Archive for the ‘Real Life’ Category

Homemade soft pretzel (plain) - Photo credit Bryan Ochalla - Used unmodified via Flickr, under CC BY-SA 2.0 license

Photo Credit: Bryan Ochalla via Flickr
Used unmodified under CC BY-SA 2.0 license

By Shelly Najjar

Carbohydrates (carbs) are mentioned a lot, by many people. In November you hear about carbohydrates because of Thanksgiving feasts and American Diabetes Month. In January you hear about people going on low-carb diets for weight loss. In the summer people try to give up carbohydrates for swimsuit bodies. Carbohydrates are in the news and in conversation, but what are they? Do we need them? Are they bad? Do they make you gain weight? This post is an introduction to carbohydrates.

What is a carbohydrate?

Medical Dictionary Definition:

any of various neutral compounds of carbon, hydrogen, and oxygen (as sugars, starches, and celluloses) most of which are formed by green plants and which constitute a major class of animal foods –Merriam-Webster Medical Dictionary

Real Life Definition:

Carbohydrates are compounds that occur naturally in foods (and can also be manufactured and added to foods) in three types (starches, sugars, and fibers).

What foods have carbohydrates?

Carbohydrates are found in dairy, starches, fruit, sweetened beverages, and dessert sweets. There can be added or naturally occurring carbohydrates in any of these. Foods do not have to taste sweet to have carbohydrates. Some examples include

  • Dairy: milk, chocolate milk, ice cream, frozen yogurt, and regular or flavored yogurt (not cheese)
  • Starches: any type of pasta, bread, rice, beans, starchy vegetables (potatoes, corn, peas, lentils, etc), crackers, cereal, etc (any starchy food)
  • Fruit: apples, oranges, grapes, melon, berries, fruit juice, etc (any fruit)
  • Beverages: fruit juice, lattes, chocolate milk, sweet tea, non-diet sodas, energy drinks, etc (any drink sweetened with anything other than non-caloric sweetener)
  • Sweets: cake, cookies, pies, candy, etc (anything made with starch or fruit ingredients and/or sweetened with anything other than non-caloric sweetener)

Plain meats, fish, poultry, cheese, eggs, and tofu (all without added sauces, which could contain carbohydrates) do not have carbohydrates. Also, non-starchy vegetables like broccoli, avocado, lettuce, carrots, onion, etc. are not counted to have carbohydrates if eaten in portions less than 1/2 cup cooked or 1 cup raw.

Are some carbohydrates better than others?

Some carbohydrates affect our blood sugar more than others, and have different benefits. The three main types of carbohydrates are starch, sugar, and fiber.

Once digested and absorbed in the body, starch and sugar raise our blood sugar, while fiber, the indigestible carbohydrate, does not have the same effect on our blood sugar. Fiber is not digested or absorbed by our bodies, but it does make us feel full and have many health benefits, so fiber-containing foods are recommended as a part of a healthy diet. Whole grain foods (which has all parts of the grain: endosperm, germ, and bran) have fiber and starch, are also recommended for overall health.

Most starches are digestible in our small intestines and will affect blood sugar, but there is also a type of starch called resistant starch that behaves more like fiber, since it continues into the large intestine without being digested. And, like fiber, many resistant starches can be digested or fermented by the bacteria in our large intestine, which helps us stay healthy (Source: Weisenberger, 2012).

Sugars can be naturally occurring or added to foods. Examples of foods with naturally occurring sugars are apples and milk. Added sugar is in many candies, cookies, and canned fruits in syrup, and includes sugars like honey, agave syrup, maple syrup, raw sugar, etc. Even if the food (like honey) has sugar naturally, when used as a sweetener, it counts as an added sugar. In general, the recommendation is to eat as few added sugars as possible.

Are carbs bad for us? Do they make you gain weight? How many carbs do we need?

Carbohydrates are neutral. We need carbohydrates to live, but too many or too few of them in our diets can cause problems. Carbohydrates on their own do not cause a person to gain or lose weight. Weight changes are caused by a variety of factors, including diet. According to the 2010 Dietary Guidelines for Americans (DGA2010):

“Strong evidence shows that there is no optimal proportion of macronutrients [macronutrients include carbs, fat, and protein] that can facilitate weight loss or can assist in maintaining weight loss […] evidence shows that the critical issue is not the relative proportion of macronutrients in the diet, but whether or not the eating pattern is reduced in calories and the individual is able to maintain a reduced-calorie intake over time. The total number of calories consumed is the essential dietary factor relevant to body weight.”

