Category Archives: Uncategorized

History of Dietary Recommendations in the United States

In some shape or form, as early as the 19th century Americans have been making dietary recommendations and heeding advice provided by experts.

Early 20th Century

Chemist Dr. Wilbur Olin Atwater’s 1904 publication “Principles of Nutrition and Nutritive Value of Food” was based on:

  • Variety
  • Proportionality and moderation
  • Measuring calories
  • An efficient, affordable diet focusing on nutrient-rich foods and less fat, sugar, and starch

Soon after the initial discovery of individual vitamins in 1910, nutritionist Carolina Hunt’s 1916 “Food for Young Children” created new categories: milk and meat, cereals, vegetables and fruits, fats and fatty foods, and sugars and sugary foods.

Mid-20th Century

The first Recommended Dietary Allowances (RDAs) were created in 1941 for calories, protein, iron, calcium, and vitamins A, B1, B2, B3, C, and D. RDAs are now defined as the “average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy people.” The Food and Nutrition Board of the National Academy of Medicine also defined “adequate intake” (AI; “established when evidence is insufficient to develop an RDA and is set at a level assumed to ensure nutritional adequacy”) and “tolerable upper intake level” (UL; (maximum daily intake unlikely to cause adverse health effects”).

From 1943 to 1956, the United States Department of Agriculture (USDA) introduced the “Basic 7” a nutritional guide devoted to maintaining standards during wartime food rationing:

  • Green and yellow vegetables
  • Oranges, tomatoes, grapefruit, cabbage, salad greens
  • Potatoes and other vegetables and fruits
  • Milk and dairy products
  • Meat, poultry, fish, eggs, beans, peas, nuts, peanut butter
  • Bread, flour, cereals
  • Butter and fortified margarine

Late 20th Century

The list was condensed down to the “Basic Four” between 1956 and 1992:

  • Vegetable and fruits: 4+ servings recommended daily
  • Milk: 4+ servings for teens and 2+ for adults
  • Meat: 2+ servings
  • Cereals and breads: 2-4 servings

In 1992 came the Food Guide Pyramid, with a particular focus on expressing the recommended servings of each food group based on their location within the pyramid. The first version of the infamous pyramid-shaped chart featured fruits and vegetables as the biggest group. But pressure from the grain, meat, and dairy industries led to the final version of the chart featuring brain, cereal, rice, and pasta as the foundation of the pyramid. The Food Guide Pyramid was replaced with “MyPyramid” in 2005, which reverted to colorful vertical wedges and a running ascending the stairs to highlight the importance of exercise.

21st Century

The USDA’s current nutrition guidelines take the form of “MyPlate” – an initiative which began in 2011 and concentrates on five key food groups:

  • 30% grains
  • 30% vegetables
  • 20% fruits
  • 20% protein
  • Small portion of dairy

Additional recommendations include:

  • Portion control
  • Eat whole grains
  • Drink fat-free or low-fat milk over full-fat milk
  • Eat less sodium
  • Drink more water and less sugar-sweetened drinks

Key criticisms of MyPlate stem from the fact that the chart does not highlight plant sources of protein like beans and nuts. A similar but more plant protein-centric chart is Harvard’sHealthy Eating Plate,” which was created in response to deficiencies identified in MyPlate.

This century-long saga of changing recommendations depicts the fickleness of nutrition science and the unfortunate influence of the food industry on governmental dietary recommendations. We’ll never know the full story, but it is likely that nutrition experts in the early nineties involved in developing the Food Guide Pyramid knew full well that the bulk of your plate should be green (i.e. veggies) and not tan (i.e. bread and pasta). But influence from other food industries kept the Food Guide Pyramid from being 100 percent reliable. Who knows how this affected the obesity epidemic that currently plagues our country…

I hope you’ll excuse my rant and accept assurance that I am of course aware that there are a lot of other factors exacerbating the issue of obesity (processed food, fast food, sedentary living and working, etc.). None of us were “in the room where it happens” back in the early nineties (yes, that’s a Hamilton nod), so we can’t say for sure why the Food Guide Pyramid was developed in the way that it was. I also think I’m particularly sensitive about this era of government dietary recommendations because this is the guide that I grew up with, and it was the first major educational exposure I had to what a healthy diet looks like.

