Wrong Omegas, Overeating Lead To Inheritable Obesity

Researchers in France reported Friday that overeating combined with the wrong mix of fats in one’s diet can cause obesity to be carried over from one generation to the next.

The scientists showed in experiments that too much omega-6 and not enough omega-3 can lead to overweight offspring.

The ratio of omega-6 to omega-3 in a typical Western diet has shifted from 5-to-1 to 15-to-1 in much of Europe, and up to 40-to-1 in the U.S.

The average ratio in the breast milk of American women has gone from 6-to-1 to 18-to-1.

Earlier studies have established a link between such imbalances and heart disease. 

However, Gerard Alihaud, a biochemist at the University of Nice-Sophia Antipolis and main researcher of the study, told AFP news that "this is the first time that we have shown a trans-generational increase in obesity."

"Omega six is like a fat-producing bomb," he said.

Experts have different opinions on whether obesity is more importantly due to the percentage of fat in one’s diet or the amount of calories consumed.

The findings add another dimension to the debate, and could shed new light on the obesity epidemic that has swept across the globe.

They also suggest that persistence within families of health-threatening weight gain may not be entirely due to environmental factors either.

Alihaud told AFP, referring to the complex process whereby the information in genes is translated into chemical activity, that the link between omega imbalance and obesity "is probably epigenetic."

"The genome and the DNA of the rodents has not been modified, but these factors can influence the way in which certain genes are expressed."

Four generations of mice were fed a 35-percent fat diet with omega imbalance in the experiments.

The result showed that the mice got progressively fatter at birth, generation after generation.

The rodents also developed insulin-resistance, a telltale symptom of diabetes 2, one of the most common consequences of obesity in humans.

Alihaud said that the equally undesirable increase in omega-6 and drop in omega-3 could partly be explained by the change from grass-fed to grain-fed livestock.

He said that grass is rich in omega-3.  "But to increase productivity, feed was shifted to grain meal, especially corn, which contains a high concentration of omega-6."

He also said that adding a small quantity of flaxseed oil to animal feed could help restore a healthy omega balance in meat and dairy products.

Saturated fats, monounsaturated fats and polyunsaturated fats are the three types of fatty acids.

France Health authorities recommend that fat intake should be between 30 and 40 percent of calories consumed.  The Food and Drug Administration suggests a range of 20-to-30 percent.

Both governments agree that most of that intake should come from polyunsaturated and monounsaturated fats like fish, nuts and vegetable oil.