Medical research has proved that obesity leads to increased risk of diabetes, heart disease and cancer. While there are several causes of obesity the risk factor for each condition, makes it complicated to cleave them apart. Sean Oldham and Rolf Bodmer at the Sanford-Burnham Medical Research Institute have led a team to formulate a theory to link diet which is high on fat diet to obesity and subsequently heart.

The researchers used fruit flies, and found that TOR (a protein) regulates cardiac fat accumulation. Controlling TOR protected from the heart from harm caused by high-fat diets.

"We noticed previously that reducing TOR had a large number of beneficial effects on aging," explained Dr. Oldham, co-senior author of the study. "We next wanted to look at TOR activity in obesity-related heart disease, but we didn't have a good system. In this study, we establish the fruit fly as a model for obesity caused by a high-fat diet."

Fruit flies of the genus Drosophila are ideal for cardiac related studies as a large part of the fundamental molecular mechanisms are akin to those found in vertebrates. Further it is relatively simple to obliterate singular genes in the fly, permitting scientists to exclusively map out the role in cardiac development and function.

The team fed the flies a diet of coconut oil which is high on fat and the obese flies showed similarities including cardiac dysfunction as obese humans. To further understand how TOR controls the effect of adipose cells on the heart, the team created flies that reduced TOR’s activity. The protein regulates an enzyme that breaks down adipose cells. Inhibiting TOR resulted in lowered fat accumulation in the heart and subsequently enhanced the cardiac health of obese flies.

According to Dr. Bodmer, director of the Development and Aging Program, "These results open the possibility that we can intervene with the effects of obesity by targeting TOR and other proteins it regulates – either directly in fat or in a specific organ like the heart."

The Drosophila model allows scientists seek answers relating to questions about diet, obesity and the heart. "One thing we'd like to know next is if fats themselves are toxic to the heart, or is it the by-products of their metabolism that are harmful?" said Dr. Birse, post-doctoral researcher and first/lead author of the study. "One good thing about using fruit flies is that, in theory, we could feed them whatever we want to screen – different fatty acids, molecules, drugs, etc. – to observe their effects on the heart or other systems."