Dietary Sources of Galactose

The glyconutrient Galactose, is a monosaccharide that coexists with glucose in the disaccharide lactose. For your information the D form is synthesised while the L form is naturally occurring. It is found mainly in dairy products, and comprises around 2% - 8% of milk solids. It is one of the eight saccharides required by the body for correct formation of cells and organs, for immunity and for communication between cells. It is not a nutrient that you want to be short of!

The part played by monosaccharides such as Galactose in the biochemistry of the body was not appreciated until relatively recently, and it is still actively under investigation. The effect of sugars on the immune system of mammals in general, and humans in particular, is not yet fully understood, and will be some time before it is so. However, it has been more or less universally agreed that the immune system is very dependant on eight monosaccharides, called the 'essential sugars' for its proper functioning.

Galactose is an essential glyconutrient in the formation of the cell messaging substances, glycoforms. The cells of the body require a means by which they can communicate to other cells just what they are. Without this communication system, cells will be unable to tell whether other cells are friendly or not. Antibodies, for example, will not know what cells to attack and what to leave alone. The immune system would break down, and the body would be open to disease. These glycoforms are situated on the surface of the cell membrane, and require Galactose for their formation.

Galactose is necessary for the formation of glycolipids and glycoproteins, the sugar-based fats and proteins necessary for these glycoforms. Glycoproteins, especially, are important in the formation of the immune system, and typical examples include the antibodies that are used to protect the body against foreign invaders. The saccharide that appears most frequently in cell and organ structure is n-acetyl glucosamine followed by n-acetyl galactosamine. These are not present in the human diet, and have to be synthesized in the body from the monosaccharides Galactose and glucose.

Although people with lactose-intolerance might suffer from Galactose deficiency, it is present in a wide variety of fruits and vegetables, and some are listed at the end of this article. It is particularly available in fruit pectin's. It is more common than glucose, and can be transformed into glucose by the liver. It is just as essential a component in the human diet as the other seven essential sugars, and if even one sugar is missing, cell communication breaks down. The type of disease that results depends on the monosaccharide that is missing, although there is a large number of potential conditions that could be affected.

When Galactose is ingested, around 30% is converted to glycogen, although the preferred substance for this is glucose. Glycogen is stored mainly in the liver and is a short-term energy source than can be used on demand. Up to 45% is converted to carbon dioxide and the rest is used to manufacture glycolipids and glycoproteins. Recent studies are indicating that both Galactose and Mannose are essential in the maintenance of a balance of these substances in the body.

The three essential sugars that you get from your diet are glucose, Galactose and fucose. Fucose should not be confused with fructose that is a different sugar altogether, and can do more harm than good if taken in excess. Fucose is common in milk and is obtainable from dairy products. From these three, the other five are produced by the body's biochemistry. One cannot be said to be more important than another, although Galactose would be regarded as the 'daddy' of the three.

The specific benefits of the glyconutrient Galactose include improved wound healing and decreased inflammation, strengthening of the digestive system, and of course, its critical effect on the immune system. There are many other potential benefits currently under investigation, and a deficiency is thought to promote arthritis, diseases of the respiratory system and even, perhaps, multiple sclerosis. There is also evidence that Galactose is necessary for good long-term memory.

It is in the immune system, however, that Galactose plays a primary role. If an arthritis patient is deficient in Galactose it appears to affect the levels of other saccharides, and appears to lead to inflammation. Galactose levels have been found to be reduced in severely ill patients, especially in the cells of the upper airway. This reinforces the other evidence available of its importance in human biochemistry. Not only humans, of course, since all mammalian biochemistry will be involved, and studies have shown a similar relationship between Galactose levels, and those of the other essential sugars, and the condition of the immune system.

Although there should be sufficient Galactose provided in a normal diet, a supplement will do no harm. The monosaccharide is so essential to health and the proper functioning of your body's biochemistry that a supplement would at least ensure that you were getting enough. There are no apparent side effects for using a supplement and Galactose-intolerance is a very rare condition.

Naturally, Galactose is obtainable from a wide variety of fruit and vegetables. Those particularly rich in the sugar are leeks, broccoli, carrots and Brussels sprouts, while plums are the best fruit source. It is easily absorbed, although, as explained above, only a fraction of it is used in the biosyntheses of glycolipids and glycoproteins.

Although a 50g daily dose has been recommended for a healthy adult, most of it will be eliminated within eight hours, and it is best to take smaller doses more frequently. The dose recommended from your supplier will be based on the strength of the supplement and should be followed, but it is more effective when taken throughout the day rather than in one dose.

The glyconutrient Galactose is without doubt essential for the proper functioning of your body, and without it your immune system would lose its effectiveness and there would likely be many more side effects. Although there is normally sufficient in a normal diet, a daily supplement will do no harm and would ensure that you did not suffer from a deficiency.

