Bone health is a contributor to healthy aging. According to the World Health Organization, there are approximately 22 million women who have osteopenia and 8 million women who have osteoporosis within the U.S. Research in the last decade has studied the relationship between oxidative stress, low-grade chronic inflammation, age-related bone loss, and nutrition. Oxidative stress may be detrimental to bone health due to increased microstructural deterioration, bone loss, bone fragility, and fracture susceptibility. Interest in attenuating bone-related oxidative stress has looked toward the antioxidant and anti-inflammatory properties of vitamin E tocotrienols.
Vitamin E consists of two subgroups called tocopherols and tocotrienols, along with their corresponding isomers (α-, β-, γ-, and δ forms). Most plants contain tocopherols, whereas tocotrienols can only be found in plants, such as the annatto, palms, grains, and nuts. Growing evidence has examined tocotrienols (particularly δ-tocotrienols) and their potential clinical relevance to obesity, cardiovascular disease, type 2 diabetes, nonalcoholic fatty liver disease, arthritis, and osteoporosis.
Tocotrienols may support bone health by protecting osteoblasts from lipid peroxidation and suppressing osteoclast differentiation, osteoclast maturation, and bone resorption activity. In general, antioxidants (such as vitamin E) may promote bone health by creating an alkaline environment, reducing urinary calcium excretion, and providing bioactive components.
A randomized, double-blinded, placebo-controlled clinical trial (n = 89) investigated postmenopausal women with osteopenia after 600 mg of annatto-derived tocotrienol supplementation for 12 weeks. The authors concluded tocotrienol supplementation attenuated bone loss, inflammatory levels, and oxidative stress by favorably altering bioactive lipids, amino acid metabolism, steroid hormone synthesis, bone degradation, and collagen turnover.
A similar study looking at the same demographics supplemented with either 430 mg of tocotrienols per day, 860 mg of tocotrienols per day, or a placebo for 12 weeks. Compared to the placebo group, both tocotrienol groups significantly increased the bone-specific alkaline phosphatase (BALP) to N-terminal telopeptide (NTX) ratio. The two tocotrienol groups also significantly decreased NTX levels, serum soluble receptor activator of nuclear factor-kappa B (sRANKL), sRANKL to serum osteoprotegerin ratio, and the oxidative stress biomarker 8-hydroxy-2’-deoxyguanosine. As a result, the tocotrienol supplement decreased bone resorption and improved bone turnover rates in postmenopausal women with osteopenia.
Research currently suggests that tocotrienols have greater antioxidant properties than tocopherols due to differing bioavailability and metabolism. For example, the short, unsaturated side chain of the tocotrienol incorporates more easily into cell membranes when compared to the tocopherol. One clinical trial (n = 71) compared 400 IU of α-tocopherol supplementation to 150 mg of tocotrienol-rich fraction supplementation for 6 months. The tocotrienol-rich fraction differed from α-tocopherol in restoring redox balance by reducing malondialdehyde, protein carbonyl, and total DNA damage levels and increasing the levels of vitamins D and E.
Research is continually exploring the connection between oxidative stress and age-related bone loss. Although further studies are needed, the potent antioxidant and anti-inflammatory properties of vitamin E tocotrienols may support healthy aging and promote bone health.
By Danielle Moyer, MS, CNS, LDN