The Hidden Dangers of Veganism: Why Your Immune Health Might Be at Risk
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#Veganuary: This month-long campaign encourages people to try veganism for January and has contributed to a substantial increase in the number of people adopting plant-based diets. Since its inception in 2014, #Veganuary has reached millions, with participants growing every year.
In recent years, veganism has emerged as a popular dietary trend, often touted as a cure-all for everything from weight loss to chronic disease prevention. Social media influencers, documentaries, and wellness communities have aggressively marketed plant-based diets as the healthiest, most sustainable lifestyle. However, as a functional nutrition practitioner with years of experience in clinical practice, I’ve seen a very different reality unfold. While some individuals may experience benefits from short-term veganism, I’ve witnessed alarming long-term consequences stemming from nutrient deficiencies, particularly when it comes to immune function.
Let me be clear: I’m not opposed to veganism as a short-term strategy or a temporary cleanse. However, for many, long-term adherence to a vegan diet can lead to significant nutrient imbalances that undermine immune health, mood, and overall well-being. As veganism continues to gain popularity, it is crucial to highlight the risks associated with this restrictive diet—especially for those who may not fully understand the complexities of plant-based nutrition.
Veganism: Not the Nutritional Miracle You’ve Been Told
One of the most dangerous myths I encounter in my practice is the belief that vegan diets are inherently healthy and nutritionally complete. The reality is that when animal products are removed without proper planning or supplementation, the body is left vulnerable to a host of nutrient deficiencies.
In my clinical practice, I frequently see clients who present with symptoms such as chronic fatigue, frequent infections, brain fog, and emotional instability, only to be shocked when I suggest that their plant-based diet might be the underlying cause. Through comprehensive lab tests and clinical assessments, we often uncover deficiencies in vitamin B12, iron, omega-3 fatty acids, zinc, and retinol —nutrients critical for maintaining a healthy immune system. These deficiencies do more than just contribute to fatigue and poor concentration—they can compromise immune function, impair wound healing, disrupt digestion, and even increase susceptibility to infections.
Bioavailability of Nutrients: A Critical Issue
Another major problem with vegan diets is the bioavailability of key nutrients. Bioavailability refers to the body’s ability to absorb and utilize nutrients from food. While plant-based foods may be rich in vitamins and minerals, they often contain compounds like phytates, oxalates, and fiber, which can hinder the absorption of essential nutrients like iron, calcium, and zinc (Lopez et al., 2009). For example, non-heme iron found in plant foods is far less bioavailable than the heme iron found in animal products. This can lead to iron deficiency anemia, a condition that can severely impair immune function and overall health (Hurrell, 2002).
Protein: The Foundation of Immune Health
Proteins are essential for virtually every cellular process, including immune function, tissue repair, and the production of antibodies. A critical misconception about plant-based diets is the belief that plant proteins can fully replace animal proteins. To understand why animal-based proteins are superior, we need to delve into the science of amino acids.
Proteins are made up of amino acids, and of the 20 amino acids, nine are essential, meaning they must be obtained through diet because our bodies cannot produce them. Animal-based proteins—found in meat, poultry, fish, eggs, and dairy—contain all nine essential amino acids in the correct proportions, making them complete proteins. In contrast, plant proteins are often incomplete, meaning they lack one or more of these essential amino acids (Zhao et al., 2019). While some plant-based foods, such as quinoa and soy, contain all nine amino acids, most plant sources (e.g., beans, legumes, grains) lack one or more essential amino acids, which may compromise protein synthesis and immune function over time.
One such amino acid, tryptophan, is crucial for the synthesis of serotonin and melatonin, both of which play critical roles in mood regulation and sleep. Deficiencies in tryptophan can lead to symptoms of depression, anxiety, and sleep disturbances—issues I commonly see in clients on restrictive diets. Inadequate protein intake can also impair tissue repair and the production of immune cells, further weakening the immune system.
The Alarming Link Between Vegan Diets and Mental Health Issues
As the popularity of plant-based diets grows, emerging research is uncovering a concerning connection between veganism and mental health disorders. A study published in the Journal of Affective Disorders found that vegans have a significantly higher risk of developing major depressive episodes compared to omnivores. This increased risk has been largely attributed to deficiencies in vitamin B12, omega-3 fatty acids, and iron—all of which are essential for maintaining proper brain function (Grosso et al., 2016).
Vitamin B12 is crucial for the production of serotonin and dopamine, neurotransmitters responsible for regulating mood, cognition, and emotional stability. B12 deficiency can impair the synthesis of these neurotransmitters, leading to depression, fatigue, and cognitive dysfunction (McCaddon et al., 2003). Studies have consistently shown that individuals following vegan diets have lower levels of B12 compared to omnivores, which may explain the high prevalence of mood disorders among vegans (Toth et al., 2020).
