Carb blockers inhibit digestive enzymes that break carbohydrates down into single units of sugar. The carbs that remain in larger units won't make it into your bloodstream because the small intestine only absorbs single sugars. This helps prevent spikes in blood sugar and may make it easier to lose weight because you won't absorb all the carb calories consumed. But carb blockers can cause digestive side effects and lead to serious problems if you're diabetic, so talk to your doctor to be sure supplements are safe for you.
Types of Carb Blockers
Some carb blockers are prescribed by doctors to help lower blood sugar in people with diabetes. The prescription meds are produced by fermenting microorganisms. Supplemental carb blockers sold in pharmacies are made from white kidney beans, or cannellini beans, which naturally contain substances that block the enzymes used to digest carbohydrates.
White kidney bean extract is marketed as a weight-loss supplement. When a group of overweight men and women took bean extract for 12 weeks, they lost about 7 pounds, according to studies cited in the Nutrition Journal in March 2011. The same review also reported that bean extract lowered blood glucose, but the results depended on the amount consumed.
Digestive Tract Distress
The carbs that aren't absorbed in the small intestine travel to the large intestine, where they're fermented by bacteria. While fermentation is beneficial because it helps good bacteria thrive, keeps the intestine healthy and supports your immune system, it also produces extra gas. As a result, common side effects from taking carb blockers are gas, bloating and abdominal pain.
Some people also report stomach upset or pain and diarrhea after taking carb blockers. Your digestive tract will eventually adjust, which means all of the gastrointestinal side effects should go away as you continue to use carb blockers, reports Consumer Search.
Low Blood Sugar
If you take insulin or other medications used to treat diabetes, don't take carb blockers until you talk to your doctor. Carb blockers also lower blood sugar, and mixing them with other diabetic medications may cause blood sugar to drop dangerously low.
The risk from supplements depends on how much you take and the amount of active ingredients per dose. Check with the pharmacist, the manufacturer or your health care provider if you have any questions about the supplement.
Allergy Alert and Other Warnings
Some brands contain wheat extract, fish, soy and other ingredients that are common allergens. When you buy carb blockers, take the time to read the label. Check all the ingredients and look for any warnings. If you're allergic to any of the ingredients, keep searching for a brand that's free of allergens.
Due to a lack of research exploring the safe use of carb blockers during pregnancy, women who are pregnant or breast-feeding should avoid these supplements. If you have any type of gastrointestinal disorder, liver disease or a problem with your kidneys, don't take carb blockers until you consult your doctor.
- Nutrition Journal: A Proprietary Alpha-Amylase Inhibitor From White Kidney Bean (Paseolus Vulgaris): A Review of Clinical Studies on Weight Loss and Glycemic Control
- Consumer Search: Carbohydrate Blockers
- MedlinePlus: Acarbose
- Beauregard Drugs: Amylase Inhibitors
- DailyMed: Acarbose -- Acarbose Tablet