All in all, I do think that MyPlate is a great tool and shows that nutrition science (and the USDA) are moving in the right direction. My hope is that nutrition science and governmental recommendations will only get better and more accurate. Plus, did you hear about recent legislation proposed by democratic Congressman Tim Ryan to create a National Nutrition Institute under the National Institutes of Health? So cool.

Advertisements

Thoughts of a Subject Matter Expert’s (SME) Deskmate

I was doing some research for an article I was writing about post-exercise performance and metabolism. The study under review was comparing results between a fasted and fed pre-exercise state. The abstract of the research article I was reading (link) mentioned the acronym “FFA” but did not explain what it meant. In my training as a technical writer, it is certainly “against the rules” to use an acronym before first spelling it out. When you play by the rules, the acronym makes its first appearance only in parenthesis. At least, this is what I was taught.

What does one do when they are not familiar with an acronym? They Google it, of course. But when I Googled “FFA” it should come as no surprise that my first ten Google search results were articles about Future Farmers of America. I knew that was not the FFA I was looking for (see image). Immediately aware that I would to dig through many layers of Google search results before identifying the “true” FFA, I finally remembered that my very own desk mate actually got her PhD in foods and nutrition and her Master’s in exercise physiology.

“Kristine, what would you think ‘FFA’ stands for in the context of post-exercise metabolism?”

Without hesitation, Kristine answers, “free fatty acids.”

Now, I have been writing about health and nutrition professionally for almost four years – many times about the importance of omega-3 and omega-6 fatty acids (check it out), but even I could not come up with the words “free fatty acids” when I came across an unfamiliar acronym. If I had to seek consultation to identify the words, how would a true lay-person with no direct access to PhDs have figured it out?

For those who care at all about scientifically literacy, we know that it is rare for a lay-person to pick up and attempt to read an academic article. There are also some who would argue (including me, depending on my mood) that a lay-person should not attempt to read an academic article, with the concern that the piece – packed with jargon and laden with passive language – would only confuse and dishearten the reader. However, for those who may be on the side of encouraging lay interaction with scientific academia, inclusion of the “FFA” acronym is an issue. What are we going to do about it?

I have some thoughts…

TO BE CONTINUED…

Getting the Tattoo

What’s happening to your skin when you’re getting a tattoo?

Getting a tattoo is like getting multiple injections of ink in a concentrated location on the skin – of course usually in a meaningful pattern according to the tattoo design. Tattoo needles take the ink through the epidermis (outer layer) into the dermis (second layer).

  • The epidermis is responsible for new skin cell production. Think about your skin peeling after a sunburn and scabs forming when you get a cut. This layer of the skin also produces melanin, dictating what color your skin is. Additionally, protective immune cells live in the epidermis. Think about how much nasty stuff your skin is exposed to on a regular basis. These immune cells are hard at work 24/7. First-degree burns are those that affect the epidermis.
  • The dermis has its own set of duties, including sweat production, sensation, hair growing, oil-making, and ferrying blood to and from the epidermis. Second-degree burns are those that affect the epidermis and part of the dermis.

The immune cells living in the epidermis don’t know that the needle piercing the skin is something you’ve voluntarily agreed to do (actually paying someone to do). They react as if the body is under attack, triggering the inflammatory response. You’re familiar with the immune response if you’ve ever cut yourself, scratched a bug bite, or gotten a sunburn. I’m going to go out on a not-to-flimsy limb here and say you’ve definitely experienced the inflammatory response during your lifetime.

When immune cells in the epidermis trigger the inflammatory response, the immune system goes on high alert, sending troops of specialized immune cells to the wound site. This is also why you feel pain during a tattoo (and other wounds) – your body is telling you that you’re under attack and you need to GTFO.

