal set for 2025, assuming that the basics have been set and have started working? Or should it be a more conservative goal that may be more realistic and within reach? There wasn’t enough time in this short session to come up with a convincing answer. Questions and dilemmas about GAPPA, including those just mentioned, are also questions of interest to public health researchers. Their work should continue to guide the work of WHO and similar organizations.

As someone new to the public health field, learning about the logic model in class was somewhat frustrating because it didn’t feel practical. Too often we read research that describes a perfectly realistic model but does not translate into palpable changes in PA or nutrition. GAPPA is a detailed, comprehensive logic model that details specific actions that will be used in implementation. It was perhaps the first time I fully understood the purpose of a logic model and how it can drive action to reach a goal.

In a seminar titled “Snacking among children: essential or excessive?”, Dr. Jennifer Orlet Fischer described some of the problems associated with children’s snack recommendations. Prevailing wisdom from the American Academy of Pediatrics and the United States Department of Agriculture is that snacks are essential to children’s nutrition. There are even federally funded programs to pay for snacking, even though there is not a universal guideline for children’s snacking recommendations. There is currently very little data on young children and snacking. Dr. Fischer presented recently found data over the subject.

The first presented study’s aim was to qualitatively characterize low-income parents’ philosophy of child snacking. What she found seems to be a standard consensus: there is no consensus on what snacking is. Dr. Fischer’s data presented that parents’ idea of what snacking is varied widely. In almost all studies, snacking is self-reported, and so if ‘snacking’ means different things to participants than to researchers, how can accurate data be collected? In the broader scheme of nutrition education, this data insinuates that snacking recommendations cannot be properly followed because they are interpreted differently by different people.

Another interesting facet of the presentation was about the children actually doing the snacking. It was found that, while increasing portion size typically resulted in a child eating more, this was not always the case. A child’s temperament will change how they’re influenced by things such as visual cues. This means a child’s attitude may dictate their food responsiveness, enjoyment of food, satiety responsiveness, and more, all of which affect a child’s risk for obesity. This poses an interesting question. Does snacking cause obesity or does obesity cause snacking? While previous data suggests over-consumption of calories from snacks can lead to obesity, the data Dr. Fischer provided may suggest that obese children are just more susceptible to over-snacking. So we are left wondering, is over-snacking a cause of obesity or a symptom of obesity? Are snacking recommendations needed to help control obesity rates, or are children’s attitudes toward food and snacking more important?

From the seminar presented, we must now consider if universal snacking guidelines for children are even possible. Not only will standardized recommendations be interpreted differently by parents, but a child’s attitude towards snacking will change their snacking behaviors regardless of outside factors. Individual counseling is needed to properly integrate parent’s and children’s attitudes, but snacking needs to be addressed on a nation-wide scale. Can we create a universal guideline that will do no harm regardless of guardian or child attitude? The need is understood, but a practical solution is not easily found.

In the seminar ‘Snacking among Children: Essential or Excessive?’ Dr. Jennifer Fisher shared her research on snacking among children and the factors that influence this behavior. She explained that snacking has been increasing among children since the 1970’s and is now accounting for a substantial portion of their daily energy intake. While the prevailing wisdom in this field is that snacking is healthy, even essential for children in order to meet energy demands of growth and development, Dr. Fisher’s research indicates the need for a better understanding of this behavior before we deem it such.   

Dr. Fisher’s research focuses on factors that interact to influence snacking; parenting, the child’s appetite, food and nutrient intakes, and obesity. While she discussed each factor briefly, her research on parenting was most fascinating. In this area, Dr. Fisher seeks to understand parental definitions, goals, and practices related to snacking. Her findings indicate that the definition of snacking is extremely variable and is dependent on factors such as time of day, type of food being offered, and context in which the food is given. Some of her research shows that parents think of ‘snacks’ and ‘meals’ as distinct with ‘snacks’ being foods that require less preparation, offer less nutritional value and balance. Conversely, parents perceived ‘meals’ as time for making memories and connecting with their child.

According to the research, parents also cite a variety of reasons for offering snacks to their children that range from providing nourishment to using snacks as a reward for good behavior or incentive to change bad behavior. One of Dr. Fisher’s more recent studies indicated that the nutritional value of the snack depended on the reason it was being offered. For example, when parents offered a snack for reasons other than providing nutrition for their child, such as to control bad behavior, that snack tended to contain more solid fats and added sugars than a snack that was given because the child was hungry.

