Chitosan Fat Blocker Side Effects

Chitosan (deacetylated chitin biopolymer) is the main ingredient in the weight-loss supplement Fat Blocker. Chitosan, a substance extracted from the hard outer shells of marine crustaceans such as lobster and shrimp, is an indigestible fiber that passes through the digestive system. Because chitosan can sweep up some dietary fat on its way, it slightly reduces the amount of fat that is digested from a meal. However, chitosan's benefits are not without side-effects.

Known side-effects

• The Food and Drug Administration acknowledges only two possible side effects of chitosan for non-allergic individuals--constipation and interference with heart contractions--but calls both rare. WebMD adds that some dieters using chitosan report minor problems with stomach upset or intestinal gas. Because there have been no long-term studies of the side-effects of chitosan on human subjects, the possible long-range effects of use of this supplement are not known.

Nutrients

• Animal studies from 1999 show that by interfering with fat absorption, chitosan might also interfere with the absorption of vital nutrients in the diet, especially the fat-soluble vitamins such as Vitamins A, D, E and K and minerals such as calcium and iron. There are some indications that chitosan might be dangerous for pregnant and nursing mothers because of its ability to interfere with nutrient absorption; it is therefore not recommended for use by pregnant or breastfeeding women.

Medications

• Because it interrupts fat absorption, chitosan also might interfere with the absorption of some prescription medications, especially medications for blood pressure or blood clotting disorders. Dieters should always inform a prescribing physician that they are taking or considering any nutritional supplement, in case there are known drug interactions. Chitosan itself is a mild anti-microbial; while some studies have shown that chitosan can help heal tooth and gum infections, it also may decrease normal intestinal bacteria levels. Intestinal bacteria are an important part of digestion and immune system function.

Counter-indications

• Many people are allergic to shellfish, and these dieters might find that taking chitosan causes allergic reactions such as itchy rashes, shortness of breath, headaches, and localized swelling, especially in the heels and wrists. Any individual with a known digestive disorder of nutrient-absorption disorder should take chitosan or any high-fiber supplement only under the guidance of a physician.

Usefulness

• Chitosan is sometimes recommended by alternative health care professionals as a natural treatment for high cholesterol and troublesome wound healing. Recent research in India and Japan shows chitosan may be useful in the treatment of some cancers. However, it has proven to be only minimally effective as a weight-loss drug for many individuals. Weight-loss products are now required by law to note on their labeling that calorie reduction and exercise are necessary for successful weight-loss.