Omega-3 fatty acids, particularly DHA (docosahexaenoic acid), are vital for brain health and are found predominantly in fish and other animal products. Deficiency in omega-3s has been associated with cognitive decline, anxiety, and depression (Gómez-Pinilla, 2008). Vegans, who typically have lower omega-3 intake, may experience increased mental health issues as a result.
The Dangerous Consequences of Vegan Diets for Children
One of the most concerning aspects of the vegan movement is the rising trend of parents imposing vegan diets on their young children. While veganism may work for adults with fully developed digestive systems and the ability to carefully monitor nutrient intake, children have very specific nutritional needs that are difficult to meet on a plant-based diet.
For instance, choline—a nutrient essential for brain development—is abundant in egg yolks and organ meats, but nearly impossible to obtain in sufficient quantities from plant sources. Insufficient choline intake in children can lead to neurodevelopmental delays, memory impairment, and cognitive dysfunction (Zeisel et al., 2009). Furthermore, children on vegan diets are often at risk for long-chain omega-3 deficiencies, particularly DHA, which is vital for proper brain growth and cognitive function (Kris-Etherton et al., 2004).
Unfortunately, the lack of critical nutrients like choline and omega-3 fatty acids can lead to severe, irreversible cognitive impairments in children, underscoring the dangers of plant-based diets for growing bodies.
Animal Foods: The Cornerstone of Immune Health
Animal-based foods are not only rich in bioavailable vitamins and minerals but also contain key nutrients essential for immune system regulation and overall health. Some of the most important nutrients include:
Vitamin A (retinol): Found abundantly in liver and other animal foods, vitamin A plays a critical role in maintaining the integrity of the gut lining, which serves as the body’s first line of defense against pathogens. Deficiencies in vitamin A are associated with weakened immune function and increased susceptibility to infections (Villamor & Fawzi, 2000).
Vitamin D: This fat-soluble vitamin is essential for the modulation of the immune system and the prevention of chronic infections. It is found in fatty fish, egg yolks, and organ meats. Vitamin D also supports calcium absorption and bone health, which in turn supports immune function (Riek, 2006).
Zinc: A trace mineral crucial for the development and function of immune cells, zinc is found in red meat, poultry, and shellfish. Zinc deficiency is known to impair immune function, making the body more susceptible to infections (Mocchegiani et al., 2012).
Rebuilding Immune Health: How to Reintroduce Animal Foods
If you’ve been following a vegan or vegetarian diet for some time and are experiencing symptoms like chronic fatigue, frequent infections, cognitive dysfunction, or mood disorders, it may be time to reconsider your diet. Through my work with clients, I’ve seen remarkable transformations after they reintroduce nutrient-dense, bioavailable animal foods into their diets. This process doesn’t need to be overwhelming. Start with small, manageable changes—such as adding wild-caught fish or pasture-raised eggs—and gradually reintroduce other nutrient-dense animal products.
Working with a functional nutrition practitioner can help guide you through this process, ensuring that nutrient absorption is optimized and that any underlying digestive issues are addressed.
A Balanced Perspective on the Planet vs. Animal Foods
While many people argue that animal farming is damaging to the environment, it’s important to recognize that regenerative agriculture—which focuses on sustainable practices, soil health, and carbon sequestration—provides a more ecologically balanced way to raise animals. Many regenerative farms are carbon-negative, meaning they sequester more carbon than they emit.
Additionally, while the environmental impact of industrial agriculture is well-documented, many vegan staples—such as quinoa, almonds, and avocados—contribute significantly to deforestation and water waste, thus undermining the supposed environmental benefits of veganism.
Conclusion: A Path to Health and Resilience
Are you tired of feeling run down, constantly battling colds, or struggling with autoimmune issues and digestive problems like SIBO? I know how frustrating it is to try everything and still not feel like yourself. If you've been following a vegan or vegetarian diet for a while, it’s possible that nutrient gaps are holding you back from regaining your strength and boosting your immune system. But here's the exciting news: you can turn it around—today!
As a functional nutrition practitioner, I’ve helped many people restore their health and rebuild immune resilience after long-term plant-based eating. By reintroducing bioavailable, nutrient-rich animal foods, we can work together to get you feeling better, stronger, and more energized—while breaking free from that exhausting cycle of fatigue and frequent illness.
You deserve to feel vibrant, healthy, and unstoppable again. My holistic approach will help you replenish your body’s nutrients, restore balance, and supercharge your immune system. Imagine waking up each day with more energy, fewer sick days, and a clearer, more stable mood.
If you’re ready to stop feeling tired and drained, and start reclaiming your vitality, I’m here to help! Fill out the intake form here, and let's craft a personalized plan that works for your body—so you can start feeling better, faster.
Let’s get you back to living your best life!
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