In episode 1, Get these foods out of your house, I talk to author, Melanie Warner, and co-founder of NoBull Burger, Elizabeth Raymond, about foods that can impair our health. I wanted to share a little bit more of the research behind our conversation for my friends with curious minds! During my conversation with Melanie, I mentioned my final paper that discussed foods that can cause or prevent autoimmune disease. This post is an adaption of my final paper because I’m sure you all don’t want to read a full 10-page research paper!
The Problem
The number of people diagnosed with an autoimmune disease in the United States is quickly increasing, and there is not a clear cure nor treatment for many of them (Antico et al., 2012; Berer et al., 2018). According to Dinse et al. (2020), from 1988 to 2012, the prevalence of the most common biomarker of autoimmunity, antinuclear antibodies, increased in United States citizens ages 12 and older from about 22 million people with antinuclear antibodies to about 41 million people (p. 1026). The researchers also found that the prevalence of antinuclear antibodies made the greatest increase in teens ages 12-19 (Dinse et al., 2020, p. 1026). The National Institutes of Health reported on this study and posed the question, if people have not genetically changed in the last 30 years, what has caused the drastic increase in antinuclear antibodies (U.S. Department of Health and Human Services, 2020a)?
Autoimmune disease is defined by the American Academy of Allergy, Asthma, and Immunology (n.d.) as “an illness that causes the immune system to produce antibodies that attack normal body tissues.” Examples of autoimmune diseases include type 1 diabetes mellitus, celiac disease, Crohn’s disease, multiple sclerosis, and myasthenia gravis (Lerner & Matthias, 2015, p. 480).
Due to the rise in autoimmune diseases, researchers are seriously studying autoimmune disease prevention and management. One key factor that researchers are exploring to determine ways to prevent or manage autoimmune disease is the connection between diet and the rise of autoimmunity. While people have not genetically changed much over the years, what people in the United States eat and how food is made has changed. The food industry in the United States is industrialized, meaning that much of the food is made in factories instead of farms. Processed foods are also popular in the western societies because they are convenient and inexpensive. However, many processed foods are lacking in nutrients and high in saturated fat, sugar, and salt. Could the switch from farms to factories be the cause of the rise in autoimmune disease in the U.S.?
Another reason scientists are looking for a connection between diet and autoimmune disease is because of celiac disease. This is because celiac disease is triggered by eating gluten, which is found in wheat-based products. The gluten causes inflammation in the small intestine of people with celiac disease (Whitney & Rolfes, 2019, p. 90). People who are diagnosed with celiac disease are told to stop eating gluten to manage their symptoms. Artisto Vojdani (2014) stated that the research done on celiac disease can help scientists discover new ways to manage other autoimmune diseases by encouraging them to look at dietary, environmental, and genetic factors (p. 12). The purpose of this paper is to discuss the possible dietary causes of autoimmune disease and ways to manage or prevent autoimmune disease through nutrition.
Possible Causes of Autoimmune Disease
As previously mentioned, one explanation for the rise in autoimmune disease in the United States is the amount of processed foods people consume. Researchers Aaron Lerner and Torsten Matthias (2015) examined the possible connection between ingredients commonly added to processed foods and the increase in autoimmune disease (p. 479). Lerner and Matthias (2015) compared how ingredients, like sugar, salt, and gluten, impacted tight junction dysfunction and increased intestinal permeability in multiple studies (pp. 482-483). Intestinal permeability is also known as leaky gut, which could be detrimental to health because it allows food particles to escape the gut and cause inflammation (Campos, 2019).
Lerner and Matthias (2015) found that the processed food additives gluten, salt, organic solvents, sugar, emulsifiers, microbial transglutaminase, and nanoparticles all caused tight junction dysfunction and leaky gut (pp. 486-487). Microbial transglutaminase is commonly found in baked goods, bread, and animal products (Lerner & Matthias, 2015, p. 482). Nanoparticles can also be found in many different kinds of processed foods to keep them fresh and improve taste (Lerner & Matthias, 2015, p. 482). The information found by Lerner and Matthias (2015) help people understand the that the ingredients added to industrialized foods, like processed and fast foods, could cause autoimmune disease in United States citizens.
A study done by Manzel et al. (2013) also examined the role that industrialized foods have on autoimmunity. The researchers labeled a diet high in industrialized foods as the “Western diet” (p. 1). Key components of the Western diet include foods high in fat, protein, sugar, and salt (Manzel et al., 2013, p. 1). After reviewing many research articles, Manzel et al. (2013) concluded that high-fat diets and excessive sodium intake could cause autoimmune disease (pp. 3-4). Manzel et al.’s (2013) findings are not surprising because diets high in saturated fat can increase the risk of multiple sclerosis, cancer, and cardiovascular disease (Berger et al., 2018, p. 8; Whitney & Rolfes, 2019, pp. 147-148). High-fat diets also promote obesity by increasing the amount of white adipose tissue, or body fat, and by causing inflammation (Manzel et al., 2013, p. 3).
Obesity is a risk factor for many chronic diseases, including type 2 diabetes mellitus and multiple sclerosis. Munger et al. (2009) wanted to discover the impact that obesity had on multiple sclerosis. The researchers examined different body sizes of female nurses and found that nurses who had large body sizes and were 20 years old had a significantly increased risk of getting diagnosed with multiple sclerosis (Munger et al., 2009, p. 1543). Based on the work by Munger et al. (2009) and Manzel et al. (2013), it is reasonable to conclude that high-fat diets and obesity could cause autoimmune disease in Americans.
