Immune health is a top-of-mind conversation these days. Immune health is discussed like it’s a new phenomenon, like we woke to the discovery that our body has a highly sophisticated yet elegant internal guide and protect system. Discussed as if it is a guide and protect system that we can switch on and off at our convenience.
In fact, like our heart beating, our blood flowing, and our eyes enabling us to see, the immune system does not have an on and off switch. The human immune system functions as an internal surveillance system. It is always on alert, working to protect us from invaders (also known as pathogens) that come our way: bacteria, viruses, fungi, and parasites. In many ways, this internal scanner is our most important ally and friend. And this scanner is free, performance subject, in large part, to the care and feeding we choose to provide.
When our immune system is challenged, due to a change in seasons, a new environment, or exposure to a pathogen, it gets activated and demands more power and supplies from our bodies. Such activation increases the rate of our metabolism (energy) and increases our need for functional and regulatory molecules (nutrients). Here is where the science of nutrition is called on to provide essential services. Nutrition is the source of that energy and these molecules, providing fuel and tools for our immune system to achieve its optimal function.
How our body responds to immune challenges is directly influenced by our nutritional status. In other words, what we eat and drink (and what we don’t eat or drink) and the supplements we take fortify our health through our immune system. While there has been focus on the important roles of vitamins C and D and the mineral zinc in immune health, there is less attention on the role of essential fatty acids, in particular EPA and DHA omega-3 from fish oil. Is that warranted?
Let’s take a look!
What do scientists understand about the role of EPA and DHA omega-3 in immune health?
They are building blocks for immune fighters: EPA and DHA are the source in our bodies of certain biochemicals (e.g., prostaglandins and leukotrienes) that support daily life functions, such as blood flow, body temperature, and normal lung function. When our immune system is activated, it triggers an increased demand for these and several other EPA and DHA-derived metabolites, which direct a cascade of interconnected events to calm the molecular storm triggered by the foreign invader and restore us to health. Randomized, placebo-controlled trials have shown that EPA and DHA lower circulating levels of inflammatory markers (such as cytokines and interleukins) that increase when the immune system is activated.
Continued activation of our immune system requires a continual supply of these biochemicals. Because our bodies cannot produce EPA and DHA omega-3s, we need to consume them from food and supplements. What’s more, it takes at least four weeks of regular consumption for human immune cells to become replenished with EPA and DHA.
They are building blocks for resolving inflammation: Inflammation is a natural and necessary part of recovering from immune system challenges. During the resolution process, special compounds called resolvins, protectins, and maresins direct the body to return to homeostasis, or a normal, balanced state of health. These specialized pro-resolving mediators (SPMs) are biosynthesized from EPA and DHA. Indeed, SPMs are now being understood to explain the important role of EPA and DHA omega-3s in lung health.
EPA and DHA complement intestinal immune support: The intestines are the largest organ of the immune system, and emerging evidence suggests that omega-3s support healthy gut microbiota and host immune function in the gut.
In summary, EPA and DHA omega-3s are integral nutrients for healthy immune function. These fatty acids are the exclusive source of specific functional and regulatory molecules needed to mount and manage our response to immune challenges, and they are the source of SPMs to help restore health balance.
The reality today is most Americans don’t get enough omega-3s to meet their daily needs and far less to support optimal immune health. Most Americans get only about 100 mg of combined EPA and DHA a day while the World Health Organization (WHO) recommends at least 250 mg per day to meet basic needs.
Experts suggest more than 2 grams (2,000 mg) of EPA and DHA per day when our immune system is facing acute challenges.
To be sure, other factors, such as genetics, lifestyle choices, and the environment influence the capability of our immune system, but at its core, the care and feeding we provide through basic nutrition and daily habits is the foundation for a strong immune system.
There is no on and off switch. The good news is that our immune system is always on and we have good measure of control on its performance. Regular maintenance is simple. Ensuring that we meet our daily intake needs for vitamins, minerals, and essential fatty acids while getting sufficient rest, fresh air, and some physical activity are low-tech practices that keep our highly sophisticated internal surveillance system fueled and tooled.
It is my hope, with 2020 as hindsight, that going forward we acknowledge our immune system as the ally that it is, and care for it accordingly.
Gretchen Vannice is the Director of Nutrition Education and Research for Wiley Companies. She is a globally recognized expert, author, and speaker in omega-3 research and education.
Disclaimer: This information is offered for educational purposes only. It is the opinion and scientific interpretation of the author. It is not intended as medical advice of any kind. The educational information provided is not intended to diagnose, treat, mitigate, or cure any disease nor has this been reviewed or approved by the FDA.
Scientific References are available upon request.