It goes on to say that we can choose healthy eating patterns that work for us, as long as they are within the right caloric range for us, and are consistent with the Acceptable Macronutrient Distribution Ranges (AMDR) established by the Institute of Medicine. The AMDRs are “ranges for the percentage of calories in the diet that should come from carbohydrate, protein, and fat” and “take into account both chronic disease risk reduction and intake of essential nutrients” (Source: DGA2010). Based on the ADMRs, we should eat between 45-65% of our total calories from carbohydrates. This includes all sources and types of carbohydrates and should be based on how your body responds and your overall health. (Your medical team can help you decide exactly how many carbohydrates you should eat – Click here to find a dietitian).

In general, most healthy people do well with about 45-50% (about half) of their calories coming from carbohydrates. For someone eating 1800 calories, this is about 200-225 grams of carbohydrates, spread out evenly throughout the day (usually about 45-60 grams at each of 3 meals, plus about 15 grams at 2 snacks between meals). Carbohydrates should come from a variety of foods, including many fiber-containing foods. Here are some helpful guides to let you know how many grams of carbohydrates are in how much of certain foods:

Summary:

  • Carbohydrates come in many types, from many foods.
  • We need carbohydrates to live, and they can and should be part of a healthy diet, coming from a variety of healthy foods.
  • While most people seem do well on a diet with up to half their calories coming from carbohydrates (about 45-60 grams carbohydrate per meal), only a medical team can help you decide what your specific health situation requires.

Read More:


Shelly Najjar, MPH, RDN is a Registered Dietitian Nutritionist and editor of Nutrition Nuts and Bolts. You can contact her on Twitter (@ShellyNajjar), LinkedIn, and at shellynajjar.com.

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Cooking oil in pan - Free use photo via morgueFile

Free use photo by cgiraldez via morgueFile

Last week I participated in a hands-on cooking class at a wonderful co-op in Seattle. While searing an oh-so-tasty chicken tarragon entrée in organic canola oil, the question arose, as it usually does at cooking classes: “What oil is best to cook with?”

Olive Oil – To Cook with, or Not to Cook with?

You may have heard that olive oil is not the wisest choice for cooking. “Why is that? But I’ve heard it’s healthy for you,” you might say. And you’re right. It is good for your health. It is rich in anti-inflammatory omega-3s, monounsaturated fats (a healthy dietary fat that may help lower total cholesterol) and is a staple of the Mediterranean Diet.

But olive oil has a lower smoke point, which means that olive oil will begin to smoke when cooking at temperatures between approximately 325°F to 460°F, depending on type. Heating olive oil or any oil to its smoke point degrades its healthy compounds, even increasing harmful, potentially carcinogenic compounds, and releasing free radicals which can ravage our cells.

Hello there olive oil and balsamic vinegar little fella. Photo Credit: Aden Davies (ad76) on Flickr

Photo credit:
Aden Davies (ad76) on Flickr
Used unmodified under
CC BY-SA 2.0 license

Olive oil has its place, though, as an ingredient in salad dressings and for sautéing vegetables over low to medium heat. Combine it with balsamic vinegar for a dipping for whole grain breads.

What Should I Use Instead?

The answer depends on personal preference as well as the type of cooking you are doing. Use oils with a high smoke point for searing, browning and all-purpose cooking. Use oils with a medium-high smoke point for baking, oven cooking, sautéing and stir-frying. Oils with a medium smoke point are best for lighter sautés, sauces and cooking over low heat.

If you’re seeking an oil with a higher smoke point for all-purpose cooking, consider canola oil, which has a neutral flavor and is loaded with those heart-healthy omega-3s. The chef at my cooking class opted for canola for the chicken tarragon, noting it is also a good source of monounsaturated fats and is versatile, good for high-heat cooking as well as baking and sautéing.

Peanut oil also has a high smoke point and is a smart choice for stir-fries and other high-heat cooking. Avocado, almond, safflower and sunflower oils are also good varieties for higher-heat cooking.

Is Rice Bran Oil in Your Pantry?

