Chitin’s health benefits—should your patients add insects to their diet?
Key Takeaways
Chitin is a digestible fiber that is found in insects.
Chitin offers many potential health benefits, including antioxidant, immunostimulant, and lipid-lowering properties.
More adventurous patients may be willing to incorporate insects into their diets to fulfill certain nutrient deficiencies.
Commonly considered sources of dietary fiber are fruits and vegetables. One source that may not be immediately apparent is the exoskeletons of insects, made up of chitin. Just like other sources of fiber, chitin may decrease the risk of obesity and other metabolic disorders. But, unlike most types of fiber, chitin can be digested through an intriguing mechanism.
What is chitin?
In preclinical research funded by the NIH, researchers out of Washington University fed mice chitin-containing diets and found that, in addition to making their stomachs expand, the chitin triggered an immune reaction in the stomach and small intestine, as well as in fat tissue. This immune reaction occurred independently of gut microbes.[]
The researchers found that chitin is digested by an enzyme called acidic mammalian chitinase (AMCase), which is produced by chief cells in the stomach. Mice lacking this enzyme were unable to digest chitin. Thus, the production of this enzyme was dependent on the immune response initiated by chitin.
To examine the metabolic effects of eating chitin, the researchers fed mice high-fat diets that contained either chitin or another type of fiber. All of the mice ate similar amounts.
The results showed that the mice fed chitin exhibited improved insulin sensitivity vs those fed with other types of fiber. Moreover, mice who were fed chitin but who were unable to break it down demonstrated the greatest immune response, gained the least weight, and exhibited the lowest levels of body fat.
Taken together, these results indicate that the immune response secondary to chitin ingestion may trigger not only the production of AMCase but also of other digestive enzymes that help with digestion. This process could be a target of obesity intervention.
Health benefits of chitin
Unlike animal sources of protein and micronutrients, insects also contain fiber and omega-3 fatty acids, which can modulate the gut microbiota.[] Authors of a review on chitin-based prebiotics published in Foods note that chitin and its derivatives inhibit the growth of pathogenic microorganisms in the gut such as Salmonella Typhimurium, enteropathogenic E. coli, and V. cholerae, while leaving beneficial bacteria such as Bifidobacterium and Lactobacillus unaffected.[]
Chitosan is the chief derivative of chitin. It has low toxicity and mutagenicity, as well as being biocompatible.
This derivative also has antitumor, anti-inflammatory, antioxidant, immunostimulant, wound healing, cholesterol-reducing, antibacterial, and antifungal properties. As part of the diet, chitosan can also contribute to the loss of body fat, decrease blood pressure, treat diabetes mellitus, control arthritis, and drive immunostimulation.
Research has shown that chitosan may have lipid-lowering properties stemming from inhibition of the digestion and absorption of visceral fats, as well as from interference with the synthesis of bile acid and with lipid metabolism.
Adding chitin to your diet
According to the Foods review, the amount of chitin varies widely among sources. The following are some examples:
1–3% in yeast cell walls
8–43% in mushroom cell walls
16–23% in lobster shells
20–44% in silkworm
25–30% in crab shells
Although the shells of crustaceans and the residue from fungi are typically considered waste, insects may be a viable source of chitin in the diet. In addition to being eaten whole, they can be processed into meals and flours, which can be used to make energy bars, cookies, condiments and spreads, and more.
One barrier to the inclusion of insects or their byproducts in foods could be their palatability. Research shows that men and younger people may be more willing to consume insects.
Insect-derived proteins are of higher biological value vs. plant sources, as the insect sources harbor 46%–96% of essential amino acids. Insects also have less saturated fat vs animal-derived foods, along with lower cholesterol levels in some cases. Insects are also a good source of calcium, copper, magnesium, iron, manganese, selenium, and zinc.
Finally, from an environmental perspective, insects can be farmed using fewer resources compared with conventional livestock.
What this means for you
Chitin has antitumor, anti-inflammatory, antioxidant, immunostimulant, wound healing, cholesterol-reducing, antibacterial, and antifungal properties, thus representing a promising source of digestible fiber in the human diet. One drawback is that consumers may find the thought of eating insects, which are the most accessible source of chitin, unpalatable. When promoting the potential benefits of eating insects or insect-derived products, you can also note that they are rich sources of omega-3 fatty acids and proteins.
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