Systematic reviews are the basis for nutrition policy and guidance, but gaps in the evidence base can impact recommendations. Presenters at the symposium “Creating the Future of Evidence-Based Nutrition Recommendations, Using Lipid Research Case Studies” sponsored by ILSI North America spoke on various aspects that inform the process of developing dietary guidance and its implementation on Saturday, March 28. Major policy and regulatory groups such as the Dietary Guidelines for Americans Scientific Advisory Committee, American Heart Association, and the Institute of Medicine use systematic reviews as the basis for their decision making, but often the ability to make recommendations can be hampered by a lack of strong evidence.
The process of developing evidence-based reviews, such as the one used by the USDA Nutrition Evidence Library, must be rigorous, transparent, and minimize bias, because these reviews inform federal nutrition policy and programs. At the outset, key systematic review questions are developed which should reflect important decisional dilemmas in public health nutrition guidance.
The next critical step is deciding on inclusion and exclusion criteria, which determines what literature is included in the evidence base. Criteria that may be considered include study design, study duration, size of groups, drop out rates, and the health status of participants. This process is thoroughly documented and transparent so it can easily be determined why a study was included or excluded. The evidence base will go on to be evaluated by expert panels in order to make recommendations and guidances.
How can scientists ensure that their research is included in the evidence base?
- When designing studies, it is important to consider the validity of the study design, the impact of endpoints, and the relevance and feasibility of interventions. Are the outcomes meaningful and are they translatable? If not, what additional information do you need? Researchers can also use the gaps in the literature identified in Nutrition Evidence Library systematic reviews to inform future investigations.
- If studying chronic disease risk, use validated surrogate biomarkers.
- Carefully consider your comparator group. One of the most common reasons studies are discounted from systematic reviews is they did not include appropriate control groups.
- Once you are ready to report your results, follow established reporting standards such as the Consolidated Standards of Reporting Trials (CONSORT) for randomized clinical trials or the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. This can help ensure that key information is included and is available for data abstraction in future systematic reviews and meta-analyses.
- Participate in the process. Once draft reports such as the Dietary Guidelines for Americans Scientific Report are issued, there is the opportunity for public comment. Feedback from scientists with expertise is strongly encouraged.
ASN's Scientific Sessions & Annual Meeting began on Saturday morning with a minisymposium on Nutrition and Cognitive and Neurological Outcomes. Researchers presented studies looking at a range of outcomes across the life course, from infants to the elderly.
Focusing on infants and preschool aged children, Sylvia Fernandez-Rao of the National Institutes of Health shared results from a randomized trial in India, in which participants received one of four interventions: micronutrient powders (MNPs), an early learning intervention, a combination of MNP + early learning, or neither. The results showed small improvements in some categories of development from both the MNP and early learning intervention but no evidence of additive effects.
Karim Bougma of McGill University presented results of a randomized trial of salt iodization in Ethiopia. The study enrolled children up to age five and distributed iodized salt in intervention communities. They found a significant difference between intervention and control areas in several measures of child development and also in maternal depression symptoms. This was true despite a significant increase in consumption of iodized salt in control areas as well as variable quality of salt iodization.
Moving on to older children, Beth Prado of UC-Davis presented results from a study that re-enrolled children ages 9-12 years whose mothers had received multiple micronutrient (MMN) supplementation while pregnant. They found that maternal MMN supplementation had small but significant positive effects on cognitive domains that were still measurable up to 12 years later. They additionally found that the cognitive benefits of MMN varied based on the mother's nutritional status.
Looking at young adults, Susan Emmett of Johns Hopkins University spoke about nutrition and hearing loss. She used data from the Nepal Nutrition Intervention Project, a randomized trial of preschool vitamin A supplementation that began in 1989. The project followed children and collected data every four months, including about any ear discharge in the previous week. Among children who had at least one episode of ear discharge, vitamin A supplementation was associated with a 42% risk reduction of young adult hearing loss.
Usha Ramakrishnan of Emory University also presented data on adults, specifically mothers. She described a randomized trial in Viet Nam, in which women received weekly pre-conceptional supplements of folic acid, iron-folic acid, or multiple micronutrients. The outcome of interest was maternal depression, but researchers found very few symptoms of postpartum depression, and there was no difference between treatment groups.
Finally, Alex Brito of UC-Davis spoke about a randomized trial of vitamin B12 in Chile, which measured neurophysiological outcomes among adults ages 70-79 years. The researchers found significant improvements in nerve conduction velocity with B12 intake but no improvements in other neurophysiological outcomes.