Arabinogalactans are an abundant class of cell surface proteoglycans widely distributed in flowering plants. Arabinogalactans are proteoglycans (a type of protein and sugar combination) found between cells of most plants. They are commonly found in larch and tamarack and herbs and can be used as soluble fiber. Since the late 1980s, arabinogalactanproteins have attracted widespread attention from plant biologists following reports of their involvement in plant development, including a role in root regeneration and seed germination.. Arabinogalactan proteins are readily soluble and possibly play a major role in cell-cell interactions during development.

A 2004 study done at the University of Minnesota that examined supplementation of arabinolactan fiber for six months did not make much of a difference in cholesterol or blood sugar control. However, arabinolactans may have immune stimulating properties. Arabinolactans are found in the plant Andrographis paniculata. Arabinolactans probably have some beneficial effects on fecal microflora.

Arabinogalactan in Food
Several vegetables and grains have arabinogalactans including tomatoes, carrots, radishes, and wheat. Arabinogalactans are also found in herbs including echinacea and certain mushrooms as reishi.

Arabinogalactan Summary
At this point it is too early to make any recommendations regarding arabinolactan use in terms of treatment or prevention of illness. We know so little about the short and long term effects of arbinogalactans on the immune system. We also know very little how arabinolactans compare to other immune system influencing herbs, mushrooms, and nutrients such as vitamin C, andrographis, beta-lactans, AHCC mushroom extract, cordyceps, and others.

Immunomodulating activity of arabinogalactan and fucoidan in vitro.
J Med Food. 2005 Winter;8(4):446-53.
Department of Biotechnology & Bioproducts Research Center, Yonsei University, Seoul, South Korea.
Many polysaccharides obtained from natural sources are considered to be biological response modifiers and have been shown to enhance various immune responses. Here, we investigated the immunomodulating effects of arabinogalactan and fucoidan in vitro. Mouse spleen lymphocytes became cytotoxic to tumor cells after culture with arabinogalactan and fucoidan at concentrations of 10-100 microg/mL. These data suggest that arabinogalactan and fucoidan are activators of lymphocytes and macrophages. This property may contribute to their effectiveness in the immunoprevention of cancer.

An arabinogalactan isolated from the medicinal plant Maytenus ilicifolia.
J Nat Prod. 2004 Apr;67(4):703-6.
An arabinogalactan was obtained from the leaves of Maytenus ilicifolia by hot aqueous 2% KOH extraction, followed by a freezing-thawing process and anion-exchange chromatography. It consisted of arabinose, galactose, galacturonic acid, and rhamnose in a 69:20:6:5 molar ratio.

An arabinogalactan from the skin of Opuntia ficus-indica prickly pear fruits.
Carbohydr Res. 2004 Apr 28;339(6):1201-5.
The cold-water extract from the skin of Opuntia ficus-indica fruits was fractionated by anion-exchange chromatography. The major fraction, which was purified by size exclusion chromatography, consisted of a polysaccharide composed of galactose and arabinose residues in the ratio 6.3:3.3, with traces of rhamnose, xylose and glucose, but no uronic acid.

No long-term benefits of supplementation with arabinogalactans on serum lipids and glucose.
J Am Diet Assoc. 2004 Apr;104(4):636-9.
Marett R, Slavin JL. Department of Food Science and Nutrition, University of Minnesota
We conducted a 6-month randomized, double-blind, parallel trial in which subjects consumed their usual diet plus arabinogalactan, a functional fiber isolated from either larch or tamarack. Healthy human subjects (28 men, 26 women) ages 18 to 55 years old consumed 8.4 g/day larch arabinogalactan (n=18), tamarack arabinogalactan (n=19), or a placebo of rice starch (n=17). Serum cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, apolipoprotein B, apolipoprotein A-I, glucose, and insulin were measured monthly. Three-day food records, body weight, blood pressure, and gastrointestinal symptom surveys were obtained monthly. Serum lipids seemed to decrease at month 2, but there were no statistically significant differences among diets for any measured endpoint. Arabinogalactan is a recognized soluble fiber and is currently being used in products because it is not viscous, is easily incorporated into foods and beverages, and is well accepted by consumers.

Antimicrobial activity of Andrographis paniculata.
Fitoterapia. 2003 Dec;74(7-8):692-4.
The antimicrobial activity of aqueous extract, andrographolides and arabinogalactan proteins from Andrographis paniculata were evaluated. The aqueous extract showed significant antimicrobial activity, which may be due to the combined effect of the isolated arabinogalactan proteins and andrographolides.

