In 2013 the United Nations declared that 2016 would be the International Year of Pulses. The hope of the 2016 International Year of Pulses (IYP 2016) is to position pulses as a primary source of protein and other essential nutrients. IYP 2016 will promote broad discussion and cooperation at the national, regional and global levels to increase awareness and understanding of the challenges faced by pulse farmers, be they large scale farms or small land holders.
Pulses and Nutrition
Pulses are part of a healthy, balanced diet and have been shown to have an important role in preventing illnesses such as cancer, diabetes and heart disease. Pulses are a low fat source of protein, with a high fiber content and low glycemic index. Pulses are very high in fiber, containing both soluble and insoluble fiber. Soluble fiber helps to decrease blood cholesterol levels and control blood sugar levels, and insoluble fiber helps with digestion and regularity.
Pulses provide important amounts of vitamins and minerals. Some of the key minerals in pulses include: iron, potassium, magnesium and zinc. Pulses are also particularly abundant in B vitamins; including folate, thiamin and niacin.
Pulses typically contain about twice the amount of protein found in whole grain cereals like wheat, oats, barley and rice, and in most developing countries constitute the main source of protein for most populations.
In addition to contributing to a healthy, balanced diet, the nutritional qualities of pulses makes them particularly helpful in the fight against some non-communicable diseases.
The World Health Organisation estimates that up to 80% of heart disease, stroke, and type 2 diabetes and over a third of cancers could be prevented by eliminating risk factors, such as unhealthy diets and promoting better eating habits, of which pulses are an essential component.
Pulses can help lower blood cholesterol and attenuate blood glucose, which is a key factors in against diabetes and cardiovascular disease. Eating pulses as a replacement to some animal protein also helps limit the intake of saturated fats and increases the intake of fibers.
Pulses have also been shown to be helpful in the prevention of certain cancers, because of their fiber content but also because of their mineral and amino-acid contents, in particular folate.
Pulses are included in all “food baskets” and dietary guidelines. The World Food Programme (WFP), for instance, includes 60 grams of pulses in its typical food basket, alongside cereals, oils and sugar and salt.
Encouraging awareness of the nutritional value of pulses can help consumers adopt healthier diets. In developing countries, where the trend in dietary choices tends to go towards more animal-based protein and cereals, retaining pulses is an important way to ensure diets remain balanced and to avoid the increase in non-communicable disease often associated with diet transitions and rising incomes.
Several studies have shown that legumes are been associated with long-lived food cultures such as the Japanese (soy, tofu, natto, miso), the Swedes (brown beans, peas), and the Mediterranean people (lentils, chickpeas, white beans) and that they could be an important dietary factor in improving longevity.
Pulses and Sustainability
Pulses play an important role for sustainability in many ways. They are an important component of crop rotations, they require less fertilizer than other crops, and they are a low carbon source of protein.
Legumes are part of the rotational crops farmers can use to maintain soil fertility. In Canada for instance, where pulses are often integrated in good soil management practices, a good crop rotation includes a variety of crops grown in sequence, including cereals (wheat, barley, oats), oilseeds (canola, flax, sunflowers), and legumes (pulses). Pulses have a positive impact on soil quality because they help fix nitrogen in the soil. This contributes to higher yields in subsequent crop rotations.
Moreover, pulses have a direct positive impact on soil quality because they help feed soil microbes, which benefits soil health. Pulses have also been shown to produce greater amounts and different types of amino acids than non-legumes and the plant residues left after harvesting pulse crops have a different bio-chemical composition than other crop residues.
It is this diversity in soil composition that comes from a good pulse rotation, which help crops to thrive and which offers greater protection against disease-causing bacteria and fungi.
Pulses are also a protein source with a low footprint, in both carbon and water. For instance, the water footprints to produce a kilogram of beef, pork, chicken and soybeans are 43, 18, 11 and 5 times higher than the water footprint of pulses.
Pulses have a lower carbon footprint in production than most animal sources of protein. In fact, one study showed that one kilogram of legume only emits 0.5kg in Co2 equivalent, whereas 1kg of beef produces 9.5 kg in CO2 equivalent.
The very low contribution of legumes is well illustrated in the graph below.
Full Lifecycle Greenhouse Gas Emissions From
Common Proteins And Vegetables
The graph shows that lentils are one of the foodstuffs that contributes the least emissions, far fewer than turkey, salmon, or other common sources of protein.
Nitrogen is the nutrient most needed in crop production and nitrogen fertilizer is manufactured using natural gas. Pulses are quite unique among other crops, as they draw their own nitrogen from the air, so they do not require the same application of nitrogen fertilizer as other crops do.
By fixing nitrogen in the soil, pulses also help reduce the footprint of other crops, so the benefits extend much further into the food production cycle. For example, a recent study showed that durum wheat preceded by a biological nitrogen-fixing crop, such as chickpeas or lentils the previous year, lowered its carbon footprint by 17% compared with durum preceded by a cereal crop. The impact was even stronger is a pulse-pulse wheat system, with the carbon footprint of the durum wheat down by 34% compared to a traditional cereal-cereal–durum rotation.