Galactose

Note: See also Economical Alternatives.

Galactose is an essential sugar found in abundance in the diet, especially in dairy products, where it co-exists with lactose, as well as in the pectins of some fruits. There are many people who are lactose-intolerant and, therefore, may also be lacking in Galactose. However, this essential sugar can easily be obtained from other foods (listed below).

Galactose is a simple sugar that is more common than glucose. Before it can be utilized by the body for energy, however, it must be transformed into glucose by the liver. It is the building block of carbohydrate chains associated with lipids (glycolipids) and proteins (glycoproteins).

As with all the essential sugars, Galactose is also necessary for cell communication. If just one of the sugars is missing in the diet, communication breaks down, resulting in disease. Depending on which sugar is missing will determine which disease forms. We are learning more all the time that these essential sugars are vital for far more than just a source of energy.

Absorption
Galactose is absorbed in the jejunum part of the intestine where it competes with glucose for transport. To some extent, Galactose is absorbed in the mouth across the buccal membrane by a transport also shared with glucose.

Bowel disorders can affect absorption of galactose, as well as any of the other sugars. Usually, it is because of abnormal brush-border cells of the intestinal epithelium which then results in diarrhea. A combination of “friendly flora” and enzyme supplementation, as well as the eight essential sugars, will, in time, correct any digestive abnormalities.

Approximately 30% of the galactose is incorporated into glycogen, although its preferred substrate is Glucose. Another 27-47% is oxidized to CO2, while the remainder is utilized for glycoprotein and glycolipid biosynthesis for nutritional distribution. It is becoming increasingly evident that both essential sugars “Galactose and Mannose” are very important for maintaining nutritional balance.

Excretion
Galactose is excreted by the kidneys, using a Glucose transporter. Although its excretion is not altered in diabetic patients, clearance is reduced in aging. Since Galactose is metabolized mainly in the liver, its clearance has been used as a marker for liver dysfunction and liver blood flow. Galactose has also been found in the feces of infants who are breast fed.

Functions

• In animal studies, Galactose inhibits tumor growth and its spread (metastasis), especially to the liver. In addition, Galactose levels were found to be decreased in the intestinal mucins of colon cancer patients, suggesting that the addition of Galactose to the diet could help prevent or reverse the disease.
• Galactose does not stimulate insulin secretion in humans. Therefore, serum Galactose levels are not affected in diabetics, which is good news.
• Although Galactose can easily be converted into Glucose when needed for energy and can be formed from Glucose, dietary sources of Galactose are still important to maintain an epimerase enzyme-mediated equilibrium. For instance, when Galactose was supplemented in the diet of patients with metabolic diseases being treated with low protein and low lactose diets, these patients showed a significant increase in Galactose concentrations in both the red and the white blood cells.
• Galactose appears to help correct many disorders, including enhancing wound healing, decreasing inflammation, and stimulating calcium absorption. It also appears to help lower the risk of developing cataracts.
• Galactose levels are usually lower in people with adult and juvenile arthritis and in those with Lupus, suggesting that this sugar is vital to preventing or correcting these conditions.
• Galactose is widely distributed throughout the body, including the brain. Studies also indicate that the saccaride triggers long-term memory formation.
• Galactose is another essential sugar concentrated in the testes, implying that these saccharides are vital in reproduction since it appears to help in the formation of sperm.
• Found in both the proximal and distal tubules of the kidney, Galactose is obviously important for proper kidney function.
• Galatose is also present in intestinal mucins which inhibit cholesterol absorption.
• Since Galactose is found in immunoglobulins and macrophages, it appears to play a primary role in the immune system, especially that of rheumatoid arthritis. In such patients, blood levels of the sugar were markedly reduced and proved that the less Galactose there was available, the more severe was the disease. During remission, the reduction in the amount of
• Galactose was reversed. To make matters worse, a lack of Galactose seemed to set off a chain reaction involving other essential sugars. A Galactose deficiency on the IgG of RA patients, also reduced the terminals for Glucosamine which, in turn, bind to Mannose proteins. This resulted in the activation of blood complement and the start of the inflammatory process.
• Galactose levels are also altered in other diseases, especially in the severely ill. Levels of this saccharide are markedly reduced in upper airway epithelial cells. This is important because such patients are more susceptible to opportunistic pathogens, especially those that target respiratory organs producing such diseases as pneumonia or bronchitis.
• Dietary Galactose is also important in maintaining normal bacterial flora in the intestines. Prolonged use of Galactose has proven to increase the number of Bifidobacteria while providing the proper environment for other beneficial bacteria in the human gut. Providing this type of environment not only strengthens digestive abilities, but also the immune system as well.
• Scientists are now turning their attention to a link seen between Galactose deficiency and MS (multiple sclerosis). This disorder has already been linked to an inablility to absorb another essential sugar, Xylose, but there also appears to be abnormal Galactose molecules present as well. In addition, the myelin sheath that covers nerves is attacked by overactive immune cells. The myelin sheath contains Galactose, as well as other essential sugars. Therefore, supplementation of all eight essential sugars could help rebuild the system to where absorption is once again possible and could reverse the condition.

Safety
There does not appear to be any side effects from using a supplemental Galactose, unless one is Galactose-intolerant, but this is an extremely rare condition. There were some concerns raised over low birth weight infants or those born prior to 37 weeks gestation. It appeared that these infants had some trouble absorbing Galactose, which researchers attributed to immature liver function. Based on research, some recommend as much as 50 grams in a healthy 150-pound adult as a safe dose. However, much less is more advisable, and since most of it is eliminated within 8 hours, dosing should occur at least twice a day to maintain optimal Galactose blood levels.

Dietary Sources
(mg of Galactose per 100 grams of produce)

• Dairy products
• Fruit: Apples (800), Apricot (600), Banana (200), Blackberries (1,000), Cherries (400), Cranberries (1,200), Currants (800), Dates (800), Grapes (300), Kiwi Fruit (700), Mango (1,700), Orange (1,600), Nectarine (1,100), Peach (1,300), Pear (600), Pineapple (700), Plums (2,600), Prunes (1,600), Raspberries (900), Rhubarb (1,500), Strawberries (500), Passionfruit (300)
• Herbs: Echinacea, Boswellia, Fenugreek, Chestnuts (2,700)
• Vegetables: Broccoli (2,700), Brussels Sprouts (4,100), Avocado, Cabbage (4,400), Carrot (3,400), Cauliflower (3,200), Celery (2,700), Cucumber (1,600), Potato (1,800), Eggplant (3,500), Tomatoes (1,600), Leeks (6,600), Asparagus (2,800), Lettuce (2,000), Green Beans (4,100), Mushrooms (not buttons) (1,100), Beetroot (1,100), Onions (4,500), Parsnip (2,200), Green Peas (800), Pumpkin (2,400), Spinach (1,400)

References