Saturday, July 25, 2009

The Mind-Body Connection

Many people remain skeptical of a clear body-mind connection – that our life experiences and emotions can have a profound effect on our hard-wired biology. While animal studies have clearly shown that a mother’s style of nurturing can affect her offspring’s lifelong behavior and physical health, scientific studies showing a clear mind-body link in people have been limited.

Now, researchers have clearly shown that the behavior of some genes can be permanently changed by psychological factors during childhood.

Researchers from McGill University in Montreal compared two groups of brain cells. Some cells were obtained from people who had been abused as children and later committed suicide, and other brain cells came from people who had committed suicide but who had not been abused as children.

The researchers, writing in Nature Neuroscience (2009; doi 10.1038/nn.2270), explained how they investigated specific stress-response genes and cell receptors for cortisol on brain cells. When people are stressed – as in the case of children who are being abused – their levels of cortisol, a key stress hormone, swell.

In most people, the brain increases the activity of stress-response genes and the number of cell receptors involved in clearing cortisol from the brain. However, these genes were roughly 40 percent less active in cells from people who had been abused as children. In other words, being abused permanently changed the activity genes that would have helped buffer the effects of stress later in life.

The biological explanation for this mind-body connection lies in the science of “epigenetics.” Every one of our bodies’ cells contains about 20,000 genes, which can be considered our “hardware.” Epigenetics is more like our modifiable genetic “software.” Nutrition, stress, and toxins are among the key modifiers of our epigenetic programming, which turns genes on and off. Amazingly, epigenetic changes caused by nutrition and experience can be passed from one generation to the next.