Olive oil in the prevention and treatment of osteoporosis after artificial menopause

Abstract

Purpose: The goal of this study was to investigate the anti-osteoporosis effect of extra virgin olive oil (EVOO) in vivo, and explore its antioxidant, anti-inflammatory properties in Sprague Dawley rats and its anticancer properties in patients.

Materials and methods: A total of 120 healthy female Sprague Dawley rats aged 6 months were divided into four groups: 1) sham-operated control (Sham group, n=30); 2) ovariectomized (OVX group, n=30); 3) ovariectomized rats supplemented with EVOO (OVX + Olive, n=30); 4) ovariectomized rats supplemented with estrogen (OVX + E2, n=30). EVOO and estrogen were administered by oral gavage at a dose of 1 mL/100 g weight on a daily basis for 12 consecutive weeks. Twelve weeks later blood samples were obtained to detect the levels of calcium, alkaline phosphatase, phosphorus, interleukin-6 (IL-6), malonyldialdehyde (MDA), and nitrate content. Dual energy X-ray absorptiometer measured bone mineral density (BMD) of ovariectomized Sprague Dawley rats that had been fed olive oil for 3 months. Blood samples from patients, who regularly consumed olive oil over a 1 year period were also used to measure carbohydrate antigen 125, carcino-embryonic antigen, α-fetoprotein, and carbohydrate antigen 19-9 levels. BMD of lumbar spine and left femur was also evaluated by dual energy X-ray absorptiometry.

Results: Animal experiments showed that EVOO significantly increased BMD and decreased phosphatase, alkaline phosphatase, IL-6, MDA, and nitrate levels. However, it had no significant effect on the Ca(2+) level. In clinical follow-up, EVOO also improved patient BMD levels on L3, L4, and left femoral neck, and reduced carbohydrate antigen 125, α-fetoprotein, and carcino-embryonic antigen levels. But it had no significant effect on the carbohydrate antigen 19-9 level.

Conclusion: EVOO illustrated significant anti-osteoporosis, antioxidant, anti-inflammatory, and anticancer properties in vivo. However, further studies are required to determine the active component(s) responsible for these effects.

Keywords: artificial menopause; olive oil; osteoporosis; prevention; treatment.

Figure 1

BMD of different groups at 12 weeks post-operation. Notes: Comparison of bone density in Sham, OVX, OVX + Olive, OVX + E₂ groups at 12 weeks post-surgery. Data represent the means ± standard deviation (SD) (n=30). (A) and (B): OVX, OVX + Olive, OVX + E₂ groups versus Sham group, bone density of lumbar spine and bone density of left femur were all lower (*P<0.05). Bone density of lumbar spine and bone density of left femur of OVX + Olive group and OVX + E₂ group declined more slowly versus OVX group (*P<0.05). OVX + Olive group and OVX + E₂ group showed no significant difference. Abbreviations: OVX, ovariectomized group; BMD, bone mineral density; E₂, estrogen.

Figure 2

Comparison of tumor marker changes of the two followed-up patients. Notes: CA125, AFP, CEA, and CA19-9 were examined in patients who did or did not take olive oil regularly after surgery. Data represents the means ± standard deviation (SD) (n=10). (A), (B), (C) revealed that after taking olive oil for 1 year in experimental group, serum CA125, AFP, CEA considerably decreased versus “exp” group (*P<0.05). Serum CEA of control group who did not take olive oil had not changed significantly after 1 year. After 1 year, in “exp’”group, CA125, AFP, and CEA considerably decreased versus “ctrl” and versus “exp” (*P<0.05). (D) CA19-9 had no obvious changes with comparison to other groups (P>0.05). “ctrl’” refers to patients who did not take olive oil for 1 year. “exp’” refers to patients who took olive oil for 1 year. Abbreviations: CA125, carbohydrate antigen 125; AFP, α-fetoprotein; CEA, carcino-embryonic antigen; CA19-9, carbohydrate antigen 19-9; exp, experimental; ctrl, control.

Figure 3

Comparison of BMD levels of followed-up patients. Notes: BMD of L3, L4, and left femur was detected in patients who did or did not take olive oil regularly after surgery for 1 year. Data represent the means ± standard deviation (SD) (n=10). *P<0.05 versus “ctrl’” and *P<0.05 versus “exp’”. “ctrl’” refers to patients who did not take olive oil for 1 year. “exp’” refers to patients who took olive oil for 1 year. Abbreviations: BMD, bone mineral density; exp, experimental; ctrl, control.