Effect over time of in-vivo administration of the polysaccharide arabinogalactan on immune and hemopoietic cell lineages in murine spleen and bone marrow.
Phytomedicine. 2003 Mar;10(2-3):145-53.
Current evidence indicates an immunostimulating role for complex carbohydrates, i.e., polysaccharides, from several plant sources. In the present work, we determined the specific in vivo effects, with time of administration, of one such compound, a neutral arabinogalactan from larch not only on immune (lymphoid) cells, but also on natural killer (NK) lymphoid cells, as well as a variety of other hemopoietic cells in both the bone marrow and spleen of healthy, young adult mice. The latter were injected daily (i.p.) with arabinogalactan (500 microg in 0.1 ml pH 7.2 phosphate buffered saline-PBS) for 7 or 14 days. Additional, aged (1 1/2-2 yr) mice were similarly injected for 14 days only. Control mice were given the PBS vehicle in all cases, following the above injection regimen. Animals from all groups were sampled 24 h after the final injection and the immune and hemopoietic cell populations in the bone marow and spleen were assessed quantitatively. The results indicated that immediately following either 7 or 14 days of arabinogalactan administration to young, adult mice, lymphoid cells in the bone marrow were significantly decreased, respectively) relative to controls but remained unchanged at both time intervals in the spleen. NK cells, after 7 days of arabinogalactan exposure, were also decreased significantly in the bone marrow, but unchanged in the spleen. After 14 days' exposure to the polysaccharide, NK cells in the bone marrow had returned to normal (control) levels, but were increased in the spleen (p < 0.004) to levels greater than 2-fold that of control. Among other hemopoietic cell lineages, none was influenced in the bone marrow or spleen by one-week administration of arabinogalactan; however, after two-week exposure, precursor myeloid cells and their mature (functional) progeny (granulocytes), were significantly reduced in the spleen, as were splenic monocytes. These lineages in the bone marrow, however, remained steadfastly unaltered even after 14 days of continuous exposure to the agent. Of the vast cascade of cytokines induced in the presence of this polysaccharide, it appears that immunopoiesis- and hemopoiesis-inhibiting ones are most prevalent during at least the first two weeks of daily exposure.

Immunological activity of larch arabinogalactan and Echinacea: a preliminary, randomized, double-blind, placebo-controlled trial.
Altern Med Rev. 2002 Apr;7(2):138-49.
Kim LS, Waters RF, Burkholder PM.
Research Department, Southwest College, Arizona
The immunomodulating effects of two Echinacea species, E. purpurea and E. angustifolia and larch arabinogalactan extracted from Larix occidentalis were examined in a randomized, double-blind, placebo-controlled, prospective four-week clinical trial at a naturopathic medical school research center. Forty-eight healthy female volunteers (22-51 y) were randomly assigned to one of six groups: standardized extract of E. purpurea (EP); ultra-refined E. purpurea/E. angustifolia (urEPA); E. purpurea/E. angustifolia (EPA); E. purpurea/E. angustifolia plus larch arabinogalactan (EPALA); larch arabinogalactan; or placebo. METHODS: Immunological tests with enumerative measurements, stool cultures for Lactobacillus acidophilus and yeast, and health-related quality of life (HRQoL) using the Medical Outcomes Study derived SF-36 self-administered questionnaire were assessed at baseline and at four weeks. RESULTS: Complement properdin increased by 21 percent in the EPA group and by 18 percent in the EPALA group (p<0.05), compared to the placebo group. SF-36 showed improvements in overall physical health, vitality, and emotional health in the same two groups (EPA and EPALA). DISCUSSION: Volunteers in the EPA and EPALA groups had increased production of complement properdin after four weeks of intervention. The increased complement properdin may be an indication of one aspect of immune system stimulation in patients treated with either E. purpurea/E. angustifolia or E. purpurea/E. angustifolia plus larch arabinogalactan.

Effects of dietary larch arabinogalactan on gastrointestinal and blood parameters in healthy human subjects.
J Am Coll Nutr. 2001 Aug;20(4):279-85.
Robinson RR, Feirtag J, Slavin JL.
Department of Food Science and Nutrition, University of Minnesota
Larch arabinogalactan is a non-digestible soluble dietary fiber that resists hydrolytic enzyme action and enters the large bowel intact where it is fermented by resident microflora. To determine whether Arabinogalactan has similar physiological properties to other soluble dietary fibers, we examined the effect of 15 and 30 g per day of a commercially available AG from Western Larch on several gastrointestinal and blood parameters. METHODS: Gastrointestinal parameters included fecal microflora, fecal enzyme activity, fecal short-chain fatty acids, fecal pH, fecal weight, transit time and bowel frequency. Blood parameters included total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, Apo-A1, Apo-B, glucose and insulin. The study consisted of two three-week diet treatments with no washout period. Participants (n=20, 11 males, 9 females) consumed their usual diet in addition to 15 or 30 g Arabinogalactan in a beverage sweetened with aspartame as compared to their usual diet with the control beverage. RESULTS: Significant increases in total fecal anaerobes were observed with 15 g and 30 g Arabinogalactan . A significant increase in Lactobacillus spp. was observed when subjects consumed Arabinogalactan for a total of six weeks regardless of dose. There were no significant changes in other microflora, fecal enzyme activity, transit time, frequency, fecal weight, fecal pH and short-chain fatty acids. Fecal ammonia levels decreased with 15 g and 30 g Arabinogalactan. No significant changes in blood lipids or blood insulin were observed. CONCLUSIONS: These data suggest that dietary Arabinogalactan is easily incorporated into the diet, well tolerated in subjects and has some positive effects on fecal chemistry. arabinogalactan larch research.