You probably know that omega 3 fatty acids in the forms of EPA and DHA reduce your risk of cardiovascular disease, and you may know these special fats also provide protection against age-associated cognitive decline and Alzheimer’s disease.
But did you know that omega 3 fatty acids also play a key role in protecting the health of our bones?
Why Omega 3 Fatty Acids (EPA and DHA) are So Important for Bone Health
The omega-3 essential fatty acids (EPA and DHA) defend our bones against osteoporosis. They do this by lessening inflammation through a large number of mechanisms.
Why is lowering inflammation so critical for protection against osteoporosis?
Anything that causes inflammation activates osteoclasts, the specialized cells that break down bone. Inflammatory signals tell these bone removal cells it’s time to get to work.
Our osteoclasts are supposed to remove old and brittle or damaged bone, a job they do very quickly. Then, they’re supposed to clear out, go on vacation and let the bone-building cells, our osteoblasts, start in on the more time-consuming job of rebuilding new bone to replace the bone our osteoclasts have removed.
When inflammation is chronic, however, our osteoclasts go on overtime. Since building new bone takes much longer than breaking down old bone, too much osteoclast bone demolishing activity can result in bone thinning (or osteopenia) and, ultimately, in osteoporosis.
By greatly tuning down inflammatory signaling, EPA and DHA send osteoclasts home, preventing excessive bone loss. Plus, EPA and DHA invite osteoblasts in and give these bone-building specialists enough time to lay down new bone.
In addition, EPA and DHA further help us to maintain healthy bones by increasing our production of osteoblasts. When more osteoblasts get produced, more of these bone-builders are available to be called in to build new bone as soon as the osteoclasts have departed.
The gist of it is pretty straightforward and simple.
EPA and DHA lower inflammation, lessen osteoclast activation and promote osteoblast activity.
But in recent years, we’ve learned that the multiplicity of ways through which the omega-3 essential fatty acids accomplish this outcome is amazingly, beautifully complex.
We now know that an intricate dance is constantly occurring within our bodies that enables inflammatory signals to be sent when needed and shut down when further inflammation could cause harm. Both types of essential fatty acids – the omega-3s and the omega-6s – are the partners in this inflammation-regulating dance. When they move together in balance, damaged bone is removed while beautiful new bone is continuously built. But when omega-3 isn’t available to partner omega-6 in this dance, the inflammatory side of omega-6 spins out of control. Osteoclasts go on overtime. Osteoblast production and activity is inhibited, and we lose bone.
The Importance of Omega 3’s For Bone Has Been Known for Many Years
Back in the early 1930s, research was published showing severe osteoporosis developed in rats deprived of essential fatty acids. (1)
In the 1950s, not only were these findings confirmed(2), but EFA deficiency was shown to cause both the replacement of bone by fat and bone demineralization (loss).
Despite these clear findings, which received little attention, the effects of the essential fatty acids (omega-3 and omega-6) on bone health have just recently become an important field of research. (3)
In the last 10 years, our understanding of how important the omega-3 essential fatty acids — eicosapentaenoic acid (EPA) and (docosahexaenoic) DHA — are for bone health has expanded exponentially.
And we now know that even the usually pro-inflammatory compound derived from omega-6 — arachidonic acid (AA) — promotes healthy bones when our intake of omega-3 is in balance with our intake of omega-6.
Getting enough omega-3s to balance the high levels of omega-6s found in the standard American (and Canadian and European) diet is crucial to prevent osteoporosis and ensure strong, healthy bones for life. The rest of this article and several others to follow share the main reasons why.
The Omega-3 Fatty Acids, EPA and DHA, Help Us Build Bone Instead of Fat
The Omega-3s encourage the production of osteoblasts, the special cells that build bone.
Mesenchymal stem cells (MSCs) are cells that live in bone marrow and haven’t yet made up their minds what they want to grow up to be. They can become osteoblasts, the specialized cells that build new bone for us, or they can become adipocytes, which are fat cells. Obviously, we’d prefer healthy bones to unhealthy amounts of fat. So, how do our MSCs choose a bone-building rather than fat-building career path? They meet with the body’s MSC career counselors.
MSCs get their career counseling from compounds derived from both omega-6 (linolenic acid [LA]) and the omega-3 (alpha linolenic acid [ALA]).
