Fiber failure

October 25, 2013 by  
Filed under Carbohydrates

Did you see the headlines today? Americans are not consuming enough fiber!… Hmmm, this really isn’t news. We’ve known for years that, as a nation, we don’t consume enough whole grains, fresh fruits, or vegetables. A recent study published in the December issue of The American Journal of Medicine (AMJ), confirms that this lack of fiber is at least partly responsible for an increased risk of metabolic syndrome, cardiovascular disease, and obesity.

How much fiber do we need?

The Institute of Medicine recommends that adults aged 19-50 years consume 25 grams of fiber per day (women) to 38 grams of fiber day (men). That may sound like a lot, but it’s surprisingly easy to meet the recommendations if you put in a little effort. It will likely require a few simple substitutions, and perhaps a couple of healthy additions.

For instance, instead of eating a highly processed breakfast cereal first thing in the morning, choose one made with whole grains (5 grams of fiber per cup). Instead of eating a sandwich for lunch made with bread from refined flour, choose bread made with whole grains (5 grams of fiber per two slices). Instead of eating refined pasta for dinner, choose whole grain pasta (5 grams of fiber per cup). And don’t forget to enjoy fruits and vegetables throughout the day as snacks –a cup of fresh fruit or vegetables is worth another 5 grams of fiber, as is half a cup of beans.

You can see that, if you focus on WHOLE GRAINS,  it’s quite possible to meet the recommendations for daily fiber intake. Unfortunately, according to the recent AMJ study, Americans consume an average of just 16 grams per day! That’s roughly half of the recommendation.

Food for thought

Why do you think that most Americans do not consume enough fiber? How much fiber do you consume on a daily basis? What sorts of substitutions or additions to your diet could you make to consume more fiber?

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“Dietary Fiber Intake and Cardiometabolic Risks Among US Adults, NHANES 1999-2010” by Kya N. Grooms, BA; Mark J. Ommerborn, MPH; Do Quyen Pham, MPH; Luc Djousse, MD, ScD, MPH; Cheryl R. Clark, MD, ScD. The American Journal of Medicine, Volume 126, Issue 12, December 2013.

Should You Be Gluten Free?

October 17, 2013 by  
Filed under Carbohydrates, Digestion, Protein

Gluten is a protein composite found in foods processed from wheat, barley and rye (and related grains). It is found in the endosperm of the grain kernel and consists of the proteins gliadin and gluterin. Gluten gives elasticity to dough, helping it rise and keeps its shape.  You may have heard or read about the health benefits of gluten-free diets and seen numerous gluten-free products in the grocery store. Proponents of gluten-free diets claim that this dietary pattern promotes weight loss and may be beneficial in numerous other ways, such as helping those with osteoporosis, anemia and diabetes. Have you wondered if this is true? Have scientific studies been conducted to back up these claims? Let’s take a closer look at some the purported health benefits and also consider who may benefit most from a gluten-free diet.

There are indeed folks that have to avoid gluten at all costs, namely, those suffering from celiac disease (also frequently called celiac sprue). This autoimmune disorder occurs in genetically predisposed people from early life onwards. People with celiac disease experience pain and discomfort in the GI tract, chronic constipation, fatigue and other symptoms. The underlying cause is related to gluten exposure. In those with celiac disease, an enzyme in the epithelium of the GI tract reacts with gluten proteins and causes an immune reaction whereby the immune system attacks the small bowel tissue. This causes an inflammatory reaction and as a result, the villi of the epithelium are blunted and malabsorption of many nutrients occurs. The only treatment for celiac disease is life-long adherence to a gluten-free diet. Clearly the preponderance of gluten-free products now available in the grocery stores benefits those with the disease. But what about other individuals, can they also benefit from gluten-free foods?

How about going gluten-free for weight loss? Gluten-free diets tend to be similar in energy content to traditional diets, but more careful planning when going gluten-free may promote making healthier food choices. So from this perspective, gluten-free may promote weight loss, for reasons not directly related to gluten. Does avoiding gluten help those with the other disorders listed above? There are few properly controlled scientific studies to support many of the gluten-free claims, so it’s hard to know for sure. Another consideration is the foods that you might avoid by going gluten-free, such as breads, pastas and other grain products. Given that these foods are important dietary sources of B vitamins, fiber, iron and other nutrients in the American diet, avoidance of them may increase risk for various nutrient deficiencies.

