The cardiovascular effects of the omega-3 fats present in oily fish are well-known. Now a new study points to a benefit for bone health.

Researchers from Ume?niversity in Sweden recruited 78 healthy young men, with an average age of 17 years, from high schools and sports clubs. Bone density – a measure of the strength and health
of bones – was then measured using a highly accurate whole body scanner called DEXA (dual energy X-ray absorptiometry). Blood samples were collected to establish circulating levels of different
types of fats. The men were followed up, on average 8 years later, in order to repeat these measurements.

It was found that blood concentrations of long-chain omega-3 fats, especially docosahexeanoic acis (DHA), were positively linked with bone density, particularly in the spine. The annual rate of
bone accrual in the spine was also linked with blood omega-3 fat concentrations.

This study supports previous research suggesting that diets high in omega-3s and relatively low in omega-6s (e.g. from margarine and vegetable oils) seem to protect bone structure. Long-term
loss of bone density is a key step in the development of osteoporosis – a condition that affects around 75 million people, mainly older women, living in Europe, the USA and Japan. Treating
osteoporotic fractures in Europe costs nearly €31.7bn a year, according to the International Osteoporosis Foundation.

Prevention of osteoporosis depends upon young people maximising their bone density early in life as this can guard against the inevitable bone losses later in life. Current lifestyle advice
includes ensuring an adequate intake of calcium and vitamin D, and taking regular weight-bearing exercise. Research also points to a positive impact of the prebiotic fibres, inulin and
oligofructose (which are used by beneficial gut bacteria as food for their growth). Clinical studies are now needed to establish whether increased consumption of long-chain omega-3 fats can be
added to this advice.

H?r? et al (2007). n-3 fatty acids are positively association with peak bone mineral density and bone accrual in healthy men: the NO2 study. American Journal of Clinical Nutrition, vol 85,
pp 803-807.