Caroline Burgum, student dietitian, Queen Margaret University.

Pears belong to the family Rosaceae, part of the species of genus called Pyrus. Despite the term ‘pear shaped’ used to describe a particular body shape, pears come in a range of shapes and sizes, with Conference, Comice, Bartlett and Concorde the most well known types of pears available in the UK. Other types include Packham’s native to Australia, Rocha native to Portugal, Anjou and Williams Bon Chretien, known for their sweet and juicy taste, great for cooking, and Nashi pears, also known as Asian pears, with a similar shape and texture to apples 1. Despite pears commonly being recognised for their yellowy green colour, some varieties are red, with all types varying in taste and texture. Pears are available in all major supermarkets all year round, however are in season between the months of September through to January 1. Experts have concluded 80g, which is roughly one small pear, or half of a large pear, with the skin on, is one of your five a day 2. The nutritional composition of one medium sized pear (150g) and the reference nutrient intake (RNI) can be found in Table 1 3 4 5 6.

Table 1: The nutritional composition of 1 pear (150g) raw, flesh, with skin and reference nutrient intake (RNI).

 

Nutrient Amount RNI
    0-12 months 1-3 years 4-6 years 7-10 years 11-14 years 15-18 years 19+

years

Energy (kcal) 64.5
Carbohydrates (g) 16.4
Fibre (NSP) (g) 2.4 15 15 20 25 25-30 30
Protein (g) 0.5
Fat (g) 0.2
Vitamin A (µg) 21.0 350 400 500 500 600 600-700 600-700
Vitamin C (mg) 4.5 25 30 30 30 35 40 40
Folate (µg) 9.0 50 70 100 150 200 200 200
Potassium (mg) 157.5 700-800 800 1100 2000 3100 3500 3500
Calcium (mg) 10.5 525 350 450 550 800-1000 800-1000 700
Magnesium (mg) 7.5 55-80 85 120 200 280 300 270-300
Phosphorus (mg) 13.5 400 270 350 450 625-775 625-775 550

 

Macronutrient

As shown in Table 1, a pear contains only 65 calories per portion, making it a low calorie food, beneficial for those trying to maintain or lose weight. Most of these calories come from natural sugars, with minimal amounts of fat and cholesterol. The recommended calorie intake in the UK for women is 2000kcal and men 2500kcal, with children’s requirements varying from the age of 0 to 18, displayed in Table 2 7.

Pears also contain fibre, making it great for satiety, therefore replacing high fat and high sugar processed food products such as crisps, chocolate, biscuits and cakes, with fruit such as one pear, not only reduces your calories, is low in fat and is the healthier option, but can satisfy your body’s needs, making you fuller quicker and less likely to snack on other foods, due to the fibre content, mostly found in the skin of the pear. Although the fibre content of one pear is only 8% of the recommended fibre intake for an adult, this is a great contribution to the 30g a day target. Pears contain both soluble and insoluble fibre which cannot be digested and absorbed by the gut, however work in different ways. Soluble fibre can help prevent constipation by acting as a gel and absorbing water, making stools softer and easier to pass, as well as slowing the absorption of cholesterol and glucose into the blood 8. It is also known that soluble fibre can enhance the good bacteria we have in our guts contributing to some of its known benefits. Insoluble fibre however works differently, known as ‘roughage’ adding bulk to stools, passing through the gut untouched, also helping to prevent constipation 9. The reasons why fibre is so important, is the evidence that has shown fibre is beneficial for reducing your risk of obesity, diabetes, cancer, cardiovascular disease and gastrointestinal disease 10, along with literature that has shown high fibre diets can reduce blood glucose levels and decrease insulin resistance in those that are diabetic 11.

