Inflammation and the foods that fuel or squelch it

What is inflammation

We hear so much about inflammation in the news today, from anti-inflammatory diets to diseases of inflammation, that the term can seem too broad to grasp. For most of us, we want practical solutions on how our diet and lifestyle can best impact the inflammation in our bodies. Here is an easy review to give you some ideas about how you can modify your meals to lower chronic inflammation and improve your health and wellbeing.

What is inflammation?

Inflammation is the body’s first line of defense of the innate immune system. (3) It is a normal and beneficial reaction by our bodies to clear threatening pathogens and begin the healing process from blunt trauma, foreign microbes, and toxic chemicals. (1, 2) There are two forms of inflammation – acute and chronic – and they each have very different purposes and outcomes.

Acute inflammation

Acute inflammation is short-term and it protects and heals the body following injury or infection. Symptoms include heat, redness, pain and swelling. This is due to the immune system’s response at the site of injury to widen blood vessels, increase blood flow, release antibodies and flood the area with white blood cells to fight invaders and infection. (4)

Neutrophils are the first white blood cells to arrive and they release reactive oxygen species (ROS) which kill the invading microorganisms, but also kill healthy human cells. (4) In addition, they release antimicrobial amino acids and pro-inflammatory cytokines, such as interleukin 1, interleukin 6 (IL-1, IL-6), tumor necrosis factor (TNF-α), and interferon. (5, 6) These cytokines cause the liver to produce C-reactive protein (CRP) and other proteins which start the systemic inflammatory response, leading to a fever and an increase in white blood cells. (6) This cascade of events continues until the invaders are removed and the injury is healed.

However, when acute inflammation continues for prolonged periods of time it becomes chronic. Chronic inflammation can be dangerous as it is associated with many diseases.

Chronic inflammation

In chronic inflammation, the primary white blood cells that are involved are monocytes and macrophages. Monocytes help to fight infection and macrophages absorb foreign invaders and wastes. (7) They also release chemicals, including IL-1, TNF-α, and prostaglandins, that continue the pro-inflammatory response. Later T and B cells arrive. T cells kill the body’s own cells that have been infected and B cells produce antibodies targeting the foreign invaders. (5) Macrophages and other white blood cells release ROS and proteases which kill the invaders but also damage the body’s own cells. (10)

Chronic inflammation symptoms

Symptoms of chronic inflammation can be more difficult to notice. They include:

  • abdominal pain
  • chest pain
  • fatigue
  • fever
  • joint pain
  • mouth sores
  • skin rash

Causes of chronic inflammation

The most common causes of chronic inflammation include:

  • autoimmune disorders
  • chronic stress
  • excessive alcohol consumption
  • excessive/insufficient exercise
  • obesity
  • smoking
  • toxins
  • untreated acute inflammation (8)

Inflammatory diseases

Chronic inflammation is involved in the disease processes of many conditions, including:

  • Alzheimer’s disease
  • arthritis
  • asthma
  • atherosclerosis
  • bursitis
  • cancer
  • celiac disease
  • crohn’s disease
  • depression
  • diverticulitis
  • gingivitis
  • heart disease
  • inflammatory bowel disease
  • obesity
  • type 2 diabetes

Labs that indicate inflammation

Common clinical indicators for inflammation include elevated blood CRP and homocysteine. Other indicators include a high erythrocyte sedimentation rate, a high white blood cell count, and a low albumin level, though these tests are not as accurate as they can indicate other non-inflammatory conditions. (4)

Inflammatory foods

Foods that are high-glycemic, meaning that they rapidly cause our blood sugar to rise, are inflammatory. (4, 11) Typical high-glycemic foods include sugar-sweetened drinks, sweets, and pasta/cereal/bread made with refined flours as opposed to whole grains. (Pro Tip: always look for the first word in the ingredients list of these products to be “whole”)

Anti-inflammatory foods

Polyphenols are anti-inflammatory and they are found in plant-based foods. They are broken down into four groups:

  • lignans – flaxseeds, cashews, etc.
  • stilbenes – grapes, berries, peanuts, etc.
  • phenolic acids – orange, lemon, thyme, pepper, cocoa, basil, etc.
  • flavonoids – parsley, oregano, turmeric, green/black tea, elderberry, chickpeas, etc. The more well-known flavonoids are anthocyanins and isoflavonoids. Anthocyanins are found in fruits and vegetables with red, blue and purple pigments. Isoflavonoids are found in soybeans.

Omega-3 & Omega-6 fatty acids. Several different omega-3s exist, but the majority of scientific research focuses on alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). (4) Sources for ALA include flaxseeds and walnuts. EPA and DHA are found in oily fish such as salmon and sardines.

