Katherine MaGrath, student dietitian, Queen Margaret University.

 

  1. Background of the wonderful garden pea.

Garden peas are an inexpensive and readily available family favourite in the UK, which can be enjoyed fresh between the months of May and October or from frozen all year round. Although a portion of garden peas (80g or 3 heaped tablespoons) counts towards your five a day of fruit and vegetables, it is in fact a legume. A legume has been defined by the FAO (Food and Agriculture Association of the United Nations) as a pulse which is harvested solely for the consumption of it’s seed (1). As garden peas are classified as legumes, they boast many of the same benefits as other legumes, for example chickpeas. The garden pea is a naturally dried seed of Pisum sativum L. which is harvested worldwide for human consumption. Garden peas grow in rounded pods that are slightly curved in shape. They have a smooth texture and are a zesty green colour. Inside the pods are small green rounded peas that are sweet and starchy to taste. Garden peas have been a staple of the UK diet for a staggeringly long time, however it’s origins are thought to be linked to central Asia and Ethiopia. It is considered to be one of the first crops cultivated by humans with the oldest pea ever found dating back almost 3,000 years. Today they are grown all over the UK with approximately 35,000 hectare of peas grown here each year. That fills about 70,000 football pitches and is equal to about 2 billion portions of garden peas (80g or three heaped tablespoons).

 

  1. The contribution towards UK dietary recommendations

Eating garden peas can contribute towards reaching the UK dietary recommendation for having at least five portions of fruit and vegetables per day (2). One portion is equal to 80 grams or three heaped tablespoons of the vegetable and contains approximately 64 calories, 4.2g dietary fibre, 1.2g fat and 5.5g protein (4).

The full nutritional composition and reference nutrient intake (RNI) of an 80 gram portion is outlined in the table below:

Table 1

Nutrient Amount per 80g Nutrient Reference Intake (RNI)
Adults

(19+ years)

Adolescents

(11-18 years)

Children

(1-10 years)

Calories (kcal) 64
Carbohydrates (g) 9.04
  of which sugars (g) 1.84
Fibre (g) 4.24 30 25-30 15-20
Fat (g) 1.2
Protein (g) 5.52
Phosphorus (mg) 80 550 775 (male) / 625 (female) 270-450
Iron (mg) 2.24 8.7 (male)/ 14.8 (female) 11.3 (male) /14.8 (female) 6.9-8.7
Folate (µg) 49.6 200 200 70-150
Vitamin C (mg) 19.2 40 35-40 30

 

  1. Macronutrients

 

Peas provide a great source of plant based protein, are rich in dietary fibre and they are also low in calories and fat making them a great addition to any diet.

 

Unknown to many, peas are rich in protein, with one serving (80g or 3 heaped tablespoons) providing a surprising 5.5g of protein. This plant based source of protein is especially beneficial for vegans and vegetarians. In addition, the high protein content contained in peas has been associated with reduced risk of cardiovascular disease and the promotion of weight loss (3).

 

Peas are considered a ‘heart healthy’ food due to the high content of dietary fibre. In the UK, we don’t eat enough dietary fibre, with the majority of us consuming as little as 14g per day. New dietary guidelines for dietary fibre were introduced recently that recommend increasing intake to 30g per day (4). This was due to strong evidence linking increased intakes of dietary fibre with reduced risk of cardiovascular disease and some cancers related to the bowel. There is also some evidence to suggest that increased intakes of dietary fibre may lead to lower cholesterol, including LDL or ‘bad’ cholesterol, and lower blood pressure (4). Consuming a diet rich in dietary fibre can also help you feel fuller for longer and contribute towards sustainable weight loss.

 

  1. Micronutrients

 

Vitamins:

 

Folate, also known as Vitamin B9, is a member of the B vitamins complex; a water-soluble group of vitamins that play a role in our cells metabolism. Folate occurs naturally in foods, while the term folic acid relates to a synthetic form of folate found in supplements and fortified foods. Folate is involved in several essential functions in the body. It has a very important role in the production of DNA and other genetic material, especially during times of rapid growth, for example: childhood, adolescence and pregnancy. Folate intake is especially important both prior to and during pregnancy to ensure proper foetal growth and reduce the risk of neural tube birth defects (5). Folate affects our brain’s functioning ability and may impact on mental health. It is also closely associated with another B vitamin, vitamin B12, for the production of red blood cells and the effective use of iron in the body. As it is a water-soluble vitamin, it cannot be stored in our bodies and must be consumed daily from our diets. Garden peas provide a rich source of folate, with one portion (80g or 3 heaped tablespoons) providing almost a quarter of the RNI requirements for adults and adolescents (24.5%) and more than 50% of RNI requirements  in younger children (6). See table 1 for more information.