The ink delivered by the tattoo is taken up by immune cells called macrophages, which specialize in engulfing particles and digesting them to “clean up debris” at a wound site. Skin cells called fibroblasts also take up ink. Whichever way the ink goes, those cells stay in the dermis permanently, providing the “a tattoo is forever” quality that makes grandmothers everywhere furrow the brows and purse their lips in disapproval.

Science Kara in 2017: Sifting Through Nutrition Research for the Truth

Following trends in nutrition science can seem confusing, frustrating, and even pointless. A lot of nutrition research is funded by big players in the food industry which can lead to published results that are potentially biased and misleading.

However, I like to encourage people not to give up on nutrition science altogether. Like anything else, it is imperfect, and more experts are dedicating their research to understanding the beneficial aspects of specific foods every day.

I am a big fan of the research conducted at the North Carolina Research Campus, where scientists focus on specific fruits and vegetables (F&V), their different components, and what these components can do for specific bodily functions. But today I refer to a recent review of nutrition studies published by the American College of Cardiology, where leading experts are focusing on digging through the controversy and returning with a “bottom line.” For example, are eggs good for you because they contain protein or bad for you because they are high in cholesterol? You have probably heard both arguments, and the contradiction can be confusing enough to make you want to forget about “trying to be healthy” all together because of the way nutrition “experts” cannot seem to agree on a dependable, official standard.

There is still a large volume of knowledge that scientists have yet to access concerning the nutritional components of F&V and other healthy foods and how they work to heal the body and prevent disease, so do not expect the recent review to be a flawless and timeless new guide to eating right. Instead, take it in as a reliable source and an accurate representation of the body of work that encompasses nutrition research.

If you decide make a lifestyle change because of the information the review has to offer, that is great, but if you continue to shun the idea of altering your eating habits because of the possibility of the information changing in the future, that is your decision. But come on, should the essential message present in the review, that relying on a mostly plant-based diet is the best way to prevent disease, really come as a surprise to you?

The review discusses different diet patterns including fads and trends, problems with modern nutrition research, and controversies about the consumption of different foods. I am going explore each topic one by one, but I also encourage you to check out the review for yourself. It is easy to read. For even lighter reading, here is a press release about the review from the American College of Cardiology. Stay tuned.

What You Haven’t Heard About the “Brain-Eating” Amoeba

A recent report of a death from a specific type of organism that causes brain disease has millions of people concerned about going swimming. The loss of life from this disease is devastating, but there’s actually almost no reason why people should stop going to the U.S. National White Water Center (WWC) in Charlotte, North Carolina, where officials are still not positive the female from Ohio was exposed to the disease-causing organism.

home_page_image_naegleria-vjf5-a
Naegleria fowleri | Credit: CDC

Naegleria fowleri is an amoeba species that causes an extremely rare infection of the brain called primary amebic meningoencephalitis. Less than ten cases per year have been reported in the United States for the past 50 years, with just 37 infections reported to the Centers for Disease Control and Prevention (CDC) during 2006 and 2015. However rare the disease may be, infections do occur as seen in the unfortunate report of an Ohio female visiting the WWC with a church youth group.

It’s difficult to resist feeling a little bit afraid after hearing this story on the news, especially since the media refers to the amoeba as “brain-eating.” The reality is that N. fowleri breaks down brain tissue, causing death from brain swelling. Meningitis, or the infection of the brain and/or spinal cord, is not unique to N. fowleri. Meningitis occurs much more often as a result of a viral infection than from an amoeba or other parasite.

Additionally, it is important to note that you are only at risk for primary amebic meningoencephalitis if N. fowleri goes up your nose. If you swallow contaminated water, you’re fine. If you’re swimming in the ocean, you’re safe (N. fowleri doesn’t like salty water). The amoeba is only dangerous if it goes up your nose, which contributes to the rarity of this disease.

“The number of yearly cases of death resulting from this rare amoebic infection is so low that there is absolutely no reason to think that the White Water Center is any more dangerous than a lake or any other fresh water body of water,” said molecular biologist Christy Esmahan, PhD. “The media likes to sensationalize rare infections, but the truth is that you are far more likely to die of drowning in a pool than of contracting this infection at the WWC or anywhere else.”