Certainly, the incidence of celiac disease is increasing in the U.S. Current estimates are that 1:100 people may have celiac disease and some of them may be undiagnosed. For these individuals, going gluten-free is necessary and will often dramatically improve quality of life. From this perspective, the current popularity of going gluten-free is beneficial. The real question though is, how beneficial is gluten avoidance for the other 99/100 people in the U.S.?

Happy World Food Day!

October 16, 2013 by  
Filed under Malnutrition

What? You didn’t know today was World Food Day? Let’s celebrate! But first, let’s learn.

Today marks the 68th anniversary of the United Nations Food and Agriculture Organization (FAO), an international effort to eliminate world hunger and malnutrition. The purpose of World Food Day is to raise awareness about the FAO and aspects of food that many of us take for granted, like access to healthy food and sustainable agricultural systems.

Even though access to healthy food is a basic human right, many people go without. In America alone 17.6 million people (14.5% of households) are food insecure (USDA 2012), meaning that they lack access to sufficient amounts of safe and nutritious food.  In other words, they are hungry. Every day. Worldwide, the number of people living with chronic hunger is 842 million (FAO 2013).

Keep in mind that the goal of the FAO is not simply to produce enough calories to feed every man, woman, and child on the face of the planet (we do that already), but to do so sustainably and equitably. That means food production with a focus on environmental and social justice. That means treating the land with respect, educating and paying agricultural workers appropriately, and distributing safe and healthy food to those in need.

Significant progress has been made in the past few decades, but a changing climate and a growing world population will continue to be a challenge. Please give some thought to the FAO, and the issues and the people they are fighting for. You can access the FAO’s latest report, “The State of Food Insecurity in the World 2013”, here: http://www.fao.org/publications/sofi/en.

Food for thought:

  • What can you do to address hunger in your community?
  • Are you familiar with agriculture and food production in your community? In the United States?
  • Do you grow any of your own food? Why or why not?

If you missed celebrating World Food Day (October 16th), don’t worry — October 24th is Food Day in the United States!

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1. United States Department of Agriculture, Economic Research Service, 2012.  Accessed at http://www.ers.usda.gov/topics/food-nutrition-assistance/food-security-in-the-us/key-statistics-graphics.aspx

2. Food and Agriculture Organization of the United Nations, 2013. Accessed at: http://www.fao.org/hunger/en/

 

Essential and trans fats

October 9, 2013 by  
Filed under Fat

Fat is the poor, misunderstood stepchild of the macronutrient world. Twenty years ago the media condemned all fat as bad and it was subsequently banned from cookies, crackers, potato chips, soups, yogurt, milk, and (the horror!) ice cream. It’s true that fat is very energy dense, but we absolutely need fat. In fact our bodies can’t survive without a certain amount of “essential” Omega-3 and Omega-6 fat. On the other hand some types of fat, like trans fat, should indeed be limited.

Essential fats: Omega-3 and 6

Omega-3 and Omega-6 fatty acids are “essential” fats, meaning that our bodies cannot manufacture these fats on its own and must therefore get them from food sources. These fats are vital components of cell membranes and help transport fat-soluble vitamins. In addition, Omega-3 fats help reduce blood pressure and inflammation, and are therefore associated with improved long term cardiovascular health (see Jamie’s recent post on the benefits of the Mediterranean Diet). Omega-6 fats, while still essential, often cause an increase in blood pressure. Although we technically need both types fat, we tend to get more than enough of the Omega-6 fatty acids and not nearly enough of the Omega-3 fatty acids.

Do a little research and see if you can answer the following questions about essential fatty acids: What are some primary sources of omega-3 and omega 6 fatty acids? What is the recommended consumption ratio of omega-3 to omega-6 fatty acids? What ratio does the typical American diet provide? Would it be possible to integrate more omega-3 fatty acids into your diet?

Trans fat

There really aren’t many foods that I consider truly “bad”, but there’s nothing good about hydrogenated or trans fat, at least from a health perspective. Hydrogenation is an artificial process used to extend the shelf life of foods and/or provide a certain mouth feel.  Hydrogenated fat is particularly bad for you because it not only increases “bad” LDL cholesterol and inflammation (major risk factors for heart disease), but also decreases your “good” HDL cholesterol.

Do a little research and see if you can answer the following questions about trans fat. What are some primary food sources of trans fat? How many grams of trans fat are recommended per day? How many grams of trans fat do you think you consume on a daily basis? What are some healthier alternatives to trans fat?

How Does a Mediterranean Diet Promote Good Health?