 

 

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin. Unlike fat soluble vitamins that may be stored in the body’s tissues for future use such as vitamins A, D, E and K; water soluble vitamins, like Vitamin C, cannot be stored in the body and so adequate amounts must be consumed through a variety of foods in the diet. Consuming Vitamin C alongside plant based forms of iron (non-haem), helps the body to absorb more than it would in its absence. Historically, Vitamin C was associated with the rare disease known as scurvy, first identified in crusaders of the 13th century where there was not enough Vitamin C in the diet. Vitamin C is an essential nutrient due to its important role in the growth and regeneration of body tissues. It helps the body synthesise collagen, a protein used to give our skin strength and elasticity, but also to make cartilage, tendons, ligaments and blood vessels. It plays a part in healing wounds and in the repair and maintenance of our bones and teeth. Vitamin C is an antioxidant, thus it has the ability to remove potentially damaging oxidizing agents, such as free radicals. Build-up of these free radicals is associated with the ageing process and may be linked to development of health conditions. Garden peas are a fantastic source of Vitamin C, with one portion (80g or 3 heaped tablespoons) providing almost half (48%) of the reference nutrient intake (RNI) for adults and more than 50% of reference nutrient intakes (RNI) requirements for adolescents and children (6). More information about reference nutrient intakes (RNI) for adults, adolescents and children  is available in table 1.

Minerals

 

Peas are a great source of lots of minerals too, including iron and phosphorus.

 

Iron is an essential mineral, which means we cannot produce it in our bodies and that it must be consumed in adequate amounts from our diet. Iron plays an important role in the production of red blood cells that store and carry oxygen around to the body and into each cell (7). Women require almost twice as much iron as men and iron deficiency is common. It may lead to symptoms including tiredness, lack of energy, shortness of breath or noticeable heartbeats. This is because there will be fewer red blood cells, meaning your body does not have as much oxygen as normal (7). One portion of garden peas (80g or 3 heaped tablespoons) provides approximately 25% of the reference nutrient intake (RNI) for men and 15% for women (6,8). Further information available in table 1.

 

Phosphorus is the second most abundant mineral in our bodies after calcium. It helps release energy from food and is used in our bodies to build strong bones and teeth (9). Garden peas provide us with 80mg of phosphorus per 80g serving, equalling almost 20% of our daily requirements.

 

  1. Preparation

 

Although garden peas may be bought fresh between the months of May and October, they are more often bought frozen. Freshly frozen peas are frozen within two and a half hours of being picked, ensuring all of the nutrients are locked in. Frozen peas are extremely useful as there is no preparation required and they can be added directly into casseroles, soups and curries. When purchasing fresh garden peas it is important to look for ones that are a bright medium green colour, with firm pods, that are velvety and smooth. Once bought, they should be stored in the refrigerator to keep them fresher for longer and to ensure the heat does not convert the sugar content into starch.

 

  1. Cooking methods to maintain nutrients

 

Garden peas contain a high nutrient density, therefore the cooking method is important to make sure as little nutrients are lost. The less water used when cooking garden peas will ensure as little Vitamin C as possible is lost. This is because Vitamin C is a water soluble vitamin. If possible, steam the garden peas and if boiling, use just enough water to cover the peas, bring to the boil and then simmer for 3 minutes. Another option is to microwave the garden peas at full power for 4 minutes with a tablespoon of water in a covered container.

 

Some suggestions for including more garden peas in your diet:

  • Add fresh peas to green salads to add a sweet fresh bite
  • Include in vegetable or chicken/beef stir fry
  • Bulk up the traditional shepherd’s pie with some garden peas
  • Add to casseroles and curries

 

 

References

(1) Food and Agriculture Organisation. Definition and classification of commodities: pulses and derived produce. 1994.

(2) Public Health England. The Eatwell Guide. in association with the Welsh Government, Food Standards Scotland and the Food Standards Agency in Northern Ireland 2016.

(3) Dahl WJ, Foster LM, Tyler RT. Review of the health benefits of peas (Pisum sativum L.). Br J Nutr 2012;108(S1):S10.

(4) SACN. Carbohydrates and Health. Scientific Advisory Committee on Nutrition 2015.

(5) MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. The lancet 1991;338(8760):131-137.

(6) Department of Health. Dietary Reference Values for Food and Energy and Nutrients for the United Kingdom. Report of the Panel on Dietary Reference Values of the Committee on Medical Aspects of Food Policy. ; 1991.

(7) Choices N. Iron deficiency anaemia. 2016; Available at: http://www.nhs.uk/Conditions/Anaemia-iron-deficiency-/Pages/Introduction.aspx. Accessed 22/03/, 2017.

(8) McCance RA, Widdowson EM. McCance and Widdowson’s The composition of foods : 7th summary edition [electronic resource]. 2015.

(9) Choices N. Other vitamins and minerals  Available at: http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Other-vitamins-minerals.aspx#phosphorus. Accessed 22/03/, 2017.