Table 2: The estimated nutritional requirements of energy (calories) for children aged 0 to 18 years

 

0-12 months 1-3 years 4-6 years 7-10 years 11-14 years 15-18 years
Girls (kcal/day) 515-865 1165 1545 1740 1845 2110
Boys (kcal/day) 545-920 1230 1715 1970 2220 2755

 

Vitamins

The most important vitamins in a pear are vitamin A in the form of beta-carotene, vitamin C, also known as ascorbic acid, and the B vitamin folate, often referred to as folic acid.

Vitamin A is a fat soluble vitamin stored in the liver, with one medium pear containing 21µg of beta-Carotene. This is essential for the synthesis of rhodopsin, a light sensitive biological pigment in the eye which aids vision, often referred to as the night vision vitamin 12. It is also involved in growth, cell differentiation, the development of bone and is required for healthy immune function 12. Beta-carotene is an important antioxidant, along with ascorbic acid and vitamin E, which aid in the prevention of cellular damage caused by free radicals 13. Free radicals are unstable electrons which react with cell membranes and DNA causing damage and even cell death. The antioxidants pair with these unstable electrons, terminating any further damage, therefore aiding in the protection against possible cardiovascular disease and cancers. These antioxidants cannot be made by the body therefore are essential in the diet 14. However, a high consumption of Vitamin A is toxic, and it is particularly important pregnant women do not exceed the RNI shown in Table 1, as this may harm their unborn baby. Watching the level of vitamin A consumed can be done by simply avoiding a high consumption of red meat, liver and liver products, along with avoiding vitamin A supplementation.

One pear contains 4.5mg of vitamin C, 11% of the RNI for adults. Along with its antioxidant role previously mentioned, vitamin C is a water soluble vitamin required by the body, which is stored in the liver and body tissues only in very limited supplies, making it essential in the diet. Vitamin C is involved in many body processes, but has a significant role in helping with the correct functioning of the immune system and the production of the protein collagen, required for the healthy functioning of blood vessels, ligaments and our skin 4. It is important to note that Vitamin C is also important for its role of enhancing iron absorption when consumed in the same meal, particularly important for those with low levels and those who have iron deficiency anaemia.

Folate, often mistaken for its synthesised partner folic acid, is found naturally in foods. It is required by the body for the formation of red blood cells, with the help of vitamin B12 and is involved in many other processes, needed for healthy functioning 12. One pear contains 9µg of folate, which is 4.5% of the RNI for adults. Although this seems a small amount, folate has been linked to a reduced risk of heart disease and stroke, due to its role in reducing homocysteine levels. Homocysteine is an amino acid which can cause atherosclerosis, blood vessel damage, at high levels 15.

Minerals

The four main minerals a pear contains are potassium, calcium, magnesium and phosphorus, which are inorganic substances which are needed in small amounts for healthy functioning of the body. A pear contains 157.5mg of potassium, a mineral significant for its role in nerve functioning, muscle contractions, acid-base balance and the balance of water and electrolytes 16. It has been well established that a high potassium diet in combination with other major health messages, can help in lowering blood pressure, therefore aiding in the prevention of cardiovascular disease 17. One pear contains 10.5mg of calcium, an abundant mineral essential for blood clotting, muscle contractions and nerve impulse transmissions 16. Calcium is present mainly in the bone and is required for the formation of bone and teeth, with the help of vitamin D and vitamin K 18. You may have heard calcium is essential for the maintenance of healthy bones, which is very true as an adequate amount of calcium included in the diet, in addition to regular physical activity, is essential to maintain healthy bodily functions and help reduce the risk of osteoporosis later in life. Your bones reach their maximum strength around the age of 30, known as peak bone mass, therefore it is so important the maximum amount of bone strength is achieved before this and is maintained after this period, through a calcium rich diet and activity 19. Phosphorus is also present in bone, with the remaining 15% present in soft tissues. Along with calcium, phosphorus is essential for the strength and structure of our bones, teeth and cells, and low levels can lead to muscle weakness, bone pain, rickets and osteomalacia 16. One pear contributes to the RNI of phosphorus by providing 13.5mg. One pear contains 7.5mg of magnesium, around 2.5% of the RNI for adults. Although this seems small, magnesium is required for many body processes as it activates enzymes and hormones needed for the metabolism of bone, in addition to aiding muscle and nerve function 16 18.