October 2, 2013 by  
Filed under General

You may have heard about the purported benefits of the Mediterranean diet (MD). Media outlets, which may sensationalize scientific studies, often report the benefits of such a dietary pattern. From the perspective of a scientist, are these reports accurate? Have studies that examined the Mediterranean dietary pattern been in agreement on the health benefits? Where did this idea originate? Let’s take a closer look at these issues.

It was first reported in the 1940s in the landmark Seven Countries study that men living on the island of Crete in the Mediterranean Sea, which is part of Greece, had long life spans and low rates of heart disease. This observation piqued the interest of nutritional science researchers, who proceeded to analyze the lifestyles and dietary patterns of these individuals. It was noted that the indigenous people of Crete lived lives that were low in stress that included daily exercise, often in the form of walking. Moreover, their diets were high in olive oil and nuts, which contain abundant mono- and polyunsaturated fat, and in carbohydrates. They also consumed fish often and regularly had wine with meals.

Over the past several decades, these observations have morphed into what we now refer to as the “Mediterranean diet”, which only partially reflects the dietary patterns of the people of Crete at that time. The modern MD is high in beans, whole grains, fruit and vegetables, fish and nuts, and low in red and processed meats, added sugars and saturated fats with moderate alcohol consumption. Studies have consistently shown that this dietary pattern is associated with a lower incidence of cardiovascular disease (CVD) and may also decrease the risk of cancer and other chronic diseases.

What is it about the MD that offers these health benefits? What are the beneficial nutrients in the MD that promote good health? For starters, higher mono- and polyunsaturated fat intake, which typifies the MD, has been associated with decreased risk of CVD. The MD also contains high potassium and low sodium, supporting blood pressure control. Fruits, vegetables and nuts are high in fiber and also contain abundant phytochemicals, some of which are known to have positive health benefits. High fiber intake is associated with reduced risk of some cancers (e.g. colon cancer) and it also decreases blood cholesterol levels. Fish contains omega-3 fatty acids, which have anti-inflammatory properties. Moreover, the MD limits red and processed meats, which are typically high in saturated fat, cholesterol and sodium. Moderate alcohol consumption has also been linked to a lower incidence of CVD, particularly red wine, which contains a powerful antioxidant phytochemical.

The MD diet thus promotes good health. If this dietary pattern is combined with regular exercise and one works at decreasing daily stress, it can certainly reduce risk for developing a host of chronic diseases. Can you think of other health benefits of the MD? How can you alter your diet so it more closely reflects this dietary pattern? Why might the MD be more beneficial than the typical American diet?

The Glycemic Index

October 2, 2013 by  
Filed under Carbohydrates

Despite the endless stream of media hype these days (Paleo Diet, South Beach Diet, Atkins Diet, etc.), carbohydrates are not all that bad. At least not all of them.

One of the primary determinants of “good vs. bad” carbs is a measure called the Glycemic Index (GI). Simply put, the GI describes how quickly your body digests and absorbs certain carbohydrate-containing foods. Pure glucose (a simple sugar) has a GI value of 100, meaning that it is absorbed into your bloodstream very quickly.  Peanuts, on the other hand, have a GI value of 10.

Are high-GI foods bad for you?

Well, it depends who you are and what your needs are. If you are an athlete who engages in prolonged intense exercise, then high-GI foods are your friends – they are the fastest way to replace your carbohydrate fuel stores and prevent the much dreaded “bonk”. But if you don’t exercise regularly, high-GI foods can be decidedly unfriendly.

High-GI foods lead to rapid spikes in blood sugar levels, which in turn lead to spikes in insulin levels. Insulin is a hormone released by your pancreas to shuttle excess blood sugar into your liver, muscles, and fat tissue. Unfortunately, insulin also stimulates an increase in blood triglycerides and LDL cholesterol, known risk factors for heart disease. Insulin spikes may also cause dramatic decreases in blood sugar, contributing to fatigue and hunger.

Low-GI foods are digested and absorbed more slowly by your body, resulting in a lower blood glucose and insulin response. Replacing high-GI foods with low-GI foods will not only reduce your risk for heart disease and perhaps type 2 diabetes, but will also help you maintain more even energy levels and prevent cravings between meals.

The take home message

High-GI foods are good and fine if you need them, but chronic consumption of high-GI foods can lead to an increased risk of heart disease and type 2 diabetes, as well as uneven energy levels and food cravings. Try to replace or combine high-GI foods with low-GI foods to mitigate your body’s blood glucose and insulin response.

Food for thought

  1. What foods tend to have high-GI values? What foods have low-GI values?
  2. When do you need high-GI foods? When/why are high-GI foods not such a good idea?
  3. What modification could you make to your diet with regard to glycemic index?