If not, you might want to seek out a bottle, but be forewarned this oil comes with a slightly higher price tag at approximately 12 cents per ounce versus 6 cents per ounce for canola oil, according to a recent comparison by Cooks Illustrated. Price aside, interestingly, the chef whipping up the divine chicken tarragon entrée recommended rice bran oil for high-heat and all-purpose cooking. Rice bran oil? I hadn’t heard of it. Apparently many others in the class hadn’t, either. “What…” we chimed, “…is that?”

Chef Pam Sawyer explained that rice bran oil is her go-to for its health benefits and variety in application. Rice bran oil contains nearly 50 percent monounsaturated fats and similar to olive oil and canola oil, is high in omega-3s. It is a good source of vitamin E, which serves as an antioxidant that rids the body of damaging free radicals that arise from normal metabolic processes and from environmental factors such as pollutants.

Rice bran oil’s versatility lends itself well for sautéing, baking and cooking at high heat given its high smoke point (approximately 495°F). Sawyer also uses less of it when cooking, in comparison to multiple dollops of other oils that she has had to use while cooking. The rice bran oil heats up nicely and evenly, is light and coats a pan with a thin sheen.

This shelf-stable oil can last approximately three years in your pantry; it is one of the most stable oil options. “You can have this oil near your stove and it won’t break down like other oils would,” Sawyer said. Canola oil, in comparison, can go rancid at room temperature in a hurry, Sawyer said; thus, she suggests refrigerating canola if that is your preferred oil.

Here’s to healthy cooking!

**Please share – what is your favorite cooking oil?**

Krista Ulatowski, MPH, RD, is based in Seattle, where she practices in the areas of nutrition writing, marketing and social media. She also counsels clients in weight loss and corporate wellness settings. Connect with her at @PhytoK or send an email: krista.ulatowski@gmail.com.

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whole wheat bread

Bread made with wheat flour is one common source of gluten.
Photo by Stacy Spensley (notahipster on Flickr)
Used unmodified under the CC Attribution license

Is the gluten-free diet a food fad that will eventually flame out, or is it a path to better health? The answer depends on whether you need to avoid gluten…and the fact is that most people don’t need to.

What is gluten and where is it found? Who should avoid it?

Gluten is a type of protein found in wheat and other members the Triticeae tribe of grasses: Rye, barley, triticale, kamut and spelt. Most people can eat these cereal grains without ill effects. However, an estimated 8 in 100 people can’t, due to a wheat allergy, celiac disease or non-celiac gluten sensitivity.

How common are wheat allergies?

Fewer than 1 in 100 children have a wheat allergy (1), and about half will outgrow it before adulthood. If you have a wheat allergy, your body’s immune system reacts inappropriately to one (or more) of the many proteins found in wheat. This may or may not include gluten. Symptoms appear within minutes or hours and can include skin rashes, intestinal discomfort, wheezing and anaphylaxis. Generally, people with wheat allergies don’t have problems eating rye and barley.

What is celiac disease? How common is it?

As many as 1 in 100 people have celiac disease (1), a genetically inherited autoimmune condition that causes the immune system to attack the lining of the small intestine after gluten is ingested. Celiac disease isn’t a food allergy in the traditional sense, because it involves different antibodies than involved in most food allergies, including wheat allergy. Celiac disease is sometimes called gluten intolerance, but this term is imprecise and falling out of favor.

With celiac disease, the reaction to gluten can be pinpointed to specific parts of the complex gluten protein: alpha-gliadins (wheat), hordeins (barley) and secalins (rye). When gluten reaches the small intestine, these so-called “celiac molecules” are freed and modified by the tissue transglutaminase (tTG) enzyme. It’s during this process that the immune system goes on the defensive in people with celiac disease, and the cells that line the small intestine get caught in the crossfire.

What happens when individuals with celiac disease eat gluten?

Intestinal Villi by Shelly Najjar for Nutrition Nuts and Bolts

Villi are fingerlike projections from the small intestine that increase your body’s ability to absorb nutrients. If a person with Celiac disease eats gluten, the villi get flattened and nutrients aren’t absorbed as easily.
(Yes, this is a Microsoft Paint drawing, but you get the point, right?)

