In this chapter you will find out why cultivating and eating legumes can contribute to the preservation of our earth as we know it today, why cultivation and consumption of pulses contribute to food security and which nutritional properties legumes have to make them fit so well within a sustainable and healthy diet. Besides the fact that beans, peas and lentils are very tasty and diverse, you’ll have even more reasons to enjoy them after reading this chapter!
Food production, food security and climate change are intrinsically linked. The effects of climate change, such as intensification of droughts, flooding and storms affects many aspects of the production of food, and thus also its availability. In addition, they provide price fluctuations. This makes for uncertainty in terms of income for rural communities worldwide and for uncertainty in the availability of affordable food.
Not every crop and region in the world is affected equally by the effects of climate change, but generally the most vulnerable communities experience the biggest impact. Climate change has a great impact on agriculture, and where one region is less suitable for plant production, another region gets more options for agriculture. Plant production itself also has a considerable impact on climate change. In particular, the production and the application of nitrogen from fertilizers and manure on the soil provides a relevant amount of greenhouse gas emissions. Therefor agriculture also needs to play it part in the solution to climate change: produce the highest possible yield, with the least amount of fertilizers and minimal energy use.
There are a number of reasons why legumes could be a part of the solution to climate change. A special feature of legumes is that most species live in symbiosis with bacteria that can bind nitrogen. These bacteria contain an enzyme that lets the gaseous nitrogen in the soil react to ammonium, which the plant can use in its metabolism. In return, the plant provides the bacteria with fuel, so nitrogen fixation is not slowed down. Pulses save the nitrogen at the roots in small root nodules. Because the plant makes its own nitrogen supply, it hardly to fertilization. During the cultivation of legumes the farmer hardly has to apply fertilizer or animal manure on the soil. The use of fertilizers has a great impact on climate change, in the form of the greenhouse gas nitrous oxide (about 300 x stronger than CO2). The cultivation of legumes therefore has less impact on the climate.
The nitrogen that is stored in the soil is not only available for the cultivation of legumes, but also for the other crops that are part of the rotation scheme on the same piece of land. The fertility of the soil is therefore enhanced. Some types of legumes are also able to free soil-bound phosphate which also contributes to increased soil fertility. When legumes are included in a rotation of crops, the activity of the biomass in the soil increases, improving the structure of the soil and increasing the availability of nutrients. This allows for better resistance to diseases and that is a good basis for food production and thus food security.
Food production and food security also play a role in malnutrition, which is still a major problem in many countries. Malnutrition can be caused by too little food, but also by eating too much of the same. Legumes can play a key role in tackling malnutrition. The first reason is that it is a relatively inexpensive product and second: because legumes have very good features that benefit our health.
A measure of how healthy a food product is, is the nutrient density. Nutrients are substances like vitamins and minerals that a products contains. Legumes contain relatively many nutrients per kilogram of product and thus have a high nutrient density. Nutrients legumes are known for include their levels of: protein, fiber, iron, magnesium and phosphorus. Iron and fiber are nutrients which we, with our Western food habits, should eat more of. Other advantages are that legumes have a low fat and salt content and do not contain gluten, making them suitable for a gluten-free diet.
In many regions in the world legumes traditionally played an important role in dietary patterns. For various reasons legumes have however become less popular and nowadays their nutritional value is underestimated. The average Dutch consumer eats four grams of legumes a day (in 2016), which amounts to about one vegetable spoon of legumes a week. That is, of course, very little. Several studies have shown that, when optimization technique is used for both environmental parameters and nutritional properties, the amount of legumes in our diet should increase considerably. An increase in the amount of pulses to about 30 grams a day would, in addition to other important changes, contribute to a reduction of the environmental impact of what we eat. So, these little round rascals can play an important role in keeping us to climate goals for 2030. Other important changes in our diet need to be reduction of the consumption of meat and cheese and an increase in the consumption of fruits, nuts, seeds, fish, soy products and vegetarian products.
Do you want to know more about optimization in favor of sustainability and health, check this.
As mentioned before legumes such as beans, lentils and peas have very good nutritional properties. These properties make sure that increasing the amount of pulses on your plate really can affect your health. It has been investigated that they can help with problems of high cholesterol or excessive levels of blood sugar. Increase in the consumption of legumes is also linked to reduced risk of heart disease, type 2 diabetes and some kinds of cancer. And in addition, there is growing evidence that embracing pulses into your daily diet can help you to keep with weight management.
The FAO has written a clear fact sheet in which you can read more information about how and why legumes can have such good effects on your health.
Taking everything into consideration, you can definitely say that the bean deserves a more prominent place on our plate than those meager 4 grams per day of the average Dutch consumer. The cultivation of legumes has advantages when it comes to the climate and soil quality and ensures better resistance of crops and food security. You can also not deny the favorable nutritional profile of legumes. More beans, lentils and peas in our diet can provide less climate impact of our food and on top of that putting legumes on the menu more often also has all kinds of health benefits.