Testing the health claims for fermented dairy products

Researchers have reviewed the scientific basis of claims that fermented dairy foods can act as a treatment for hypertension.

“Fermented milk has been promoted as a nonpharmacological treatment for hypertension, mainly because of the lack of undesirable side effects, but as yet, there is insufficient evidence to support this according to the European Food Safety Authority (EFSA),” lead investigator Belinda Vallejo-Córdoba, PhD, of the Center for Food Research and Development, Sonora, Mexico, explained.

Reporting in the Journal of Dairy Science, the team of investigators established that the most common strategy to select fermented milks with antihypertensive potential was to identify angiotensin-converting-enzyme (ACE) inhibitory peptides by in vitro studies. However, they observed that some strains inhibiting ACE activity in vitro did not reduce blood pressure in rats. They evaluated 13 studies with spontaneously hypertensive rats and seven randomised controlled clinical trials in which an antihypertensive effect was demonstrated. Most were based on Lactobacillus helveticus.

The investigators note that several fermented milk products already on the market attribute their antihypertensive effect to the bioactive peptides present in the fermented milk. However, they point out that these products may also contain minerals such as potassium and calcium, which may have a positive effect on blood pressure.

“Although much research related to antihypertensive peptides has already been done, there is a great need for exploration of new lactic acid bacteria that possess the ability to generate this bioactivity as well as good technological properties for the production of fermented dairy products,” Dr Vallejo-Córdoba commented.

The authors recommend future studies to include in vitro lactic acid bacteria screening for ACE-inhibitory effects, in vivo studies with spontaneously hypertensive rats and clinical trials to test the efficacy of the fermented milk product. “It is also important to develop the regulatory legislation that allows the introduction of health claims for functional dairy foods, especially in countries where this subject is underdeveloped,” Dr Vallejo-Córdoba concluded.