Nutritional Deficiencies on Plant-forward Diets | Nutrition Mythbusters
Balanced is excited to bring to you our Nutrition Mythbusters series in which we debunk eight major myths about the links between diet and health! We believe that accurate, evidence-based nutrition information should be accessible to everyone. That’s why we created this educational series dispelling some of the most common and persistent misconceptions regarding healthy, balanced eating and diet-related disease. You can find the video episode of today's blog on our YouTube channel.
It is important now, perhaps more than ever, that Americans eat for their health. This includes getting more whole grains, plant proteins, fruits, and vegetables. Nutrition information, however, can be difficult to understand, especially when generated with ulterior interests. For example, there are several frequently noted dietary “deficiencies” attributed to plant-forward and plant-based diets as compared to the Standard American Diet (SAD). However, when following a balanced diet, this sentiment is simply untrue. The SAD, however, is characterized by inadequate intake of nutrient-dense foods like fruits, vegetables and whole grains.
Many of the claims supporting the value of the SAD are rooted in aggressive marketing schemes rather than honest, evidence-based science. These claims are also pushed by the food industries themselves, namely fish, egg, meat, and dairy. For example, it is difficult to find dairy research that is not funded by the dairy industry itself.
The meat industry is much the same. Studies funded from the meat industry often produce results favorable for the industry. For example, one study claims that protein intake is negatively compromised if meat and saturated fat intake is reduced. The authors of this study received funding from the meat industry. As it is, most Americans consume much more protein than is required.
The truth is that those who consume plant-forward or plant-based diets do not have more nutritional deficiencies than those who consume the conventional SAD or Western diet. In fact, those consuming plant-forward or plant-based diets experience greater nutritional benefits and health outcomes. Let’s dissect the frequently mentioned dietary “deficiencies.”
It is often claimed that those following a plant-forward or plant-based diet are iron-deficient because they do not consume meat or consume little of it. Heme iron is found in meat while plants contain non-heme iron. Though the bioavailability of non-heme iron from plant sources is less efficient than heme iron, there is no evidence that this results in an elevated risk of iron-deficiency anemia. Bioavailability aside, meat consumption is not the most healthful way to obtain iron. In fact, it actually poses some risks. A high intake of heme iron has been linked to diet-related disease risks, namely for type 2 diabetes and metabolic syndrome. Conversely, the body actually does a better job of regulating non-heme iron.
Another frequently hypothesized dietary deficiency is calcium. Adverse health effects associated with low calcium intake include osteoporosis and bone fractures. Calcium adequacy is often associated with the consumption of dairy products. (Remember the “Got Milk?” campaign?) However, research has found that fracture risk does not increase with plant-based diets as long as calcium intakes from plant sources meet adequate levels. There are many plant-based sources of calcium, including kale and broccoli. In fact, the calcium content in kale and broccoli is more effectively absorbed than the calcium in milk. In addition to their calcium content, these vegetables provide many other nutritional benefits.
According to the 2015-2020 Dietary Guidelines for Americans, the majority of Americans far exceed the recommended protein intake. Much of this excess is driven by the three major sources of protein in the U.S.—milk, beef, and poultry. Rich sources of plant-based protein are numerous and include lentils, peas, beans, soy foods, seeds, and nuts. Unfortunately, legumes are not a major component of the mainstream U.S. diet partly due to the Western preference for animal products.
Safely enjoying the sun is a fantastic way to obtain adequate levels of Vitamin D. In addition, certain types of mushrooms are a great dietary source if grown with UV light. Vitamin D can also be obtained through certain brands of fortified, plant-based milks. Regardless of diet, however, most Americans would benefit from regularly taking a vitamin D supplement, as any diet is bound to be lacking in this nutrient and because modern life means we simply do not spend enough time outdoors anymore.
Plant-based sources of Vitamin B12 include enriched cereals and soy products fortified with the vitamin. Nutritional yeast, a cheese-flavored seasoning, is often very high in vitamin B12, and non-soy, plant-based milks increasingly are fortified with B12 as well. When not regularly consuming these foods on a plant-based diet, it is simply best to take a supplement.
Those following an omnivorous dietary pattern, including the SAD, may experience more dietary deficiencies than those following a vegetarian diet.
SAD is not rich in fiber, unlike plant-forward and plant-based dietary patterns. The recommended fiber intake is as follows:
25 grams/day for women
38 grams/day for men
In reality, fiber intake among U.S. adults is abysmally low, ranging from about 15-17 grams per day. It is difficult to make major changes to your diet overnight, but replacing two ounces of cooked ground beef with a cup of cooked beans drastically increases fiber intake while offering the same grams of protein.
Overall, there are numerous nutritional benefits of following a diet centered on plant-based foods. This dietary pattern includes rich sources of calcium, fiber, folate, magnesium, vitamin C and vitamin E.
The SAD often equates to low intake of fruits and vegetables, putting people at risk of numerous deficiencies. Not surprisingly, evidence shows that those following a vegetarian dietary pattern consume more fruits and vegetables than those following omnivorous dietary patterns. They also consume much less sodium than omnivores. A reduced sodium intake in combination with high fruit and vegetable consumption contributes to a reduced risk of hypertension and other diet-related diseases.
In short, don’t fear for your nutritional intake when replacing a few servings of animal products with plant-based alternatives; you are almost certainly improving it when you do so!