LA (omega-6) and ALA (omega-3) are the parent compounds from which all the EFA “children” are derived. The offspring of LA convince MSCs to become fat cells, while those of ALA put MSCs on the path to — a much more rewarding career for our bones — life as an osteoblast.
The first child produced from omega-6, arachidonic acid (AA), almost always chooses to join a bone-demolition crew as its way of life. AA is an anarchist, who enjoys lighting fires and promotes bone resorption in several ways:
- AA in gangster-mode “suggests” to MSCs that they become fat cells, which results in fewer MSCs becoming osteoblasts
- If some MSCs say, “Nope, I wanna be an osteoblast,” AA throws up roadblocks that make it really hard for them to differentiate into osteoblasts
- AA’s favorite pastime is promoting inflammation. One way AA does this is by lowering the production by mature bone-building osteoblasts of an anti-inflammatory compound called osteoprotegerin (OPG).
OPG looks just like another, but very pro-inflammatory, compound called RANK (receptor activator of nuclear factor-kappa B). For RANK to become active, it has to be turned on by another compound called RANKL, which stands for the RANK ligand. When RANKL binds to RANK, this sets off a whole series of inflammatory events that results in the production of osteoclasts ready to resorb (remove) bone. When RANKL binds to OPG, no inflammatory signals get sent, and no osteoclasts get produced.
It’s important to note here, however, that we do want to have some RANKL to RANK binding. We need osteoclasts to remove old brittle bone so that room is made for new healthy bone to be laid down to replace it. And, RANKL’s binding to RANK is also necessary for the activation of immune cells (our T and B cells, specifically). We must have functional immune systems to survive. What good are great bones if we’re easy prey for destruction by infections or cancer?
The key here – and in all the many ways we’ll be talking about through which the children of omega-3 and omega-6 work to promote healthy bones – is BALANCE. The nifty way our body has worked out this balancing act among RANKL, RANK and OPG is just one example.
I always think of RANKL as a Conan the Barbarian kind of guy, and see OPG as standing for “Oh, Pretty Girl!” Enough OPG around and RANKL will be too busy being amorous to light lots of fires, but RANKL to RANK binding will not be eliminated, so a few fires will get started where and when we need them (to remove old brittle bone and get our immune cells ready to protect us).
In contrast to omega-6 and its offspring, AA, omega-3 and its offspring EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), and their children (the resolvins and protectins) – are all peaceful folk who enjoy building bone, and all are extraordinary firefighters.
The omega-3 clan inhibit the production of osteoclasts, thus slowing the rate of bone removal, plus the omega-3s encourage MSCs to become osteoblasts, increasing the available number of the cells that build new bone.
And this is just one of more than a dozen ways the omega-3 essential fatty acids help us to have healthy bones!
In our next article, we’ll talk about:
- How inflammation causes MSCs to choose to be fat cells instead of bone-building osteoblasts – especially as we age
- Why we tend to have way too much omega-6 and not enough omega-3 in our diet
- And how getting enough omega-3 to restore balance lets us lower inflammation and promote the healthy bones we need to age vibrantly
- Borland VG, Jackson CM. Effects of a fat-free diet on the structure of the kidney in rats. Arch Pathol 1931;11:687–708
- Biran LA, Bartley W, Carter CW, Renshaw A. Studies on essential fatty acid deficiency. Effect of the deficiency on the lipids in various rat tissues and the influence of dietary supplementation with essential fatty acids on deficient rats. Biochem J 1964;93:492–8.
- Wauquier F, Léotoing L, Philippe C, et al. Pros and cons of fatty acids in bone biology. Prog Lipid Res. 2015 Apr;58:121-45. doi: 10.1016/j.plipres.2015.03.001. Epub 2015 Mar 30. PMID: 25835096
- Casado-Díaz A, Santiago-Mora R, Dorado G, et al. The omega-6 arachidonic fatty acid, but not the omega-3 fatty acids, inhibits osteoblastogenesis and induces adipogenesis of human mesenchymal stem cells: potential implication in osteoporosis. Osteoporos Int. 2013 May;24(5):1647-61. doi: 10.1007/s00198-012-2138-z. Epub 2012 Oct 27. PMID: 23104199
- Kelly OJ, Gilman JC, Kim Y, et al. Long-chain polyunsaturated fatty acids may mutually benefit both obesity and osteoporosis. Nutr Res. 2013 Jul;33(7):521-33. doi: 10.1016/j.nutres.2013.04.012. Epub 2013 Jun 10. PMID: 23827126