Are Your Diet Choices Based in “Fact” or “Faith?” One Religion Professor Thinks It’s the Latter

by Katherine Pett

Looking for a nutritional antidote to food fears? Take a look at new release The Gluten Lie by Alan Levinovitz, PhD, and stop being scared of your sandwich.

51FKliVgjSL._SY344_BO1,204,203,200_

Despite what the sinister cover of The Gluten Lie by Alan Levinovitz, PhD, suggests, this book is not about gluten… entirely. When I first picked it up, I assumed the author meant to proclaim that gluten sensitivity, the diagnosis du jour, is nonexistent. But the book makes little attempt to determine what is and isn’t healthy. In fact, it’s the exact opposite of a diet book.

A religion professor at James Madison University, Levinovitz remains agnostic about the existence of gluten sensitivity: to him, it may exist or may not. In fact, he takes this neutral tone with every food fad he discusses, from banishing sugar to forbidding fat. There is evidence for and against each recommendation, but not as much as you’d think.

Levinovitz is primarily concerned with the belief systems that cause sweeping dietary crazes. As a professor of religion, no one is more capable of delivering the Good Word: Many of our beliefs about food are more religious than rational in nature. We unconsciously base food choices and food fears on faith, not facts.

The strict-sounding title is based on the book’s thesis: If you tell people something is true when the research is inconclusive, it’s a lie. Unlike religious leaders for whom myths are tools to give hope and guidance to a congregation, people who invoke science—rather than God—to inspire behavior change have an obligation to the truth, the whole truth, and nothing but the truth.

In the book, Levinovitz uncovers which nutrition “facts” are more rooted in legend than reality and reveals the (sometimes sordid) history behind them. For each of these hotly-debated food elements (ex., gluten, fat, salt, and sugar), there are authorities who swear that eliminating it will fix your life.

For example, gluten restriction, especially as a part of the CrossFit/Paleo paradigm, can seem a little, well, cultish. But it’s nothing compared to the originators of sodium-restriction who formed an actual cult. Known as “Ricers,” these people were a group of extremist dieters who followed low-sodium, rice-diet guru Dr. Walter Kemper of Duke University. The Rice Diet was not unlike today’s Paleo or Bulletproof diets in that it attracted a lot of attention and plenty of celebrity adherents, such as Buddy Hacket, Dom DeLuise, and multiple NFL players. It was different, however, in the sense that its founder kept a harem of devoted dieting women in houses he owned, connected their housing via walkways, and was named an heir in their wills.

But why, you might be wondering, would people believe that a no-sodium, all-rice diet will solve your problems? Especially now when people have access to Google, PubMed, and a world of scientific references and textbooks that tell us that balance is key to health? It turns out that it isn’t hard to make a convincing and seemingly science-based argument. All you need to do is pick a few studies, conveniently tweak the details so they match your framework, add a few scary statistics and unproven claims and, boom, you’ve written the next Wheat Belly.

To prove his point, Levinovitz shows how it’s done with a diet of his own invention: The UNpacked DietTM. In the book’s last chapter, Levinovitz creates a mock first chapter of a “science-based” diet book that explains how plastic packaging will make you sick and fat. The diet comes complete with numerous citations, references to seemingly authoritative researchers, and excellent graphics tracking bottled water use and the rise in obesity. Even though I knew the diet was meant to be facetious, I found myself seriously considering some of the arguments. “That sounds reasonable,” I heard my inner-voice saying.

Just after he nearly convinced me that plastic really is the source of all my problems, Levinovitz then repeats the entire chapter, but with cartoon thought bubbles pointing out each flaw in the reasoning. Every single point that seemed so meaningful is actually a careful misrepresentation of evidence that doesn’t prove nearly as much as the “author” would like. The similarities between the writing in The UNpacked DietTM and any other diet book gracing the bestseller list are uncanny. In fact, it made me wonder if Dr. Levinovitz missed an opportunity by deciding to pull back the curtain on the genre, rather than to partake in its riches.

Overall take? If you work in wellness or you’re just an avid follower of nutrition in the news, you need this book. If you have an annoying friend who bugs you about the newest “antinutrient,” you need this book so you can toss it to your annoying friend while you run away. This book is timely, given the wake of The Food Babe, expands understanding of the belief systems that underlie our country’s disordered eating culture, and acts as a reset button for our own food prejudices.

While he may not make the point directly, it is implied throughout the book: You can’t cheat death with “one simple trick” to get rid of belly fat. There is no toxic nutrient that causes all disease. So chill out. Eat your sandwich.

