Just Omega

Research -> Physiological Benefits

Bone and Joint Health

Excessive omega-6 relative to omega-3 intake may lead to lower hip bone density, study suggests

Omega-3, role in bone health and applications

Preliminary study suggests that fish oil may prevent bone loss in people with rheumatoid arthritis

Bhattacharya A, Rahman M, et al. Inhibition of Osteoporosis in Autoimmune Disease Prone MRL/Mpj-Faslpr Mice by N-3 Fatty Acids. J Am Coll Nut, 2005; 24(3)200-209

Objective: Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disease involving the breakdown of cartilage and juxta-articular bone, which is often accompanied by decreased bone mineral density (BMD) and increased risk of fracture.
Anti-inflammatory omega-3 fatty acids may prevent arthritis and bone loss in MRL/lpr mice model of arthritis and in humans.

Methods: In this study, the effect of long term feeding of 10% dietary n-3 (fish oil (FO)) and n-6 (corn oil (CO)) fatty acids begun at 6 weeks of age on bone mineral density (BMD) in different bone regions in an MRL/lpr female mouse model of RA was measured at 6, 9, and 12 months of age by dual energy x-ray absorptiometry (DEXA).

After sacrificing the mice at 12 months of age, antioxidant enzyme activities were measured in spleen, mRNA for receptor activator of NF-B ligand (RANKL) and osteoprotegerin (OPG) was measured by RT-PCR in lymph nodes, and synovitis was measured in leg joints.

Results: At 6, 9 and 12 months of age, BMD was significantly higher (p < 0.05) in distal femur, proximal tibia, and lumbar spine of FO fed mice than those of CO fed mice. Spleen catalase (CAT) and superoxide dismutase (SOD) activities were also significantly higher (p < 0.01) in FO fed mice than in CO fed mice.

Histology of knee joints revealed mild synovitis in CO fed mice, which was not present in FO fed mice. RT-PCR analysis of lymph nodes revealed decreased RANKL mRNA (p < 0.001) expression and enhanced OPG mRNA expression (p < 0.01) in FO fed mice compared to CO fed mice.

Conclusions: These results suggest beneficial effects of long-term FO feeding in maintaining higher BMD and lower synovitis in this mouse model.
These beneficial effects may be due, in part, to increased activity of antioxidant enzymes, decreased expression of RANKL, and increased expression of OPG in FO fed mice thereby altering the RANKL/OPG ratio.

These significant beneficial effects on BMD suggest that FO may serve as an effective dietary supplement to prevent BMD loss in patients with RA.

Observations made between Omega-3s and periodontal health

News - Improved omega-3: omega-6 ratio helps prevent bone loss

Essential fats may prevent bone loss. USA Today. Vol. 134, No. 2725, pp 15(1)

Maintaining a proper balance of dietary fats may ward off much of the bone loss associated with postmenopausal osteoporosis, states a study by scientists at the Indiana University School of Medicine, Bloomington, and Purdue University, West Lafayette, Ind.

The researchers found that diets with a low ratio of omega-6 fatty acids to omega-3 fatty acids minimizes the bone loss typically brought on by estrogen deficiency, which is common in post-menopausal females.
Omega-6 is found in foods such as grains and beef, while omega-3 is contained in products like walnuts and salmon.

"Many people don't realize it, but our bones are not static structures," explains Mark Seifert, professor of anatomy and cell biology at Indiana University.
Bones undergo a process called "remodeling," in which they continuously are broken down and rebuilt.
Two types of cells govern this process--bone resorption cells, which remove small portions of bone, and bone building cells, which fill in the gaps.
Estrogen blocks some of the inflammatory compounds associated with bone resorption, which may explain why osteoporosis typically progresses after estrogen levels fall with the onset of menopause.

"Our lab and others have shown that omega-3 fatty acids help promote bone formation," reports Bruce Watkins, professor and director of Purdue's Center for Enhancing Foods to Protect Health. "We also have shown that higher intakes of omega-6 fatty acids lead to an increased production of compounds associated with bone loss."

While both types of fats are essential for human health, diets with a high ratio of omega-6 to omega-3 fatty acids often are associated with cardiovascular disease, cancer, and inflammatory and autoimmune diseases.

A low ratio, however, is believed to promote cardiovascular health, improve memory and, as the study demonstrates, protect bone health.

"We saw in this study that omega-3 fatty acids are associated with a better blood profile of bone health, and with higher bone mineral density, in the absence of estrogen," Watkins notes. "A five-to-one dietary ratio of omega-6 to omega-3 fatty acids led to a conservation of bone mineral content that we didn't see with a 10-to-one ratio."

The average American's dietary ratio is approximately 10 to one, which is inflated by the types of foods people eat and the methods used to produce those foods, especially those containing vegetable oils. "Our foods are different today than they were yesterday," he says. "Omega-6 fatty acids have been an important part of our diet but, over the past 80 years, the human diet has shifted in a way that increased the ratio of omega-6 to omega-3 fatty acids."

The omega-6 fatty acids in today's animal feed incorporate right into the animals' tissues where they become part of the eggs, poultry, meats, and pork served in households and restaurants across the country.

Animal study indicates DHA significantly improved calcium bioavailability

Omega-3s positively influence bone formation

Preliminary investigation reports that GLA with EPA, both essential fats, improves calcium balance in bones