•Ugu (Pumpkin leaves)
Citing unhygienic conditions and the risk of contamination, nutrition experts have asked Nigerians to stop having vegetables sliced in open markets without first washing them.
Apart from increasing the risk of food poisoning, the nutritionists warned that slicing vegetables in open markets before washing them could lead to the loss of vital nutrients and introduce harmful microorganisms into the body due to poor hygiene.
The food safety experts explained that vegetables should be washed under running water before being cut and handled with the utmost care, from the point of harvest to the consumer’s plate, reports Sunday PUNCH.
It is common to see Nigerians ask vegetable sellers to slice their vegetables at the point of purchase, whether in markets or by the roadside, a practice that raises hygiene and food safety concerns.
The World Health Organisation says unsafe food contaminated with harmful bacteria, viruses, parasites or chemical substances can cause more than 200 diseases, ranging from diarrhoea to cancer.
The global health body, in June 2026, disclosed that unsafe food causes 866 million illnesses and 1.5 million deaths annually, with young children at the highest risk.
“Unsafe food results in a vicious cycle of disease and malnutrition, particularly affecting infants, young children, older people and the sick,” the WHO said.
It noted that children under five face almost three times the risk of illness from unsafe food compared with older children and adults.
Speaking in an exclusive interview with our correspondent, a registered dietician-nutritionist and Assistant Director of Dietetics, Lagos State Health Service Commission, Olusola Malomo, said there were serious hygiene concerns associated with slicing vegetables in the open market before washing them.
Malomo described the practice of slicing vegetables before washing them, especially in open places such as markets, as unhealthy, warning that it could cause food poisoning.
“It is unhealthy to slice vegetables in the market without washing them first. First, let us look at the environment of the open market; obviously, it is unsafe.
“Now, when you get home to wash them, some of the vital nutrients will escape, and you will not get the actual amount of nutrients in the vegetable. So, the nutrients are washed away with the water”, he explained.
The dietician further noted, “When you do a qualitative analysis of the vegetables sliced in the market and washed, and those that were bought, brought home and washed before slicing, you will find that the ones that were washed before slicing have more nutrients than those that were sliced in the market before washing.
“Some even bring these vegetables home and cook them without washing, thereby eating contaminated food. For us to eat healthily, we must wash our vegetables before slicing them.”
The nutritionist noted that some of the vegetables might have been exposed to chemical fertilisers, insecticides and pesticides on the farm a few days before being taken to the markets.
“That is the reason we discourage slicing vegetables right at the point of purchase in the market.
“Some of these chemicals may be trapped in the vegetables, and when they get into the body, they can be harmful.
“Again, anything could have happened in the process of slicing because of the seller’s hygiene.
“He or she cannot maintain good hygiene in that open market. If you look at the environment in the open market, bacteria can contaminate the vegetables. This will not be beneficial to the body because the vegetables may introduce microorganisms into the body,” he said.
Malomo reiterated that slicing vegetables before washing them had nutritional and health implications and should therefore be discouraged.
Another Registered Dietician-Nutritionist, Nwabumma Asouzu, said raw vegetables could be contaminated by physical agents, including sellers whose hands might not be clean or who might have obtained the vegetables from an unhygienic environment.
“Other sources of contaminants, such as faecal matter, parasites, maggots, insects, sand and even small pieces of stones, can be introduced in the process.
“Another risk of this wrong practice is possible food poisoning from Salmonella, E. coli, Cryptosporidium, Listeria, etc. All vegetables should be treated with the utmost care, from the point of harvest to the consumer’s plate.
“Vegetables generally should be handled carefully as they contain antioxidants that can be lost when cut or mishandled. So, never buy damaged or bruised fresh vegetables,” the dietician said.
Asouzu said there could also be nutrient losses in cut vegetables, including ascorbic acid, B vitamins and folate.
Listing ways to prepare vegetables and make them safe for consumption, the food expert said, “Add a little quantity of salt, wash, and then rinse all vegetables under running tap water or clean water. While rinsing under running tap water, rub or scrub firm-skinned vegetables with a clean vegetable brush.
“Never use detergent or bleach to wash fresh fruits and vegetables, since these products are not consumable. When shopping, separate fresh vegetables from household chemicals and raw foods, such as meat, poultry and seafood.
“During preparation, remove and discard bruised or damaged portions of vegetables before cooking.”