Interested? Check out a recent lecture by Levinovitz, where he explains the concept of his book:

Katherine Pett is a first-year Biochemical and Molecular Nutrition student at The Friedman School.  Follow her on twitter @smarfdoc or contact her at katherine.docimo@tufts.edu. 

The Yolk is Back in Town: Does Cholesterol Still Matter?

by Ally Gallop, BSc, RDN, CDE

Cherry picking through the Dietary Guidelines Advisory Committee’s (DGAC) February report is a nutrition communicator’s nightmare. Though the report is 571 pages deep, media headlines repeatedly echo the lack of a recommendation surrounding a seemingly new leniency towards cholesterol. This year, the DGAC points to inadequate evidence linking high dietary cholesterol to high serum cholesterol. So what changed? And why should we, as nutrition communicators, care?

The 2015 DGAC’s report recommends withdrawing cholesterol’s longstanding upper limit of 300 milligrams (mg) per day when updating the 2015 dietary guidelines set to occur later this year. Since the federal government’s dietary guidelines were first officially released in 1980, there has always been a focus on cholesterol and saturated fat. The initial guidelines stated to “avoid too much fat, saturated fat, and cholesterol.” It took until the fourth version in 1995 to place a hard number on cholesterol: 300 mg daily for the general population. A stricter 200 mg was advised for those with high cholesterol, at risk of cardiovascular disease (CVD), or diabetes. It also took until 1990 for specific limits on saturated fat to be made: less than 10% total caloric intake from saturated fat (the 2010 goal is now less than 7%).

So how did eggs become roped into this? In the 1950s, egg consumption averaged 374 per year or roughly a daily egg. With 186 mg cholesterol and 1.6 grams saturated fat per large egg, this dietary staple was a clear target. At the time, dietary cholesterol was thought to increase LDL (the “bad” cholesterol”) and one’s risk of CVD. Fast-forward to the 1990s and consumption plummeted to 236 (0.6 eggs per day). Even with this reduction, CVD remains the leading cause of death for both men and women. Marion Nestle relates this to poor communication with the public. Assumptions that Americans would adopt these dietary restrictions by replacing butter, beef, and cheese “with healthy fruits and vegetables… was naïve.” Americans were eating more refined carbohydrates, sugar, and sweeteners, items known to contribute to excess body weight, increased LDL, type 2 diabetes, and CVD risk.

Yet as far back as the 1990’s, experts began to learn that eating cholesterol does not necessarily parallel large increases in one’s risk of CVD. In 1999, the Journal of the American Medical Association found that despite an egg’s cholesterol, daily consumption did not increase one’s risk. Harvard’s School of Public Health’s Walter Willett has voiced how although this recommendation was initially based on well-intentioned theory, it stuck around due to inertia. The restriction was based on and supported by short-term studies with no consistent, hard, and direct evidence

So too, agreed the joint American Heart Association-American College of Cardiology task force in 2013 when it reported that cholesterol’s initial strict limit was based on studies too broad to find a direct link. Even so, the United States remains the only country to include a cholesterol limit within its dietary guidelines.

Adding to the complexity, cholesterol is produced by the liver having multiple roles throughout the body. It’s necessary for the production of steroid hormones, is present within the membrane of every cell, and is a requirement for fat absorption due to its role as a precursor for bile acids. In fact, the liver produces upwards of 85% of the body’s total cholesterol levels. Additionally, Willett shares how “It has become clear that eggs raise both LDL and HDL [the “good” cholesterol], so the impact on heart disease is less clear, and of course eggs contain much more than cholesterol.” And so they do. Eggs improve our:

  • Eyes: due to the antioxidants lutein and zeaxanthin, which help prevent macular degeneration
  • Brain: dietary choline is hard to come by, so eggs are a unique source
  • Muscles: there’s a reason why this high quality protein is rampant in a weight lifter’s diet
  • Satiety: the protein keeps us feeling full for longer, thereby being a useful addition to weight loss and maintenance eating patterns

But guess what? Your dietary advice hasn’t really changed.

The implications surrounding food communicators involve the public’s perception that nutritionists are forever changing their minds as to what’s healthy and what’s not. But taken together with saturated fat, the recommendations don’t really change.

The USDA and the Department of Health and Human Services will be responsible for updating the forthcoming dietary guidelines. If they adopt the DGAC’s recommendations, no longer having a guideline does not mean that foods containing cholesterol should be consumed without restraint. The vehicle that cholesterol is carried in still matters. As mentioned, cholesterol tends to coincide with saturated fat and exists primarily in animal foods, to which the DGAC continues to recommend restricting to no more than 7% of all calories. For instance, items with both high cholesterol and saturated fat include cheese and other high-fat dairy products; pizza; and many cuts of beef, pork, and poultry (with the skin).

