Nine in 10 raw milk samples tested in Malawi’s informal markets contained added water and chemical neutralisers, exposing widespread adulteration that cheats consumers and raises concerns over food safety.
A study of 384 raw milk samples from Lilongwe, Thyolo and Karonga found that 350 contained added water, while the same number tested positive for neutralisers used to counter acidity. Fourteen samples contained urea, with some containing multiple adulterants.
The findings suggest that consumers may be paying for milk whose nutritional value has been reduced, while potentially exposing themselves to health risks from contaminated water, unsafe chemical additives and bacteria in poorly handled raw milk.
Titled Patterns of Raw Milk Adulteration in Informal Markets in Malawi: A Multivariate Statistical Analysis, the study was conducted by four researchers affiliated with Mozambique’s Eduardo Mondlane University, Malamulo College of Health Sciences and the Lilongwe University of Agriculture and Natural Resources (LUANAR).
The study was conducted between June and September this year and its findings were published in the journal Dairy on October 1, 2026.
Lilongwe recorded the highest prevalence of water adulteration, with all 78 samples tested containing added water. Neutralisers were particularly prevalent among vendor samples in Thyolo and Karonga.
The researchers also found that milk purchased from vendors was more likely to contain added water and neutralisers than milk obtained directly from farmers.
“Coupled with the predominant sale of milk in informal markets and an untraceable dairy supply chain, this exacerbates exposure of Malawians to chemical hazards, especially milk adulteration,” the study reads.
Milk adulteration is often driven by the desire to increase volumes and maximise profits. Adding water allows sellers to sell more milk without increasing production, while neutralisers can mask rising acidity associated with deterioration. Urea may also be used to manipulate theApparent composition of diluted milk.
However, these practices undermine the nutritional value and integrity of a product consumed by households, including children, as a source of protein, fat, calcium and other essential nutrients.
Public health expert and Kamuzu College of Health Sciences professor Adamson Muula said in an interview yesterday dilution reduces milk’s nutritional value, particularly its fat content, while unsafe water can introduce disease-causing organisms.
“When selling milk, we want nutrition. But when it is diluted, that milk lacks fats. Apart from that, there is a risk of people contracting diseases such as diarrhoea,” he said.
The health risks extend beyond nutritional loss. Water contaminated with faecal matter or other pathogens can transmit infections, while consuming contaminated raw milk can cause foodborne illnesses associated with bacteria such as E. coli, Salmonella and Campylobacter. Symptoms can include diarrhoea, vomiting, abdominal pain and fever. Severe infections can cause dangerous dehydration and, in some cases, kidney complications, particularly among young children and other vulnerable groups.
Consumer health activist Madziko Matemba warned in an interview yesterday that chemical substances used to neutralise acidity could mask signs of spoilage without necessarily eliminating harmful bacteria.
Malawi’s Milk and Milk Products Regulations prohibit dealing in adulterated milk, while the Public Health Act prohibits the sale of adulterated, contaminated or unwholesome food.
However, the researchers noted that routine testing of raw milk for chemical adulterants is not mandatory and that detection often relies on visual inspection. They also highlighted the absence of certification for small-scale milk producers and vendors, making it difficult for consumers to establish the quality and safety of the milk they purchase.
Consumers Association of Malawi executive director John Kapito blamed weak regulatory monitoring and enforcement for allowing the practice to persist.
He said regulatory systems that previously monitored milk quality, including veterinary officers responsible for inspection and enforcement, had weakened.
Kapito said consumers could not reliably determine whether milk had been diluted simply by looking at it, making routine inspections and quality testing at points of sale essential.
Consumer activist Wazamazama Katatu said the findings exposed weaknesses in consumer protection and raised questions about the effectiveness of institutions responsible for food safety.
He urged government and regulatory agencies to use the findings to review their operations and strengthen enforcement of food-safety standards.
The findings put the spotlight on the need for regular testing, traceable milk supply chains, effective inspection of vendors and stronger action against those who adulterate food for profit. For consumers, the challenge is not simply to identify watered-down milk, but to have confidence that the milk sold to them is safe, nutritious and worth the price they pay.