The reason it’s important to lower inflammation by boosting one’s omega-3s, is to lower the ratio of omega-6 to omega-3 fatty acids, which is roughly 15:1 in the U.S. It is estimated that humans evolved on a diet with an omega-6 to omega-3 fatty acid ratio of 1:1. (4) Therefore, we would benefit by lowering consumption of omega-6 fatty acids, which are found in vegetable oils used in processed snacks such as chips, desserts and fast foods.

Fruits and Vegetables have been inversely associated with CRP levels and other biomarkers of inflammation. (4) Specifically choose those with vibrant, bright colors – focus on eating the rainbow.

Carotenoid levels of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein, and zeaxanthin have been inversely associated with circulating levels of CRP, thus they are anti-inflammatory. (4) Sources of carotenoids include carrots, sweet potatoes, winter squash, tomatoes, watermelon, citrus, dark green leafy vegetables, cruciferous vegetables, salmon and eggs.

Arginine. Higher intakes of arginine are also associated with lower levels of CRP. (4) Common sources of arginine are nuts, seeds, beans, peas, turkey and beef.

Alpha-lipoic acid. Supplementation with 300 mg/day of alpha-lipoic acid was found to result in a decline in blood levels of interleukin-6 which is an inflammatory biomarker. (4) Food sources of alpha-lipoic acid include spinach and organ meats, such as cow liver, heart and kidney.

Exercise. Physical activity decreases inflammation, as measured by reductions in CRP and pro-inflammatory cytokines. (4) However, too much of a good thing can cause problems as excessive exercise can increase systemic inflammation, therefore, moderate exercise is best.

Conclusion

With an abundance of options to lower your chronic inflammation – from colorful fruits and vegetables like berries and spinach to tasty spices like basil and pepper and drinks that include green and black tea, as well as dark chocolate and salmon – it should be easy to incorporate more anti-inflammatory goodness into your life so you can improve how you feel.

Consider adding more colorful foods into your meals, and your mealtimes will not only be healthier, but they’ll also be tastier and more pleasing to the eye. After all, we consume a meal not only through our mouths, but also with our sight.

To your heath!

Jessica Mollet, RDN, LDN

References

  1. Nair, A., Thankachen, R., Raj, J. and Gopi, S., 2022. Inflammation, symptoms, benefits, reaction, and biochemistry.
  2. Cause of inflammation in diabetes identified. (n.d.). ScienceDaily. Retrieved February 8, 2022, from https://www.sciencedaily.com/releases/2016/11/161102080309.htm‌
  3. Aristizábal, B., & González, Á. (2013). Innate immune system. In http://www.ncbi.nlm.nih.gov. El Rosario University Press. https://www.ncbi.nlm.nih.gov/books/NBK459455/‌
  4. Inflammation. (2016, November 7). Inflammation. Linus Pauling Institute. https://lpi.oregonstate.edu/mic/health-disease/inflammation‌
  5. Scott A, Khan KM, Roberts CR, Cook JL, Duronio V: What do we mean by the term “inflammation”? A contemporary basic science update for sports medicine. Br J Sports Med 2004; 38(3): 372-80.
  6. Feghali CA, Wright TM: Cytokines in acute and chronic inflammation. Front Biosci 1997; 2: d12-26.
  7. Differentiated cells and the maintenance of tissues. In: Alberts B, Bray D, Lewis J, et al., eds. Molecular biology of the cell, 3rd ed. New York: Garland Publishing, Inc.; 1139-1193.
  8. Inflammation: What Is It, Causes, Symptoms & Treatment. (n.d.). Cleveland Clinic. https://my.clevelandclinic.org/health/symptoms/21660-inflammation‌
  9. Cory, H., Passarelli, S., Szeto, J., Tamez, M., & Mattei, J. (2018). The Role of Polyphenols in Human Health and Food Systems: A Mini-Review. Frontiers in Nutrition5(87). https://doi.org/10.3389/fnut.2018.00087
  10. Bian XW, Chen JH, Jiang XF, Bai JS, Wang QL, Zhang X: Angiogenesis as an immunopharmacologic target in inflammation and cancer. Int Immunopharmacol 2004; 4(12): 1537-47.
  11. Esposito K, Nappo F, Marfella R, et al.: Inflammatory cytokine concentrations are acutely increased by hyperglycemia in humans: role of oxidative stress. Circulation 2002; 106(16): 2067-72.

Published by Jessica Mollet, RDN

Optimizing your health with nutritional assessments and couseling to improve your well-being.

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