Читать книгу Gluten Exposed: The Science Behind the Hype and How to Navigate to a Healthy, Symptom-free Life - Rory Jones, Dr. Green Peter - Страница 16

Nutrition

Going “gluten-free” may cure symptoms for some, and is a necessity for those with celiac disease, but eliminating gluten from your diet also removes much of the fiber and some essential vitamins and minerals from your food supply.

Wheat, rye, and barley are flavorful, vitamin-and fiber-filled grains. Ironically, manufacturers also regularly fortify wheat flours as well as the cereals, breads, and other processed products made from them with the vitamins and minerals that might have been removed during processing. Conversely, gluten-free foods, with a few exceptions, have not caught up with this fortification. Some, like quinoa, may not need this as much as rice flour.

The breads, cereals, cookies, cakes, and snacks with gluten-free grains also put people at risk for potential problems with excess fat, sugar, and salt. These ingredients are used to bind gluten-free products—gluten is the “glue” that holds breads and cakes together—and to make them as tasty as their wheat-filled counterparts.

People with celiac disease who embark on a gluten-free diet without the help of a nutritionist can easily develop vitamin and mineral deficiencies, especially iron and the B vitamins. Calcium can also be deficient if dairy is restricted. This is a double problem because many start the diet already suffering from malabsorption due to the damage to their small intestine. Missing a favorite sweet or breaded dish, they often make poor food choices to satisfy a craving.

Lost fiber and nutrients need to be replaced with fresh fruits, nuts, beans, vegetables, and other gluten-free grains (e.g., quinoa, millet, buckwheat, sorghum) to maintain a “nutritional” diet. If you are going to take gluten out, put its nutritional value back in. (For more, See chapter 31, “Eating Healthy.”)

Heavy Metal (Not of the Musical Variety)

Rice, a common substitute in a gluten-free diet, may contain high levels of arsenic as well as cadmium and mercury. Other heavy metals (e.g., tin, lead, and mercury) have also been found both in gluten-free food and flours and the people ingesting them.

While the raised levels do not approach toxic levels, there should be a warning. A greater number of patients with celiac disease develop neurological symptoms over the ensuing years after starting a gluten-free diet. While this has been attributed to the development of a new autoimmune disease, the recent concern about the occurrence of metals such as lead, mercury, and arsenic in people on a gluten-free diet may in fact be a manifestation of heavy metal toxicity.

Arsenic with Your Rice?

Arsenic occurs naturally in the environment and is also released into soil and water by fertilizers and pesticides as well as manufacturing practices. It is absorbed into anything growing in these environments—in particular, rice absorbs arsenic more readily than many other plants. The Environmental Protection Agency (EPA) published a “hazard summary” about arsenic in 2012 stating that “food is the major source of exposure” for most people and that chronic exposure can result in GI effects as well as central and peripheral nervous system disorders and certain cancers. Studies suggest that it may also affect a baby’s immune system when ingested by a mother during pregnancy.

The Food and Drug Administration (FDA) has not released a finished assessment of the potential health risks associated with arsenic in rice and other foods made from rice, but Consumer Reports and other studies urge caution.

Consumer Reports tested several different rices from growing regions around the world and concluded that organic rice is no different from conventionally grown rice—they both take up arsenic in the same manner from soil and water. Brown rice often has the highest levels because metallic elements accumulate in the husk and bran, which are milled off when rice is processed. Nevertheless, brown rice still contains more nutrients and is more fibrous.

It is possible to reduce the risk of arsenic in cooked rice by rinsing the raw rice before cooking, and by using excess water during the cooking process and throwing it out before serving; this sacrifices some nutritional value but can reduce the arsenic content by almost a third.

Almost everything that’s gluten-free has some rice in it. Suzanne Simpson, R.D., of the Celiac Disease Center at Columbia University cautions patients: “Rice doesn’t have a lot of nutritional value. It doesn’t have a lot of fiber or protein; it is basically just carbs. Most of the [gluten-free] breads, pasta, tortillas, cookies, and flour mixes contain rice. And people eat rice on top of it.” Children who are on a gluten-free diet that also contains rice pasta, cookie, and bread products as well as cooked rice should be monitored to lessen arsenic exposure.