In defense of the DGAC, Tufts own Dr. Alice Lichtenstein reports how the average American now consumes between 250 and 350 mg daily. Among other pertinent dietary factors, focusing on cholesterol is no longer of dire concern for the DGAC. However, although dietary cholesterol may not be of concern to the committee, saturated fat still is.

Rather than focusing on specific nutrients, its not enough for food communicators to solely depend on moderation and the importance of whole foods and diets when counseling patients. From experience, they want specific answers. So here’s what you need to know:

  • In 2012 3% of Americans had diabetes, another 86 million were in the prediabetic state, and 1.7 million new cases were diagnosed. In total, 85.6 million Americans suffer from CVD or the aftermath of stroke. Acknowledging that the dietary guidelines are intended for the general population, with numbers this large nutrition communicators need to avoid making broad strokes when advising the public.
  • A daily egg is fine, except for those with diabetes* who should limit their intake to no more than three yolks per week.
  • For those with or at risk for CVD and/or diabetes, continue with a 200 mg restriction.
  • Remain conservative with foods high in saturated fat. For instance, avoid 3-egg omelets with a side of bacon and sausage.
  • Opt for high-fiber foods and whole grains, since refined carbohydrates can lower HDL (nay) and fiber can help lower LDL (yay!).
  • For those pregnant or immune-compromised, cook eggs fully.

Remember that as of 2012 9.3% of Americans had diabetes, another 1.7 million new cases were diagnosed, and 86 million were in the prediabetic state. In total, 85.6 million Americans suffer from CVD or the aftermath of stroke. Acknowledging that the dietary guidelines are intended for the general public as a preventative health measure, with numbers this large nutrition communicators need to avoid making broad strokes when advising the public.

And ultimately, Dr. Lichtenstein reminds us how “all bets are off as to what the 2015 [dietary guidelines] will be.” Only time will tell if the 300 mg restriction lives on.

Want to have input on the 2015 dietary guidelines? The public comment period was recently extended until May 8, 2015. Click here to have your voice heard.

Ally Gallop, BSc, RD, CDE is studying towards an MS/MPH focusing in nutrition communication and behavior change. Her favorite egg dish is a scrambled egg, avocado, black beans, sweet potatoes, and Sriracha sauce.

To Juice, to Soup, or to Just Eat

by Emily Finnan, RD, LDN

Gwyneth Paltrow, Dr. Oz, and future bachelorette Kaitlyn Bristowe are a few embracing the latest weight loss and health solution: souping. Yes, move over juicing—souping is what’s hot.

The Soup CleansePea Soup

A soup cleanse doesn’t mean alternating between minestrone and clam chowder for a week. The soups are akin to smoothie, made of blended fruits and vegetables. Soupure, kitskitchen, and Real Food Works are a few companies offering soup cleanses. Some soups are served hot, others cold. There’s a romaine lettuce and tomatillo soup, strawberry sprouted cashew soup, and one of the few animal based soups: curried chicken.

The premise is simple. For one to five days, you eat only the soup shipped to you.  For about $60 a day you’ll get between four and six soups. Some companies offer additional flavored water and broths as part of their cleanse package.

The Juice Cleanse

Souping and juicing are the same concept. In juicing, for one to five days you drink only water or tea and five to six fruit and/or vegetable juice blends. Pressed Juicery and Suja offer juice cleanses between $55 and $72 a day.  Joe Cross, the star of Fat, Sick, and Nearly Dead, is the founder of Reboot with Joe. This company provides free recipe plans for a juice cleanse; accompanied by juicer and personal coaching marketing.

Health Claims

Souping and juicing boast similar health claims; including, detoxing from said built-up toxins, weight loss, energy boost, rest for your gastrointestinal tract, and a host of other claims. Some cleanse diets also instruct people to undergo periods of fasting or laxative use.

Studies on juicing or souping are limited. In one German study, participants drank 150-300 Calories of juice per day for about a week. They found some favorable changes in blood fat levels.  However, a week later, all levels were back to where they’d started. This speaks to the fact that any type of diet, followed only in the short-term, will have likely have little overall impact. This applies to weight loss claims too. A person could potentially lose weight on these low-Calorie cleanses, but if they switch back to their high-Calorie habitual diet, the weight will surely return.

