Chitosan's therapeutic uses
Chitosan is a natural fiber derived from the shells of crustaceans, such as shrimp and crabs, and has been explored for various therapeutic uses. It is primarily recognized for its potential to bind dietary fat in the digestive tract, which has led to investigations into its efficacy for lowering cholesterol and aiding weight loss. However, scientific studies have produced mixed results, indicating that while there may be slight benefits in reducing certain cholesterol levels, significant weight loss effects are not well-supported.
Beyond cholesterol management and weight loss, chitosan has been assessed for its impact on kidney failure, showing some promise in reducing harmful substances in the body and improving overall strength in affected individuals. Additionally, its antimicrobial properties have been highlighted in contexts like wound healing and oral health, suggesting it may help prevent infections and cavities. Chitosan's antioxidant and anti-inflammatory characteristics could also offer protective benefits against chronic diseases.
Despite these potential uses, there are important safety considerations. Long-term use of chitosan can lead to malabsorption of essential vitamins and minerals, posing risks such as osteoporosis and altered gut flora. Therefore, individuals considering chitosan supplements should consult with healthcare professionals, especially those who are pregnant, nursing, or have shellfish allergies. Overall, while chitosan presents intriguing therapeutic possibilities, more robust scientific evidence is needed to substantiate its effectiveness and safety in various health applications.
Chitosan's therapeutic uses
- DEFINITION: Natural substance used to treat specific health conditions.
- PRINCIPAL PROPOSED USES: None
- OTHER PROPOSED USES: Antimicrobial, high blood pressure, high cholesterol, kidney failure, preventing cavities, weight loss, wound healing, anti-inflammatory, antioxidant, drug delivery, tissue engineering
Overview
Chitosan is a form of fiber chemically processed from crustacean shells. Like other forms of fiber, such as oat bran, the human body does not digress chitosan well. As it passes through the digestive tract, it seems to have the ability to bond with ingested fat and carry it out in the stool. For this reason, it has been tried as an agent for lowering cholesterol and reducing weight. However, the results of the studies were mixed. Additionally, chitosan has been tried as a treatment for kidney failure and as an aid in wound healing. There are several other proposed therapeutic uses for chitosan.
Requirements and Sources
Chitosan can be extracted from shrimp, crab, or lobster shells. It is also found in yeast and some fungi. Another inexpensive source of chitin is squid pens, a by-product of squid processing. These are small, plastic-like, inedible pieces of squid removed before they are consumed.
Therapeutic Dosages
The standard dosage of chitosan is 3 to 6 grams (g) per day, to be taken with food. Chitosan can deplete the body of certain minerals. For this reason, when using chitosan, taking supplemental calcium, vitamin D, selenium, magnesium, and other minerals may be helpful. Also, according to a preliminary study in rats, taking vitamin C along with chitosan might provide additional benefits in lowering cholesterol.
Therapeutic Uses
Chitosan is supposed to bind fat in the intestines, so it has been tried as a treatment for high cholesterol. However, the evidence regarding whether it works has been mixed. One 2018 study found that supplementation with chitosan lowered cholesterol in study participants; however, other studies have shown minimal to no results.
Chitosan has also been proposed as a weight-loss treatment based on the same principle. However, despite some mildly positive results, the balance of evidence suggests that chitosan does not significantly aid weight loss.
Weak evidence hints that chitosan may be helpful in kidney failure. When used for this purpose, it is thought to work by binding with toxins in the digestive tract and causing them to be excreted.
Studies in dogs have found that topically applied chitosan can help heal wounds. This effect might be caused by stimulation of new tissue growth; in addition, topical chitosan appears to kill bacteria, such as those in the Streptococcus species, which may also contribute to wound healing. Chitosan may also have activity against Candida albicans, a form of yeast that causes vaginal infections.
Preliminary evidence suggests that oral chitosan may inhibit the expected rise in blood pressure after a high-salt meal. Other weak evidence hints that chitosan chewing gum might help prevent cavities. It has been suggested that chitosan can stimulate the immune system and prevent cancer, but there is no reliable evidence yet that it offers these benefits.
Animal studies suggest that some forms of chitosan may help to prevent bone loss, but because chitosan also interferes with mineral absorption, the net effect in humans might actually be to increase bone loss.
Other evidence suggests that chitosan is used to prevent infectious diseases because of its bioactivity, biosafety, and biocompatibility. Chitosan may be an effective agent in drug delivery systems. It can encapsulate drugs, releasing them gradually at the target delivery site, increasing effectiveness and reducing side effects. Chitosan may also be helpful in tissue regeneration and cell growth. Finally, chitosan’s anti-inflammatory and antioxidant properties may protect against free radicals that can lead to chronic health conditions.
Scientific Evidence
High cholesterol. An eight-week double-blind, placebo-controlled trial of fifty-one women found that the use of chitosan at a dose of 1,200 milligrams (mg) twice daily slightly reduced low-density lipoproteins (LDL, or bad cholesterol) compared with a placebo but did not affect total or high-density lipoprotein (HDL, or good cholesterol) levels. Another eight-week trial, enrolling eighty-four people, also found modest benefits.
However, a four-month double-blind, placebo-controlled trial of eighty-eight individuals found no improvement in cholesterol with 1,000 mg three times daily of a different chitosan product. A seven-month study of eighty-four men given a placebo or 1,200 mg of chitosan daily also failed to find any benefit. Furthermore, in a ten-month double-blind, placebo-controlled study of 130 men and women, using a special microcrystalline form of chitosan at a dose of 1,200 mg twice daily failed to improve cholesterol profile. These contradictory results suggest that if chitosan improves cholesterol profile, it does so to a minimal extent.
Weight loss. Chitosan has been widely advocated as a weight-loss supplement because of its supposed ability to bind fat in the digestive tract. However, despite some positive results, the largest and best-designed trial failed to find benefit. In this six-month double-blind, placebo-controlled study of 250 overweight people, use of chitosan at a dose of three grams daily failed to enhance weight loss to any meaningful extent compared with a placebo.
Kidney failure. People with kidney failure experience numerous health problems, including anemia, fatigue, and loss of appetite. In one open study, researchers tested chitosan supplements in eighty people with kidney failure receiving ongoing hemodialysis treatment. Half the participants were given forty-five mg tablets for a total of about 1,500 mg of chitosan daily for twelve weeks, and the other half were not given a supplement. Those in the treatment group showed a significant decrease in urea and creatinine levels. Further, they had a rise in hemoglobin levels and reported improved overall strength, appetite, and sleep.
Safety Issues
There is significant evidence that long-term, high-dose chitosan supplementation can result in malabsorption of some crucial vitamins and minerals, including calcium, magnesium, selenium, and vitamins A, D, E, and K. In turn, this appears to lead to a risk of osteoporosis in adults and delayed growth in children. For this reason, adults taking chitosan should also take supplemental vitamins and minerals, making especially sure to get enough vitamin D, calcium, and magnesium. Another possible risk of long-term ingestion of high doses of chitosan is that it could change the intestinal flora and allow the growth of unhealthful bacteria.
Finally, there has been a case report of arsenic poisoning caused by long-term use of chitosan supplements. It appears that shellfish can concentrate arsenic in their shells as part of their normal development. This, in turn, may lead to arsenic-laced chitosan supplements. Pregnant or nursing women, young children, and individuals with shellfish allergies should probably avoid chitosan altogether.
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