ARA 6: Larch Arabinogalactan
Greg Kelly, ND
I went to lunch yesterday at a local health food store (they make great soup) and while I was walking through the supplement section I noticed an attractive floor display. But what really grabbed my attention about this particular display was that it contained a "new" immune-boosting product called "Larch Arabinogalactan." It makes me smile to see this product getting attention in the natural foods industry, because this product is far from new to Naturopathic Physicians. Ultimately the reason Naturopaths are so familiar with this compound, and probably the lion's share of the reason it now graces the shelves of health food stores can be traced to one individual—Peter D'Adamo, N.D.
The historical story of "Larch Arabinogalactan," as I have heard it, is actually quite interesting, so I will share parts of it with you. Arabinogalactan is a specific polysaccharide, and polysaccharides interact with blood type. So, it is not surprising to discover that Dr. D'Adamo has had a passionate interest in polysaccharide research for more than a decade. Because of this interest, years ago now, Dr. D'Adamo was scanning research articles and came across a Japanese study (written in Japanese) which just happened to have several words written in English..."Echinacea" and "Arabinogalactan." This ignited the spark that would eventually lead to his use of this product.
While information on the health benefits of Arabinogalactan were non-existent to scarce at this point in time, the connection with Echinacea led Dr. D'Adamo to ponder whether it might have immune benefiting effects. However, a source of concentrated arabinogalactans was not as easy to find 8-10 years ago as it is today. His search for a source of Arabinogalactan eventually led him to the lumber industry. The larch tree, as it turns out, is a rich source of this polysaccharide. But up until this point in time, it had been regarded solely as a fiber. Before long, 50-100 pound bags of bulk "Larch Arabinogalactan" began to show up at the D'Adamo Clinic in Greenwich, CT. Dr. D’Adamo’s research of this natural product now moved into full swing. In fact, patients will still tell you stories about the plastic baggies filled with a "fluffy, white powder" and how this product helped them.
By the time I was in naturopathic school, Dr. D'Adamo had introduced the use of this product into Naturopathic Medicine. Before I had graduated, he had published his first review article on the health benefits of Larch Arabinogalactan. The rest, as they say, is history.
So, from its rather inauspicious beginnings—as an underutilized leftover from the logging industry—to one man's curiosity—Larch Arabinogalactan has now arrived as an emerging new darling of the natural foods industry.
So let's learn a bit more about this natural product. As I have said, arabinogalactans are a class of polysaccharides found in a wide range of plants; however, they are most abundant in plants of the genus Larix (larch tree is Larix occidentalis). High-grade or nutraceutical-grade Larch Arabinogalactan (the grade typically utilized for supplements) is composed of greater than 98% arabinogalactan. As produced, Larch Arabinogalactan is a dry, free-flowing powder, with a very slight pine-like odor and sweetish taste. It is 100% water-soluble and produces low viscosity solutions. Because of its excellent solubility and mild taste, the powder mixes readily in water and juices and is easily administered (even to children).
The longest recognized use of Larch Arabinogalactan is probably as a source of dietary fiber. It has been shown to increase the production of short-chain fatty acids (SCFA's), principally butyrate and proprionate. These special fatty acids are critically important for the health of the colon. In fact, having an adequate supply of SCFA's is thought to make colon cells more resistant to both tumor promotion and a variety of intestinal disease.
Larch Arabinogalactan also acts as a food supply for friendly bacteria. The term used to describe this action is "prebiotic." The most well known prebiotic substance is "fructooligosaccharides" or "FOS." Larch Arabinogalactan acts in the same manner as FOS in humans. In effect, when we consume Larch Arabinogalactan, we are rewarded by this significant positive effect on our gut microfloral balance. Specifically, this fiber acts to increase good bacteria like bifidobacteria and lactobacillus, while decreasing bad bacteria. Since these friendly bacteria are critically important for the health of our digestive and immune systems, detoxification and hormone regulating capabilities, and nutrient formation and absorption; the growth promoting effects of Larch Arabinogalactan on these organisms alone makes it a valuable addition to our diet.
While Larch Arabinogalactan has a huge impact on digestive health, it has received even more attention for its ability to promote the health of our immune system. It was this possibility that first drew Dr. D'Adamo's curiosity.
The immune system is a very complex system. A healthy immune system is, in many respects, the core of prevention or resistance against disease. While it might be easy to assume that, with respect to immune system function or response, "more is better"...this is not always the case. In fact, like most things in life, your immune system's performance is more about an "appropriate" response, than it is about simply an "increased" response. Many chronic health challenges are predictably associated with some parts of your immune system "under-achieving;" however, it is just as common in these same circumstances to have other parts of the immune system "over-achieving." So, in simple terms, immune system health is all about "balance."
Substances, which promote a balanced response to stress, are called "adaptogens." Larch Arabinogalactan appears to act as an "adaptogenic" agent on your immune system...lifting up weak aspects and balancing down over-achieving aspects. So, while this supplement is currently primarily thought of as something to improve or stimulate immune system activity, it would be more appropriately described as a substance with an ability to build a more responsive immune system...or in effect, an immune system that is better able to function in a balanced and appropriate manner in the face of the challenges we face today.
Safety and dosage
Larch Arabinogalactan is FDA approved for use in food applications. Toxicity tests in animals indicates that Larch Arabinogalactan is significantly less toxic than methylcellulose (one of the most commonly supplemented fibers). Clinical feedback suggests an occasional reaction of bloating and flatulence in less than 3 percent of individuals (most often women). This side effect is probably secondary to the effect Larch Arabinogalactan has on beneficially altering gut microflora and will often disappear after several days to 1 week.
As an addition to the diet, the usual dose is 1-3 grams daily (1000-3000 mg). However, much larger amounts can be taken if desired (up to 2-3 tablespoons daily). Larch Arabinogalactan is available in powder, capsules, and tablets from various supplement companies. Since it mixes very well with juice or water, and is more cost-effective as a powder as compared to capsules or tablets, I usually use the powder form. However, its effectiveness is similar whether taken as powder, capsule or tablet.