This 2010 Sprout article examined the controversy surrounding detox diets. The “detoxing” concept, to put it plainly, doesn’t make sense. Juices and soups do not eliminate toxic compounds from the body. The only things that can do this are your liver, kidneys, intestines, and lungs. Life-long healthy habits, including a good diet, are important to keep these organs in good shape.

Soup and juice cleanse makers do not – as they should – recommend following their diets long-term. Doing so, as will be discussed in this article, would certainly be unfavorable in terms of health.

Souping vs. Juicing

Soups can satisfy

Soups may provide more satiety, or feeling of fullness, than juices. One study found that participants felt significantly less hungry after eating apple soup or an apple compared to apple juice. In another study, participants ate the same amounts of an apple, applesauce, or apple juice. Like the previous study, the apple and applesauce group felt significantly less hungry. They were then offered lunch 25 minutes later. They found that that the apple and applesauce group ate significantly less Calories at lunch than the juice groups. The apple group ate the least. Some soups in soup cleanses are served cold, sort of like applesauce.

The side-by-side

For easy comparison, one day of a soup cleanse, one day of a juice cleanse, and the dietary guidelines’ nutrient composition are lined up in the table below. I chose one day of a Reboot with Joe plan and one day of Soupure’s soup cleanse. The companies provided the nutrient information. The 2010 US dietary guidelines shown are based on a moderately active woman who is 31 to 50 years old.

Juice Soup DGs

*percentages do not sum to 100% as Calorie information was calculated from rounded gram values
**WHO 2002 recommendation

Juicing, compared to souping, has more sugar and carbohydrates, with less protein, fiber, and very little fat.  Both met guidelines for sodium intake and were low in calories. Souping is slightly above the US saturated fat goal.

Super sugary

The juice diet doesn’t meet recommendations for fiber and is very high in carbohydrates and sugar. More than half of the calories come from sugar! High-sugar diets are linked to unhealthy levels of insulin and triglycerides, but also more serious conditions, like non-alcoholic fatty liver disease and heart disease.

Juice diets are devoid of the nutrient-rich pulp and fiber-rich skin of fruits and vegetables. Pro-juicers typically claim that juicing “compacts” nutrients as it take several whole fruits or vegetables to make just one cup of juice. It is true that some nutrients may be present in higher levels, but so is sugar. Other vitamins and minerals that reside in the pulp would be lost. Furthermore, unlike whole fruit that has more fiber, the sugar in juice is in a liquid package.  Liquid sugar is absorbed more quickly and raises blood sugar to a higher level.  Below is a table comparing a cup of raw apple slices to a cup of apple juice.

Apple NF

Source: USDA Nutrient Database

As you can see, in the juice you’re getting more calories, more sugar, and less fiber. The juice does supply more potassium, but less vitamin C and folate.

Few fats

The juice diet provides very little fat.  An American Heart Association science advisory panel, led by Tufts University’s Dr. Alice Lichtenstein, examined diets less than 15% fat. They cautioned, in the short-term, these diets can lead to an unhealthy triglyceride level and decreased HDL or “good” cholesterol .

This juice diet is actually so low in fat that an essential fatty acid deficiency (EFAD) could be a concern. Your body can make some of the fats it needs for normal function, but others – essential fats – you must eat. EFAD is normally only seen in people receiving parenteral, or IV, nutrition who get too little fat. In parenteral nutrition, a minimum of 2-5% of Calories from fat are needed to prevent EFAD. It isn’t known, in food, what the minimum level is. Deficiency did occur in one man who ate a diet less than 7% fat for several months.

The Verdict

Variety is an essential part of a healthy diet. Many souping and juicing plans eliminate entire beneficial food groups like whole grains, lean meats, seafood, eggs, and dairy. This puts you at risk for nutritional inadequacies. It is clear that both souping and juicing don’t measure up as a long-term healthy diet.

If you are a healthy adult, there are (probably) no negative health effects of cleanse diets in the short term. If you are searching for a cleanse, it does appear that souping beats juicing. Souping offers a more ideal provision of sugar, carbohydrates, fats, fiber, and protein in terms of health.

Emily Finnan is a pediatric dietitian and a first year biochemical and molecular nutrition master’s student. While she does enjoy a good soup, she’ll stick to eating her fruits and veggies with a fork.

How Does a Ketogenic Diet Affect YOU? Part 3: C-Reactive Protein: A Marker of Inflammation

by Katie Mark

The latest craze surrounding the ketogenic diet has us further investigating whether or not a high-fat/low-carbohydrate lifestyle might be an appropriate dietary approach for some people. In this 3-part series (click here for part 1 and part 2), we’re evaluating how the ketogenic diet affects biomarkers.

