• Rachel in Food SustainabilityVegetarian

Plant-Based Diets and Sustainable Eating

The scientific evidence supporting the link between environmental sustainability and plant-based eating is overwhelming. The Eat Lancet Commission Report confirmed that one of the biggest things we can do for the environment (and our health) is to cut back on animal foods. The report states ‘Food is the single strongest lever to optimize human health and environmental sustainability on Earth.’ (1)

There are a number of factors that make plant-based eating the right choice for our health and the health of the environment. By understanding how our food choices play a role in transforming the planet’s ecosystem and how this has a direct effect on our health will help us make the sustainable changes needed to ensure the well-being of current and future generations.

Plant-Based Diets and Sustainable Eating

Recipe for the Best Lentil Salad

Health Benefits of a Plant-Based Diet

Benefits of Vegetarianism

Traditionally, we have seen that the research into vegetarian and plant-based diets has focused mainly on potential nutrient deficiencies. In recent years we have seen a shift, and studies are confirming the health benefits of plant-based diets. Now it is well recognized that plant-based eating is not only nutritionally sufficient but also poses as a way to reduce the risk of many chronic illnesses.

Vegan Diets Protect Against Chronic Diseases

According to Dietitians of Canada “A well-planned vegan diet is high in fibre, vitamins and antioxidants. Plus, it’s low in saturated fat and cholesterol. This healthy combination helps protect against chronic diseases. Vegans have lower rates of heart disease, diabetes and certain types of cancer than non-vegans. Vegans also have lower blood pressure levels than both meat-eaters and vegetarians and are less likely to be overweight.” 

Plant-Based Diets Protect Against Cardiovascular Disease

There is some good evidence to suggest that vegetarians have a lower risk of cardiac morbidity and mortality. Data from 5 prospective studies compared the death rates from common diseases of vegetarians with those of non-vegetarians with similar lifestyles. The results from over 76,000 participants showed that vegetarians were, on average, were 25% less likely to die of heart disease (2).

Plant-Based Diets and Diabetes Risk

Research suggests that a predominantly plant-based diet can reduce the risk of type 2 diabetes. This was seen in studies of Seventh-day Adventists in which a vegetarians member’s risk of developing diabetes was half that of non-vegetarians, even after taking BMI into account.

Plant-Based Diets and Diabetes Management

Diabetes Canada’s clinical practice guidelines also outline the benefits of a vegetarian diet. Systematic reviews and meta-analyses of available randomized controlled trials are outlined in the guidelines and demonstrated that vegetarian and vegan dietary patterns have resulted in clinically meaningful improvements in A1C and Fasting Blood Glucose in people with type 1 and type 2 diabetes, as well as body weight and blood lipids in people with and without diabetes (3).

Benefits of A Mediterranean Diet

One of the most well-studied eating patterns is the Mediterranean diet, a plant-based eating pattern that has its foundations in vegetables, fruit, legumes and healthy fats. It also includes fish, poultry, eggs, cheese, and yogurt a few times a week, meats and sweets are had less often.

In both large population studies and randomized clinical trials, the Mediterranean diet has shown a reduced risk of heart disease, metabolic syndrome, diabetes, certain cancers (specifically colon, breast, and prostate cancer), depression, and in older adults, a decreased risk of frailty, along with better mental and physical function.

Healthy Coleslaw Recipe with Toasted Almonds

The Consequences of Livestock Agriculture

How Much Meat Are We Eating?

Despite the well-documented benefits of a plant-based diet, Canadians are still eating on average 76 pounds of chicken per year. Beef consumption is around 40 pounds per year and pork consumption is 36 pounds per year.

Livestock Agriculture and Greenhouse Gas Emissions

Switching out our burger for lentils is not only good for our health, but it can also be one of the biggest steps we make towards lowering our individual carbon emissions. According to the Environmental Working Group, beef production produces 13 times as many greenhouse gas emissions as vegetable proteins like beans and lentils. On top of this, global livestock production creates more greenhouse gas emissions than the entire transportation sector, representing over 14% of human-induced greenhouse gas emissions (4).

Effects Of Meat Production On Land and Water

It is not only our greenhouse gas emissions that livestock agriculture is negatively affecting. The raising of animals for food also plays a negative role in land degradation, water pollution and biodiversity loss.

Comparing Greenhouse Emissions Of Animal Proteins

With over 14% of human-induced greenhouse gas emissions coming from livestock, it is beef and dairy that account for the majority of these emissions at 41% and 20% respectively. Pork, and poultry and eggs contribute 9% and 8% respectively to agriculture emissions (4).

The majority of these emissions come from the livestock’s feed production and processing, and also the methane production caused by the enteric fermentation in ruminants. A smaller portion, but no less cause for concern is the emissions from the processing and transportation of the animals and animal products.

