by Craig Weatherby

Swedish study finds bone benefits in boys who eat ample omega-3s; Findings underscore the bone-density harm done by diets high in omega-6 fats

Evidence that omega-3 fatty acids help build strong bones—while Americans' excess omega-6 fat intakes blunt bone strength—keeps growing.

New findings from Sweden suggest that the bones of boys who eat more omega-3 fatty acids and fewer omega-6 fats than average tend to build denser, stronger bones.

The evidence in favor of omega-3s for bones has been building for many years.

Four years ago, a population-diet study showed that the hip bones of older people who ate lots of omega-6 fatty acids and few omega-3s—the typical American diet pattern—were less dense and more prone to fracture.

In contrast, people who consumed more omega-3s and fewer omega-6s had denser, stronger bones (see “Omega-3s Seen as Stellar Bone-Builders”).

And two years ago, a Swedish study indicated that young men's bones benefit from diets higher than average in omega-3 fatty acids and lower than usual in omega-6 fatty acids. (See “Omega-3s May Build Young Boys' Bones”.)

Those findings were especially credible because the researchers took blood samples to determine the participants' omega-3 and omega-6 fat intakes, rather than relying on diet questionnaires to estimate the young men's intake levels.

Now, findings from a second Swedish study appear to extend the benefits of a high omega-3/omega-6 dietary intake ratio to third-grade boys.

Omega-3s aid boys' bones; An excess of omega-6s thins them
A team from Sweden's University of Gothenburg analyzed markers for bone mineralization density in 85 eight-year-old boys (Eriksson S et al. 2009).

The results showed that the boys with higher omega-3 intakes had better bone mineral density—a sign of sturdier bones— while those with lower omega-3 intakes and higher omega-6 intakes had lower bone density.

These outcomes provide yet another reason to include healthy fish fats into children's diets, while underscoring the downsides of diets that are, like most Americans' diets, overly high in omega-6 fats.

And the findings of a previous study among the same group of children dent the bone-health reputation of milk.

Contrary to popular belief and the ad campaigns of the National Dairy Council, (Eriksson S 2009), it appears that “full-fat” milk may harm bone health.

The Swedish researchers found that children who consumed full-fat milk regularly had lower bone mineral density readings, compared to those who seldom or never drank milk.

These finding are likely due to the high concentration of omega-6 fatty acids found in full-fat milk... especially milk from standard, grain-fed dairy cows. (Milk from dairy cows fed more on pasture than grain tends to have higher levels of omega-3s, and fewer omega-6 fats.)

Omega-6 fats reduce bone density by activating a certain receptor (PPAR-gamma) in bone marrow cells.

Omega-6s abound in standard grain-fed meats and poultry, and predominate in the most commonly used vegetable oils (soy, corn, canola, sunflower), and in most processed and takeout foods containing vegetable oils.

And research shows that we are eating too many of these essential fats for our own good.

For more on that subject, see “Report Finds Americans Need More Omega-3s and Less Omega-6s” and search our newsletter archive for “omega-6”.

  • Eriksson S, Mellström D, Strandvik B. Fatty acid pattern in serum is associated with bone mineralisation in healthy 8-year-old children. Br J Nutr. 2009 Aug;102(3):407-12. Epub 2009 January 28.
  • Eriksson S. Studies on nutrition, bone mineralization and metabolic markers in healthy 8-year-olds in an urban Swedish community. ISBN 978- 91-628-7847-4. Intellecta Infolog, Göteborg, 2009. Accessed online October 2, 2009 at
  • Högström M, Nordström P, Nordström A. n-3 Fatty acids are positively associated with peak bone mineral density and bone accrual in healthy men: the NO2 Study. Am J Clin Nutr. 2007 Mar;85(3):803-7.
  • Weiss LA, Barrett-Connor E, von Mühlen D. Ratio of n-6 to n-3 fatty acids and bone mineral density in older adults: the Rancho Bernardo Study. Am J Clin Nutr. 2005 Apr;81(4):934-8.