The immune system’s defensive attack causes inflammation and damage to the small intestine. Over time, the small finger-like projections (villi) of the intestinal lining become flattened, or atrophied. This is significant, because the villi greatly increase the surface area of the intestinal wall, allowing for adequate absorption of nutrients from the food we eat. When the villi become atrophied, the body has trouble absorbing certain nutrients, including iron, calcium, vitamin D and folate. Down the road, this can lead to health problems like anemia and osteoporosis.

Potential symptoms of celiac disease include diarrhea, vomiting and poor appetite, as well as weight changes, chronic fatigue and neurological problems. Infants and young children may be short for their age or fail to gain weight. However, many people (adults in particular) with celiac disease have no obvious symptoms, which means the intestinal damage and poor nutrient absorption can continue unchecked unless they are tested for the disease.

Can I inherit celiac disease?

Celiac disease is associated with two human leukocyte antigen (HLA) genes, HLA-DQ2 and HLA-DQ8. About 95 percent of people with celiac disease test positive for the HLA-DQ2 gene. The remaining 5 percent usually have the HLA-DQ8 gene, and there are a number of other genes that collectively contribute in small ways to celiac disease risk (2). However, only a fraction of people who are carriers of the HLA-DQ2 gene, will go on to develop celiac disease, suggesting that being genetically predisposed is necessary but not sufficient.

How is gluten sensitivity different from celiac disease?

An estimated 6 in 100 people suffer from non-celiac gluten sensitivity (NCGS) (3), which has similar symptoms but does not cause damage to the intestines.

What is the treatment for celiac disease and gluten sensitivity?

The only known treatment for celiac disease is total, lifelong avoidance of gluten. This means avoiding not just the gluten-containing grains themselves, but foods that contain the isolated gluten. There is no known safe level of gluten consumption for people with celiac disease, and even tiny amounts have the potential to cause intestinal damage and long-term health problems. Oats cause problems for some people with celiac, but it’s unclear whether this is due to cross-contamination or to an actual protein component of the oat. People with gluten sensitivity can often be less strict about avoiding gluten, letting their symptoms be their guide.

How are celiac disease and gluten sensitivity diagnosed?

Because celiac disease is a lifelong condition that requires total avoidance of gluten, while gluten sensitivity is less severe, it’s important to get an accurate diagnosis. Testing for celiac disease starts with blood tests for specific antibodies. If the test results are positive, the final step to confirm diagnosis is to take biopsies from four to six areas of the small intestine to look for flattening of the villi.

For accurate diagnosis it is important to undergo testing before giving up gluten. The symptoms, intestinal damage and antibody levels associated with celiac disease resolve quickly when gluten is removed from the diet.

There is no standard method of diagnosing gluten sensitivity. The first step is to rule out wheat allergy and celiac disease, as well as other conditions that can cause intestinal inflammation and distress, including irritable bowel syndrome (IBS). Then, if symptoms improve on a gluten-free diet and return after adding gluten back to the diet, gluten sensitivity is the likely culprit.

Can a gluten-free diet improve my health or help me lose weight?

There are many healthful, naturally gluten-free foods that have benefits for everyone. For example: fruits and vegetables, beans, fish, nuts, eggs, yogurt, poultry, lean meat and gluten-free grains like quinoa and brown rice. However, gluten-free cookies, cakes, crackers and other processed foods may be just as processed and filled with artificial ingredients as their gluten-containing counterparts. Even worse, most gluten-free flours and grain products are not vitamin-enriched. The bottom line for all eaters is this: Consider what you are eating as well as what you aren’t eating.

Carrie Dennett, MPH, RDN, is a Seattle registered dietitian nutritionist and a graduate of the Nutritional Sciences Program and the Graduate Coordinated Program in Dietetics at the University of Washington. She writes a nutrition column, “On Nutrition,” for the Sunday Seattle Times. She also blogs at Nutrition By Carrie.

(1) Pietzak M. Celiac disease, wheat allergy, and gluten sensitivity: When gluten free is not a fad. J Parenter Enteral Nutr 2012 36: 68S

(2) Sapone A et al. Spectrum of gluten-related disorders: Consensus on new nomenclature and classification. BMC Medicine 2012, 10:13

(3) Volta U et al. Non-celiac gluten sensitivity: Questions still to be answered despite increasing awareness. Cellular & Molecular immunology 2013 10, 383-392

by Shelly Najjar

Note: an easier-to-read version of this article can be found here.

