The Effect of β-Carotene on Lumbar Osteophyte Formation

Abstract

Cross-sectional cohort study of elderly people. The relationships of osteophyte formation on plain lumbar radiographs with serum levels of antioxidants (carotenoids, vitamin A, vitamin E) and other factors were investigated to examine whether antioxidants are involved in lumbar spine degeneration. Antioxidants have inhibitory effects on the onset of many diseases. However, the association of lumbar osteophyte formation with antioxidant levels in the general population has not been investigated. The subjects were 286 people (103 men and 183 women; mean age = 68 years) who underwent resident health screening. Osteophyte formation on lumbar lateral radiographs (Nathan classification), lumbar lordosis angles, sacral inclination angles, serum levels of antioxidants, triglyceride levels, body mass index, osteoporosis, back muscle strength, history of alcohol intake, and smoking history were studied in these subjects. Lumbar osteophyte formation was detected in 48 subjects (17%). Osteophyte formation was significantly more common in elderly persons, men, and subjects with a history of alcohol intake; and had a significant correlation with sacral inclination angle. The levels of α-tocopherol, β-tocopherol, zeaxanthin/lutein, cryptoxanthin, lycopene, α-carotene, and β-carotene were significantly lower in subjects with osteophytes. Logistic regression analysis adjusted for all factors showed that a higher age (odds ratio [OR] = 1.1, 95% confidence interval [CI] = 1.02-1.16; P = 0.02) and a low β-carotene level (OR = 6.7, 95% CI = 1.39-32.6; P = 0.02) were risk factors for osteophyte formation. The serum levels of carotenoids and vitamin E were significantly lower in subjects with lumbar osteophyte formation, and a low β-carotene level was the strongest risk factor for lumbar osteophytes. This is the first evidence of an association between carotenoids and lumbar osteophyte formation. This finding suggests that appropriate dietary intake of antioxidants is important for inhibition of lumbar spine degeneration in a rapidly aging society.