The ketogenic diet is a very low-carbohydrate (<10% of total calories), moderate protein and high-fat (>70% of total calories) diet. After at least two weeks of keto-adaptation, the body’s energy source switches from glucose to fat.

In part one of “How Does a Ketogenic Diet Affect YOU?” we found studies suggesting that nutritional ketosis lowers fasting glucose and insulin levels and possibly increases insulin sensitivity. In part two, we investigated the impact of ketosis on cortisol. We found that a high-fat, carbohydrate-restricted diet may increase certain forms of cortisol, but blood cortisol levels are only half the story. Further research is needed to clarify the relationship between ketosis and an increase in certain forms of cortisol: the active form (cortisol), the inactive form (cortisone) and metabolites of cortisol from enzymatic breakdown.

Now let’s evaluate how the ketogenic diet affects C-reactive protein (CRP).

Increased CRP: Is there a need to worry?

C-Reactive Protein

C-Reactive Protein Model

CRP is considered a marker of inflammation. The liver makes CRP when inflammation in the body is present. High levels of CRP are influenced by genetics, high stress, exposure to environmental toxins and a sedentary lifestyle. Diet can also impact CRP levels, especially diets high in refined and processed foods.

There are two blood tests to measure CRP. The non-specific test indicates acute CRP levels that result from general inflammation in the body. The more sensitive measure is the highly sensitive CRP (hs-CRP) test, which accurately measures basal levels of CRP by measuring inflammation in blood vessels. The hs-CRP test is the accepted measure to determine the risk for cardiovascular disease (CVD).

Higher CRP levels signify a higher risk for developing CVD and abdominal obesity. Weight loss is known to decrease markers of inflammation such as CRP.

It is believed that a high saturated fat and very low carbohydrate diet (VLCARB) increases the risk for CVD. A study published in Nutrition Metabolism (London) compared a VLCARB diet to two low saturated fat, high carbohydrate diets to determine their effect on body composition and CVD risk. The isocaloric (similar calorie composition) diets were: very low fat (CHO:fat:protein; %SF 70:10:20), high unsaturated fat (50:30:20; 6%) and VLCARB (4:61:35, 20%). The study concluded that weight loss resulted in a reduction of CRP regardless of the dietary macronutrient composition. Yet, it is uncertain whether or not the macronutrient composition of a diet influences inflammation.

A study published in The Journal of American College of Nutrition found an increase in CRP in overweight women who followed a short-term low carbohydrate, high-fat weight loss diet. The study reported that an increase in CRP might have resulted from the oxidative stress caused by this type of diet.

Another study published in Obesity (Silver Spring) looked into the inflammatory response caused by a high-fat, low-carbohydrate weight loss diet (HF) by randomly assigning 19 overweight men and women to either an antioxidant (AS) or placebo (P) supplement. The objective was to see if the antioxidants vitamins C and E could decrease the inflammation reported in a HF diet.

CRP decreased 32% in the AS group and increased 50% for the P group; however, this was statistically insignificant. The HF diet did not decrease CRP within the short-term 7-day study even though other markers of inflammation decreased.

The study could not confirm if oxidative stress was causing the inflammation. It was concluded that further research is needed to determine the different CRP responses over the long term, especially while using antioxidant supplements. This is important considering most fruits and vegetables, which are low in fat, contain antioxidants.

The Verdict

A ketogenic diet may increase CRP levels, but weight loss reduces CRP levels. The reason for the increase in CRP is unclear. One plausible explanation is that low intakes of magnesium, vitamin C and other nutrients while on a ketogenic diet may lead to this effect. When magnesium is low, CRP increases. It has been reported that increased vitamin C intake may reduce high CRP levels.

An imbalance between anti-inflammatory fats (omega-3 fatty acids) and pro-inflammatory fats (omega-6 fatty acids) is another possible explanation. Polyunsaturated vegetable oils primarily contain the pro-inflammatory omega-6 fatty acids. Eating less grain-fed meats and chicken and more grass-fed meats and free-range chicken is also important to consider. Grain-fed animals have higher omega-6s whereas grass-fed animals have higher omega-3s. Omega-3s are anti-inflammatory and important for normal body functions, including regulating blood clotting and building cell membranes in the brain. Omega-3s are also suggested to protect against heart disease.

An elevated CRP level is never a good thing. If you are opting for a ketogenic diet, increasing magnesium and vitamin C intake as well as choosing grass-fed products may reduce CRP levels.

Katie Mark is a first year Nutrition Communication/Master of Public Health student who enjoys road cycling and traveling.