The minisymposium reflected just some of the diversity of interventions and outcomes within the very broad topic of nutrition and cognitive and neurological outcomes. It made clear that, as with many topics at EB 2015, this area is rich with future research opportunities, and there is still much to learn.
Read the entire issue here or find copies throughout the Convention Center in Boston.
ASN's Scientific Sessions & Annual Meeting on Sunday, March 29. In the linked interview she describes her career path and shares how she uses the dietary guidelines in her practice.
Running on Empty – Is There a Metabolic or Cognitive Benefit to the Morning Meal?” session at ASN's Scientific Sessions on March 29, the Kent State assistant professor of psychology will explain why, from a cognitive standpoint, it's best not to miss this meal. In the following interview she talks to ASN about what constitutes a breakfast; what it will take to sell the public on the benefits of eating when they wake up; and what is lacking in the current research on the topic. Read the entire text and leave your questions for Mary Beth in the comments.
Nutrition may be a relatively young science, but perhaps the intuition of our elders has informed us more than we realize. Food superstitions are as old as culture itself and essentially every civilization has added its share to the ever-growing list of dos and don'ts. In respect to two months in a row with Friday the 13ths this year, I investigated how some long-standing tales about what we eat might actually be grounded in truth.
Spilling salt brings bad luck. This widely recognized superstition originating in ancient Greece may hold some hidden truths. One of the most commonly believed concepts about sodium (salt) today is that eating too much can aggravate conditions such as hypertension, cardiovascular disease, and chronic kidney disease. The American Heart Association and National Kidney Foundation recommend limiting salt consumption to about 1,500 mg/d. So whether you believe the superstition or modern medicine, you will think twice and shake the habit of spilling salt onto your meal.
Eating garlic, onions, and mustard seeds is good luck by granting blessings or warding off evil. This superstition is rooted in many proverbs, and it just so happens that vegetables in the Amaryllis (onions, garlic, etc) and Brassicaceae (mustard, broccoli, etc) families are being investigated as anticarcinogens. Many of the naturally occurring phytochemicals in these plants may serve to halt the formation of cancer causing compounds, enhance repair of damaged DNA, and induce apoptosis of tumor cells. Chowing down on these luckily talismans could ward off disease, but don't forget that those same beneficial compounds may also scare off your friends with the odors they leave lingering behind.
Bringing bananas on a boat will cause fishermen ill will and a bad catch. Green bananas, coincidentally, may just cause some unwanted symptoms of illness. Un-ripened bananas are a good source of resistant starch. Depending on your personal disposition, fermentation of resistant starch could either provide a healthy dose of short-chain fatty acids to the intestines, or a healthy dose of gas and diarrhea. Any angler would have difficulty landing the big one between frequent trips to the loo, and that's no fish tale.
Planting parsley will help a woman become pregnant. Of course having good nutrition is important for increasing chances of beginning a pregnancy, but parsley is specifically of interest for the health of the newly developing fetus. This ubiquitous herb is a good source of many vitamins and minerals, including folic acid. In the first few weeks, adequate folate is especially important for preventing neural tube defects in the rapidly growing baby. Consider sowing seeds of parsley before sowing your wild oats.
Every day we find out more and more about how our eating habits affect our bodies, but in some cases we shouldn't overlook what prior generations have already provided us. Tell the researchers and your grandma thanks for the advice.
1. Cobb, L.K., Anderson, C.A.M., Elliott, P., et al. Methodological issues in cohort studies that relate sodium intake to cardiovascular disease outcomes: A science advisory from the American Heart Association (2014) Circulation, 129 (10), pp. 1173-1186. http://www.scopus.com/inward/record.url?eid=2-s2.0-84895928005&partnerID=40&md5=75ecd90a4f86d73a8c200d300b4ca6c8
The EB 2015 program is online! A highlight for me will be the symposium Approaches to Account for the Effects of Inflammation on Nutrient Biomarkers: Nutrition Determinants of Anemia (BRINDA) project, scheduled for Monday, March 30 at 3:00 pm. BRINDA has brought together data from 15 countries, accessing surveys that include preschool children, school age children, and women of reproductive age, to examine the relationship between inflammation, nutrition biomarkers, and anemia.
