A good quality supplement can help you lose weight and improve your body composition. They are built around nutrients that boost healthy fat loss and support physical activity to improve your and health and fitness.
Poor quality supplements on the other hand often make outrageous claims about losing weight quickly without taking into account long term health. They are often not subjected to rigorous studies and make claims that science cannot back up.
So which category does chitosanfit into? In this article we take a look…
What Is Chitosan?
Chitosan is derived from chitin, a fibrous sugar that forms the main component of insect and crustacean exoskeletons.
It is the most abundant amino polysaccharide [1] and when eaten it provides a form of insoluble fiber that the body cannot absorb or digest.
Chitosan is used primarily in the medical setting to treat those with Crohn’s, high cholesterol and kidney failure patients who are on dialysis. It has also been used to treat tooth decay too, by rubbing it directly onto the gums or by adding it to chewing gums.
Over the last few years though the drug has been used to treat obesity and it is available as an over-the-counter weight loss supplement.
The idea is that chitosan is different to other fibers as it has a positive ionic charge and is therefore able to bond chemically with the negatively charged fats in your body.
As you can’t absorb or digest the fiber it pulls the fats away from your digestive tract and is eliminated without absorption [1]. For this reason it is classed as a fat binderor ‘fat magnet’ rather than a fat burner.
However, although many clinical trials have been conducted on the drug as a weight loss supplement, it’s efficacy remains in dispute [2].
So does it help you lose weight or is it another case of medical intervention being used for the wrong reasons?
Let’s have a look at what the studies say…
Key Point: Chitosan comes from the skeleton tissue of crustaceans and insects. It has been used to treat a number of medical disorders.
Does Chitosan Help You Lose Weight?
When you’re looking for evidence on weight loss products (or anything else for that matter) you should always go to the most rigorous study designs.
The gold standard study design is a Randomized controlled trial (RCT) as it provides unbiased, clinical evidence of whether a drug or supplement has an effect. Another good quality design is the systematic review. This is a secondary research tool where a range of clinical studies such as RCTs are collected and analyzed as one mega study. Together these research methods for the cornerstone of evidence-based medicine.
Study #1.
Taking that information on board, The journal Obesity Reviews conducted a systematic review of all relevant RCTs on chitosan and its effect on weight loss [3].
In the review, 14 separate studies containing a total of over 1000 participants were included. Initially, the reviewers thought they had found some clinical benefits to chitosan – an additional 1.7 kg weight loss over a 4 week period or more. That is a big amount.
However, when the analysis was conducted again – this time with only high quality studies included – that additional weight loss disappeared. The high-quality trials found that the effect of chitosan on body weight was minimal and unlikely to be of clinical significance.
Study #2.
This high quality study used an RCT design and 250 overweight participants to assess the effects of chitosan on weight loss [2].
Over a 24-week period the participants were given either 3 g of the drug or a placebo. At the end of the study both groups had lost weight. Chitosan however didn’t cause any more weight loss than the placebo. There were also no differences seen between groups for cholesterol levels, blood pressure blood sugar or quality of life either.
Study #3.
This study used a meta-analysis design [4]. These are like systematic reviews but contain their own statistics – a very high-quality approach to clinical research.
Altogether, 386 patients from 5 separate studies were included in the data. The research team wanted to assess if Chitosan helped those who were between 10-25% overweight, lose fat mass.
They found a weak, but statistically significant difference with the Chitosan group losing more weight than placebo groups.
However, the author of the review study recorded that they had concerns over the quality of some of the studies – particularly those that were funded by manufacturers of Chitosan products.
Key Point: Large research reviews have found no benefit to using Chitosan for weight loss. The studies that did report benefits may have been confounded with poor research methodology.
Are There Any Side Effects to Chitosan?
If you’re allergic to shellfish then you probably want to avoid this supplement.
There’s an ongoing debate about people being allergic to shellfish meat not the shell itself, but until that is settled we’d suggest you give it a miss.
Even if you’re not allergic to shellfish you need to be aware that chitin can increase blood arsenic levels. The shell itself can contain relatively high amounts and long-term use can put you at risk of poisoning [5].
Additionally, if you are taking blood thinning medication then you’d need to speak to your physician before you considered using it. It’s the same if you on any type of diabetes medication.
As this drug eliminates fats from the body without digestion you run the risk of malabsorbtion and fat soluble vitamin deficiency if you use it over a long period of time. Vitamins A, D , E and K are all transported in fats and chitosan may stop you absorbing them. It’s the same for minerals such as magnesium, calcium and selenium too.
This could lead to a number of medical concerns.
Other than that, the side effects you can expect from this drug are stomach discomfort, gas and constipation. It can also cause nasuea too.