How Does a Ketogenic Diet Affect YOU? Part 2: A Deep Look Into Cortisol

by Katie Mark

Recent high hopes for high-fat diets have us further evaluating the ketogenic diet for a wider population. In this three-part series, we’re examining how the ketogenic diet affects biomarkers. Part 1 of this series investigated what ketosis does for fasting glucose and insulin. In Part 2, we look at how a ketogenic diet may affect cortisol levels.

High-fat…high cortisol…high stress?

Cortisol is considered the “stress hormone,” and it influences blood sugar levels, blood pressure, immune response, and stress response. Chronically elevated levels of circulating cortisol can hinder cognitive performance, disrupt sleep, impede immune function, increase abdominal fat, and cause blood sugar imbalances.

Studies have found that cortisol levels increase on a ketogenic diet, but some say the relationship between ketosis and high cortisol needs to be made clearer. First, chronically elevated cortisol correlates with metabolic syndrome, a group of symptoms such as high blood sugar, excess abdominal fat, and abnormal cholesterol levels that increase the risk for diabetes, heart disease, and cancer.

It seems possible that ketogenic diets may cause metabolic syndrome because higher cortisol levels suggest the onset of metabolic syndrome. However, this isn’t the whole picture: It’s also possible that there are multiple forms of cortisol, and their measurements mean different things.

Cortisol is measured in bodily fluids, including urine, saliva, and blood. Multiple forms of cortisol are measured from these samples: cortisone (the inactive form), free cortisol (the active form), and metabolites of cortisone and cortisol resulting from enzyme activity. Equally important, these levels of cortisol biomarkers can vary depending on the time of day.

A holistic understanding of cortisol metabolism relies on looking at the enzymes 11β-hydroxysteroid dehydrogenase (11β-HSD) and 11β-HSD1 (a subtype of 11β-HSD). 11β-HSD1 is found in every cell, but the highest amounts are found deep within fat cells. In fact, it does not matter if a person’s blood cortisol level is low, medium, or high because a highly active 11β-HSD1 will generate a high amount of cortisol inside cells.

Here is a breakdown of cortisol metabolism:

  • Production: 11β-HSD converts cortisol (active) to cortisone (inactive)
  • Regeneration: 11β-HSD1 converts cortisone to cortisol
  • Clearance: Other enzymes help metabolize cortisone and cortisol into metabolites

The cortisol profile of metabolic syndrome, which the ketogenic diet reverses, consists of:

  • High cortisol production
  • High cortisol clearance rates
  • High 11β-HSD1 expression in adipocytes and low 11β-HSD1 expression in the liver (the location that determines where and when cortisol is regenerated)

Now, let’s see how a 24-hour urine proxy is used for detecting cortisol. This proxy results in a less-than-clear picture because cortisol levels are affected by production, regeneration, and clearance. For instance, if clearance decreased or if regeneration increased, cortisol levels could go up if production stayed the same or lowered. This is analogous to simply measuring someone’s total cholesterol without observing LDL and HDL.

Take home message: levels may appear similar when there is a big difference in cortisol metabolism.

One study, published in The Journal of Clinical Endocrinology and Metabolism, used 17 obese men and randomly assigned them to an ad libitum (eat as much as you want) high fat-low carbohydrate (HF-LC) diet (66% fat, 4% carbohydrate) or moderate fat-moderate carbohydrate (MF-MC) diet (35% fat, 35% carbohydrate) for four weeks.

The study found a reversal of the previously described metabolic syndrome cortisol profile for only the HF-LC group: blood cortisol increased, clearance decreased and regeneration increased (due to an increase in 11β-HSD1 activity in the liver). According to the researchers, the ketogenic diet improved the cortisol profile because it was different from the cortisol profile seen in metabolic syndrome.

Furthermore, even though the MF-MC group lost a similar amount of weight, there was no change in 11β-HSD1 activity. This increase in 11β-HSD1 activity in the HF-LC group was independent of the differences in energy intake and weight loss because the same effect was seen in the controls.

A final component to note is that obesity is associated with high cortisol. However, the connection between obesity and elevated serum levels of cortisol has not always been a consistent connection.

Some people with high stress and lots of abdominal fat had normal or low levels of cortisol in their blood. Usually, chronically elevated levels of cortisol leads to increased adiposity; yet, there have been cases of people with high stress and high cortisol, but no obesity. And as we saw in “The Basics of the Ketogenic Diet,” the ketogenic diet has demonstrated effectiveness as a weight loss tool.

What’s the verdict?

