Page 18 - Today's Dietitian (February 2020)

Senior Wellness By KC Wright, MS, RDN

bone pain. Yet the significance of vita-
min C on bone metabolism has become
evident in just the past few decades.
Most of the human studies on vitamin C
and bone health have been observational
but have shown significant positive
effects. As an antioxidant, the benefits of
vitamin C are regulated through a series
of complex mechanisms of interaction
essential to building both cartilage and
bone by stimulating the production of
osteoblasts. Vitamin C also prevents
osteoclast differentiation. Although
there’s some inconsistency in studies
conducted in humans, most conclude
that reduced serum vitamin C levels or
intake may be associated with the devel-
opment of osteoporosis and increased
risk of fracture. 5
The Framingham Osteoporosis Study
(an ancillary study of the Framingham
Heart Study) also investigated vitamin
C in suppressing osteoclast activity
through its antioxidant action. The study
Beyond Calcium and Vitamin D reviewed data from food-frequency
questionnaires along with BMD among
the original cohort of subjects between
Plant Antioxidants Strengthen Bone Health the ages of 68 and 96. Men with higher
4
D uring the past few decades, with higher bone mineral density (BMD), femoral neck BMD loss compared with
dietary vitamin C intake showed less
along with less BMD loss over time.
4
the lowest tertile of dietary vitamin
osteoporosis has emerged
as a major public health
C consumption. For both genders,
Recently, the role of plant-derived com-
concern among the boom-
ing older adult population. pounds has been examined, based on participants in the highest category
of supplemental vitamin C intake had
the idea that certain phytochemicals
Approximately 10 million Americans increase the rate of bone deposition by 69% fewer hip fractures compared with
have osteoporosis, while another 44 osteoblasts (cells that secrete the matrix nonsupplement users.
million have low bone density, plac- for bone formation) and decrease the
ing them at increased risk of the condi- rate of bone breakdown by osteoclasts Carotenoids
tion. Women especially are vulnerable (cells that break down bone). Some stud- Dietary carotenoids, especially the bright
1
to increased bone loss during and after ies have implicated oxidative stress in red carotenoid lycopene, reduce oxida-
menopause. the pathogenesis of osteoporosis. tive stress associated with the risk of
Medications to treat osteoporosis Bone health depends on a dynamic osteoporosis and the levels of bone turn-
have been effective, but currently there equilibrium maintained between the over as seen in postmenopausal women.
6
are no FDA-approved drugs that can constant production of new bone via In the original cohort of the Framing-
help prevent it. Calcium plus vitamin osteoblasts and the resorption of old ham study, lycopene intake was protec-
D supplementation along with exer- bone by osteoclast activity. Osteoblasts tive against lumbar spine BMD loss in
cise have been the mainstays of preven- synthesize collagen and protein for the women. Participants with the highest
tion, but studies on these measures have bone matrix and promote calcification. tertile of total carotenoid intake had 46%
shown only marginal improvement in In osteoporosis, bone mass and density lower hip fracture risk, and participants
2,3
slowing bone loss. Although dietary decrease with the loss of bone matrix with higher lycopene intake had 34%
calcium does lower bone turnover by and mineralization; bone resorption lower risk of hip fracture. Other studies
about 10%, it hasn’t been demonstrated exceeds bone formation, leading to of low lycopene intake have shown signif-
to reduce bone fracture rates. thin, fragile bones subject to spontane- icant increases in oxidative stress param-
Evidence from research studies con- ous fracture. eters, which were reversed with lycopene
7,8
tinues to suggest that certain vitamins, supplementation. Taken together, these
minerals, food groups, and even dietary Vitamin C results suggest a protective role of several
th
patterns play an important role in skele- During the 15 century, maritime carotenoids for BMD and fracture risk in
tal health. For example, greater fruit and explorers suffering from scurvy due to older adults with most consistent results
vegetable intakes have been associated a vitamin C deficiency reported severe for lycopene intake.
18 TODAY’S DIETITIAN • FEBRUARY 2020