Plants as a primary source of nutrition are growing in popularity – and that’s a good thing. Plant-based foods contain an abundance of phytonutrients that animal foods do not. In fact, eliminating animal foods entirely, going vegan, is trendy right now. A search on Google Trends shows interest in veganism started to pick up around the end of 2010 and has continued to increase since then.
You may have heard various sources say that you can’t get all the nutrients your body needs from plant-based sources. True or false? It is possible to stay healthy on a completely plant-based diet but you’ll need to work harder to get some vitamins/minerals and, in some cases, may need to take a supplement. If you only eliminate meat and not dairy, it’s a bit less challenging.
On the other hand, if you purge both meat AND dairy from your diet, you’ll need to take extra steps to make sure your body stays nutritionally balanced. Let’s look at some of the vitamins and minerals you may not get enough of when you adopt an exclusively plant-based diet.
If you eliminate both meat and dairy, your risk of vitamin B12 deficiency goes up. It may take time since your liver can store vitamin B12 for years. It can take 5 years or more of eating exclusively plant-based foods to deplete your vitamin B12 stores. Why is vitamin B12 so important? Vitamin B12 deficiency affects red blood cells production, leading to anemia, and can also damage your nerves permanently, if you’re deficient and don’t correct it quickly enough. Low B12 is also linked with a higher risk of heart disease and, possibly, Alzheimer’s disease.
You’re at highest risk if you eat a vegan diet as opposed to a vegetarian or flexitarian one. If you continue to eat dairy, you can supply your body’s vitamin B12 needs by drinking milk and eating eggs. Most plant foods contain little or no vitamin B12. One exception is nori seaweed but unless you eat a lot of it, you’re still at risk of deficiency.
Some packaged foods, such as cereal, meat substitutes, non-dairy milk, and bread, are fortified with vitamin B12 but, again, you have to read the labels and track your consumption to make sure you’re getting enough. The safest approach, if you eat only plant-based foods, is to take a vitamin B12 supplement. If you don’t eat meat or dairy, make sure you know where you’re getting your vitamin B12 and that you’re getting enough.
Omega-3s are important for heart and brain health. Omega-3s are polyunsaturated fats associated with a variety of different fatty acids. The most important of these are DHA, EPA, and ALA. DHA is best known for protecting visual and brain health and is abundant in the brain. It’s crucial during brain development, which is why pregnant women need it. EPA is a powerful anti-inflammatory omega-3. DHA and EPA are found mainly in fatty fish, not plants, although algae has some DHA.
Finally, there’s ALA. Unlike the other two ALA is found in plant-based foods, particularly flaxseed, chia seeds, walnuts, and sesame seeds. The health benefits of ALA are less clearly established. ALA differs in structure from DHA and EPA, both of which are long-chain omega-3s. ALA is a short-chain omega-3. Your body can convert a portion of the ALA you take in through diet to DHA and EPA but it’s not efficient at doing this. In fact, research shows that you only convert around 5% of the ALA you take into long-chain omega-3s. So, plant-based foods aren’t an ideal source of omega-3s. If you don’t consume meat or dairy, there are vegetarian omega-3 supplements made from algae that can help you get more of these fats.
You can get enough calcium on a completely plant-based diet but, keep in mind, calcium isn’t as easily absorbed from plant-based foods. A number of plant-based foods are rich in calcium but some plants are also high in oxalates and this reduces calcium absorption. Examples of high-oxalate plants that aren’t the best sources of calcium, due to their oxalate content, include spinach, rhubarb, beet greens, and Swiss chard. Other leafy greens are better options since they’re not as high as oxalates. Other good sources of easily absorbed calcium include soy (made with calcium-based coagulant), almonds, seeds, and non-dairy milk alternatives fortified with calcium.
A vegan diet can also be low in iron and zinc. Zinc is critical for immune health, fertility, and wound healing. Although zinc is in many animal-based foods, particularly seafood, it’s also abundant in lentils, beans, nuts, seeds, and whole grains. If you follow a vegan or vegetarian diet, make sure these foods are in your diet.
In terms of iron, the type of iron your body most readily assimilates is heme-iron, the kind found in animal foods. Non-heme iron, the form in plant foods, is a bit harder for your body to use. You can make up for this by including plenty of non-heme foods in your diet. Good examples are whole grains, beans, lentils, tempeh, seeds, kale, raisin, prunes. If you consistently include these foods in your diet, you can meet your body’s iron requirements without consuming meat or dairy. The good news is seeds, nuts, legumes, and whole grains usually contain significant amounts of both iron and zinc. Another way to boost iron absorption from plant-based foods is to sprinkle them with lemon juice. The vitamin C in lemons boosts absorption.
Benefits of a Plant-Based Diet
Eating exclusively plant-based foods by adopting a vegan diet has benefits based on research. Because plant-based foods are nutrient dense and low in calories, they’re linked with better weight control. Plants also contain a variety of anti-inflammatory phytochemicals. Since inflammation is a driving force behind a number of health problems, plant-based phytochemicals may lower the risk of these diseases. Research also shows that a vegan diet has beneficial effects on blood lipids and blood sugar. Plus, the high fiber content of plant-based foods provides nourishment for friendly gut bacteria. Who doesn’t want a healthier gut?
The Bottom Line
Adopting a plant-based diet has health benefits, as long as you get a balanced array of vitamins and minerals. Now, you know which ones to watch out for. Also, be aware that you can also benefit from simply eating more plant-based foods. You don’t have to go vegan or vegetarian to enjoy the benefits plant-based foods offer.
AuthorityNutrition.com. “16 Studies on Vegan Diets – Do They Really Work?
Appl Physiol Nutr Metab. 2007 Aug;32(4):619-34.
WebMD. “Vitamin B12 Deficiency”
Harvard T.H. Chan School of Public Health. “Omega-3 Fatty Acids: An Essential Contribution”
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