Pregnant women who drink milk regularly could help their children avoid osteoporosis later in life. New research shows teenagers are more likely to have strong bones if their mothers drank milk every day.The findings are significant because bone mass starts to decline in your 20s. But while dairy foods have long been linked to healthier bones, it has been less clear whether the mother's diet during pregnancy had much impact. In the study, Tasmanian researchers measured the bone density of 216 teenagers. Their mothers had taken part in a study in the late eighties, during which they gave details of their diet during pregnancy. The results showed that those born to mothers with the highest milk intake had the strongest bones. But those born to women who drank little milk and ate fatty foods, such as burgers and chips, during pregnancy had lower bone density. Tackle knee pain with gentle sound waves are being used to treat knee pain caused by osteoarthritis. In a new clinical trial, low intensity ultrasound therapy is being prescribed to men and women with mild or moderate knee osteoarthritis.The theory is that the therapy boosts the thickness of knee cartilage, improving its cushioning effect and reducing pain. This follows small studies, which have suggested that up to 40 per cent of people might benefit, though big improvements - up to 30 per cent - have also been seen in people who had placebo treatments. Other research has shown that ultrasound increases blood flow in the treated area, which speeds the healing process, and also reduces swelling, which is one of the main sources of pain. In the new trial at McMaster University in Ontario, Canada, patients will have 24 sessions of the therapy. Could fish oil reduce asthma symptoms? Fish oil could be a new treatment for asthma. In a trial, doctors are prescribing five high-dose fish oil capsules a day for three weeks to sufferers with mild symptoms. It follows smaller studies that found fish oil supplements can help prevent coughing, constriction of the airways and wheezing. If successful, the oil, which doesn't appear to have side-effects, could be an alternative to the standard treatment, inhaled steroids, or reduce the dose needed. The fish oil treatment could be particularly helpful to long-term asthma users who can experience distressing side-effects from steroids, such as weight gain, increased bruising and hoarseness. It's thought the benefits are down to the fatty acids (omega-3s) found in fish oil, which have an anti-inflammatory effect, say the researchers at the Firestone Institute for respiratory Health in Canada. Fish rich in omega-3 include salmon, tuna, mackerel, herring and sardines.