Consumption of raw fruits and vegetables. How safe are we?
The intake of raw fruits and vegetables is indeed sometimes the best and healthier option, considering the benefit of enjoying in entirety all the rich store of vitamins, minerals and other plant chemicals (phytochemicals) found in these food groups.
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This is mainly due to the conservation of these essential nutrients which could otherwise be lost to heat or high temperatures used during cooking or processing.
In sub-Saharan Africa, including Ghana, where there is nutrient insufficiency from animal and diary sources, fruits and vegetables consumption is proposed as alternative source of micronutrients including essential vitamins such as vitamin A, B and C and key minerals like iron. Low consumption of fruits and vegetables accounts for increased chronic diseases such as heart diseases and strokes. The World Health Organisation (WHO) estimated that 2.6 million deaths could be averted by adequate fruits and vegetables consumption.
Health benefits of fruits and vegetables
Include the following:
- Their antioxidants properties reduce the risk of cancer.
- Their high fibre content lowers caloric intake and weight, manages and reduces risk of diabetes, constipation and colon cancer.
- Their high mineral content (magnesium and potassium) reduce risk of hypertension, heart attack and stroke. The potassium content reduces the risk of kidney stones and decreases bone loss.
- Their high vitamin content protect against several micronutrient deficiencies.
Though there is minimal loss of nutrients in raw fruits and vegetables consumption, major concerns have been raised regarding their safety, such as:
(a) EFFECT OF PRE-HARVEST ACTIVITIES
Fertilisers and pesticides are used in crop production to improve yield and quality due to increased food demand. However, wrongful use can be detrimental to health as farmers and consumers are exposed to health hazards due to their toxic residues. The Ghana Environmental Protection Agency categorised these pesticides into three: general use, restricted use and banned pesticides.
Organochlorine pesticides such as DDT and lidane are banned, yet they are still in use due to weak import controls and inadequate monitoring. The indiscriminate use of pesticides, especially during fruiting and pre-harvesting stages, and non-adoption of safe waiting periods have led to pesticide residues accumulating in the produce. These residues in fruits and vegetables are more apparent as they are mostly eaten raw. Here are some consequences:
- Acute effects such as dizziness and diarrhoea.
- Chronic health effects like cancer, birth defects, infertility, brain, nervous, immune systems and organ damage.
Additionally, the production of fruits and vegetables in Ghana depends on the quality of water used. Water is used during chemical application, irrigation and food processing. The use of waste water in the production of fruits and vegetables may be acceptable; however, farmers are required to allow a waiting period of two weeks before harvest to ensure reduction in microbial load. Unfortunately, this is not observed by some farmers due to inadequate knowledge and poor supervision by regulators. Consequently, produce are contaminated, although they appear fresh. The associated risk is the spread of microorganisms such as Escherichia coli, Salmonella and hepatitis A virus.
(b) EFFECT OF POST-HARVEST ACTIVITIES
Additives such as mineral oils, colours and some waxes used on fruits and vegetables to give a fresh, attractive appearance is prohibited. However, bee, carnuba and shellac waxes are allowed for coating fresh fruits in accordance with regulations.
Chemicals such as calcium carbide, ethephon and oxytocin are used to force-ripen fruits and vegetables against the standards. Carbide, for instance, is carcinogenic. However, ethylene gas, a fruit ripening plant hormone, is acceptable when used in low concentration of 10-100 ppm exogenously.
Ripened produce can be identified as artificial or natural by placing them in water. Sinking to the bottom indicates natural maturity. Artificial ones usually float, lack colour uniformity, are poor in flavour and less sweet.
Again, it is common to see ready-to-eat fruits and vegetables sold in plastics. The water used in cleaning these produce during processing for supermarkets contain chlorine which can reduce vitamins content. Furthermore, injuries during harvesting and excessive heat from the sun during marketing and at storage result in vitamin loss.
Evidenced-based recommendations to safety of raw fruits and vegetables:
- Select produce without spots or lesions.
- Peel fruits and vegetables and discard outer leaves of leafy-vegetables such as cabbage before consumption to reduce pesticides residues. Wash fruits and vegetables with potable water and vinegar or salt but not detergents; before eating, cutting or cooking.
- For produce with thick skin such as carrots, use brush to help wash away hard-to-remove microbes.
- For produce with lots of nooks and crannies such as cauliflower or lettuce, soak for one to two minutes in cold water.
- Vegetables to be eaten raw at homes or sales outlet should be preserved in a refrigerator or in ice to prevent microbial growth.
- Avoid buying and consuming cut fruits from open markets.
Conclusion
To a large extent, one’s safety in the consumption of raw fruits and vegetables in Ghana depends on safety measures from farm to plate. To ensure quality, individuals are encouraged to grow their own vegetables and fruits at home using container-gardens where land is not available.
The WHO recommended per capita intake of 400g per capita per day is equivalent to five servings of fruits and vegetables daily. For adequate intake, in any state of health, guidance must be sought from a registered dietician.