Tips for choosing the best pear

Once a pear is ripe, it becomes perishable and bruises very easily. To avoid this, it is advised that they are stored in a cool place, such as the fridge, until they ripen. It is likely ripe pears will be sold in the supermarket along with overripe and under ripe pears, therefore to ensure the pear is not overripe, simply press gently on the top of the pear near the stem, and make sure it does not leave a large pressure mark, which is a sign of the fruit being overripe, and if the pear feels extremely soft, this may also be a sign of the pear being overripe and squishy in texture. It is important to check the pear you select does not have any bruises and dark soft patches, as this will affect the taste and quality. Prior to eating, ensure the pear has been washed and dried to remove any dirt or pesticide residue, as the skin is highly nutritious and contributes to the texture of the fruit. If you wish to cut the pear into smaller pieces, remember the pear will quickly turn brown in colour, due to its exposure to oxygen, and can be prevented by mixing the pear slices with acidic juices such as lemon, lime or orange juice. If you’re not a fan of fresh, raw fruit on its own, then why not try tinned pears in juice or syrup, or cooked pears to add to a dessert, or simply add them to porridge in the morning to add a sweet juicy flavour. The options are endless, but it is best to eat pear whilst it is fresh to get the optimum nutritional benefits discussed, and remember, health is key!

 

References

 

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  3. Food Standards Agency and Public Health England (2014).McCance and Widdowson’s the Composition of Foods. 7th Cambridge: Royal Society of Chemistry.
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  5. Department of Health (1991). Dietary Reference Values for Food and Nutrients for the United Kingdom. London: HMSO.
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  8. British Dietetic Association (2016). Food Fact Sheet: Fibre. [Online]. [Viewed on 27 March 2017]. Available from: https://www.bda.uk.com/foodfacts/fibrefoodfactsheet.pdf
  9. Sass, C (2017). What’s the Difference Between soluble and Insoluble Fiber? [Online]. [Viewed 26 March 2017]. Available from: http://www.health.com/nutrition/types-of-fiber
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  11. Goff, L. and Dyson, P (2016). Advanced Nutrition and Dietetics in Diabetes. 1st West Sussex: Wiley Blackwell.
  12. Gropper, S. S and Smith, J. L (2013). Advanced Nutrition and Human Metabolism. 6th Australia: Wadsworth Cengage Learning.
  13. Rickus, A and Saunder, B (2009). OCR Home Economics for A2 Food, Nutrition and Health Today. 1st London: Hodder Education.
  14. Lobo, V., Patil, A., Phatak, A and Chandra, N (2010). Free radicals, antioxidants and functional foods: Impact on human health. Pharmacognosy Review. December, vol. 4, no. 8, pp. 118-126.
  15. British Dietetic Association (2016). Food Fact Sheet: Folic Acid. [Online]. [Viewed on 27 March 2017]. Available from: https://www.bda.uk.com/foodfacts/FolicAcid.pdf
  16. Barasi, M. E (2003). Human Nutrition: A Health Perspective. 2nd London: Hodder Arnold.
  17. Blood Pressure Association (2008). Salt and blood pressure: Cutting down on the white stuff could you’re your life. [Online]. [Viewed 29 March 2017]. Available from: http://www.bloodpressureuk.org/microsites/salt/Home/Whypotassiumhelps
  18. British Nutrition Foundation (2017). Minerals and Trace Elements. [Online]. [Viewed on 27 March 2017]. Available from: https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/minerals-and-trace-elements.html?showall=1&limitstart=
  19. Bonjour, J. P., Theintz, G., Law, F., Slosman, D and Rizzoli, R (1994). Peak bone mass. Osteoporosis International. 4, no. 1, pp. 7-13.