Plant-Based Diets: Are They Really Healthy?

A plant-based diet can be a healthy choice, but it is not without its drawbacks. While it may lower the risk of cardiometabolic diseases, it has been associated with adverse health outcomes, such as nervous, skeletal, and immune system impairments, hematological disorders, and mental health problems. One of the main concerns with a plant-based diet is the potential for micro and macronutrient deficits, particularly vitamin B12, vitamin D, calcium, iron, and omega-3 fatty acids. These deficiencies can lead to health issues such as increased risk of certain cancers, stroke, bone fractures, and preterm birth. Additionally, the time and effort required to plan and prepare plant-based meals, as well as the challenge of giving up favourite foods, can be considered a negative aspect of this diet.

Increased risk of stroke

While a plant-based diet is associated with a reduced risk of heart disease, some studies have found a link between vegetarian and vegan diets and an increased risk of stroke. However, it is important to note that the evidence is not conclusive, and more research is needed to confirm this potential association.

The Studies

The EPIC-Oxford study analysed data from 48,000 people over 18 years and found that vegetarians and vegans had a 20% higher risk of stroke compared to meat eaters. This amounted to three extra cases of stroke per 1,000 people over ten years. Similarly, the Oxford-EPIC cohort study showed that vegetarians had a 20% higher risk of stroke than meat eaters, equivalent to three more cases per 1,000 people over a decade.

However, it is worth noting that the EPIC-Oxford study combined vegetarians and vegans into one group due to the small number of vegan participants. Therefore, it is unclear whether the increased risk of stroke applies to all vegetarians or only to vegans. Additionally, the Oxford-EPIC cohort study did not find a higher risk of stroke among pescatarians (fish eaters), suggesting that the association may be specific to vegetarian or vegan diets.

Potential Reasons

The reason for the potential increased risk of stroke among vegetarians and vegans is not fully understood. One factor may be low LDL cholesterol levels, as low LDL cholesterol is a known risk factor for haemorrhagic stroke, the type of stroke that was more common among vegetarians in the EPIC-Oxford study. Additionally, vitamin B12 deficiency, which is common in vegans, has been linked to an increased risk of stroke. Other nutrient deficiencies, such as vitamin D and omega-3 fats, could also contribute to the increased risk.

Other Considerations

It is important to consider that the association between plant-based diets and stroke risk may not be causal. For example, it is possible that vegetarians and vegans who have a family history of stroke may be genetically predisposed to a higher risk of stroke, rather than their diet being the primary factor. Additionally, the EPIC-Oxford study was conducted over two decades ago, and vegetarian and vegan diets have likely evolved since then, with more convenience foods and alternatives available today.

While there may be an increased risk of stroke associated with plant-based diets, the benefits of these diets for heart health and the prevention of ischaemic stroke may outweigh this potential risk. More research is needed to confirm the association and understand the underlying reasons. In the meantime, it is essential for those following plant-based diets to ensure they consume a well-planned and varied diet that includes essential nutrients to maintain optimal health.

Nutritional deficiencies

• Vitamin B12 deficiency: Vitamin B12 is naturally found in animal products, and its deficiency can lead to serious health issues such as nerve damage, neurologic and haematologic problems, and increased risk of certain cancers. Vegans must rely on supplements or fortified foods to meet their B12 needs.
• Iron deficiency: While plants contain iron, the body does not absorb it as efficiently as iron from meat. However, it is rare for vegans and vegetarians to have low iron levels. Beans, spinach, and raisins are good plant-based sources of iron.
• Calcium deficiency: Dairy products are a major source of calcium, and their exclusion can increase the risk of bone fractures. Green leafy vegetables and tofu are plant-based sources of calcium, and calcium-fortified foods like cereal and plant milk can also help prevent deficiencies.
• Omega-3 fatty acid deficiency: Omega-3s, particularly DHA, are essential for brain health and are commonly found in fish. Plant sources like walnuts and flaxseeds provide ALA, which the body can convert to DHA, but the conversion is often inefficient, potentially leading to cognitive issues.
• Zinc deficiency: Zinc is found in meat, dairy, and eggs, and while some plant foods contain zinc, their bioavailability is reduced due to the presence of phytate. Zinc deficiency may be linked to mental health issues, dermatitis, diarrhoea, and hair loss.
• Vitamin D deficiency: Vitamin D deficiency is common, and those following a plant-based diet may need to pay particular attention to their intake. Supplements or fortified foods can help ensure adequate levels.

While a plant-based diet can provide a wide range of nutrients, careful planning is necessary to avoid potential deficiencies. Supplements and fortified foods can play a crucial role in meeting nutritional requirements when following a vegan or vegetarian diet.