Foods that are high in fat include animal products. A study completed by Shoda et al. (1996) aimed to discover why there was an increase in Crohn’s disease in Japan. The researchers found that increased consumption of animal protein, including dairy, positively correlated with a Crohn’s disease diagnosis in Japanese patients (Shoda et al., 1996, p. 743). Additionally, a study done by Jowett (2004) examined dietary factors that might cause a relapse of the autoimmune disease ulcerative colitis in patients in England (p. 1479). Jowett (2004) found that high consumption of meat, meat products, eggs, and alcohol increased the incidence of relapse in ulcerative colitis patients (p. 1479). One reason that animal products high in fat could cause autoimmune disease is because they include haem, which inflames the gut (Anderson et al., 2011, p. 190). Additionally, when meat is cooked or processed, certain compounds may form that have been linked to cause cancer (Anderson et al., 2011, p. 190). Processed meat is even recognized as a carcinogen by the World Health Organization (Red meat, processed meat and cancer, n.d.). Processed meats include foods like bacon, beef jerky, and hot dogs. The studies by Shoda et al. (1996) and Jowett (2004) show that many different industrialized countries are seeing an increase in autoimmune disease. The studies also show that eating high-fat animal products and processed meats could cause autoimmune disease.
Another feature of the Western diet that Berger et al. (2018) shared is that it is typically low in fiber (p. 1). Fiber is critical to people’s health. According to Ellie Whitney and Sharon Rady Rolfes (2019), fiber improves gut health and may prevent cancer, diabetes, and heart disease (p. 100). Foods that are high in fiber include whole grains, legumes, fruits, and vegetables (Whitney & Rolfes, 2019, p. 100). Because industrialized diets that are typically high in processed foods and low in plant-based foods containing fiber, one could conclude that eating a diet low in whole grains and vegetables could lead to autoimmune disease.
Along with dietary causes of autoimmune disease, researchers are also investigating other potential causes like environmental factors and genetic factors. However, as previously mentioned, our genetics have not drastically changed over the last 30 years, and Gershteyn et al. (2020) stated that genetics can only predict about 22% of autoimmune disease diagnoses (p. 771). That leaves researchers to look to other factors that could be responsible for the increase in people diagnosed with an autoimmune disease. Some environmental factors that could cause autoimmune disease are intake of antibiotics, lack of sun exposure, and smoking (Anderson et al., 2011, p. 186; Lerner & Matthias, 2015, p. 480; Antico et al., 2012, p. 128). Anderson et al. (2011) found that children who consumed antibiotics when they were younger had a greater risk of developing an inflammatory bowel disease (p. 186). This may be due to the impact that antibiotics had on children’s gut bacteria, causing leaky gut. In addition, Vitamin D supports the immune system and is synthesized in the body when exposed to sunlight (Whitney & Rolfes, 2019, p. 351). In environments that do not have a lot of sunlight or in which people must remain indoors, it is harder for people to obtain Vitamin D (Antico et al., 2012, p. 128). In summary, there are many dietary and environmental factors that could cause autoimmune disease. The dietary factors include eating industrialized and processed foods; eating diets high in fat, animal products, sodium, and sugar; and eating diets low in fiber and Vitamin D.
Conclusion
While there are many limitations to the current research regarding the relationship between nutrition and autoimmune disease, the research is clear about general health practices to prevent autoimmune disease. Prevention is critical, especially during a global pandemic that targets the immunocompromised. People in westernized countries, like the United States, should minimize the consumption of processed foods with common additives like salt and sugar. They should not consume more than 2,300 mg of sodium nor more than 100-150 kcalories of added sugar per day to prevent negative consequences (Whitney & Rady Rolfes, 2019, pp. 112-425). Additionally, people should avoid overconsuming fats by only eating 20-35 percent of daily kcalories from fat, with only ten percent or less of daily kcalories coming from saturated fat (Whitney & Rolfes, 2019, p. 149). To add, when choosing animal products to eat, people should choose products with less fat and that have been minimally processed. Eating Western diets high in fat, sugar, and salt also increase the risk of leaky gut, inflammation, and obesity, all of which are risk factors for autoimmune diseases. These risk factors can create an environment for antibodies to develop and attack healthy cells.
To lower the risk of obesity and to get adequate vitamin D from sunlight, people who are able should go outside and move their bodies daily. People who want to prevent or manage autoimmune diseases should also try fasting because it can encourage a reduction of calories and suppress autoimmune cells. Another way to lower people’s risk of developing an autoimmune disease is by eating a diet rich in whole grains, fruits, vegetables, legumes, nuts, seeds, and fish. People should include all of these foods in their diet to ensure that they are getting enough fiber, vitamin D, and polyunsaturated fatty acids. One diet that emphasizes all of these foods is the Mediterranean diet. The Mediterranean Diet Pyramid from Oldways (n.d.) also includes engaging in physical activity daily.
Researchers Giugliano and Esposito (2008) wanted to learn more about the health benefits from following the Mediterranean diet. After reviewing many studies, the authors concluded that the Mediterranean diet could help people manage chronic illness like type 2 diabetes and obesity because of its anti-inflammatory effect on the body (Giugliano & Esposito, 2008, p. 1). As previously mentioned, reducing inflammation is one way to prevent or manage autoimmune disease. Therefore, finding a diet that reduces inflammation and encourages intake of fiber, polyunsaturated fat, and vitamin D, like the Mediterranean diet, could help prevent or manage an autoimmune disease. It is crucial that people in the United States and other industrialized countries decrease intake of processed foods and increase consumption of whole foods without harmful additives, like vegetables and legumes, to stop the rise in autoimmune diseases cases.
If you are interested in how to put this research into practice in your own life, check out my 7 Day Meal Plan in my resources section! This meal plan is based off of this research, the information in my book, the suggestions from the Mediterranean Diet, and more!
References
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