Stick of butter, Creative Commons-Attribution by Robert S. Donovan

Photo Credit: Robert S. Donovan
(booleansplit) via Flickr

Here’s another post based on a paper I wrote for school. I got interested in the topic because we learned about how oxidation (mentioned more later) is bad, and that rancid fats are oxidized, so it made sense to me that rancid fats would be bad. But, science is complicated, and I wanted to know if this was true, or if I was oversimplifying.

What is rancid fat?

Rancidity is the term used to describe the process and properties of a fat that is stale, smells bad, and is discolored. Scientists  studied rancid fat since before the 1800s, with great progress on discovering the process of rancidity and methods to prevent or slow the process. The consequences of eating rancid fat have also been investigated, sometimes prompted by scientific curiosity and sometimes by outbreaks of illness.

How fats go rancid

Fats can become rancid through oxidation, irradiation, enzymatic lipolysis, and heat. Light and metal ions can also quicken these processes. One of the main ways that rancidity happens is through oxidation, so that is what I’ll talk about here. (For a good overview of the other processes, see Kubow, S. Free Radic Biol Med 12(1):63-81, 1992.)

Lipid (fat) oxidation occurs through a chain reaction process. The stages of this chain reaction are initiation, propagation, and termination. Fats are many carbon molecules linked together. Initiation is the event that begins the chain reaction by removing an electron from a carbon in the fat. (Source: Gropper, Smith, and Groff, 2009 – commissioned link*). This is bad because now the fat interacts with the body differently, including continuing this chain reaction.

How rancid fats get in our bodies

Rancid fats are found in the human diet in places such as cooking oils and fats, deep-fried foods, and some ethnic foods that are purposely made rancid. However, any fat, given the right conditions and amount of time, can go rancid. That means that any food containing fat can become rancid.

This does not mean you should stop eating fat, though. It just means you have to be smarter about how you store fat and what you choose to eat.

Here are some examples of why this is important.

But… we do not see all the same health effects in humans that we do in animals. Human health information on this topic comes from reported cases of toxicity due to eating rancid fat, since it is unethical to experimentally test toxicity on humans. However, the scientific community is involved in describing health outcomes, determining and quantifying exposures, and identifying treatments when cases are reported.

So, what do the human cases show us?

Spain location

Photo Credit: The World Factbook – Public Domain

Case Study #1: Spain, 1981-2†

In the early 80s, one region in Spain experienced an epidemic of what seemed to be pneumonia, but with additional symptoms (Source: Morb Mortal Wkly Rep. 1982 Mar 5;31(8):93-5.). It was eventually discovered to be a new disease, named toxic oil syndrome (TOS), because it is thought to be caused by consumption of adulterated cooking oil. As a result of this disease, in the first two years 356 people died and over 20,000 people were affected.

This disease has three phases: acute, intermediate, and chronic. (Source: World Health Organization, 2006)

  • Acute – fever, rash, muscle pain, and problems with blood vessels and white blood cells; respiratory failure (lungs stop working) is main cause of death
  • Intermediate – muscle pain, muscle wasting, fluid retention, high triglycerides, pulmonary hypertension (high blood pressure in the lungs), liver disease, and sicca syndrome (aka Sjogren syndrome, an autoimmune disorder that stops tear and saliva production and is often accompanied by rheumatoid arthritis); main causes of death were thromboembolism (a blood clot that moves to an area of the body like the heart, brain, or lungs) and pulmonary hypertension
  • Chronic – continuation of the intermediate phase plus nerve pain, scleroderma (connective tissue disease where fibrous tissue, like scar tissue, is made in the skin and other organs, causing tissue hardening and thickening), carpal tunnel syndrome, Raynaud’s phenomenon (cold temperatures or strong emotions cause blood vessel spasms that block blood flow to the fingers, toes, ears, and nose); deaths were caused by respiratory failure, central nervous system infection (infections of brain and spinal cord), and pulmonary hypertension

The people who are still living are at high risk of cardiovascular diseases (heart and blood vessel problems like heart attacks), even though they do have high HDL (“good cholesterol”), which is normally something that protects from having cardiovascular disease.

