A vast amount of epidemiological evidence suggests that diets high in Omega -3 fatty acids (also termed n-3 FAs) may prove highly beneficial for skeletal health. In this article, we will explore the various ways in which Omega-3 fatty acids can play a critical role in bone reabsorption, increasing skeletal mass, and regulating calcium balance within the body. We will also touch on the abundance of food sources that can provide ample omega-3 fatty acids, as well as the role age plays in the development of bone integrity.
The Concerns Surrounding Osteoporosis
Osteoporosis, long considered a significant public health risk, predominantly affects our older population. This debilitating condition of the human skeletal system often causes an uptick in both morbidity and mortality, largely due to the aftermath of fractures in the hip, spine, and wrist. Characterized by diminished bone mass coupled with the deterioration of bone tissue, osteoporosis poses challenges not only for the health of an already compromised demographic but also for healthcare expenditures.
While most physicians tell their senior patients to expect some weakening of the bones as they advance through the golden years, several factors may actually accelerate this process and increase the risk of osteoporosis, including the following:
- Maximal bone mass: Most individuals will reach a point of peak bone mass in their early thirties. While genetics may play a role here, lifestyle choices also make a difference in outcomes.
- Endocrine health: Women in particular tend to feel the effects of variances in the body’s endocrine system as it relies to a large extent on hormone production. Low estrogen levels can impact bone health at various stages of life, from amenorrhea in elite teen athletes or those dealing with eating disorders all the way to perimenopause and menopause itself, when bone loss can exceed 4% with each subsequent year.
- Medical considerations/medications: Certain diseases, such as hormonal/endocrine disorders, gastrointestinal conditions and some types of cancer, can raise one’s chances of developing osteoporosis. Similarly, long-term use of some pharmaceuticals, such as proton pump inhibitors and glucocorticoids, elevate the risk of developing osteoporosis.
- Lifestyle choices: Heavy consumption of alcohol, low levels of physical activity and long-term cigarette smoking can all play roles in hastening the onset of skeletal system problems. Weight-bearing exercise excels at developing and maintaining bone health. Decisions about nutrition/food choices will also either promote or impede the development of peak bone mass.
- Insufficient specific nutrient intake: Meal plans lacking in calcium, vitamin D, protein, Omega-3 fatty acids and/or overall calories can increase the risk for osteoporosis and fractures. Sometimes this occurs as a result of the natural decline in appetite associated with aging.
Omega-3 Fatty Acids and Bone Health
In the research world, scientists have begun studying fatty acids for their potentially beneficial effects on bone structure. Classified as polyunsaturated fatty acids, Omega-3 fats mainly contain 3 substrates: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). In decades past, experts tended to focus solely on dietary intake of both calcium and vitamin D as a means of warding off osteopenia and osteoporosis. However, despite these efforts, the incidence of osteoporosis-related fractures has not markedly slowed, suggesting that other dietary factors may play a role in bone health, namely omega-3 fatty acids.
The mechanisms by which scientists believe Omega-3 fatty acids work to support bone health rest on a dual platform: that of modulating the body’s immune responses and regulating its calcium balance. We will address each of these attributes separately.
Halting the Immune Response
To a large extent, the aforementioned EPA and DHA serve as precursors to various anti-inflammatory metabolites. Before we delve any further into this discussion, we must have a basic understanding of the bone formation process. Our skeletal system, essentially a dynamic, living entity, functions in a cycle where tissues consistently get broken down and rebuilt. Two main types of cells drive this process: osteoblasts, the builders of new bone, and osteoclasts, the cells that break down old bone tissue and lead to bone resorption.
The anti-inflammatory metabolites in Omega-3 fatty acids increase osteoblast activity, thereby fostering the laying down of new bone tissue. Concurrently, pro-inflammatory cytokines stimulate osteoclast activity, promoting greater bone resorption. Working together, these actions help minimize the decline in bone mass across various age populations.
Calcium and Omega 3’s
EPA and DHA may also influence bone health by affecting calcium regulation. The fatty acids can embed themselves in cellular membranes throughout the body, enhancing calcium channel activity and regulating circulating calcium levels. By improving calcium retention and reducing calcium loss, Omega-3 fatty acids may positively impact the skeletal system and bone health.
The Link Between Fatty Acids, Estrogen and the Anti-Inflammatory Response
Dr. Mark Seifert, Professor of Anatomy and Cell Biology at Indiana University’s School of Medicine, has done extensive research on the effects of Omega-3 fatty acids on the body. “We believe Omega-3s may minimize bone loss with estrogen deficiency in association with their anti-inflammatory effects,” he says.
A class of molecules known as cytokines elicit inflammation and also stimulate the breakdown of bone tissue. Estrogen blocks some of the inflammatory compounds associated with bone resorption, which may explain why osteoporosis typically progresses after estrogen levels fall with the onset of menopause.
How Different Ages Groups Respond to Omega-3 Fatty Acids
As previously mentioned, age has a great deal of influence over bone density and overall bone health. One research study sought to examine age-related differences in the impact of Omega-3 fatty acids on bone health. The scientists hypothesized that these differences may arise as a function of variations in bone turnover rates and calcium absorption with age.
