Right now everyone is focused on boosting the immune system to its peak performance to lessen viral illness severity. While we are sitting at home and scrolling through social media and news stories to scare the living daylights out of ourselves, most people really want to DO something rather than wait to get sick.
There are lots of ways to help improve your immune baseline function or boost your immune system when you are sick (more content on that coming soon!). There are some specific things that anyone can do regardless of your current health status, medications, age, income or location. Those are things I love to share because they can make a huge difference in someone’s life.
The number of things that can positively affect your immune system function is a very long list. However, today I will share one of the biggest tips that I feel hinders health overall and especially the immune system. Ready?
Yes, some of you may think I just uttered dirty words. But let me explain why. The majority of people in Western countries and particularly the US eat the Standard American Diet (SAD) which is based on the current USDA recommendations – 1992-2011 the Food Pyramid, 2011-current My Plate. I grew up seeing the food pyramid everywhere so it’s grilled into my mind, and is still thought of as the standard go-to graphic for food recommendations for many people. The base of the food pyramid was grains in the form of breads, pasta, rice, cereal, crackers, etc. Many of the grains in this category are extensively processed into flours and then crafted into various baked goods. 40-60+% of most people’s daily calories is in the form of very processed carbs, and this is what the guidelines said was healthy. Our food industry gave us every form of processed grain products for every occasion until it became our cultural norm to ingest processed wheat flour many times per day, and those who try to (or have to) avoid it are considered weird.
Today, we see the evidence that 30+ years of those recommendations have devastated our health in the form of rampant obesity, cardiovascular disease, cancers, and multitudes of chronic health conditions. Before you think that is just correlation and not causation, let me say I am not the first doctor to point a finger at the processed carb industry for many woes. If you want awesome studies and history on how the wheat industry has changed over the past century and how that is affecting us now, read Dr. William Davis’ book, Wheat Belly. It’s a great foundation for turning around your health in many ways.
In case you don’t know, processed grains (flour, the most common of which is wheat flour) breaks down into its sugar components very rapidly when eaten. In some cases, this starts happening within minutes of it hitting your mouth. This sugar gets absorbed into your bloodstream and your blood sugar goes up rapidly and takes hours to return to baseline. Since most people eat processed carbs 6+ times throughout a day with meals and snacks, you have frequent sugar spikes without a rest. While this causes many health problems, I am only focusing on how this directly effects the immune system today.
And then of course there is sugar itself in our diets, which is a simple carbohydrate. 74% of all packaged and processed foods on our store shelves have added sugars in some form. Over a century ago, the average annual sugar consumption for an American was 4 lbs per year. Today, we consume 152 lbs of sugar and 133 lbs of sugar equivalent from flour annually, which means we are getting ¾ cup of sugar daily in our bodies. That’s 580 calories a day from sugar, far more than any guidelines would allow for (If you need a visual, go get a measuring cup from your kitchen and pull out the sugar. It’s a lot!). While some labels may just say sugar, hundreds of labels will have some other form of sweetener listed, many of which end in -ose. Sugar goes by 61 different names on labels. Most of these still break down into the individual sugar components of glucose and fructose in various ratios, so it matters very little which form you are eating (with a few exceptions) when it comes to the immune system impact.
Natural sugars on the other hand found in fruits, veggies and other whole foods require the body to break down many molecules before they get to the sugars, so these sugars reach the bloodstream much slower, and they are delivered along with a host of nutrients and minerals that cells need to process those sugars. Over 83 studies have shown a diet rich in fruits and veggies improves immune function. I think that it’s unfortunate that in the phrase “fruits and veggies” fruit gets top billing. Veggies should always be a higher percentage of produce that you eat; they should not be consumed in equal amounts. While fruits are far better for you than processed sugars and flours, they should still be eaten in moderation. So, all that to say, the value of the carbs from a cucumber to your body is vastly different than the value of the carbs from a lollipop. All carbs are not equal, and whole foods are always better than processed. When I say “eat low-carb” I mean cutting out processed carbs and refined sugar and stick to healthy carbs – you will eat far fewer carbs when you fill up on whole foods.