No treatments have been successful long term, probably because scientists are still unsure of what exactly caused the disease. It is similar to an autoimmune disorder (where the body attacks itself) triggered by the oil. The oil was deceptively sold as olive oil and possibly developed toxic compounds when it was processed with excessively high heat to remove the dye that had been added to mark the oil for industrial use only. (Source: Patterson R, Germolec D. J Immunotoxicol 2005;2(1):51-8.)

†Please note: It has come to my attention that the suspected toxic compounds created with the high heat in this case are not the same thing as rancid fat. However, I am leaving this case in this post to show that it is very important to be cautious when refining and storing oils.

India Location

Photo Credit: The World Factbook – Public Domain

Case Study #2: India, 1992

A group of 45 children were hospitalized with vomiting, abdominal pain, and diarrhea, which prompted an investigation. (Source: Bhat RV, et al. J Toxicol Clin Toxicol 1995;33(3):219-22.) The investigation turned up a total of 71 children and 9 adults who were affected by eating rancid cream-filled biscuits the children had found in the street and shared with their families. Most children ate 0.5 to 2 biscuits (because they were bitter), and were discharged from the hospital within 24 hours; one girl ate 12 biscuits and remained in the hospital for 7 days.

There were two types of biscuits, both rancid, but the pineapple flavoring of one covered the taste of the rancidity. The biscuits had an inner and outer wrapper which contained different information. The inner wrapper said the biscuits expired almost 6 years before they were consumed, and the outer wrapper said they had expired 3 years before. It appeared that the biscuits had been packaged for export, but no one knew why they were in the street. All the hospitalized children were treated successfully, and the researchers decided that the cause of the illness was the oxidative rancidity of the cream inside the biscuits.

Taiwan Location

Photo Credit: The World Factbook – Public Domain

Case Study #3: Taiwan

Despite low rates of smoking, lung cancer is the leading cause of death for women in Taiwan; similar patterns have been noticed in Chinese women living elsewhere. (Source: Ko YC, et al. Am J Epidemiol 2000;151(2):140-7.) Researchers suspected inhaling cooking oil fumes increased cancer risk, so they observed non-smoking lung cancer patients and compared them to randomly selected community members and other non-cancer hospital patients.

They found that cooking frequency and methods were related to lung cancer.

  • Cooking more meals increased the risk of developing lung cancer.
  • There was also an association between lung cancer and the temperature of the oil at the time the food was added.
  • Women who experienced eye irritation during cooking were more likely to develop lung cancer than those who did not have eye irritation.
  • There was a higher risk of lung cancer if the women waited to use the oil until it was hot enough to produce fumes.
  • If the women used a fume extractor, the risk of lung cancer was reduced (but not completely gone, which the authors suggested meant the air still had some fumes from the oil that were not being removed).

The researchers attribute these findings to the high level of carcinogens found in high temperature cooking oil fumes, which the women were inhaling.

The reason this occurs was explained in another study (Totani N, et al. J Oleo Sci 2007;56(9):449-56.), which showed that compounds are released from the oil through the steam created from deep-frying foods containing water, which vaporizes in the hot oil and rises to the surface, taking with it volatile compounds (compounds that evaporate easily). The amount of these compounds increases rapidly as heating time increases, because oils are only stable to certain temperatures for limited amounts of time. When heated beyond the point at which they are stable, more of these compounds (which can cause oxidative damage to cells) are created (a process that can be considered a type of rancidity). Since heated oil not used for deep-frying contained more of these compounds, the researchers think the steam created during deep-frying is an essential part of removing these compounds from oil (preventing people from eating them), and moving them into the air (so people can breathe them instead). Breathing these compounds was associated with a higher risk of lung cancer, most likely due to the damage in the lungs caused by the compounds in the fumes from the deep-frying oil.

Tunisia, Algeria, Morocco Location

Photo Credit: The World Factbook – Public Domain

Case Study #4: Tunisia, Algeria, and Morocco

Another type of cancer, nasopharyngeal carcinoma (NPC), was noted to be high in certain populations although rare worldwide. (Source: Feng BJ, et al. Int J Cancer 2007;121(7):1550-5.) People living in North Africa have a high incidence, and a possible relationship between certain foods and the incidence of cancer had been implied. In 2007, researchers performed a large and detailed observational study on this topic, to find specific foods that may be related with increased risk of NPC. Patients with cancer from five hospitals were compared with non-cancer hospital patients and cancer-free friends and family of patients with cancers other than NPC.