Easy Ginger French Lentil Stew on Couscous

Sustainability of Lentils and Legumes

Environmental Sustainability of Legumes

The sustainability benefit of legumes has been well documented. I have shared some key sustainability points in my post How To Cook Lentils + 5 Reasons Why We Should Eat Lentils, and in some of my recipes including this Easy Vegetarian Bean Soup.

Legumes Fix Nitrogen

Much of the greenhouse gas emissions for agriculture come from the nitrogen fertilizers used in feed production (5). Nitrogen fertilizers are manufactured using intensive fossil fuels, and the products of breakdown contribute to eutrophication of water resources and are potent greenhouse gasses (nitrous oxide).

Legumes, including lentils and other pulses, are able to fix atmospheric nitrogen through nodules in the soil, allowing the plant to grow with a reduced reliance on industrial nitrogen fertilizers. This is achieved through their special relationship with certain types of soil bacteria, namely Rhizobium and Bradyrhizobium (6).

Legumes Improve Soil Fertility

The process of nitrogen fixation also works to improve soil fertility. When a crop of spring wheat or barley is grown after a legume crop, it will have a 20% to 35% increased yield thanks to legumes ability to fix nitrogen (7).

Legumes Sequester Carbon

Legumes are also prized for their ability to sequester carbon in the soil which greatly reduces greenhouse gas emissions. They have the capacity to store 30% more soil organic carbon when compared to other plant species.

Water Benefits of Legumes

Legumes are highly water-efficient and use much less water than other crops. Peas, lentils and chickpeas are well-adapted to semi-arid conditions and can tolerate drought-related stress. Legumes are also able to extract water and nutrients from the soil through their deep roots, minimizing the impact of surface water stress (6).

Land Benefits of Legumes

The presence of pulses in agro-ecosystems helps to maintain, or even increase, vital microbial biomass and activity in the soil. A soil that has a high biodiversity gives way to an ecosystem that has a greater resistance and resilience against disturbance and stress and also improves the ability of ecosystems to suppress diseases. By nourishing the development of these organisms that are responsible for promoting soil structure, the nutrient availability in the soil is also increased.

Legumes and Food Security

Aside from contributing to a very low water footprint and promoting soil biodiversity, legumes offer an affordable lower-cost and lower-emissions alternative to animal-based protein. On top of this, when legumes have a role in crop system rotation, this translates into a more efficient use of resources, including light, water and nutrients, as well as higher yields and lower risk of overall crop failure (8).

Health Benefits of Legumes

Legumes Are High In Plant-Based Protein

Legumes including lentils and chickpeas are not consumed as often as we might think. It is estimated that only one in ten people eat them daily in Western countries. Legumes are a great source of plant-based protein, which can contribute to complete protein with all essential amino acids when eaten as part of a varied diet (by including other staples such as rice).

Legumes Are A Great Source of Iron and Zinc

They are also rich in folic acid which is important for women in pregnancy. Lentils are one of the best plant-based sources of iron, with ¾ cup cooked providing up to 5 milligrams of iron. Legumes are also a great source of zinc (see my post Zinc Rich Foods For Vegetarians and How To Get Enough Zinc for Vegans and Vegetarians).

Legumes Are High In Antioxidants

All legumes are rich in antioxidants and phytochemicals which have a number of favourable physiological properties that are beneficial against chronic diseases (see my post What Are Antioxidants Good For). I’ve included some more on the health benefit of eating lentils in my recipe BEST Lentil Salad with Mustard Vinaigrette.

Sustainability of Other Plant-Based Proteins

The Sustainability of Hemp

Hemp gets a green light for sustainability because it can be grown in a variety of climates and soil types, including right here in Canada, which helps to cut down on the transport costs. Hemp also grows quickly and like a “weed” which decreases the need for most herbicides, pesticides and fungicides, and also means hemp requires less water compared to most other crops.

Using Hemp As Food

Hemp is relatively new to the Canadian market, so we can expect to see more hemp-based products in the near future. Currently, hemp hearts (hemp seeds with the hull removed) are widely available and are a great addition to smoothies or added to salads. Hemp also makes a great milk alternative base (see Hemp Milk Nutrition & Hemp Milk Recipe.) Want some more hemp recipes?

Vegan Ranch Dressing Recipe

The Sustainability of Soybeans

Soybeans have long been linked to deforestation and ridiculed for their contribution to climate change, though it is important to note that much of the worlds soybean consumption goes into feed for cattle and other livestock. The process of converting soybeans into animal protein is incredibly inefficient, taking between 8 to 16 pounds of soybeans to produce 1 pound of beef.

