Last updated: Glucomannan is a complex sugar that may lower cholesterol and blood sugar and prevent constipation. Early research has shown that it can also help with weight management, gut health, and skin protection. Continue reading to learn more about the potential benefits.
What is Glucomannan?
Glucomannan can be described as a complex sugar or soluble fiber. Konjac glucomannan is the most common type. It is extracted from tubers of konjac (a native Asian plant [1].
It can also be extracted from [1]
* Eastern white pine
* Higanbana
* Lily
* Orchid
* Ramie
* Redwood
* Suisen
It is extremely absorbent and has the highest level of viscosity ([2]).
A few grams of glucomannan can transform a glass (8 ounces) worth of water into a gel.
This fiber is used as a preservative, a fat substitute and in thickening and binding foods.
Because of its weight loss reputation, it has been popularized as a dietary supplement.
Mechanisms of Action
Glucomannan works by:
* Takes up space in your stomach and makes you feel fuller, so you eat less.
* Reduce hunger hormone ghrelin [3]
* To decrease the absorption (proteins and fats) of nutrients [4, 1]
* Removal of bile acids [5]
* Promoting good bacteria growth in the gut [6, 7,]
Potential benefits of Glucomannan
Glucomannan has been approved for use as a food ingredient, but it is not approved for use in medical conditions. They are subject to regulations, but they don’t guarantee their safety or effectiveness. Before you start supplementing, consult your doctor.
It may be useful for
1) Cholesterol
Cholesterol is the main ingredient in bile acids. Glucomannan binds with bile acids to help eliminate them from the body. The body must convert more cholesterol to bile acids, which lowers cholesterol levels [5].
Two meta-analyses were conducted, one involving 12 and the other encompassing 14 studies. Both showed that this supplement significantly reduced LDL and non HDL cholesterol types. LDL and non HDL cholesterol raise the risk of developing heart disease when they are elevated [8, 9,].
In a with 120 people with high cholesterol, glucomannan combined with policosanol or chromium-polynicotinate reduced total and LDL cholesterol but didn’t affect HDL or triglyceride levels [10].
Another trial showed that glucomannan and chitosan reduced total, HDL, and HDL cholesterol in 21 overweight individuals [11].
2) Diabetes
Some researchers believe that glucomannan can cause slower sugar absorption, which may reduce spikes in blood sugar [1].
This fiber was found to lower blood sugar levels and cholesterol in 22 diabetics [12].
Additionally, two studies showed that glucomannan, taken before eating, decreased blood sugar spikes and appetite in diabetic adults [13, 3,].
In the same way, type 2 diabetics who ate glucomannan-enriched foods had lower blood sugar levels [14].
Another study with 11 type 2 diabetics showed that the supplement did not lower blood sugar but that it reduced total: HDL cholesterol ratio, and blood pressure [15].
Study of 34 pregnant women revealed that fiber safe reduced blood glucose levels in diabetic and non-diabetic subjects [16].
3) Constipation
Six studies showed that glucomannan was effective in relieving constipation [17, 18, 19, 6, 7, 20, and 20].
In a study with 72 children, however, the fiber did not perform better than the placebo when treating constipation [21].
There is insufficient evidence
These purported benefits can only be supported by low-quality, limited clinical studies. The evidence is not sufficient to support the use glucomannan in any of these uses. Talk to your doctor before you take glucomannan supplements. Never use them instead of what your doctor prescribes.
4) Weight Management
Multiple clinical studies have shown that glucomannan supplementation can increase weight loss over a placebo [22-23-24, 25, 26, 26].
In other studies, however, it didn’t have any significant effect on weight loss [27-28, 29].
Glucomannan might help with weight loss in some groups, but not others. Future research will help to clarify.
5) Gut Health
Glucomannan was found to increase the beneficial gut bacteria (lactic acid bacteria, and bifidobacteria), in seven constipated patients and eight healthy adults [6, 7,].
The production of short-chain fat acids (SCFAs), and the number of beneficial bacteria in mice and rats was also increased by small amounts of this fiber [30, 31].
6) Polycystic Ovary Syndrome
Insulin resistance can be caused by polycystic Ovary Syndrome (PCOS). A study of 30 PCOS-related women found that glucomannan supplementation reduced insulin and glucose levels.
7) Hyperthyroidism
A study of 48 patients with hyperthyroidism found that those who received glucomannan in addition to standard treatment had significantly lower levels of thyroid hormones within the first week [33].
8) Skin Damage
Glucomannan reduced UV-induced skin reddening in five volunteers and protected skin cells from UVB-induced damage [34].
Animal & Cell Studies (Lacking evidence)
There is no clinical evidence to support the use of glucomannan in any of these conditions. Here is a summary from animal- and cell-based research that should help guide future investigation. The following studies should not be taken as supporting any health benefit.
9) Acne
In a cell study, probiotic bacteria and glucomannan prevented the growth of acne-causing bacteria [35].
10) Inflammation
This supplement reduced inflammation in arthritis-suffering rats [36].
It also reduced inflammation in the gut and skin of mice [37,38].
These studies showed that glucomannan reduced Th2 response (IL-4, IL-13).
11) Allergies
This supplement prevented allergic skin and nose reactions in mice [39-40].
It did this by decreasing IgE levels (41, 42).
12) Antioxidant Activity
This supplement raised antioxidant and antioxidant enzyme levels in rats and mice [43, 44 and 45].
13) Aging
This supplement slows down the aging process in rats and mice [46, 47].
Side Effects and Precautions
Since 1994, Glucomannan is FDA-approved safe. It has been approved in the food industry as a binder since 1996 [48, 1,].
Supplementation can cause side effects such as flatulence, stomach pain, or obstruction [2, 49].
You should drink enough fluids to prevent it from forming and blocking your gut. It is also recommended that you do not take it before going to sleep.
Glucomannan can also interfere with the bioavailability and absorption of ingested drugs [2,49].
This supplement lowers blood sugar. It can also be used in combination with diabetes medication to lower blood sugar.
Talk to your doctor before taking glucomannan. This will help you avoid unexpected interactions and adverse reactions.
Supplementation
Dosage
Because there is not enough evidence to prove one, there is no safe or effective dose of glucomannan that can be used for any purpose. However, certain doses have been shown to be beneficial in clinical trials.
Researchers usually take 1 to 5 grams of the supplements daily, and 2-3 times per day. The supplements are taken with water an hour before meals [23, 24, 25, 25, 9, 18].
User Reviews
According to users, glucomannan can be used for:
* Controlling blood sugar levels
* Weight loss
* Hunger control
* Constipation
* Lowering cholesterol
* Insulin resistance in PCOS
Some report:
* Dizziness
* Nausea
* Bloating and gas