Rancid sheep fat and rancid butter were both discovered to increase risk of NPC. A preserved meat dish called quaddid (dried meat stored in oil) was also found to increase risk, which supports the findings of the earlier studies. One explanation the authors provided for some of these findings is that rancid butter has a certain compound that can activate the Epstein-Barr virus in white blood cells. Activation of this virus is a major risk factor for NPC, and may be an example of indirect toxic effects of rancid fat.

Recommendations

So, what do you do about all this information? Should we quit eating fat because it might become rancid? Do we need to be concerned about every fat-containing food?

Case studies #1-2 involved unintentional exposure, and #3-4 addressed exposure through common cultural food practices. Through these and animal studies, many recommendations have been formed to prevent the negative human health effects caused by rancid fat. The recommendations fall into two major categories: 1) prevent (or slow) the process of rancidity and 2) decrease the effects rancid fat has on the human body.

Here are three things you can do to protect yourself from the effects of rancid fat:

  • Avoid fat or fat-containing products that have a rancid or stale smell.
  • Store oils and fats correctly.
    • Since light and heat can start the oxidative process, fats and oils should be stored in cold, dark places away from sources of heat such as the stove top.
  • Consume antioxidant-containing foods such as dark green vegetables
    • Antioxidants, whether natural or synthetic, have been shown to decrease the amount of oxidative damage to lipids and prevent the formation of other chain reaction initiation factors, as well as preventing oxidation of vitamins like biotin. (Source: Pavcek PL, Shull GM. J Biol Chem 146(2):351-5, 1942.) Fruits and vegetables are great sources of natural antioxidants.

**Note: an easier-to-understand version of this article can be found here.**

Shelly Najjar, MPH, RDN is a Registered Dietitian Nutritionist and editor of Nutrition Nuts and Bolts. You can find her on Twitter (@ShellyNajjar), LinkedIn, and at shellynajjar.com

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By Shelly Najjar

Alcoholic drinks in minibottles, photo credit: jekert gwapo, Creative Commons: Some Rights Reserved, from http://www.flickr.com/photos/jekert/3522147659/

Photo Credit: jekert gwapo via Flickr

The title of this post was my research question for a class paper last quarter, and I wanted to share what I learned with you.

Some background

Alcohol is metabolized (broken down) in the liver, usually by an enzyme called alcohol dehydrogenase (ADH). In the late 70’s, a couple of researchers  did a study on whether women in different phases of their menstrual cycle were affected differently by the amount of alcohol they drank (citation: Jones and Jones, 1976, Ann NY Acad Sci). It was a poorly designed study, so most scientists discussing this study don’t consider it strong of a conclusion as it could have been, but you’ll still hear people state that there may be effects.

Why it’s plausible

Throughout the menstrual cycle, levels of estrogen and progesterone (hormones) rise and fall. Researchers (citation: Holdstock and de Wit, 2000, Psychopharmacology) thought estrogen was going to increase euphoria and a drinker’s preference for alcohol, because they both can act on the dopamine system in the brain. They guessed that progesterone would increase sedation (sleepiness) and decrease ability to do tasks (impaired performance), so the effects of alcohol (which also does these things) may seem stronger. On the other hand, estrogen was thought to increase ADH activity (it would work better and faster), which would lead to faster elimination (citation: Mumenthaler, 1999, Alcsm Clin Exp Res).

So, overall, it was thought that at certain times of the menstrual cycle, the effects of alcohol may be more intense, but that it wouldn’t last as long.

What the research says

Although there are several older studies on the topic, their study designs (how they set up the study) were not very good. There are now three things that researchers say are essential for any study on this topic:

  •  Use a within-subjects design (testing different things on the same person at different times in their menstrual cycle, rather than testing different things on different people at different times). This allows better comparison, since it limits the effects of variation between individual people.

  • Confirm menstrual cycle phase using hormone testing (rather than just relying on counting days since the last period). This increases accuracy, since there is variation and inaccuracies if you just count days.

  • Don’t use people with anovulatory cycles (a cycle when the egg does not get released). This is important because estrogen and progesterone don’t rise when this happens, so effects caused by changes in estrogen and progesterone won’t be seen (citation: previously mentioned Mumenthaler article).

