Friday, November 26, 2010

Dad's eating habits weigh heavily on offspring

We've known for a while that a mother's diet impacts the life of her child. Now there is new research that shows that the diet of the father also shapes the life of the child.

If this is not reason enough for men to step up and eat healthier, I don't know what else to say.

Dad's eating habits weigh heavily on offspring


Fathers' bad eating habits may have insidious long-term effects on their unborn daughters, according to a provocative study in rats.

Fathers' bad eating habits may have insidious long-term effects on their unborn daughters, according to a provocative study in rats.

Fathers' bad eating habits may have insidious long-term effects on their unborn daughters, according to a provocative study in rats.

It found that feeding high-fat diets to male rodents predisposed their daughters to metabolic problems and diabetes — the first study in any species to show that a fathers' nutritional legacy reaches well into the next generation.

"A female can develop a diabetes-like disease due to a high fat content in her father's diet before she was conceived," according to one of two reports on the study to be published Thursday in the journal Nature.

When Margaret Morris and her colleagues at Australia's University of New South Wales put male lab rats on a high-fat diet the initial outcome was not all that surprising — the male rats packed on weight and body fat.

What was new is that female offspring of the fat male rats developed a diabetes-like condition in adulthood even though they had normal weight. The daughters also inherited hundreds of altered and abnormal genes linked to metabolic problems and diabetes.

"This indicates that the fathers' high-fat diets altered the development of their sperm, which then promoted an adult-onset disease in the daughters," Michael Skinner, at Washington State University says in an accompanying report.

Obesity and diabetes are fast reaching epidemic proportions. More than two million Canadians have Type 2 diabetes and five million more are at risk for the disease, which disrupts sugar uptake in the blood.

The epidemic has long been tied to sedentary lifestyles and the modern diet of food laced with sugar and fat. Researchers say there is increasing evidence "intergenerational transmission" plays a role.

One theory is that exposure to a diabetic environment in a mother's uterus may predispose babies to Type 2 diabetes. Another is that obesity and diabetes can alter sperm, triggering metabolic problems in the next generation.

Proving it is tricky, as it is not easy to run feeding experiments on people.

To test whether fathers "can initiate intergenerational transmission of obesity/metabolic diseases" Morris and her colleagues fed male rats a high-fat diet and mated them with females on a control diet. The nine males packed on so much fat their weight increased to more than 700 grams, compared to the males on the control diet that weighed in around 550 grams. The males on the high-fat diet also developed glucose intolerance and insulin resistance, hallmarks of diabetes.

Their daughters were not overweight, but the researchers say they soon developed "early onset" impaired insulin secretion and glucose intolerance that worsened with time.

When the researchers examined the genes of the females they found hundreds of abnormal genes. The fathers' high-fat diet "altered the expression of 642 pancreatic islet genes in adult female offspring."

The genes are involved in pathways associated with diabetes. The researchers have yet to test male offspring or whether the genetic changes carry on to subsequent generations.

The findings point to a "paternal role" in the early onset and "amplification of the diabetes epidemic," the Australian team concludes.

Skinner says the work suggests "a molecular mechanism for environmental factors such as diet to affect health and to influence subsequent generations through the germ line."


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