So, on to the immune system.
Sugar has far-reaching effects in the body - from hormonal to metabolic, from cellular to organ systems. Every cell in your body has the ability to process sugar, so an abundance of sugar effects every single cell, whether short-term or long-term. Since every system in the body is connected, it effects the immune system both directly and indirectly.
A major direct effect is that neutrophil efficacy is lowered by up to 60% within several hours of ingesting sugar. Neutrophils are special white blood cells (WBCs, part of your immune system) whose main job is phagocytosis – eating and digesting bacteria and other small foreign particles like viruses. Neutrophils are part of the first-line immune defense and show up to an area of infection or inflammation within 1 hour. Their levels are also boosted with an active infection, and in 3-4 days the bone marrow will produce 20-50x more than baseline.
A study[i] from 1972 in humans showed the phagocytic (eating) ability of the neutrophils against bacteria started dropping within 30 minutes (the first time they checked the blood). It was most suppressed 1-2 hours after sugar intake, and was still suppressed after 5 hours later when the study ended. The number of neutrophils was not decreased, just how well they could do their job. Further studies since then show how that is possible. Sugar competes inside the neutrophil for space against vitamin C. Neutrophils need vitamin C in order to destroy bacteria and viruses, and the sugar molecule has a similar structure, close enough so it can take up the same space where vitamin C should be. This makes the cell less effective in destroying pathogens when sugar levels are high.
That means there is an immediate effect on making you more susceptible to infections for hours after a high-carb, high-sugar meal. Why do people always seem to get sick when they go on vacation? A part of it may be the foods eaten and the environments we go to that get us sick. For example, you head to an amusement park, eat horrible-for-you carnival style food, then proceed to be crammed into rides or areas where thousands of people have just touched the same thing. Or you head to an airport and eat a fast-food meal before boarding a plane with recirculated air and not-so-clean surfaces. When there is such a huge immediate effect on the immune system, it’s not hard to imagine that sugar plays a bigger role in our daily immune status than we thought possible.
Another direct role processed carbs play is through a process called glycation (just remember “sticky sugars”). The sugars stick to various proteins throughout the body which blocks their function. Think of proteins as little tools – they have one specific job to do or place to bind. When there are lots of sugars floating around from a standard carb-heavy diet, they will stick to proteins, including important ones in immune function. This slows down many processes, transport, and function of parts
of the immune system. One such example is how T cells work. T cells are independent travelling cells that are one part of our immune defense. They sort of “touch and feel” cells they pass by to make sure those cells are “us” and not something foreign, or that a cell has something foreign inside itself. The T cells have special proteins that stick out of their cell membranes for this “touch” process. All other cells present proteins outside their membranes like name tags that say, “this is who we are; here’s what’s inside me.” When a T cell passes by, these proteins touch briefly. It's like a handshake between the cells, and the hands are proteins. Imagine what sticky sugars will do when they bind to these proteins and block them. The cells cannot communicate and the T cells never get the message that a cell is infected with a pathogen. This slows down T cell activation.
Yet another way the immune system is suppressed is due to blood sugar spikes trigging cortisol, which is a stress hormone. Normally, your body releases cortisol from the adrenal glands in response to stress (any kind – physical, chemical, emotional) to prepare you for “fight or flight” to get away from or deal with that stressor, and it’s meant to be short-term. One of cortisol’s effects is to down-regulate the immune system, since all the body’s energy is diverted to deal with the stressor. Many of the immune system processes involve activating inflammation markers to call certain cells to an area or start a destruction sequence to battle foreign pathogens. Since the body doesn’t want to get overwhelmed by inflammation, cortisol is the “protective” way of putting the immune inflammation on the back burner. Cortisol also weakens the immune system by inhibiting T cell development, and also shutting down one subset of T cells, called Th1 cells which generate the most inflammatory cytokines. Th1 cells are also one of the most important players in fighting viruses. Here’s the problem: cortisol release is constantly being triggered by two major factors in most people – chronic stress and frequent sugar spikes. This means we could have constant immune system suppression, and be especially at risk for viral infections.