She recommends that people do not use rice pasta and minimize their rice intake for variety as well. We also advise people on a gluten-free diet to see a dietitian regularly to ensure that the diet is diverse and not simply various versions of rice. (See Appendix C, “Arsenic and Mercury Guidelines.”)

Corn Fungi

The other grain staple of a gluten-free diet is corn. A recent study comparing the gluten-free diet of people with celiac disease versus those on a regular diet found a mycotoxin (a chemical produced by fungi/mold that is harmful to humans and domestic animals) in a number of corn products. The levels of this particular mycotoxin—a fumonisin associated with nervous-system and cancer-causing damage in animals—were high, raising concern regarding the long-term safety of various corn-based products.

The contamination of corn products with fumonisins has also been reported in other European studies, suggesting the potential of toxicity for anyone on a gluten-free diet ingesting a fair amount of corn-based products. While little is known about the fumonisin in the American diet, it is an area for further research and emphasizes the need to diversify the diet!

Mercury and Other Metals

Mercury is a naturally occurring heavy metal that appears to be increasing/accumulating in the food chain because of its use in medications, dental amalgams, thermometers, blood pressure machines, batteries, and fluorescent lightbulbs, and its presence in the fish we eat. Mercury can damage the nervous system, kidney, and lungs and remains in the body for a long time, where it affects inflammation and the immune system.

A recent study showed a fourfold increase in mercury blood levels of celiac disease patients following a gluten-free diet. No differences were found in their fish intake or number of amalgam fillings—both sources of mercury found to increase the amount of this metal in the body—but other dietary sources were not examined. Another study found elevated blood levels of mercury, lead, and cadmium and urinary levels of tin and arsenic in people eating a gluten-free diet, some with and some without celiac disease.

The reason for the increased levels in these people is unclear—whether it is food related, altered absorption, or response to mercury in these people. There might also be a genetic tendency in these people to accumulate it or to be more susceptible to specific toxic effects.

Additional studies to determine what is causing the increase in heavy metals in people following a gluten-free diet are needed. It is a potential pitfall that cannot be ignored.

Gluten Weighing In

The weight-loss potential of a gluten-free diet seems to be one of its biggest attractions for some people. Numerous Hollywood names attest to its effectiveness. If you cut out all bread, pasta, cake, cookies, and snacks and do not replace them with gluten-free alternatives, you will probably lose weight. It’s called the no–white food, no-carb, gluten-free diet.

But many people following a gluten-free diet are surprised when they find themselves gaining weight from the many fat-, sugar-, and sodium-filled gluten-free products they are now eating to replace what has been removed. People with a double diagnosis of diabetes and celiac disease who must count carbohydrates are initially surprised to see that the gluten-free substitute is often much higher in carbs.

I was eating everything—and constantly—and lost 25 pounds in the year before I was diagnosed (with celiac disease). Once I went on a gluten-free diet, I ate the same amount and gained 30 pounds in about seven months. I went from sick and skinny to healthy and chubby. The pasta and bread and cakes were gluten-free and didn’t go right through me, so I realized I had to retrain and restrain myself.

(SHEILA, 46)

People with celiac disease also often gain weight on a gluten-free diet because their intestine is healing and they are now able to digest food properly. Depending on how you define “going gluten-free,” you may actually find that one of the things it “gives” is added pounds.

No Shelf Life Means More Money

The costs involved in buying shelf space from the retailer are prohibitive for the smaller manufacturer. It is one of the reasons why you see mainly larger national brands in your local stores. Also, the range and types of ingredients we use are more costly, and gluten-free products fit in the “natural” and “organic” world, where retailers often charge a premium over regular products. Many items are also made by smaller manufacturers who don’t have the same big-company processing efficiency. These are some of the reasons gluten-free food is costlier.

