This guestpost was written by Pixie Turner from Plantbased Pixie. All info and links to her blog can be found at the end of the post!
A vegan diet eliminates all animal products – meat, fish, dairy, and eggs – and focuses entirely on plant foods. The reasons given for adopting veganism are usually related to ethics or the environment, but sometimes health reasons are given too. But is a vegan diet healthier than an omnivorous diet? Is it even healthy?
Often an association is made between vegan diet and health, but just because vegans can only eat plants that doesn’t guarantee a diet is high in nutrient-dense foods.
There are a great many vegan foods which are extremely nutrient-poor.
Certain nutrients are harder to obtain on a vegan diet, including: complete sources of protein, essential omega-3 fatty acids, iron, zinc, calcium, and vitamin B12. That is not to say that if you follow a vegan diet you will be deficient in these, more the case that a poorly-thought-out vegan diet runs the risk of potential deficiencies in these areas, and therefore should be carefully considered!
- Complete proteins: meat is the obvious source of protein people think of, and the reason it’s a great source is because it contains all 9 essential amino acids. Most plant sources of protein contain some, but not all of these, so it’s important to mix and match well.
- Essential omega-3 fatty acids: these are, as the name suggests, essential! The best sources are from oily fish and eggs, but flaxseeds are an amazing vegan source. Vegan omega-3 supplements are also available.
- Iron: plants that are good sources of iron also usually contain phytates, which inhibit iron absorption. Take spinach for example; the iron is there but your body can’t access it easily unless you cook it and break down the phytates first.
- Zinc: often overlooked, zinc is important to the immune system, hair, skin, and nails. Good plant-based sources are beans, oats, and nutritional yeast.
- Calcium: again, plants that are good sources of calcium also usually contain oxalates, which inhibit calcium absorption. This makes spinach a pretty poor source of calcium, whereas greens like kale contain calcium that’s much more bioavailable. Other vegan sources of calcium include fortified plant milks, tofu and tempeh.
- Vitamin D: make sure to buy a plant milk that’s fortified with vitamin D, and to supplement in winter as it’s now recommended to everyone in the UK! Also make sure to go outside with bare skin in summer months (April-October).
- B12: the key vitamin that’s almost impossible to obtain from plant sources. Even fortified plant milks probably won’t quite give you enough, so supplementation is vital. Spirulina is not a reliable source of B12! Often it contains B12 analogues which can inhibit B12 absorption!
There aren’t too many high quality studies that compare vegan diets to omnivores; the focus tends to be more on vegetarianism. The health benefits (or lack thereof) of a vegan diet include:
- Vegans tend to have a lower BMI due to a lower calorie consumption
- There may be a lower risk of heart disease among vegans
- There is no benefit of a vegan diet overall on all-cause mortality, cancer mortality, cerebrovascular disease or cardiovascular-disease-related mortality
- Vegans have a lowered risk of metabolic syndrome compared to omnivores
- There is inconclusive evidence on diabetes and glycemic control
There is an increased risk of deficiency in omega-3, iron, zinc, vitamin D, vitamin B12, and calcium. But with an appropriate diet and supplementation where necessary, this can easily be avoided.
Despite some individual studies showing beneficial results, it’s important to look at the overall picture, and the overall evidence suggests there is no great health benefit to a vegan diet. Of course, it goes without saying that veganism often extends beyond diet, with the primary focus being ethics or environment.
However, as a nutritionist my focus and expertise is purely on the nutritional aspect of veganism.
If you’re thinking of switching to a vegan diet and want to make sure your diet is as nutritionally balanced as possible, please don’t reply on Google, please see a registered dietitian or nutritionist.