Sugar levels effect cortisol by two different pathways. The normal way most people understand is that when blood sugars drop rapidly (a stressor), cortisol is released which tells the liver to make sugar, and cortisol blocks the effects of insulin which normally carries sugars out of the blood stream and into the cells. The overall effect is that blood sugars go up – an important life-saving measure in this case. However, studies[ii] have also shown that cortisol is also released when blood sugars spike suddenly. A meal of processed and refined carbs and sugar will cause a blood sugar spike. When the body senses a sugar spike it releases a surge of insulin to pull the sugar out of the blood quickly. Unfortunately, this creates the famous drop in blood sugars several hours afterwards. A big blood sugar peak means a big sugar drop. In this study cortisol was shown to be released while the sugar was still going up, but was likely from the insulin surge because the body anticipated that that much insulin release would cause a huge drop on blood sugar. So, the cortisol release was trying to get ahead of the expected sugar drop. Why do I go into all this detail? To show that even if you have no chronic stress in your life (and I’m not sure who that would be), or maybe you’re on a two-week vacation or you are a peaceful person, etc., each meal you eat can directly suppress your entire immune system, and put you more are risk for viral infections.
A general way the immune system is hampered is when breaking down processed sugars, the body has to steal nutrients and minerals from the cells since these simple sugars came in nutrient-poor foods. Goldfish crackers and pretzels have very little (if any) nutrients that the cells need. Even when a flour product says it is “fortified” that just means the grain was stripped of its original vitamins and minerals during the processing and a synthetic vitamin panel complex was added back into the flour. When you read the rest of the label after the flour, you will find most ingredients are either flavorings or preservatives (most of which you will not be able to pronounce). When the body is given lots of sugar with little other nutrients, it has to take minerals like magnesium directly from cells in order to break it down. This leaves all cells weakened, but especially immune cells which travel through the body in surveillance or have very active roles in attacking and digesting foreign matter.
OK, does your brain hurt yet?
The point is refined sugars and simple processed carbs are more than just “bad for us” in a general sense. They are crippling to the well-being of our immune systems. While many, many things influence the health of immune function, I chose this to be a number one influencer because it’s something people have active control over changing. No one forces us to eat packaged snacks, cereal, sweets, and baked goods. The amount of these foods that are normal in an average diet is stunning, and we have the power to cut back on these foods. In a time when we are all thinking about how to boost immune function, and many of us have more time at home (to cook healthier things, of course) we can be making a big impact on the current and future health of ourselves and our families by starting with this one area.
Be encouraged! If you made it through this article then you are either really nerdy or really searching for answers to improving your immune system. It can be done! Start by reading labels and looking at sugars and carbs. Start eating whole foods instead of packaged, boxed or canned foods. Start to learn some new cooking skills and recipes. It does take time to change these habits of convenience, but it is so worth it, for much more than your immune system!
[i] Role of sugars in human neutrophilic phagocytosis Albert Sanchez, et al The American Journal of Clinical Nutrition, Volume 26, Issue 11, November 1973, Pages 1180–1184, https://doi.org/10.1093/ajcn/26.11.1180 https://academic.oup.com/ajcn/article-abstract/26/11/1180/4732762 [ii] A Short Study Exploring the Effect of the Glycaemic Index of the Diet on Energy intake and Salivary Steroid Hormones. Al-Dujaili EAS, et al Nutrients. 2019 Jan 24;11(2). pii: E260. doi: 10.3390/nu11020260. https://www.ncbi.nlm.nih.gov/pubmed/30682835