Even children have been sucked into America's viscious vortex of “diabesity” … the self-reinforcing cycle of overweight and weak control over blood sugar.
Good news is hard to come by, but the results of a small clinical trial suggest one possible way to help deter diabetes among the rapidly growing ranks of overweight teens.
First, some background is in order.
There's no evidence that the long-chain omega-3 fatty acids from seafood (EPA and DHA) can treat or cure type 2 diabetes in adults.
In fact, omega-3s can raise blood sugar levels slightly and temporarily in adults with type 2 diabetes … though there's no evidence that this minor, transitory effect presents any health risk.
On the plus side, omega-3s seem to help curb components of the pre-diabetes condition known as metabolic syndrome (MetS) … and help deter some of the adverse cardiovascular effects of type 2 diabetes.
For example, omega-3 supplements improved insulin sensitivity (i.e., reduce insulin resistance) in overweight women predisposed to chronic inflammation … a known risk factor for diabetes and cardiovascular disease (Browning LM et al. 2007).
The chief fat-related risk factors for cardiovascular disease are high intakes of saturated, omega-6, and trans omega-6 fatty acids.
In contrast, the main fat-related risk factors for diabetes and obesity are low intakes and/or blood levels of omega-3 fatty acids (Storlien LH 1994; Mozaffarian D et al. 2005; Ailhaud G et al. 2006).
Further, the fat composition of skeletal muscle, liver, and adipose (fatty) tissue plays key roles in the development of insulin resistance, and the maintenance of insulin sensitivity is related to the fat composition of muscle (Borkman M et al. 1993; Weiss R et al. 2003; Manios Y et al. 2008).
Early omega-3 intakes influence later outcomes
The link between omega-3s and the risk for diabetes and/or obesity appears strong with regard to fetuses, infants, and children.
Two recent studies found that obese children had lower blood levels of omega-3s, compared with their lean peers (Karlsson M et al. 2006; Scaglioni S et al. 2006).
And as we reported last year in “Omega-3s May Oppose Child Obesity,” a Harvard study linked omega-3-rich prenatal diets and omega-3-rich newborn cord blood with lower body fat in infants through age three.
Conversely, higher maternal omega-6 intakes and omega-6 umbilical cord blood levels were linked to a higher risk of child obesity.
These findings dovetail with evidence that omega-3s enhance many aspects of child development, while American kids' typically excessive consumption of omega-6 fatty acids raises serious health risks.
Swedish trial finds omega-3s benefited obese teen girls
A team of Swedish researchers decided to test whether omega-3 supplements could improve the metabolic profiles of obese adolescents and reduce metabolism-related cardiovascular risks (Dangardt F et al. 2012).
Girls with obesity are at greater risk for impaired insulin sensitivity than obese boys are, so they included both genders in the study.
In order to isolate the effects of supplemental omega-3s, the teens were asked not to change their diets or levels of physical activity.
Scientists from Sweden's University of Gothenburg recruited 25 obese boys and girls between the ages of 14 and 17 for a trial lasting 23 weeks.
They assigned the teens randomly to one of two groups:
  • Placebo supplements containing medium chain triglycerides (MCT)
  • Omega-3 supplements providing 1.22 grams (930mg EPA + 290mg DHA) daily*.
*Note: The omega-3 capsules also contained 100mg of omega-6 gamma-linolenic acid (GLA) and 18mg of vitamin E, which would be unlikely to impact outcomes significantly.
Each group took its assigned capsules for three months, and then stopped taking any capsules for a six week “washout” period.
Then the two groups switched places, and took the other groups' supplement regimen for three months.
Blood samples were taken before and after the trial so that the investigators could measure the teen's fasting blood glucose, cholesterol, and insulin levels. The subjects also underwent glucose tolerance tests and skeletal muscle biopsies.
Results show omega-3 benefits for obese girls
The outcomes of the trial differed depending on gender:
In girls only, the omega-3 supplement regimen produced key benefits:
  1. Improved insulin sensitivity by 17 percent
  2. Improved glucose tolerance by 39 percent
  3. Raised insulin levels by 34 percent during a glucose tolerance test, indicating an improvement in the girls' response to dietary sugars.
However, none of these blood-sugar control benefits were seen in the boys taking omega-3 supplements.
But like the girls, the boys showed higher tissue levels of omega-3s, and lower levels of omega-6s: an effect associated with lower metabolic risks.
(See “Omega-6/Omega-3 Imbalance Pushes Heart/Diabetes Perils” and other articles in the Omega-3 / Omega-6 Balance section of our news archive.)
The Swedish team concluded that supplementation with omega-3 fatty acids from fish (EPA and DHA) may benefit obese adolescent girls by improving their blood sugar control.
As they wrote, “… our data indicate that omega-3s, or the balance between omega-6 and omega-3 fatty acids, play a role in the insulin and glucose metabolism in obese girls at this young age” (Dangardt F et al. 2012).
They speculated on the gender difference, noting that, “… boys might need a longer or more intensive [higher dose] supplementation. The difference in results might also be related to the lower number of boys in the study” (Dangardt F et al. 2012).
Omega-3 tissue levels and omega-3/6 ratios rose in both genders
The omega-3 supplements raised omega-3 levels in all of the participants' skeletal muscle … by 47 percent and 45 percent in girls and boys, respectively.
Blood levels of omega-3 EPA rose more than 115 percent in both genders after omega-3 supplementation while levels of omega-3 DHA increased less, but significantly.
Unsurprisingly, the blood and muscle levels of omega-6s dropped in both genders after omega-3 supplementation, thereby raising the teens' omega-3/omega-6 ratios.
The authors' measurements led them to conclude that the increased glucose tolerance seen in girls after omega-3 supplementation was due to an improvement in insulin sensitivity rather than increased insulin secretion.
As they wrote, “… our data indicate that omega-3s, or the balance between omega-6 and omega-3 fatty acids, play a role in the insulin and glucose metabolism in obese girls at this young age” (Dangardt F et al. 2012).
It would seem that fish oil supplements should be a given for all children … along with a concerted effort to cut back on omega-6-rich vegetable oils.
For more on the subject of excess omega-6 intake – and how to measure it – see “America's Sickening Omega Imbalance.”
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