Many Facebook users and Twitter scrollers are probably more likely to click “share” or “retweet” than they are to actually read any of the dozens of news stories covering this incident. Let’s look at some of the lead titles:

“Teen dies from brain-eating amoeba infection after visit to Whitewater Center”

“Brain-Eating Amoeba Eyed in Death of Ohio Teen”

“Ohio woman dies from infection caused by ‘brain-eating amoeba’”

Am I hooked after reading these titles? Yes. Is my mom canceling her trip to the WWC this weekend? Most likely. Does this title really describe the situation? Not entirely.

Let’s go over some of the key points:

  1. Meningitis from this particular amoeba is extremely rare. You’re no more likely to contract this disease from the WWC in Charlotte than you are at any lake, river, or other non-saline body of water in the world.
  2. Officials are not even sure if it was actually the WWC where the amoeba was contracted. The WWC is still running under regular operation, and scientists are testing the water for amoeba right now.
  3. You are not at danger from contracting meningitis from this amoeba by drinking contaminated water. It has to go up your nose to be dangerous.

Know the facts, stay informed, and don’t be afraid!

https://twitter.com/ScienceKara 

Whitewater-2000x800_c
Credit: U.S. National White Water Center

Capturing Truly Renewable Energy

Scientists have reached a major milestone in the search for renewable energy, and it is in the form of an altered enzyme encased in a protective viral capsid.

From Indiana University, lead researcher Trevor Douglas and his team used two Escherchia coli (E. coli) genes, hyaA and hyaB to produce hydrogenase in the lab. E. coli is commonly used in the lab as a model organism and can often be the cause of food poisoning (CDC). While being sheltered in a protective shell from bacteriophage 22, a virus that infects bacteria, modified hydrogenase has the power to catalyze the formation of hydrogen by breaking the chemical bonds of water.

In nature, hydrogenase is required by most microorganisms for energy metabolism (Structure). Harnessing the power of hydrogenase could be key for creating renewable energy.

“You don’t need to mine it; you can create it at room temperature on a massive scale using fermentation technology; it’s biodegradable,” said Douglas on the modified enzyme. “It’s a very green process to make a very high-end sustainable material.”

The new enzyme is called “P22-Hyd,” and Douglas’ team reports that it is 150 times more efficient than the enzyme in its natural state.

“The end result is a virus-like particle that behaves the same as a highly sophisticated material that catalyzes the production of hydrogen,” Douglas said. His study was published in Nature Chemistry earlier this month.

P22-Hyd costs less to make, is more environmentally friendly, and can also reverse its effect, recombining the chemical bonds of water to generate power.

“It’s truly renewable,” Douglas said.

Next, Douglas and his team set out to make P22-Hyd the best candidate for creating hydrogen power by activating a “catalytic reaction with sunlight.” If they continue to be successful, highly efficient, modified hydrogenase could be the future of providing inexpensive and efficient fuel.

(Image credit: pulseheadlines.com)

What’s the deal with gluten?

In the last decade, the presence of “gluten-free” products has drastically increased on our grocery store shelves, TV commercials, and in our conversations. “She’s gluten free now” is a statement we hear often while catching up with friends. Why is gluten all of a sudden such a problem? What IS gluten? Should everyone eliminate gluten from their diet? All of these questions and more will soon be answered in a 3-part series of blog posts about gluten and the recently popular gluten-free diet trend. I plan to describe gluten and the foods it is naturally found in and also discuss the nature of gluten-free substitutes. Plus, look forward to exclusive interviews with UNC Chapel Hill student, Bailey Brislin, as she explains why she follows a gluten-free diet, and Dr. Vaishali Mankad, a practicing allergist at Allergy Partners of Raleigh.

Understanding the biology surrounding gluten as well as its impact on our health is important. We are constantly in search of the best diet to follow for optimal health, and the media has a huge impact on what we think will help us lose weight or be healthier.

Is eliminating gluten from your diet the right choice for you? Stay tuned to find out! 