Although most of Dr. Fisher’s research is cross-sectional, the relationships between factors related to snacking and the possible health implications are evident. Her findings demonstrate the need for reevaluation of public health guidelines that promote snacking for young children. Improved guidelines may do more to inform parents of the role snacks play in a child’s overall diet, appropriate purposes for offering snacks and how to choose snacks based on nutritional quality. Further, before we can recommend snacking as a public health practice for children, we need much more information on the various factors that impact this behavior.

Until the research on this subject advances, practitioners should do their best to continue educating parents on appropriate foods to offer children both during meals and as snacks. It is also important to promote strategies that help parents understand the role of snacks as part of their child’s overall diet and nutrient intake. Developing one-pagers or brochures on these topics might a way to provide this information to parents, patients and consumers in an easily accessible manner.

Do you want another reason to add green leafy vegetables into your diet? How does, ‘having a more efficient central nervous system and better visual function’ sound?

Dr. Billy R. Hammond recently gave a seminar to the University of Georgia Foods and Nutrition department, entitled “The influence of the macular carotenoids on the central nervous system.” Dr. Hammond works with carotenoids, which are pigments (color compounds) found in colorful fruits and vegetables.

What do carotenoids do?

Carotenoids are important antioxidant compounds. They can be found in high concentrations in the retina (the part of the central nervous system directly behind the eye) and in the brain. Both the brain and retina use a lot of energy, and because of this, are vulnerable to damage by dangerously reactive forms of oxygen. These reactive forms of oxygen are products created by normal cellular processes. Our bodies handle these destructive forms of oxygen by using antioxidants (such as vitamin E, vitamin C, and carotenoids) to cancel them out. Having carotenoids to work as antioxidants in these active parts of our bodies protects us from damage.

In addition to preventing damage, carotenoids help our central nervous system by improving the communication between nervous system cells (neurons). Because carotenoids improve the communication between neurons, then they, in theory, would make our central nervous system more efficient (or faster). A faster central nervous system could result in improved reaction time. Dr. Hammond has conducted several studies evaluating if carotenoid supplements make the central nervous system faster.

Do carotenoids make our central nervous system more efficient?

Using two types of carotenoids, lutein and zeaxanthin, Dr. Hammond has studied the effects of supplemental carotenoids on vision and cognition in multiple groups of people. In a study of UGA baseball players, a population for which rapid visual processing is very important, the researchers found that lutein and zeaxanthin supplements improved visual processing and speed.

In other studies of both college-age students and adolescents, Dr. Hammond’s research team has found that lutein and zeaxanthin supplementation improved cognitive function and neural activity.

What does this information mean for you?

The standard American diet is very low in fruits and vegetables. When we don’t eat a variety of fruits and vegetables or take a supplement, we don’t get the carotenoids we need for efficient functioning of our central nervous system and vision. I think it is important for findings such as these not to be misinterpreted or blown out of proportion. The findings of Dr. Hammond’s work do not mean that Americans should eat carotenoids to become super smart humans with super hero vision. The findings do indicate that the carotenoids lutein and zeaxanthin play important roles in vision and cognition, and are worth including in your daily diet to support an efficient central nervous system.

You can increase your intake of lutein and zeaxanthin by incorporating leafy greens such as kale, spinach, swiss chard, mustard greens, turnip greens, or collards into your diet.

One of my favorite ways to eat kale is in  kale apple salad. Here is a link to a recipe you can try: https://cooking.nytimes.com/recipes/1013732-kale-salad-with-apples-and-cheddar

Enjoy!

Last week, Dr. Billy R. Hammond from the Department of Psychology at UGA presented a seminar on his carotenoid research. Carotenoids are a group of pigments found in plants that give them yellow, orange, or red color. They are considered phytonutrients, compounds that are naturally found in food and appear to have a health benefit. Dr. Hammond’s research explores the benefits of two specific carotenoids, lutein and zeaxanthin. They are found in high levels in the retina of the eyes and the brain, so his lab has studied the roles of these two compounds within the central nervous system.

The research presented provided compelling arguments for the benefits of lutein and zeaxanthin. One of their primary functions in the body is to serve as antioxidants, compounds that reverse cell damage. Cell damage is a normal part of aging and exposure to things in our environment. For example, exposure to the sun can damage skin cells over time. To demonstrate lutein’s antioxidant ability, they studied its effects on the skin. The group who took a lutein supplement had increased skin hydration, elasticity, and less damage to skin cells compared to those who did not. To translate this to the central nervous system they did a similar study but looked at the retina of the eye, because its cells can be damaged by blue light. Lutein resulted in improvements in vision by reducing glare and stray light. Again, these types of damage in our body cannot be entirely prevented, but these compounds can act as a natural defense.

