People may inherit conditions linked to obesity from their grandmother, researchers from the University of Edinburgh reported in the journal Endocrinology.
The authors explained, as background information, that maternal obesity during pregnancy has been associated with a higher risk of obesity and cardiometabolic disease in offspring, what they describe as “a phenomenon attributed to developmental programming (epigenetics)”. They added that programming effects may be passed on across generations through both paternal and maternal inheritance. Nobody is sure what the mechanism for this is.
There have been many studies demonstrating a link between maternal obesity and obesity-like diseases among first-generation offspring. Scientists at the University of Louisville found that maternal obesity was associated with diabetic complications in resulting offspring.
In this latest study, Dr Amanda Drake and team wanted to find out what the effects of maternal obesity might be on first and second generation offspring. They worked with laboratory mice and diet-induced the females to become moderately obese. Their aim was to observe weight gain and glucose-insulin homeostasis in the pups and the following generation as well.
The team found that conditions associated with obesity could skip a generation, leaving the first generation from moderately obese mothers apparently healthy.
The next generation were found more likely to become obese and suffer from obesity-related diseases, such as hypertension (high blood pressure), type 2 diabetes, hypercholesterolemia (high blood cholesterol levels), and hyperlipidemia (high fat levels in the blood).
Dr. Drake said that their findings add to growing evidence that our lifestyle choices today can impact on the genes not only of our children, but also our grandchildren. In other words, if we are obese our grandchildren are more likely to become obese too.
Dr. Drake said “Given the worldwide increase in obesity, it is vital that we gain an understanding of how future generations may be affected.”
In an Abstract in the same journal, the authors concluded:
“(Our findings) suggest that the consequences of the current dietary obesity epidemic may also have an impact on the descendants of obese individuals, even when the phenotype of the first generation appears largely unaffected.”
At the end of 2011, 27.5% of American adults were obese, compared to 26.9% a year earlier. From 2001 through 2011, obesity rates among US adults rose 37.5%. Not one US state today has an adult obesity rate below 20%.
According to latest statistics from the NHS Health and Social Care Information Center, United Kingdom, only one third of British men are considered to be of normal weight today. The number of Brits being hospitalized because of obesity-related problems has increased significantly over the last ten years.
Dr. Drake and colleagues plan to determine how disease risk may be passed down through more than one generation in humans. They say their current and future studies should help public health organizations when they issue recommendations regarding lifestyle choices.
Dr Drake said “Future studies could look at these trends in humans, but they would need to take into account genetics, environmental, social and cultural factors.”
Some studies have looked at how susceptibility to certain conditions and diseases may be inherited from grandparents. Researchers from the Sahlgrenska Academy, Sweden, reported in the Journal of Clinical Endocrinology & Metabolism that hip fractures in grandfathers are linked to low bone density and smaller bone size in their grandsons.
Written by Christian Nordqvist