Although many of us think of iron when we think of anemia – and it is widely accepted that iron deficiency is the major cause of anemia worldwide – we also know that there are many other factors influencing hemoglobin levels. Deficiencies of vitamins A, C, E, B6, B12, riboflavin, folate, copper, and zinc can all cause anemia through varied biological mechanisms. Other important factors affecting hemoglobin include inflammation, chronic disease, infection with parasites, and hemoglobinopathies.
Inflammation not only causes anemia but also affects the biomarkers that are used to measure anemia and nutrient status. Hemoglobin itself is influenced by inflammation: just as smoking and high altitudes lead to decreased oxygen levels in the blood, inflammation has a similar effect, increasing hemoglobin concentrations. Similarly, ferritin is commonly used to measure iron status, but ferritin increases in the acute phase response (APR). Retinol binding protein, which is used to measure vitamin A, decreases in the APR. Thus, inflammation can distort estimates, making it difficult to measure the actual prevalence of anemia or nutrient deficiencies. Initial findings from BRINDA suggest that inflammation is common across the sample and should be taken into consideration when measuring nutrient status.
What can be done about this? How can nutrition programs account for inflammation when measuring nutrient status? Is there a correction factor that one can apply to the standard measurements? How can programs most reliably estimate the etiology of anemia in their target populations? Given the prevalence of anemia worldwide, it is crucial to have a better understanding of its risk factors and approaches to measure them. The symposium will address these questions.
The topics above will be further addressed in two minisymposia on March 31: the Medical Nutrition Council's “Nutrition and Inflammation” at 10:30 am and the Global Nutrition Council's “Advances in Biomarker Development and Use” from 3:00-5:00 pm. In the first session, Leila Larson and Yaw Addo will share findings from BRINDA on specific methods to account for inflammation when measuring retinol binding protein for vitamin A and transferrin receptor for iron status. In the second, Rebecca Merrill will present data on the prevalence of inflammation among preschool children across twelve countries and its association with growth. These presentations from the BRINDA team can have wide-ranging implications and will be of interest to policy makers, program implementers, and academic researchers alike.
Americans are more aware of what we are eating than ever before, but how we choose to track this information varies quite a lot. Some simply choose to eat more or less of a specific type of food while others record every single thing that they consume. In light of this, I decided to give a few programs a test run. I've rated them with 3 stars being the highest.
SuperTracker **½ overall
(free online tool, part of the MyPlate website published by the USDA)
At first impression I was overwhelmed by the multitude of –initially- empty tables and graphs. Once I got into the swing of things, however, my concerns transformed into amusement.
Ease of Use – **
While only be accessed through a web browser, the mobile site is an apt adaptation of the desktop version. Searching for each food is simple enough, but things get cumbersome when selecting the number of units. There is a multitude of units to choose from (e.g. fluid ounces, grams, slices, etc) but the number of those units is limited to a select few choices in a drop down menu.
Foods Available – **
Only some name brands and restaurants are available as choices. However, I could build the majority of complex foods using the basic selections that were available.
Nutrient Information ***
I was surprised by how much detailed information this program offers. Nearly every macronutrient, vitamin, and mineral was addressed in the “Nutrients Report”. This report offers target and average intake side-by-side plus expandable menus that explain which foods contributed (and by what percentage) to that nutrient's intake.
Recommendation Information – ***
This is where the graphics are exceptionally helpful. They compare my intake to recommendations on the basis of food groups (broken down into things such as refined versus whole grains), empty calories, and individual nutrients.
(subscription-based website provided by Pearson)
It happens to be the tracker utilized by my university's introductory nutrition course, so naturally I had to give it a try.
Ease of Use – *
It is only available through a web browser, and the mobile site was not very user-friendly. Commonly chosen foods were under a completely separate menu unhelpfully named “Fast Entry” and only 7 days of intake could be store at one time.
Foods Available – ***
This program has the most specific food items I have seen in a tracker program. Most of the major chain restaurant and grocery brands are represented, cutting out the guesswork involved when building an item from scratch.
Nutrient Information – **
They come awfully close to matching SuperTracker in this respect, but MyDietAnalysis falls short since nearly the same information is presented… on several different pages.
Recommendation Information – **
The “Actual Intakes –vs- Recommended Intakes” report shows you just that for all of the nutrients side-by-side. The bar graph is a nice touch, but the scale for percent of goal met could use a little help, given that I didn't even realize that it was there at first.
