The toothpaste ingredient some Kenyans are avoiding

The introduction of fluoride in toothpaste and mouthwash has been credited with a sharp decline in tooth cavities.

In Kenya, as in much of the world, fluoride remains a central ingredient in most toothpaste brands. But in recent months, amid the rise of digital health influencers and alternative wellness movements, fluoride — once universally hailed as a public health triumph — has become a topic of renewed scrutiny.

Claims shared across TikTok, WhatsApp, and X (formerly Twitter) allege that fluoride may be harmful to human health, linking it to conditions such as hormonal disruption, weakened bones, kidney dysfunction, and discoloration of teeth. While many of these claims are not supported by science, their viral nature has prompted some Kenyan consumers to abandon fluoridated toothpaste in favor of “herbal” or “fluoride-free” alternatives.

Fluoride is a naturally occurring mineral found in water, soil, food, and air. It has long been recognised for its role in strengthening enamel — the hard outer surface of the tooth — and preventing tooth decay by making teeth more resistant to acid produced by bacteria in the mouth.

The introduction of fluoride in oral health products such as toothpaste and mouthwash has been credited with a sharp decline in cavities in countries where its use is widespread.

Toothpaste with fluoride concentrations of between 1,000 to 1,500 parts per million (ppm) is considered effective in reducing cavities. Most major toothpaste brands in Kenya fall within this range.

While concerns about fluoridated toothpaste are making rounds online, Kenya’s real fluoride issue has always stemmed from its water sources. These naturally high fluoride levels in water, especially in the Rift Valley, have sparked concerns among some Kenyans that adding more fluoride through toothpaste could further compound the risk. Yet, experts caution that this perspective oversimplifies the issue.

What Science Says

Dr Olive Akunga, a consultant physician and medical epidemiologist, emphasises that the health impacts of fluoride depend primarily on total exposure and method of intake.

“Fluoride is a common component in oral hygiene products such as toothpaste and mouthwash due to its well-documented efficacy in prevention of dental caries,” Dr Akunga said. “Additionally, public water fluoridation in several settings promotes community-wide dental health, where the tolerable upper intake level (UL) for fluoride is 10 mg/day for adults, but much lower levels are recommended for young children to avoid toxic effects.”

She added that at high concentrations — especially when ingested — fluoride can indeed cause dental fluorosis, and in extreme cases, skeletal fluorosis. There are also studies, she notes, that have loosely associated excessive fluoride with other health risks.

“Despite the benefits, fluoride toxicity has also been linked with skeletal fluorosis. Other inconclusive studies have also associated excessive fluoridation with brain, kidney and thyroid toxicity,” she said. “The recommendation is to ensure that public water and oral hygiene products adhere to safe concentrations of the fluoride constituents.”

Crucially, she explained that topical use of fluoride in toothpaste — which is not swallowed — is very different from consuming fluoride through water or food. “When used correctly, fluoridated toothpaste poses no significant health risk.”

Dr Olive Akunga, a consultant physician and medical epidemiologist

The Kenya Bureau of Standards (KEBS) is the body mandated with regulating the composition and labeling of consumer products, including toothpaste. While KEBS follows international guidelines, including those of the Codex Alimentarius and ISO standards for oral care products, its specific fluoride content thresholds for toothpaste are not readily available on public platforms.

Internationally, multiple scientific reviews have reaffirmed the safety of fluoride in toothpaste when used as recommended.

Regulation of Fluoride in Kenya

While fluoride is beneficial in small amounts, studies reveal that excessive exposure can lead to dental fluorosis, a cosmetic condition that causes white or brown stains on teeth.

Kenya does not currently fluoridate its public water supplies. However, several parts of the country — including Baringo, Nakuru, parts of Nairobi, and the wider Rift Valley — are known to have groundwater with naturally occurring fluoride levels that exceed the World Health Organization’s recommended limit of 1.5 mg/L. In some cases, fluoride levels in borehole water have been recorded at over 10 mg/L.

In 2021, Davis & Shirtliff, a leading water and energy solutions company, released data showing that up to 70 per cent of boreholes tested in Nakuru and surrounding areas had fluoride levels above the recommended threshold. In these regions, dental fluorosis is visibly common among both children and adults, particularly in communities that rely on untreated borehole water.

The Ministry of Water, Sanitation and Irrigation has previously acknowledged these concerns, and in some counties like Nakuru, efforts have been made to blend high-fluoride water with safer supplies.