We see that diet, especially a carbohydrate-restricted one such as the ketogenic diet, may increase certain forms of cortisol. But blood cortisol levels are only half the story—cortisol levels inside cells illustrate the other half. Also, cortisol will vary depending on the time of day, with levels highest in the morning. Caffeine, stress, and exercise can also increase cortisol levels.

Ultimately, further research is needed to better understand the connections as to why cortisol increases on a ketogenic diet and if cortisol levels are more affected by other variables, such as the activity of the 11β-HSD1 enzyme.

Katie Mark is a first year Nutrition Communication student from Miami, Florida. Due to Boston’s Snowpocalypse, she does not foresee herself living in Boston in the future, so she will return to South Beach following graduation.

Mechanism that Causes Cataracts Discovered in Mice: The Latest in Nutrition and Vision at the HNRCA

by Nusheen Orandi

Although it may be hard to see through seven feet of snow and gray slush, the Human Nutrition Research Center on Aging (HNRCA) is still hard at work, especially in the Nutrition and Vision lab.

The Nutrition and Vision lab, directed by Dr. Allen Taylor, just published a paper in the Janurary Online Early Edition of Proceedings of the National Academy of Sciences about how tinkering with one protein, called ubiquitin, leads to other biochemical reactions that result in the clouding of the eye lens, known as cataracts. Not only is this publication groundbreaking in vision academia, but this knowledge applies to other diseases in the body that are affected by the same process, such as Alzheimer’s and Parkinson’s disease. Dr. Taylor is a Professor of Nutrition at Tufts University Friedman School of Nutrition Science and Policy, Professor of Ophthalmology at the School of Medicine, and part of the faculty of the Department of Developmental, Molecular, and Chemical Biology at the Sackler School of Graduate Biomedical Sciences. He gave insight to the progress of the lab, where nutrition fits in, and where research is going from here.

How does it work?

Many age-related diseases, like cataracts, are related to the accumulation of damaged or abnormal proteins. Ubiquitin is a protein part of a proteolytic (protein breakdown) pathway that regulates this protein buildup to prevent a number of diseases. As Dr. Taylor put it, ubiquitin is important for “cleaning up bad proteins.”

“We’re interested in what forms cataracts and age-related macular degeneration and its nutritional correlate,” he explained. Dr. Taylor and his colleagues examined how damage to the ubiquitin proteolytic pathway can cause the improper degradation of these bad proteins to lead to cataract formation.

In the experiment, Dr. Taylor and his research team identified a mechanism that leads to the formation of cataracts in the mice. The team mutated one of the lysine amino acids of the ubiquitin protein, which altered gap junction proteins called connexins and caused calcium to be retained in the cells of the eye lens. The resulting levels of calcium initiated the biochemical pathway of another protein called calpain, which is a digestive enzyme responsible for shredding proteins. The hyperactivation of calpain in the eye eventually led to the opaqueness of the lens, known as a cataract.

Cataracts are the leading cause of blindness worldwide and affect over 85% of the elderly. The inefficient degradation of proteins that cause cataracts is a significant investigation. The same ineffective ubiquitin proteolytic pathway leads to congenital cataracts as well, which is the leading cause of childhood blindness.

So, what does nutrition have to do with it?

Diet affects many diseases, and cataracts are no exception. Although having cataracts is mainly an age-related disease, nutrition can impact disease development.

“There’s a nutritional correlate to inefficient proteolysis,” Dr. Taylor explained. “It can be caused by anything that causes too much stress in the body. If you have inefficient nutrition, you won’t have enough antioxidants, and this causes oxidative stress. It messes up the proteolytic pathway and disease builds up. You don’t have enough proteolytic machinery to fight these toxic proteins.” An example he gave was having a diet high in sugar and lacking fruits and vegetables. The excess sugar causes oxidative stress on the body that accumulates with age. Without the proper antioxidants, regulatory proteins like ubiquitin can’t operate at maximum capacity. Eat healthfully because it affects your vision!

Is this research only related to vision?

No, and that’s what makes this research even more exciting. The accumulation of toxic proteins and ineffective proteolysis mechanisms is also related to neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease. Maybe you thought ubiquitin was a curious name for a regulatory protein, but it was actually a conscious term, being ubiquitous, or everywhere, in the body.

“Protein buildup takes place everywhere, like the brain,” offered Dr. Taylor. This relates to Alzheimer’s disease, where without the proper proteolysis mechanisms, plaques can form and cause the gradual neuronal breakdown. Defective ubiquitin proteosome in the brain, caused by oxidative stress and inflammation by the neurotoxin known as MPTP, is associated with one of the causes of Parkinson’s disease.

