Immunity from any number of germs, viruses and diseases is a hot topic year-round, but the year of 2020 and the appearance of the novel COVID-19 virus, has increased public attention to topics surrounding infection prevention. This is especially true in relation to those with high risk factors.
It has long been known that obesity is a significant risk for chronic diseases. In recent years, it has been linked to viral illness as well. For example, a 2017 study on obesity and influenza compiled data gleaned from the 2009 H1N1 swine flu. They report that obesity, defined as BMI of 30 or greater, was identified as an “independent risk factor for increased morbidity and mortality resulting from pandemic H1N1 (pH1N1) infection”. This increased risk was found to impact even those who had received vaccines. They note: “Compared with vaccinated healthy-weight adults, vaccinated obese adults have twice the risk of influenza or influenza-like illness despite equal serological response to vaccination.”
Why does obesity have such a drastic impact on immunity?
A 2005 paper published in the The American Journal of Clinical Nutrition points out the significant changes in the diet of humans since the inception of agriculture and animal husbandry. Our “advancements” in these areas may have made things easier, but they also led to both a change in quantity and quality of the foods we eat. It outlines seven “crucial nutritional characteristics of ancestral hominin diets” which have been altered:
1) glycemic load,
2) fatty acid composition,
3) macronutrient composition,
4) micronutrient density,
5) acid-base balance,
6) sodium-potassium ratio, and
7) fiber content.
For example, while oils have been produced from plants and nuts for a few thousand years; except for olive oil, most of the early usage tended to be used for illumination, lubrication and medicine. However, the industrialization and mechanization of the oil-seed industry, led to a remarkable increase in their usage for food. Between 1909-1999, the US saw an increase of per capita consumption of salad and cooking oils of 130%, shortening consumption increased 136%, and margarine consumption increased and astounding 410%!
Another example is that refined grains now make up 85% of the grains consumed in the US. Since refined grains contain 400% less fiber than whole grains (by energy), this dilutes the total dietary fiber intake even more.
Today, over 70% of the typical total daily caloric intake in the US comes from dairy products, cereals, refined sugars, refined vegetable oils, and alcohol. Just a few hundred years ago, these foods would have comprised little to none of the typical American diet. Now, what is often called the “Western diet” (WD), is comprised of high amounts of saturated fat (HFD), refined carbohydrates and sugars, and low levels of fiber, unsaturated fats, and antioxidants.
In a study published in July 2020 titled, “The impact of nutrition on COVID-19 susceptibility and long-term consequences”, authors state that too much consumption of saturated fatty acids (SFAs) activates the innate immune system, including the stimulation of inflammatory signaling pathways that produce proinflammatory effects. Additionally, the WD or HFD inhibits function in the adaptive immune system, possibly by increasing oxidative stress, which then impairs the multiplication and maturation of vital immune cells. In short, they conclude that the “WD significantly impairs adaptive immunity while ramping up innate immunity, leading to chronic inflammation and severely impairing host defense against viral pathogens.” In regards to susceptibility, the researchers place emphasis on considering the impact of consumption of unhealthy diets.
Obesity – the growing epidemic
Unfortunately, the trend towards obesity seems to be worsening. A 2016 report, culled information from 1,698 population-based data sources, with more than 19 million adult participants (9.9 million men and 9.3 million women) in 186 of 200 countries for which estimates were made. From 1975-2014, the global incidence of being underweight decreased from 13.8% to 8.8%. In that same time, global incidence of obesity increased from 3.2% to10.8% for men and 6.4% to 14.9% for women. It is a sobering fact that the prevalence of obesity surpassed that of underweight in 2004 for women and in 2011 for men. Almost 20% of the world’s obese adults (18.4%) live in high-income, English speaking countries. While other countries are also seeing significant increases, more than 25% of severely obese men and almost 20% of severely obese women worldwide, live in the US.
Fight Back Against Obesity and Help Improve your Immune System
These studies demonstrate that eating a well-balanced, diet can help our bodies be healthier and allow our immune system to function better. Take your eating habits back to the basics: fresh fruits and vegetables, lean meats, whole grains, and minimally processed foods when possible.
Making simple steps, like choosing a baked potato instead of french fries, can add up. Scale back the salt in favor of herbs and discover a whole new world of flavor. Only use as much oil as is absolutely necessary. Look for lean cuts of beef and other meats.
Talk to your doctor of chiropractic about your eating habits at your next appointment. With training in nutrition, your doctor can help you determine where you need to make changes and if dietary supplements might be beneficial. Your chiropractor can also help you with fitness recommendations that are appropriate for your current health situation. By giving your body necessary nutrients, along with a healthy lifestyle, your body will be better prepared to fight off the germs that you come in contact with every day.
Butler M, Barrientos RM. “The impact of nutrition on COVID-19 susceptibility and long-term consequences” Brain, Behavior, and Immunity. Volume 87, July 2020, Pages 53-54. https://doi.org/10.1016/j.bbi.2020.04.040
Green W, Beck M. “Obesity Impairs the Adaptive Immune Response to Influenza Virus” Annals of the American Thoracic Society, Volume 14, Issue Supplement_5 2017 https://doi.org/10.1513/AnnalsATS.201706-447AW
Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JA, Brand-Miller J. “Origins and evolution of the Western diet: health implications for the 21st century.” The American Journal of Clinical Nutrition, Volume 81, Issue 2, February 2005, Pages 341–354, https://doi.org/10.1093/ajcn.81.2.341
NCD Risk Factor Collaboration (NCD-RisC) “Trends in adult body-mass index in 200 countries from 1975 to 2014: a pooled analysis of 1698 population-based measurement studies with 19·2 million participants” The Lancet, Volume 387, Issue10026, P1377-1396, April 2, 2016. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)30054-X/fulltext