—GEORGE CHOOKAZIAN, FOODS BY GEORGE

Gluten-free products are generally much more expensive and less widely available than their gluten counterparts. There are a number of reasons that manufacturers give for this.

Ingredients as well as facilities have to be certified and adhere to specific labeling regulations and testing, which incurs costs. Ingredients must also be grown and milled contamination-free and are often purchased in smaller batches than those used by larger manufacturers, again adding expenses. Many breads, cakes, and muffins are frozen to preserve their freshness. They have a shorter shelf life than preservative-filled products, and spoilage adds to their cost.

Some manufacturers have started lowering prices as competition in the market increases, but gluten-free products can still add to a family’s grocery bill.

You Have Isolated the Wrong Issue

One of the biggest dangers of going on a gluten-free diet before properly isolating and testing for what is causing symptoms is postponing and/or missing a correct diagnosis. Numerous other serious medical conditions—including microscopic colitis, SIBO, inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS)—often present with the same symptoms as food-induced dyspepsia or other GI complaints. Gas, bloating, pain, diarrhea, and constipation can be distress signals for almost any and every GI disorder and disease. And neuropathies, headache, and fatigue can signal a number of underlying autoimmune and neurological diseases.

Many people mistakenly believe that their symptoms can be treated and cured through food elimination. By the time you finally get to a doctor, the gluten-free diet may have intensified another condition and taken away your health.

You May Be Eating Gluten Anyway

The biggest hurdles? Contamination. If I had to sum it up, I’m very comfortable with the lifestyle, very comfortable feeding my family, the options are enormous, but I never sit down at a dinner and say, “This is perfectly right.” The kids want pizza and pasta. But when they have gluten-free pasta on the menu I still worry that they don’t know how to prepare it safely. I still struggle with it.

(ILYSSA, 39)

One pitfall in a gluten-free diet is trying to adhere to it when gluten is a hidden ingredient in or on your food. This may be due to contamination or confusion about gluten-free labeling and regulations or actual false labeling.

Cross-contamination and a lack of awareness in restaurants accounts for most of the “I got glutened” comments from people trying to follow a gluten-free diet. For preparing gluten-free meals, restaurant kitchens often use fryers or pasta water in which dishes that are breaded or contain gluten have been cooked. The cross-contamination that occurs in manufacturing also usually relates to shared equipment, confusion about barley and malt—which contain gluten but not from wheat, which is required to be listed as an allergen on labels—or gluten that finds its way from crops that share fields and storage facilities with nongluten grains.

Testing can be spotty. Several groups offer “gluten-free certification,” but they are not all using the same ELISA (enzyme-linked immunosorbent assay) tests to ascertain gluten content. It is also physically impossible to test every batch of a cereal or packaged product to ensure that it contains less than 20 parts per million, the standard set by the FDA for all foods with a “gluten-free” label.

Reading labels and talking to food servers is crucial to avoiding hidden ingredients and cross-contamination. Doing so is a source of stress and disruption for many people.

We were in a restaurant with a gluten-free menu, so I probably didn’t ask enough questions. But my daughter ate the salad and what looked like a plain chicken breast, and within 20 minutes she was vomiting all over the tablecloth. I knew she’d gotten gluten no matter what they told me.

(CISSY, 42)

Whenever we go away I go right to the head of food services in every hotel. I don’t bombard them but ask how they can help me and how I can help them. So they have the knowledge for the next person who comes with celiac disease. We get amazing dedication and great service.

(ILYSSA, 39)

Less Microbiotic Diversity

Any restrictive diet reduces the diversity of the microbiota in the gastrointestinal tract, a potentially unhealthy change. While there is no one healthy microbiome, a gluten-free diet removes foods that the intestinal microbiota dine on. Studies show that the FODMAP diet may not be a healthy one to maintain for that reason, and patients are cautioned about the consequences of remaining on it for a long period of time. (See chapter 5, “Supplements and Probiotics.”)