When it comes to choosing baby formula milk, parents should focus on the stability of the supply rather than the manufacturers' descriptions of ingredients, the Consumer Council says. Descriptions of beneficial ingredients might be misleading or exaggerated, the council warned. Some nutrients are not essential for babies; others are used by most producers, making their products similar. While individual studies show commonly used ingredients - such as probiotics, soluble fibres, DHAs (docosahexaenoic acids), AA (arachidonic acids), and PhD (phospholipids) - have beneficial effects, further research is needed to confirm whether they should be used routinely in infant formula milk, the watchdog says. 'At the moment, experts tell us that not all of the claims can be supported by clinical studies,' Ambrose Ho Pui-him, chairman of the council's publicity and community relations committee, said yesterday. Producers claim 'probiotic' ingredients boost the digestive or immune system of babies, but clinical studies do not support that, according to the department of paediatrics and adolescent medicine at the University of Hong Kong. Instead, consumers should choose brands with a stable supply, Ho said, ensuring an infant was not fed different formulas. The Society of Hospital Pharmacists of Hong Kong said various studies had reached different conclusions about the effects of DHA and AA on brain and eye development. The Hong Kong Infant and Young Child Nutrition Association, a lobby group for infant formula milk producers, said its members had been spending US$3.18 billion annually on scientific research. The group said that its members conducted 205 clinical studies last year. A spokesman said all formula milk advertisements were reviewed by the appropriate regulators before broadcast, and they had been deemed as accurate and appropriate. Separately, a Consumer Council test shows that laundry balls - advertised as a cheaper and more environmentally friendly substitute for detergent - have no greater cleaning power than water. The watchdog tested three types of laundry balls, priced between HK$29 and HK$560, which failed to prove claims that they last between 60 and 1,000 laundry cycles.