Do omega-3 fatty acids from seafood help deter development of diabetes?

This question matters more than ever, amidst rising disease rates ... and evidence that even lean-looking people can develop it, unbeknownst.

We lack a full answer, given the limited number and quality of human studies and clinical trials conducted to date. 

Animal and human studies alike suggest that omega-3s should help, due to their effects on relevant aspects of metabolism … including adiponectin, the so-called the “starvation hormone”. 

For an overview, see “Fish & Omega-3s May Help Deter Diabetes”, “Green & Marine Omega-3s May Deter Diabetes” and related research reports from the Omega-3s & Metabolic Health section of our news archive. 

Encouragingly, the authors of a recent analysis concluded that every 80 grams [2.8 oz] of oily fish (e.g., salmon, tuna, and sardines) consumed daily may reduce the risk of diabetes by 20 percent (Zhang M et al. 2013). 

It's also critical to note that the extreme “omega imbalance” in the standard America diet – too few omega-3 fats and far too many omega-6 fats – appears to raise the risk: see “Omega-6/Omega-3 Imbalance Pushes Heart/Diabetes Perils”.

Now, a small but well-designed clinical trial from India provides more evidence that omega-3s exert diabetes-deterring effects.

Its results suggests that supplemental omega-3 fatty acids – and two key bodily antioxidants – can improve diabetes. 

Clinical trial sees benefits from omega-3s, lipoic acid, and vitamin E
The randomized, double blind, placebo controlled trial was conducted by researchers from B J Medical College in Pune, India.

It involved 104 patients diagnosed with diabetes and a key metabolic cause known as insulin resistance.

Participants were divided into four groups, each of which took different capsules:
  • Placebo capsules
  • Omega-3 fish oil
  • Alpha lipoic acid – a key, potent antioxidant made by the body
  • Vitamin E – an essential dietary nutrient with antioxidant properties
The scientists measured two key factors in diabetes risk and severity, before and after the 90-day trial:
  • Fasting blood glucose
  • Glycated hemoglobin (HbA1c)
HbA1c is a form of hemoglobin measured to identify the average blood sugar (glucose) level over the previous several months.

Higher levels of HbA1c predict higher risk for diabetes, cardiovascular disease, kidney disease, and retinal disease.

In short, the results showed that each of three nutrients lowered the levels of HbA1c and blood glucose.

After 90 days, levels of HbA1c dropped substantially in all three groups (omega-3s, vitamin E, and alpha lipoic acid).

Fasting blood sugar levels also dropped in all three groups, but less significantly.

And the outcomes showed that omega-3s were the most effective of the three supplements:
“… the maximum improvement in blood glucose and HbA1c was with omega 3 fatty acid.” (Udupa A et al. 2013) 

As the researchers concluded, “ALA (alpha lipoic acid), omega 3 fatty acids and vitamin E can be used as add-on therapy in patients with type 2 diabetes to improve insulin sensitivity and lipid metabolism.” (Udupa A et al. 2013) 

They noted that it may make sense for physicians to prescribe all three nutrients, because their mechanisms and effects on insulin sensitivity differ: “… combining these [supplements] might prove as an attractive option in patients with type 2 diabetes …” (Udupa A et al. 2013).

That seems wise, since all three are affordable, bring broad benefits and possess excellent safety records.

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  • Djoussé L, Biggs ML, Lemaitre RN, King IB, Song X, Ix JH, Mukamal KJ, Siscovick DS, Mozaffarian D. Plasma omega-3 fatty acids and incident diabetes in older adults. Am J Clin Nutr. 2011 May 18. [Epub ahead of print] doi:10.3945/ajcn.111.013334 
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  • Guebre-Egziabher F, Rabasa-Lhoret R, Bonnet F, Bastard JP, Desage M, Skilton MR, Vidal H, Laville M. Nutritional intervention to reduce the n-6/n-3 fatty acid ratio increases adiponectin concentration and fatty acid oxidation in healthy subjects. Eur J Clin Nutr. 2007 Aug 15; [Epub ahead of print] 
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