I looked at two studies because they had these three features and were fairly recent.

Study #1: Holdstock and de Wit, 2000 (cited earlier)

These researchers used 16 women who each usually drank an average of 3.5 alcoholic drinks and 6 caffeinated beverages each week. Participants didn’t use drugs for at least 12 hours before and didn’t eat at least 2 hours before the test. Women were tested at 4 times through their cycle, each time being tested in the evening with spiked, sugar-free Kool-Aid. Each person drank 3 drinks over an hour, and their BAL (breath alcohol level) was tested. In addition, each woman did tasks that measured eye movement and mood.

After statistical analysis, this study didn’t show any effect of menstrual cycle on alcohol effects.

The study report was detailed and all measures, tests, and kits they used were reported (this makes a study more repeatable because another researcher has enough details to use the same technique to verify the results). Tests were done in a laboratory setting, which the researchers listed as a strength because it decreased the effect of the environment (example, you don’t have other people in the bar talking or flirting, or music playing, etc). However, this means that generalizability to a “real-world” setting is limited (do you act the same in a bar and a lab?). Although the researchers tested many phases, they decided not to test when estrogen was highest (during ovulation, when the egg is released), because it is very difficult to schedule people to come in for testing (ovulation period is only 2 days long). The researchers admit that there may be the possibility that the effect of estrogen on alcohol is only seen at high levels of estrogen, but since they didn’t test it, we don’t know. Finally, there were only 16 people in this study, but the measurements they used were accurate enough to detect a single drink’s effects, so if there was an effect that wasn’t noticed, it could be because the effect of menstrual phase is smaller than the effect of one additional drink.

Study #2: Corrêa and Oga, 2004 (citation in J Stud Alcohol)

This study used 10 women who, on average, drank 3 alcoholic drinks each, per week. Each woman didn’t use alcohol or drugs 30 hours before the tests, and had no food at least 6 hours before sessions. Women were tested at 2 points in the menstrual cycle, each test started in the morning, and lasted for 6-7 hours. Each person drank Scotch whiskey over a 10 minute time period, and then were tested throughout the day for BAL. Women received a “standard midday meal” 2 hours after they drank the whiskey, and “afternoon snacks” later in the day.

After statistical analysis, researchers didn’t find that menstrual cycle affected alcohol metabolism or elimination.

Like the first study, the tests and kits that were used to determine hormone levels were reported, which increases the study’s repeatability. In addition, since they only tested two phases of the menstrual cycle, it was good that they chose two with the largest potential difference in hormone levels. This would have the best chance of showing whether changes in menstrual cycle hormone levels affect alcohol metabolism. However, food and fasting can both affect alcohol metabolism, but the researchers never discussed this issue, although it has been noted that food, menstrual cycle, and alcohol can all change the amount of time it takes for things that go in your mouth to come out the other end. Although one study (the Mumenthaler study mentioned earlier) found that a “nonfatty breakfast” 1 hour before drinking doesn’t change BAL, the current study didn’t mention that, or the specifics of what they fed the participants.

Why it matters

Although these two studies used different approaches, they both came to the same conclusion, which also agrees with what is considered to be one of the best studies on the topic (Mumenthaler study mentioned earlier).

The implications of these results could range from research settings to social settings. In research, if the menstrual cycle doesn’t affect the metabolism of alcohol or the effects caused by drinking, then researchers may not have to control for which phase of the cycle female participants are in. As noted before, the lab setting is very different from social settings. Also, the doses used in many studies are higher than that of a standard drink and are usually consumed without food (and without having eaten for many hours). With a higher alcohol intake but less food to slow down absorption, you would think that any effects (if they exist) would be more obvious. Still, there is reason to be cautious because although alcohol levels may not be affected by the menstrual cycle, the effects may be seen with some of the things alcohol gets broken down to in the body.

So, like every research topic, more research is needed. However, if you do decide to drink, please do so with moderation, and know your body. If you think alcohol affects you differently at different times, be smart and adjust your intake. 

Shelly Najjar, MPH, RDN is a Registered Dietitian Nutritionist and editor of Nutrition Nuts and Bolts. You can find her on Twitter (@ShellyNajjar), LinkedIn, and at shellynajjar.com

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