A recent study from Brazil has shown that the consumption of fish oil increases insulin response in non-obese type 2 diabetic individuals.
A recent study from Brazil has shown that the consumption of fish oil increases insulin response in non-obese type 2 diabetic individuals.
Written by Pragna L Krupa
With quotes from Dr Jothydev Kesavadev (diabetologist)
While the benefits of fish oil in reducing cholesterol and hence improving heart health have been proven before, a new study has shed light on its role in reversing insulin resistance. A study conducted by Brazilian scientists, recently published in Nutrients, says the anti-inflammatory effects of fish oil may reverse insulin resistance in nonobese individuals with type 2 diabetes. The study shows fish oil can weaken insulin resistance and reduce glucose intolerance by modulating the body’s inflammatory response.
According to the study, fish oil, abundant in omega-3 fatty acids, can shift the body’s immune response to anti-inflammatory and improve blood glucose tolerance, lowering the risk of diabetes.
Observations from the study
The study was conducted on non-obese rats with a condition similar to type 2 diabetes. The condition was marked by elevated blood sugar levels due to decreased insulin efficiency.
“Our experiments involved Goto-Kakizaki [GK] rats, an animal model for nonobese type 2 diabetes. We found that insulin resistance can be reduced in these animals by modulating the inflammatory response so as to change the profile of defense cells [lymphocytes] from a pro-inflammatory state to an anti-inflammatory state. This process parallels the response of obese individuals with insulin resistance to omega-3 fatty acid supplementation,” said Rui Curi, Director of Butantan Institute’s Education Center, Professor of Interdisciplinary Graduate Studies in Health Sciences at Cruzeiro do Sul University (UNICSUL), and coordinator of the study, in a statement. He added, “In previous studies, we observed alterations in both lymphocytes and macrophages [large white blood cells often residing in adipose tissue and are part of the innate immune system] in non-obese rats with insulin resistance. In such cases, these cells produce more pro-inflammatory cytokines, as is central in obese people with diabetes.”
Researchers observed that the administration of 2 g fish oil per kilogram of body weight (equivalent to 540 mg/g of eicosapentaenoic acid or EPA and 100 mg/g of docosahexaenoic acid or DHA) three times per week for eight weeks reduced insulin resistance in non-obese rats. They also displayed improved blood sugar levels, inflammatory markers and lipid features, including total cholesterol, LDL (bad cholesterol) and triglycerides.
Effective in nonobese individuals
The study concluded that fish oil supplementation benefited GK rats by improving glucose intolerance, suppressing insulin resistance and modulating lymphocytes, cells of the immune system that fight infection toward Treg polarization.
“Fish oil supplementation reversed this pro-inflammatory profile, displaying a significant anti-inflammatory effect and reducing polarization of Th1 and Th17 cells [lymphocyte subtypes that perform crucial functions in inflammation], followed by a rise in the percentage of Tregs [regulatory T-cells], which can inhibit the activation of pro-inflammatory lymphocytes. Thus, the action of omega-3 fatty acids on lymphocytes, modulating them from a pro-inflammatory state to an anti-inflammatory state, may have triggered the reduction in insulin resistance in these animals,” shared Tiago Bertola Lobato, the first author of the study, during whose PhD candidacy the study was done.
According to researchers, the fish oil immunomodulatory effects indicate a potential effect of omega-3 to reduce inflammatory response in lean people with type 2 diabetes. The study highlights that the anti-inflammatory effects of fish oil can contribute to the increased insulin response in nonobese people with type 2 diabetes.
Despite the interesting findings of the study, researchers stressed the need for more research to confirm their findings.
Benefits of omega-3 fatty acids for people with diabetes
The use of omega-3 fatty acids in treating diabetes has long been a controversial topic, says Dr Jothydev Kesavadev, chairman of Jothydev’s Diabetes Research Centre, Thiruvananthapuram, Kerala. “Going by science, the study is useful in understanding the role of omega-3 fatty acids in insulin resistance. However, earlier studies showed positive results in some people — not in all. The issue is that non-responders [in humans] could be more than 60-70%,” he said.
Dr Kesavdev added that some studies have shown that the use of omega-3 fatty acids in people above the age of 60 years can result in an irregular heart rhythm called atrial fibrillation. Hence, it is not recommended for such people. “Apart from omega-3 fatty acids, there are more effective medicines for insulin resistance. Most studies indicate that sleeping for seven to eight hours per day and exercising for more than 30 minutes, irrespective of whether one is obese or not, is shown to have profound benefits in insulin resistance,” he said. If a person is overweight, losing 5-7% of body weight can improve insulin sensitivity, he added.
Takeaways
- A recent Brazilian study has shown that fish oil supplementation helps in reversing insulin resistance in non-obese people with type 2 diabetes.
- The study conducted on nonobese rats has shown improvements in blood sugar levels, inflammation markers, and lipid profiles.
- Omega-3 fatty acid in fish oil also helps in reducing the risk of diabetes.