MyFitnessPal *½ overall
(free website and mobile application)
Definitely the app most-mentioned by patients and friends who claim to track their eating habits, tempting me to give it a go.
Ease of Use – ***
By far the greatest strength of this program is its availability as a mobile app. Eating lunch out? Just whip out your phone and track it on the spot. Another handy feature puts the foods you eat most often in a checklist immediately under the search box.
Foods Available – *
What I see as both a major weakness and strength of this app is the ability of any user to create foods, which can then be shared community wide. Sure, it's great for the company, but the problem lies in the room for inaccuracies and errors.
Nutrient Information – *
Disappointingly, only nutrients routinely found on the nutrition facts panel were available. Again accuracy depends upon who actually entered the food into the database.
Recommendations Information – *
Only 6 of the nutrients could be displayed on my homepage at a time, and the printable report doesn't even include all nutrients available, nor any averages of my intake compared to recommendations.
So are any of these inaccuracies, shortcomings, or lack of information harmful? I'd say probably not. The important thing here is that any of these tools can get people aware of what they are eating so that healthy changes can be made. With that I say happy tracking and please discuss in the comment section below.
The other day I was sitting in class and the professor showed us a music video that compared sugar to drugs, which really got me thinking about the types of nutrition messaging. There are many campaigns out there targeting nutrition-related areas for change, particularly in the childhood obesity arena. However, many of these campaigns use bold images and scare-tactics to convey the message. Is this the approach we should be taking to create a healthier change?
The obesity epidemic has sparked an urgent need for preventative action. The Institute of Medicine released a report in 2012, Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation, which expressed the need for transformative approaches to changing the environment, especially for “messaging environments.” Due to the increased use of social marketing, product marketing and labeling, and public media campaigns, the potential for utilizing communication in the prevention of obesity is great (1). There have been many campaigns floating around the media in the past decade. A memorable one was Strong4Life, which was created in 2011 by Children's HealthCare of Atlanta, a leading pediatric hospital. This initiative used “in-your-face advertising” to aggressively fight Georgia's childhood obesity problem (1). The initial advertisements featured somber children describing their struggles with obesity (1).
These advertisements generated concern among public health experts due to the fear that the portrayals of overweight children could intensify the weight-based stigma (1). This type of message emphasized the negative health and social consequences of obesity. Health communications can be framed to emphasize either the benefits of participating in a type of behavior (a gain-frame), or the consequences of not participating in a type of behavior (a loss-frame) (2). There is evidence that suggests non-stereotypical, positive media portrayals of obese and overweight individuals can effectively decrease weight-based stigma, while negative portrayals may even worsen the stigma (3). Further, gain-framed communications seem to be more effective than loss-framed communications in endorsing prevention behaviors (2). When the message is framed to stimulate core values, the persuasion factor increases, since the person is more likely to pay attention and accept the message (4).
Campaigns should highlight information that is new to the desired audience and necessary for behavior change (5). It would be useful for health communications to incorporate the “how to” and “when to” knowledge in order to support behavior change (5). Also, misconceptions about the issue may need to be addressed, along with other real and perceived barriers to behavior change (5). Ideally, before public release, communication strategies should be evaluated to determine how effective they would be in supporting the target outcome and without exacerbating any sort of stigma (1). As the use of technology continues to increase, there certainly will be no shortage of health campaigns. Hopefully, the messages will be effective in inspiring positive health changes without creating negative stigma or fear.
1. Barry CL, Gollust SE, McGinty EE, Niederdeppe J. Effects of messages from a media campaign to increase public awareness of childhood obesity. Obesity, 2014; 22: 466–473. doi:10.1002/oby.20570
2. Gallagher KM, Updegraff JA. Health message framing effects on attitudes, intentions, and behavior: A meta-analytic review. Ann Behav Med, 2012; 43: 101–116. doi:10.1007/s12160-011-9308-7
3. Pearl RL, Puhl RM, Brownell KD. Positive media portrayals of obese persons: impact on attitudes and image preferences. Health Psychol, 2012; 31: 821–829. doi:10.1037/a0027189
4. Gollust SE, Niederdeppe J, Barry CL. Framing the consequences of childhood obesity to increase public support for obesity prevention policy. Am J Public Health, 2013; 103: e96–e102. doi:10.2105/AJPH.2013.301271
5. Snyder, LB. Health communication campaigns and their impact on behavior. J Nutr Educ Behav, 2007; 39: S32–S40. doi:10.1016/j.jneb.2006.09.004