Higher rates of depression and anxiety

Plant-based diets have been linked to lower rates of heart disease, type 2 diabetes, and some cancers. However, some studies have also associated plant-based diets with higher rates of depression and anxiety. This may be due to a variety of factors, including nutritional deficiencies, food restriction, and food group exclusion.

Nutritional deficiencies

Some plant-based diets may be deficient in certain nutrients, such as vitamin B12, vitamin D, iodine, selenium, riboflavin, and omega-3 polyunsaturated fatty acids. These deficiencies can contribute to depressive symptoms and lower mood. For example, vitamin B12 is known to help combat depressive symptoms, and omega-3 polyunsaturated fatty acids play a vital role in brain function and mood outcomes.

Food restriction and food group exclusion

Food restriction and the exclusion of certain food groups, such as meat, can also impact mental health. A study found that meat abstinence was associated with higher levels of depressive symptoms when compared to other dietary patterns. Additionally, vegetarians and vegans may experience increased stress due to social desirability bias and the stigma associated with being a morally motivated minority.

Protective effects of plant-based diets

However, it is important to note that some studies have found protective effects of plant-based diets on mental health. A study published in the British Journal of Psychiatry found that individuals eating whole foods reported fewer symptoms of depression compared to those consuming mostly processed foods. Another study found that vegetarians reported more positive moods than meat eaters.

While there may be a link between plant-based diets and higher rates of depression and anxiety, the relationship is complex and multifaceted. Further research is needed to understand the bidirectional relationship between diet quality and depressive symptoms across different dietary patterns.

Difficulty finding affordable plant-based foods

While some people may be hesitant to adopt a plant-based diet due to the misconception that it is expensive, this is not necessarily true. In fact, there are plenty of delicious plant-based recipes that are budget-friendly and easy to make.

Inexpensive ingredients

Staple foods such as beans, lentils, and grains are very affordable and can be used to create a variety of nutritious meals. By focusing on whole, unprocessed foods and cooking from scratch, it is possible to save money on a plant-based diet. For example, cooking dry beans yourself is much cheaper than buying canned beans.

Budget-friendly recipes

There are numerous budget-friendly plant-based recipes available online, such as creamy mushroom pasta, lentil curry, breakfast scrambles, oatmeal, baked potatoes, and chickpea avocado sandwiches. These recipes often include inexpensive ingredients like rice, beans, vegetables, and fruits.

Tips for saving money

• Stick to a grocery list when shopping and avoid impulse purchases.
• Shop at discount grocery stores or buy in bulk to save money.
• Choose store brands or generic brands over name brands, as they are often more affordable and just as good.
• Focus on whole foods like rice, beans, vegetables, and fruits, which are usually cheaper than processed foods.
• Avoid buying processed vegan junk food and frozen premade meals, as these can be expensive.
• Cook in larger batches and freeze leftovers for quick and easy meals.

Meal planning and preparation

Meal planning and preparation can also help to keep costs down. Here are some ideas:

• Use meal prep services that offer plant-based options, providing pre-portioned ingredients and recipes.
• Take advantage of plant-based meat alternatives, such as Beyond Meat and Impossible Foods, which can be more affordable than animal-based meats.
• Stock up on pantry staples like rice, beans, and canned tomatoes to create affordable and nutritious meals.
• Get creative with ingredients and experiment with different flavors and spices to add variety to your meals without breaking the bank.

In conclusion, eating a plant-based diet on a budget is possible and can be delicious and satisfying. By focusing on whole, unprocessed foods and being mindful of costs, you can create budget-friendly meals that are both nutritious and delicious.

Potential for weight gain

Calories In, Calories Out

Plant-based diets are not automatically lower in calories. Weight gain occurs when more calories are consumed than are burned off. Plant-based diets can be high in calories, especially if they include foods like avocados, olive oil, whole grains, lentils, nuts, and plant-based meat substitutes.

Portion Control

It is easy to overeat plant-based foods because they are tasty and assumed to be healthy. For example, a whole cup of nuts can exceed 700 calories. It is important to pay attention to serving sizes and not to overeat.

Liquid Calories

Liquid calories from drinks such as smoothies, juice, sports drinks, flavoured coconut water, soda, and alcoholic drinks can add up quickly. For example, some drinks can contain a thousand calories depending on the size.

High-Calorie Toppings

Low-calorie foods like kale and other salad greens can become high-calorie meals when topped with high-calorie dressings and croutons. Similarly, black coffee can become a 500-calorie drink when topped with cream, chocolate sauce, and other sugary syrups.

Vegan Junk Food

Just because a food is vegan does not mean it is healthy. Vegan junk food, such as chips, cookies, doughnuts, French fries, and dairy-free ice cream, can be very high in sugar, fat, and calories.

Frequently asked questions