Soybeans and Glyphosate

Considering soy’s contribution to climate change, it is not only deforestation that is cause for concern. Glyphosate, the active chemical compound in the herbicide Roundup, is used internationally on soybeans and is under scrutiny by The International Agency for Research On Cancer (IARC).

The IARC evaluated the findings from a US Environmental Protection Agency report and concluded that there is sufficient evidence of carcinogenicity in experimental animals, exposed to glyphosate. It deemed glyphosate as “probably carcinogenic to humans” based on “limited” evidence of cancer in humans (from real-world exposures that actually occurred) and “sufficient” evidence of cancer in experimental animals (9).

The herbicide is not only associated with human health concerns, but it is also well documented that it has vastly negative effects on biodiversity and is actively contributing to soil erosion.

What Is A Flexitarian Diet?

Are you wanting to become a planet-conscious eater but don’t know if you can commit to a fully plant-based diet? Flexitarian eating encompasses a plant-based eating style but allows for some dairy, eggs, fish or meat.

Usually, animal products are limited but there is no specified amount. Those who follow a flexitarian diet may have animal products once per week or as little as once per month. Any reduction in animal protein consumption will have a beneficial impact on the environment. For more information on flexitarian eating see my post What Is A Flexitarian? The Environmental Sustainability of Eating Meat.

Sustainable Eating Recipes

Feel inspired to eat more plant-based? Here are some of my favourite sustainable eating recipes, featuring plant-based proteins:

Practical Tips For Eating More Plant-Based Meals

  • Items such as green lentils are a great substitute for ground meat. Try serving a vegetarian shepherd’s pie by replacing the ground meat with green lentils. Your family members will appreciate the familiarity of the dish, and the addition of fibre and nutrient-rich lentils will increase the overall nutrition of the dish.
  • No need to fully replace the meat, even reducing the animal protein by half will confer some health and environmental benefits. Try making a spaghetti bolognese with half minced meat and half red lentils. The red lentils will break apart making a delicious and thick bolognese sauce.
  • Instead of dairy-based snacks such as yogurt and cheese, try snacks based on nuts, seeds and legumes. Apple and peanut butter, or crackers and hummus are delicious and convenient snack options.
  • Tofu pairs well in many Asian-inspired dishes. Try baked tofu in a mild Thai style curry, or use cubed-firm tofu in place of paneer in a spinach-based Indian dish.

Concluding Plant-Based Diets and Sustainable Eating

The jury is in on the benefits of a plant-based diet for human health and the health of our planet. Even small steps towards offering more plant-based foods – including fruits, vegetables, nuts, seeds and whole grains, while limiting animal-sourced foods are positive steps towards helping us achieve the lower emissions we require to conserve the health of our planet.

Looking towards resources such as Meatless Mondays can help inspire small or large changes. Making healthy foods more available, accessible and affordable in place of unhealthier alternatives is another step in the right direction, and the health of our population and our planet will be thankful for it.

Save This Article For Later!

This article was originally written for the Canadian Society of Nutrition Management magazine.

References

1) The Eat Lancet Commission on Food, Planet and Health. The Eat Lancet Commission Report: Healthy Diets From Sustainable Food Systems

2) Mortality in vegetarians and nonvegetarians: Detailed findings from a collaborative analysis of 5 prospective studies. American Journal of Clinical Nutrition. 1999.

3) Diabetes Canada Clinical Practice Guidelines Expert Committee. Nutrition Therapy. 2018.

4) Gerber PJ, Steinfeld H, Henderson B, et al. Tackling Climate Change through Livestock – A Global Assessment of Emissions and Mitigation Opportunities. Rome: Food and Agriculture Organization of the United Nations; 2013.

5) Pulse Canada. http://www.pulsecanada.com/food-industry/pulse-benefits/sustainability/

6) 1 Nulik J, Dalgliesh N, Cox K and Gabb S. (2013) Integrating herbaceous legumes into crop and livestock systems in eastern Indonesia. Australian Centre for International Agricultural Research (ACIAR), Canberra.

7) International Atomic Energy Agency. Pulses for a Sustainable Future. 2016. https://www.iaea.org/newscenter/news/pulses-for-a-sustainable-future

8) Food and Agricultural Organization of the United Nations. Pulses and Biodiversity. 2016. http://www.fao.org/3/a-i5389e.pdf%20

9) International Agency for Research On Cancer. World Health Organization. 2015. https://www.iarc.fr/wp-content/uploads/2018/07/MonographVolume112-1.pdf

10) Grains and Legumes Nutrition Council. Cost Effective Protein. 2013. https://www.glnc.org.au/legumes/legumes-nutrition/protein-foods-cost-comparison/

Rachel:
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