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Surprising Side Effects of Going Vegan, Expert Says

Here are some unfavorable outcomes that you could experience.
FACT CHECKED BY Kiersten Hickman

The vegan diet is an excellent lifestyle to follow if you have the time and resources to put into it. Because it's a more restrictive diet, you do run the risk of missing out on several key vitamins and minerals. You could also gain weight if you fall into the trap of eating processed, carb-heavy vegan products over non-vegan protein sources like fish and lean meat.

All of this can be avoided if you're equipped with the knowledge—and quite frankly the funds—to properly follow the vegan diet. So you know what to watch out for, here are four negative outcomes that could take place. Also, be sure to catch The 7 Healthiest Foods to Eat Right Now!

Greater risk of vitamin B12 deficiency.

vitamin b12 foods

Vitamin B12 is essential for giving you energy, and it even plays a role in DNA and red blood cell generation. The body cannot make this vitamin on its own, which means that it's vital to source it from what you eat. Foods that vegans avoid, such as dairy, fish, and meat, are all rich in vitamin B12. With a few exceptions, most plant-based food don't contain it. As a result, vegans are at high risk of vitamin B12 deficiency, which can cause nerve damage, according to Dr. Niket Sonpal, board-certified gastroenterologist and professor at the Touro College of Osteopathic Medicine.

"A Vitamin B12 deficiency also creates a greater risk of neuritis, inflamed nerves found outside the spinal cord and the brain," he says. "Symptoms of neuritis include but are not limited to muscle weakness, stabbing pain, and in severe cases, paralysis of the affected area."

To ensure optimal health, it's critical for vegans to take a vitamin B12 supplement. Sonpal says our bodies can last between two and four years without external vitamin B12 supplementation before symptoms of nerve damage kick in, such as confusion, difficulty walking, muscle weakness, and tingling in the hands.

Now, be sure to check out A Vitamin B Deficiency Might Be the Reason You're Tired All the Time.

Increased risk of hormone disruptions.

mapo tofu bowl

Tofu is an excellent plant-based protein to eat, especially as a substitution for red meat. Soy-based food items, such as edamame, tempeh, tofu, and unsweetened soy milk or yogurt are minimally processed, which means they're loaded in vitamins and minerals.

However, Sonpal warns that heavily processed soy-based foods, such as energy bars, protein powders, and sweetened soy milk and yogurt, could potentially cause disrupt hormones in the female body due to their high concentration of isoflavones (a type of plant estrogen, also known as phytoestrogens).

"Phytoestrogens can bind with hormone receptors, similar to the way human estrogen does," he says. "High doses of soy can cause infertility problems because of its strong anti-estrogen effects, but you need to eat a lot of it for this to happen."

In short, as long as you're not consuming more than the recommended amount of soy protein powder in your smoothie on a regular basis, you have nothing to worry about.

Higher likelihood of ingesting toxic metals.

Soy foods edamame tofu tempeh

As Sonpal notes, those who follow a vegan diet consume a greater amount of soy protein than those who identify as vegetarian or omnivore. While soy-based foods are often great for gut health and provide adequate amounts of protein, they could also contain a toxic heavy metal called cadmium.

In fact, one 2011 study found that people who consumed tofu products showed the most "robust association" with cadmium concentration in urine samples in comparison to those who consumed none.

"Cadmium is very toxic to the kidney and can cause kidney disease or cause the bones to become weaker," Sonpal says.

Eating a balance of soy-based foods and other plant-based protein sources like lentils and quinoa will help to keep exposure levels down!

Risk of iron deficiency.

Iron foods

While there's conflicting research on whether or not vegans are at higher risk of iron deficiency than the general population, it's true that several non-vegan friendly foods like eggs, fatty fish, and red meat are rich in iron. That being said, spinach, pumpkin seeds, legumes, and broccoli are also all rich in this mineral. The key is to make sure you're getting enough of these foods in your diet on a regular basis in order to keep your iron levels in check.

Be sure to check out these 6 Signs of an Iron Deficiency You Should Never Ignore to learn more about the symptoms.

Cheyenne Buckingham
Cheyenne Buckingham is the former news editor of Eat This, Not That! Read more about Cheyenne
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