The protective effect of Omega-3 consumption on bone health appears more pronounced in younger individuals, likely due to their higher bone metabolic activity. The pronounced benefits of Omega-3 intake observed in this age demographic further underscore the need for age-specific dietary interventions. Other studies found similar age-related variations, suggesting that younger adults might more effectively integrate Omega-3 fatty acids into all of their cellular structures, including bone. In contrast, the metabolic changes associated with aging could diminish the efficacy of Omega-3’s in older adults, possibly due to a slower lipid metabolism or a change in how fatty acids get incorporated into older bone tissues.
Nutritional Sources
Given the abundance of data showing that Omega-3 fatty acids may play a critical role in bone health, the need for dietary recommendations that encourage Omega-3 consumption as a preventive measure against osteoporosis seems pressing, beginning as early as middle childhood.
The following serve as excellent sources of Omega-3 fatty acids that can easily fit into a variety of meal plans:
- Fatty Fish: mackerel, trout, salmon, herring, anchovies, oysters and sardines
- Flax Seeds
- Walnuts
- Chia Seeds
- Fortified Foods: some brands of milk, yogurt and eggs get enriched with omega-3’s prior to going to market
- Caviar
- Soybeans
- Cod Liver Oil
- Hemp Seeds
- Blueberries
- Basil
- White Beans
Options Abound for the Vegan Athlete
Plant-based sources of Omega-3 fatty acids may promote faster recovery in athletes who choose a plant-centric lifestyle. Vegans can acquire some Omega-3’s through ALA-rich foods, but even these may leave athletes somewhat deficient. If necessary, these athletes may also consider an algae-based Omega-3 supplement to meet their nutritional needs.
Microalgae surfaced as a promising alternative source of DHA and EPA. Recently, scientists have discovered the merits of microalgal oil as a sustainable and limitless source of the Omega-3 fatty acids for vegan athletes. One study sought to assess and then compare the DHA and EPA plasma bioavailability of microalgal oil with that of fish oil.
Seventy-four adult males and females took part in this study. Scientists analyzed the subjects’ plasma phospholipid levels after 6 and 14 weeks of consuming Omega-3 supplements derived from either microalgal or fish oil. As it turns out, the bioavailability of DHA and EPA in plasma phospholipids from microalgal oil supplements was on par with that of fish oil supplements, despite the differences in their production process and composition.
Can Omega-6 Fatty Acids Harm Bones?
Many individuals have raised questions about the differences between Omega-3, -6 and-9 fatty acids. As it turns out, each of these confers different properties on the human skeletal system, and the importance centers on the ratio between them.
The average American or Western diet elicits a ratio of Omega-6 to Omega-3 fatty acids that approximates 10-to-1, influenced to a large extent by our food choices and the methods used to produce those foods, especially foods containing vegetable oils. “A 5-to-1 dietary ratio of Omega-6 to Omega-3 fatty acids leads to a conservation of bone mineral content that we don’t see with a 10-to-1 ratio,” says Bruce Watkins, professor and Director of Purdue’s Center for Enhancing Foods to Protect Health.
Indeed, a primary manner in which consumption of Omega-6 fatty acids negatively impacts bone health centers on a line of stem cells found in the bone marrow called mesenchymal stem cells (MSCs). MSCs can evolve into either osteoblasts (bone-building cells) or adipocytes (fat cells). The determining factor involves the Omegas.
MSCs get influenced by compounds derived from both Omega-6 (linoleic acid [LA]) and Omega-3 (alpha-linolenic acid [ALA]) fatty acids. While signals from Omega-6 fats steer MSCs in the direction of adipocytes, signals from Omega-3s encourage the formation of osteoblasts. Therefore, the greater the number of Omega-6 fatty acids, the fewer bone-building cells result, in favor of additional fat cells, which will not foster healthy bones.
Arachidonic acid (AA), a particularly troublesome Omega-6 fat, not only inhibits the formation of osteoblasts but also lowers the production of an anti-inflammatory compound called osteoprotegerin (OPG), produced by mature bone-building osteoblasts. In high enough concentrations, OPG inhibits osteoclast formation, giving the bone-building cells an advantage. When lacking, however, osteoclasts proliferate, leading to the situation whereby bone breakdown outpaces bone formation.
Despite the collective evidence we presented here supporting Omega-3 fatty acids’ role in strengthening the skeletal system, strong conclusions regarding these fats and bone disease remain limited due to the small number and modest sample sizes of the research trials. Still, experts seem to agree that consumption of dietary Omega-3 fatty acids may deliver even better results for skeletal health when individuals also consume adequate amounts of calcium. When clients ask personal trainers about ways to strengthen bones in addition to their current weight-bearing efforts, we can feel confident steering them toward dietary Omega-3 fatty acid food sources.
References
omegaquant.com/can-omega-3-prevent-osteoporosis/
blog.algaecal.com/why-omega-3-fatty-acids-are-crucial-for-healthy-bones/
pmc.ncbi.nlm.nih.gov/articles/PMC12524788/
sciencedirect.com/science/article/abs/pii/S0955286310001427
frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1467559/full