Lutein and zeaxanthin (LZ) are also beneficial because they improve brain signaling. Signals in the brain are sent through brain cells (neurons), and supplementation with LZ has been shown in their research to improve communication between these cells. For example, when one group took LZ and the other did not, they found that the LZ group had faster visual processing and reaction time. To confirm these results, similar studies were done in different age groups (pre-adolescents, undergraduates, and older adults) looking at brain function outcomes. Again, groups with LZ had increased academic performance (pre-adolescents), visual and reasoning ability (undergraduates), and brain activation (older adults). These studies point to the importance of lutein and zeaxanthin for brain activity and processing throughout the lifespan.

These results are desirable and dramatic, but should everyone take LZ supplements? Right now, a conclusion has not been made for recommended intake. Although they have health benefits, they are not considered essential nutrients. The best recommendation is to include adequate food sources of lutein and zeaxanthin in your diet. Some of the top food sources are dark green leafy vegetables (kale, spinach, turnips, collards), zucchini, summer squash, egg yolk, and corn.¹ It is a good health habit to eat fruits and vegetables in a variety of colors to ensure you are getting different nutrients and phytonutrients. Make sure to include some bright red, yellow, and dark green vegetables to boost lutein and zeaxanthin in your diet.

Source:

1. United States Department of Agriculture. Food Composition Database version 3.8.6.1. Nutrient List: Lutein + zeaxanthin (micrograms). (2017, July 28). Retrieved August 30, 2017, from https://ndb.nal.usda.gov/ndb/nutrients/report?nutrient1=338&nutrient2=&nutrient3=&fg=1&fg=9&fg=11&max=25&subset=0&offset=50&sort=c&totCount=1002&measureby=g.

America Walks, a national, nonprofit organization aimed at improving the walkability of communities across the country, sponsors and promotes research in line with those goals. One webinar they conducted, titled “Lessons from Dissemination and Implementation Research for Interventions Promoting Walking and Walkability,” featured two prominent researchers in the field, with lots of experience introducing walking interventions into different communities, who detailed lessons they’ve learned from their work in public health.

Dr. Ross Browson, a public health research at the University of Washington at St. Louis, spoke about the unique field of dissemination and implementation (D&I) research. The key characteristics of D&I research were multilevel complexity, scalability and sustainability, adaptiveness, and respect for diverse approaches. In other words, he argued that intervention programs need to fit the size and complexity of the community and need to be able to change based on how the community responds. In his experience, the most critical issues arose in the connection between research and public policy and whether those areas worked harmoniously. His advice to clinicians looking to implement interventions was to utilize hybrid designs that test both effectiveness and implementation simultaneously and to keep several “key ingredients” in mind when designing studies and applying for grants to fund them. These ingredients included clearly defining the evidence-based practice that will be utilized, using a D&I framework, documenting each member of the team’s D&I experience, and measuring more than one effectiveness endpoint or goal.

Dr. Jacqueline Kerr, a researcher in family medicine and public health at the University of California at San Diego, spoke about her experience in developing peer-led physical activity (PA) programs for seniors in retirement and senior center settings. Her group found great success in decreasing PA decline in this population and successfully partnered with a pedestrian advocacy organization (WalkSanDiego) to clean pedestrian bridges and create safer crosswalks and sidewalks. The most impactful aspect of her study, which she highly encouraged other practitioners to include in their interventions, was in-person counseling and employing educated, motivated, and excited staff to run the day-to-day programs. She also suggested using rolling recruitment throughout the program and creating a clear plan for how to seamlessly transition leadership so as not to interrupt the program.

The most interesting part of this webinar was the similarity between the two talks, primarily in relation to the hurdles they had to overcome. Their success was directly dependent on the community they came into, how they were received by the people in that community, and their ability to adjust accordingly. As exercise science researchers, we often feel far removed from study subjects. We publish papers about the benefits of exercise and cannot fathom why that doesn’t convince people to change their behavior. Public health takes almost the opposite approach and it’s fascinating to see how different problems arise. Different techniques from different fields need to work together to overcome inactivity.

One way to tailor this course to your personal interests is through your selection of seminars, webinars, and additional readings. Your blogs and comments are an opportunity to learn more about healthy eating and active living (HEAL) projects, and to share this information with your peers. The purpose of the blogs and comments is to practice concise, professional writing that translates science to a lay audience. Your journal entries (submitted via eLC) are for reflecting professionally and/or personally on the information you learn in seminars and webinars. Examples of higher scoring posts are available here. Further instructions for blog posts and comments, and journal entries are available on our eLC course website.