Obesity is already rightfully getting a pretty bad rap--it's linked to woes like increased risk of heart attack and stroke, osteoarthritis, diabetes, trouble breathing and even some cancers. Now scientists are adding one more crime to the list and asserting that obesity also can harm your ability to remember and learn.

As reported by Laura Sanders in ScienceNews, in a recent study, researchers fed mice a high fat diet that caused the rodents to weigh 40 percent more than mice on regular diets. The obese mice had more trouble remembering where objects were and escaping mazes compared to normal-weight mice. When the researchers looked at the brains of these mice, they found that there were fewer dendritic spines--little doorknob-shaped protrusions--on their nerve cells. The problem was significant in several parts of the hippocampi, which are parts of the brain associated with learning and memory.

Scientists are still discovering all the functions of dendritic spines, but researchers believe that they are critical for communication in the brain because they help transmit electrical signals to the body of the neuron. Because the spines can change in shape and number, thereby influencing the strength of specific neural connections and networks, scientists believe they are closely linked to the ability to learn and remember information.   

So what caused the destruction? The culprit appears to be immune cells called microglia. The obese mice had more microglia, and when the researchers interfered with them, the dendritic spines were protected, resulting in better results on the tests from the obese mice.

Taken in a broader context, the research appears to offer additional details about how the weight and the immune system are linked. Scientists already know, for example, that obesity causes inflammation in the body, which can cause a range of metabolic conditions. They also know that obesity can impair overall immune system function, increasing the odds of getting sick.

The research suggests that, with 39.8 percent of Americans (93.3 million) suffering from obesity, a lot of us might do our brains a favor if we just dropped a few pounds. That said, there's zero reason to use weight as an excuse--in the workplace or otherwise--for discrimination and shaming. We also should acknowledge that what stands as a healthy weight for one person might not work for someone else. Collaborate with your doctor to find the ideal for you. Then support yourself and others by promoting healthier initiatives and programs. Even little changes like bringing whole wheat bagels to the morning meeting instead of donuts can make a difference.