UNC Chapel Hill joins GlaxoSmithKline in the fight against HIV/AIDS

This morning at 9:30, UNC Chapel Hill Chancellor Carol Folt, along with GlaxoSmithKline CEO Andrew Witty, announced the collaboration of their respective institutions with a shared goal in mind: finding a cure for HIV/AIDS.

Just 24 hours after leading the commencement ceremony for 6,053 UNC Chapel Hill students, Folt introduced the new company to UNC’s campus, Qura Therapeutics. Folt assured listeners that everyone involved, scientists and investors alike, will be 100% committed to the project. Folt also stressed the significance of their goal as cure science (as opposed to treatment therapies). Although the HIV/AIDS cure efforts at Qura Therapeutics are projected to last for at least a decade, Folt discussed the sense of urgency that everyone involved in the project feels on a daily basis.

GSK will be 300 years old this year, an age even greater than UNC Chapel Hill, the nation’s oldest public university. The UNC/GSK collaboration will be a 50/50 partnership, a surprising move for GSK, which already brings in millions of dollars as the second largest producer of drugs for treating HIV. In addition to words from Chancellor Folt, there were also speeches from GSK CEO Andrew Witty, NC Governor Pat McCrory, and major scientific contributors: Dr. David Margolis from the UNC School of Medicine and Dr. Zhi Hung from GSK.

Stressing the significance in working together was a common theme throughout the morning announcement. Governor McCrory also mentioned the opportunity to simultaneously “save lives and create jobs.” McCrory highly praised UNC as the top university in the state and Chapel Hill as the “capital of the research area” in North Carolina. He brought to light the significance of the UNC/GSK partnership as bringing deserved attention to the research projects conducted in North Carolina at our prestigious universities – a force to be reckoned with on the same level as in Silicon Valley, Boston, and New York. However, McCrory also reminded the audience and those watching on YouTube via a live feed that the most important priority was saving lives through curing HIV/AIDS.

The collaborative research and development model to be implemented by the fusion of efforts between UNC and GSK is a monumental move in the search for a cure to HIV/AIDS.

However, questions that remain are as follows:

How long until scientists find and produce a cure?

Will the cure be affordable and accessible to the lower classes in our nation and abroad?

There is a long road ahead. In the words of UNC professor Dr. David Margolis, “it’s time to get to work.”

 
GSK Press Release:

Enhancing an Education

Life-saving medication, innovative cancer treatments, and stem cell therapy are all amazing discoveries that began in a research laboratory. Some students may not realize that they can participate in research as early as their undergraduate years. Many students beginning their studies at UNC as natural science majors are often presumed to be bound for medical school. However, many science majors choose to spend their time preparing for a career in research and academia. The unique opportunities at many research-oriented universities provide invaluable potential experiences for undergraduates to supplement and enhance their studies in a variety of subjects. Every student should try research, whether as a potential career or as a way to gain a deeper understanding of scientific concepts.

Every semester Dr. Gidi Shemer, the Director of Undergraduate Research in Biology, holds an informational seminar on getting involved in undergraduate research at UNC. For incoming first years

Image 1 - Brittany Simpson pipettes a few microliters of broth-cultured S. aureus into a microcentrifuge tube in preparation for making diluted solutions of bacteria.
Image 1: Brittany Simpson pipettes a few microliters of broth-cultured S. aureus into a microcentrifuge tube in preparation for making diluted solutions of bacteria.

and others unfamiliar with the research field, it can be ambiguous as to what research entails. During the seminar, Dr. Shemer explains:

  • how to find a lab
  • how to get class credit for doing research
  • availability and variety of different projects going on in various departments
  • value in and opportunities present when pursuing a career in research

For Brittany Simpson, who has worked in Dr. Tony Richardson’s microbiology lab since the summer of 2014, applying biological concepts and techniques in the lab has greatly enhanced her appreciation for active learning (Image 1). Although admitting lab work is a “rather large time commitment,” Simpson shares that it is “cool to get to do the stuff you learn about in your biology classes.” Many students find lab work a helpful supplement while learning material in their science classes. Thus, involvement in research not only prepares students for their future (if pursuing graduate studies), but also enriches their current learning. One of the projects Simpson works on in the Richardson lab involves testing the anti-microbial properties of cancer drugs on Methicillin-Resistant Staphylococcus aureus (MRSA) (Featured Image).

