The results of research by a team based at the National Research Centre in Cairo suggest that flaxseed oil has a beneficial effect on bone mineral density and reduces markers associated with osteoporosis, indicating that this dietary supplement could be beneficial to women with diabetes or older women in reducing their risk of osteoporosis.
The findings were published in the International Journal of Food Safety, Nutrition and Public Health.
Osteoporosis is characterised by low bone mass, which leads to an increase risk of fractures, especially the hips, spine and wrists. An estimated 75 million people suffer from it in Europe, the US and Japan.
Women are four times more likely to develop osteoporosis than men and the authors of this study explained that previous research indicates that diabetes decreases bone turnover that is associated with impaired osteoblastic maturation and function.
According to the International Osteoporosis Foundation, the total direct cost of osteoporotic fractures in Europe is €31.7bn so boosting bone density in high-risk and post-menopausal women could ease the burden of osteoporosis.
The researchers explained that they studied 70 female albino rats of which 30 had their ovaries removed (ovx) to simulate the post-menopausal state whereby oestrogen is decreased and another group of rodents was rendered diabetic (Type 1) in order to determine the impact of diabetes on the development of osteoporosis.
“Bone status was tested through estimation of serum bone formation biomarkers IGF-1 and osteocalcin and bone resorption biomarker deoxypyridinoline,” said the team.
They explained that a sham and normal control group were also included in the study.
The authors added that flaxseed oil (rich in omega-3 fatty acids) replaced corn oil (rich in omega-6 fatty acids) in the diet of some of the diabetic and the ovx-diabetic groups with the aim of testing for the impact of this oil on either delaying or preventing the development of osteopenia in ovx rats.
They reported that, after two months, urine and blood samples were taken from the rats, and IGF-1 and the bone-creating protein osteocalcin were also measured.
The researchers found that the serum concentrations of IGF-1 and osteocalcin were increased in the ovx and diabetic ovx groups but their lowest levels were detected in the diabetic group.
And the team said that bone mineral density and content in diabetic group were reduced and normalised after receiving flaxseed oil.
The researchers also found that the levels of deoxypyridinoline in the urine were raised in the diabetic group. Deoxypyridinoline is normally present in healthy bone and its presence in urine is a specific marker for bone resorption associated with osteoporosis.
Levels of this marker compound fell when the rats were given flaxseed oil, continued the authors.
The team concluded that diabetes has a more pronounced effect on bone health than ovariectomy and they suggest that diabetes in post-menopausal women may also be a greater risk factor for osteoporosis than the decline in sex hormones associated with the menopause.
They said that that the presence of so-called ‘n-3 fatty acids’ in flaxseed oil may play a role in protecting the processes of matrix formation and bone mineralization, which apparently are compromised by diabetes and the menopause.
"We recommend further investigations using animals and humans to confirm the effect of using dietary flaxseed oil to improve bone health and to prevent osteoporosis," concluded the team.
Source: International Journal of Food Safety, Nutrition and Public Health
Published online ahead of print:
Title: Impact of feeding flaxseed oil on delaying the development of osteoporosis in ovariectomised diabetic rats’
Authors: M. Elwassef, M. Anwar, M. Harvi, M.MA. El Moneim, G.S. El-Saeed, S.I. Salem, H. Wafay.