Immune system, good nutrition & IBD

The Immune System

Every part of your body, including your immune system, functions better when protected from environmental assaults and bolstered by healthy-living strategies such as these: don’t smoke, eat well, exercise regularly, maintain a healthy weight. ~the internet

The immune system protects against pathogens, tumor cells, and other foreign invaders. The digestive system is made up of your mouth, esophagus, stomach, intestines, and the organs associated with digestion including the liver, gallbladder, pancreas, etc. This system breaks down and absorbs nutrients from food and drink. Within the digestive system we find the gastrointestinal (GI) tract – the long tube through the body composed of stomach and intestines – which functions as a management and coordination system that allows beneficial substances into the body while keeping harmful things out. The digestive system is actually 25 feet in length and is made up of strong muscular tubes lined with thick and specialized cells. These tubes act as an important connection to (and barrier between) the external environment.

All of the digestive processes have one goal: to deliver nutrients into the bloodstream for use in our cells. The major area of nutrient absorption is the small intestines, which contains the largest surface area in the digestive system and has as many neurons as the spinal cord. If laid out flat this surface would be the size of a tennis court, but it is only one cell layer thick! When this delicate surface is damaged, inflammation spreads throughout the brain and body. Our digestive enzymes reside on this delicate one cell layer of intestinal cells. When it is damaged we cannot digest our food properly. Suddenly we have partially digested food particles from normally innocuous foods ”leaking” into our bloodstream through the leaky gut.

Since over 60 percent of our immune system is located right under that one cell layer of intestinal cells lining our digestive tract, our bodies react by increasing our immune response and generating inflammation. Our immune system, normally used to seeing fully digested foods (like proteins broken down to amino acids, fats broken down to fatty acids, and carbohydrates broken down to simple sugars), suddenly “sees” foreign (meaning partially digested) proteins.

So the immune response does what it is designed to do – attack and defend. Those with IBD have abnormalities of the immune system, but whether these problems are a cause or a result of the disease is still unclear. The immune system protects from infection by identifying and destroying bacteria, viruses, and other potentially harmful foreign substances. With IBD the body’s immune system is believed to react abnormally to bacteria in the digestive tract.

A common misconception with UC and other forms of IBD is that spicy or fried food can trigger a flare, but it’s not true. “Often people severely limit their diet out of fear of a flare, which isn’t necessary as long as they’re eating healthy in general,” says Esrailian. Still, it doesn’t hurt to avoid foods that you know cause you trouble.

“It is important to live a healthy life in general to put your body in the best situation to fight off illness and UC symptoms in case you experience a flare,” says Esrailian. “Simply, this means getting adequate sleep and exercise and paying attention to good nutrition.”

Good Nutrition Defined

Good nutrition is defined by Precision Nutrition in The Essentials of Sport and Exercise Nutrition as having these following four characteristics:

  1. Properly controls energy balance
  2. Provides nutrient density
  3. Achieves health, body composition, and performance goals
  4. Is honest and outcome-based

The above characteristics have been used at Precision Nutrition to achieve tremendous results with numerous Olympic-level athletes, professional athletes, and your average weekend warriors. Let’s see how these characteristics can be applied to you, someone living with IBD.

  • Properly controls energy balance – Energy balance represents the relationship between “energy in” (food calories taken into the body through food and drink) and “energy out” (calories used in the body for our daily energy requirements). This relationship dictates whether weight is lost, gained, or remains the same. Energy balance also has a lot to do with what’s going on in your cells. Both a positive energy balance (more energy in than out) and a negative energy balance (more energy out than in) affect everything from your metabolism to your hormonal balance to your mood. It’s pretty safe to say that anyone with IBD has gone/is going through a negative energy balance. When food can be such a challenge it’s very difficult to ingest an adequate level of nutrients to sustain and increase proper bodyweight levels. Each feeding opportunity becomes that much more important, and you’ll want to get the most “bang for your buck.” Eating empty calories isn’t really an option anymore if your goal is to add muscle and increase strength levels. We need to eat healthy foods that provide quality nutrients.
  • Provides nutrient density – Nutrient density is the ratio of nutrients (vitamins, minerals, fiber, etc.) relative to the total calorie content in a food. A food with a high nutrient density would contain a large amount of key nutrients (protein, iron, zinc, B vitamins, etc.) per 100 calories of food. When digestion and absorption are such key issues for health – even more so for those with IBD – eating foods that provide calories without adequate nutrients is literally a waste of time, energy, and money. The biological process of eating is increasingly important. Each time we have the opportunity to eat food, we must choose wisely. Picking nutrient-dense foods will always be a wise choice, regardless of any diet plan or physique goals. Don’t waste a feeding opportunity on inferior quality foods.
  • Achieves health, body composition, and performance goals – Good nutrition is more than about weight loss or gain, both of which are just transient indicators of energy balance, since energy balance and weight can change from one day to the next. Therefore, finding a long-term set of dietary habits should be based on the intersection of the following three goals:
    • 1. Improved body composition
    • 2. Improved health
    • 3. Improved performance


Rather than focusing solely on the visual outcome of body composition, focus on improving health (reduce inflammation, increase good cholesterol, reduce body-fat percentage, and increase lean body mass) and performance (improved energy levels and stamina, fitting into clothes better) as well, regardless of whether you are an elite athlete or only watch them on TV. Having gone through ulcerative colitis and the rapid weight loss, I know it can be easy to become preoccupied with the actual numbers on the scale. I have been guilty of this. For some reason weighing 175 lb. just seemed to feel better than weighing 174 lb. when in reality the difference was all in my head. Try to rely less on the numbers on the scale. Instead, focus on how you feel. Do your clothes fit better? Are you living with more energy? Are you happy? These answers tell us so much more than any numbers on a scale ever could.

  • Is honest and outcome-based – While good nutrition controls energy balance; boosts nutrient intake; and targets health goals, body composition goals, and performance goals, it also has to be honest about whether it hits the mark. Evaluate the quality of a nutritional plan by observing what happens to your body when you follow the plan. In an outcome-based world, theory is meaningless and results are everything. We can only judge a plan based on the results consistently produced. Good nutrition helps improve health and achieve results.

What you can do today

  • Remove and offending actions that may be compromising your immune system5Rs_IBD
  • Find 1 way to measure and track that your good nutrition habits are honest and outcome-based. A simple and effective method is to record your food intake. Pick the easiest method to track what you’ve been eating for at least 3 days. Take pictures, use an food tracking app, or just write it down. The main idea is to get honest information about what it is you have been eating. Then review that and see what you are doing well. Do more of that.

These topics (the immune system and nutrition) are not simple ideas. There are many methods that can be taken to improve both. My approach – and the approach of this post – is to help you find 1-2 easy ways to begin your journey of improvement.


You might be interested in …