Simpson’s inspiration for pursuing research stemmed from curiosity and uncertainty about post-graduation plans. Another undergraduate, Cory Breaux, joined a lab in the UNC Neuroscience Center after finding it as an option for work study jobs.  For two years, Breaux developed skills in DNA sequencing, immunochemohistory, tissue preservation, and animal care. Breaux appreciates his experience for “learning more about the academic scientific process and how researchers take ideas to reality.” In his statement, Breaux touches on an important aspect of engaging in research in addition to attending lectures for class. Application of ideas cannot be adequately learned and practiced through reading a textbook or flipping through a PowerPoint – rather these connections can be made through conducting experiments and facing the tribulation of trial and error techniques. Like Simpson, Breaux recognizes and appreciates this enhancement of learning.

Savannah Nunnery, a junior biology major preparing for Physician’s Assistant (PA) school, decided to get involved with undergraduate research at UNC to take advantage of the incredible opportunities that come with attending a major research university. She utilized the research directory available online to search for available student positions in genetics and molecular biology labs. Nunnery emailed a few professors explaining her background in biology and her interest in their lab’s research. She found a match and joined Dr. Gregory Copenhaver’s lab in the biology department. Currently, Nunnery is in her second semester involved in research. She works with plant model organism Arabidopsis thaliana while

Image 3: A. thaliana plants, a model organism for meiotic recombination used by Nunnery's lab.
Image 2: A. thaliana plants, a model organism for meiotic recombination used by Nunnery’s lab.

researching meiotic recombination and regulation (Image 2). Specifically, Nunnery extracts DNA, runs Polymerase Chain Reactions (PCR), and genotyping of A. thaliana. She mentions learning about PCR and gel electrophoresis techniques initially in a genetics lecture before conducting these procedures on a daily basis in the lab. “It’s an entirely different way to think and learn about biology,” Nunnery explains. “My daily research broadens concepts I learn in class from something I memorize to something I understand how to use.” As Nunnery explains, it is typical of a biology major to learn in class the steps of and probably to draw the process of meiosis, the cell division process all eukaryotes use to reduce the number of chromosomes by half. It is not as typical to extract DNA from plants to directly assess their fertility qualities based on molecular tests of a specific protein involved in meiotic recombination, which is part of Nunnery’s project.

Often the skills that make a student successful while pursuing research go past acing lecture exams. Many students find a knack for navigating the scientific process and enjoy the potential to discover new metabolic pathways or enzymatic activities beyond the classic models we learn in class. The ability to make a career out of growing our knowledge is exciting for students who enjoy understanding how life works. Many research opportunities also have clinical aspects, which might interest students who are interested in seeing the connection between research and a medical application. Simpson found value in active learning during her time in the lab, Breaux appreciated learning deeper about the scientific process, and Nunnery enjoyed the synergistic learning experience of learning in class lectures while conducting the experiments herself in lab. Ultimately, there is large value in a research career. A researcher is creative, innovative, patient, and appreciative of discovering the truth. Students should take the opportunity to partake in research as an undergraduate if possible, for no matter what career path they choose, they will always appreciate the depth of knowledge they gain from conducting their own research.

UNC students: No matter what your major is or what your career interests are, consider getting involved in research! There are so many resources available to us while attending a university with such top-notch research projects being conducted. You’ll never know who you’ll meet or what you’ll learn. See for yourself!

References

  1. Interview with Brittany Simpson. 9/30/14.
  2. Interview with Cory Breaux, 9/29/14.
  3. Interview with Savannah Nunnery. 2/9/15.

Image Sources

  1. Photo by Brittany Simpson
  2. Photo by Kara Marker
  3. Photo by Savannah Nunnery

This article was previously published in Carolina Scientific Magazine, Spring 2015. 

http://www.carolinascientific.org/