The Nutrition and Vision Lab at the HNRCA demonstrated the importance of adequate nutrition on age-related diseases, such as cataract formation, giving further indications of a parallel with Alzheimer’s disease and Parkinson’s disease. How we take care of ourselves goes a long way and causes a domino effect of all the biochemical pathways in our body.

Nusheen Orandi is a first-year student from California in the Nutrition Communication program and likes to spend her time tea-shop hunting, tensely watching the Tottenham Hotspurs, and cooking and eating with friends and family.

9 Reasons to Attend Friedman’s 9th Annual Student Research Conference

by Matt Moore

The Future of Food and Nutrition Graduate Student Research Conference (SRC) takes place on Saturday, April 11. Students from Friedman and across the country will attend and present original research from a range of topics related to nutrition and food systems. Last year’s conference drew over 200 attendees from 30 institutions across the country. The Sprout presents nine reasons for Friedman students to attend.

1. Content

The conference has grown every year, and the planning committee received a record-breaking number of abstract proposals from schools across the country. The final agenda will include something for everyone: presentations are expected to cover a range of domestic- and international-focused topics such as agriculture, nutrition science, policy and programming, food security, climate change, food systems, and epidemiology.

2. Support Friedman

Students who attend will provide an audience for their classmates who are presenting, and it is a great way to discover what colleagues outside their own concentration have been working on. Furthermore, the conference is scheduled to coincide with the accepted student open house, so current Friedmanites will be able to answer questions and recruit for the new class.

3. Collaboration

Students from over 35 colleges and universities across the United States are expected to attend this year. Not only do they share common interests with Friedman students, but they will enrich discussions by bringing new and different ideas and perspectives to the table.

4. Angela TagtowAngela Tagtow, Executive Director, Center for Nutrition Policy and Promotion

The new Executive Director of the USDA’s Center for Nutrition Policy and Promotion (a position first held by Friedman’s own Eileen Kennedy) will present this year’s keynote: “Nutrition Policy at a Crossroads: Dietary Guidelines for Americans Application and Evolution.” Tagtow has a background in sustainable diets and has worked to promote social and environmental justice in the national food system. She founded the Journal of Hunger & Environmental Nutrition, the Iowa Food Systems Council, and the Iowa Food Access & Health Work Group. She is also a former Food & Society Policy Fellow at the Institute for Agriculture & Trade Policy.

5. Expert Panel

In addition to the keynote, an expert panel titled “Sustainable Diets and the Implications for Dietary Guidance in the United States” will tackle the topic of sustainable diets. The panel will be moderated by Parke Wilde and will feature Dr. Miriam Nelson, member of the 2015 Dietary Guidelines Advisory Committee (DGAC) and chair of the Food Sustainability and Safety Sub-Committee, and Dr. Andrew Rosenberg, Director of the Center for Science and Democracy at the Union of Concerned Scientists.

6. Sustainable Diets

The topic of sustainable diets has been at the heart of the national food policy debate. It has caused a bit of controversy in Congress, and almost everyone in the nutrition field has an opinion on whether sustainable diets should be a factor in shaping the Dietary Guidelines. Most recently, the DGAC released its Scientific Report, and the sustainability consideration has been the center of attention. At the SRC, attendees will have a chance to jump in and discuss the issue with people actively working in the field.

7. Networking

Attendees will have a chance to meet with presenters, faculty, and students to engage and further discuss the topics of the day. There will be time for mingling throughout the conference during lunch and refreshment breaks. Then to cap off the event, there will be a post-conference networking reception at Trade, located a short walk from the Friedman Schools (540 Atlantic Avenue). Free food will be provided, of course.

8. Student-Run

The SRC is entirely planned and executed by Friedman students. Led by co-chairs Janeen Madan (FPAN ‘15) and Claire Anglim (NUTCOM ‘16), a group of 25 students has been working since last October to coordinate the conference. Nobody is better qualified to develop a program of content that will appeal to current graduate students than the colleagues they work with every day.

9. Cost

Any Tufts student can attend for just $15, which is grad-school-budget friendly and a bargain for a full-day event, including breakfast, snacks, lunch, and appetizers at the networking reception.

Anyone interested in attending can get more information and register at the SRC website. The final schedule will be released this month, and students can take advantage of early-bird registration until the week of the conference.

Matt Moore is a first-year AFE student who received a lot of help from Abbie Steiner and Janeen Madan in writing this piece. He looks forward to a Spring Break trip to his bed. 

Follow

Get every new post delivered to your Inbox.

Join 71 other followers