As a dietitian with somewhat of a reputation as having expertise in disordered eating/eating disorders, I have often found myself in the middle of debates about whether or not a structured "meal plan" approach or an "intuitive eating" approach is best. I don't really agree with either, alone, though I do think that restoring someone's ability to eat intuitively should be the ultimate goal.
A recent research project helps me to define why I say that.
Mood disorders are associated with changes of fatty acid content in the brain. A group of neuroscientists finally decided to use their technology to look at how blood flow in different brain regions differed in depression, and to look at how those differences correlated with essential fatty acid levels.
In neuro-ese, here are the results:
DHA% and AA% correlated positively with rCMRglu in temporoparietal cortex. In addition, DHA% correlated negatively with rCMRglu in prefrontal cortex and anterior cingulate. No correlations were seen with EPA%. Thus, under conditions of low plasma DHA, rCMRglu was higher in temporoparietal cortex and lower in anterior cingulate/prefrontal cortex.
Translated into English, what that means:
1. In depressed subjects, the lower the level of DHA and ARA in the tempoparietal cortex, the less blood circulation there appeared to be. This is the part of the brain that integrates and coordinates sensory information.
2. Blood circulation to the prefrontal cortex and the anterior cingulate were compromised when DHA levels were low.
The prefrontal cortex is thought to be important for memory retention and coordination of complex behaviors.
The anterior cingulate is important for carrying out executive, evaluative, cognitive, and emotional functions. It is also important for learning and problem solving, error detection, motivation, and emotional modulation.
I believe, and have written profusely about it on this blog, that imbalance in fatty acids not only causes depression, but it causes changes in brain chemistry that change eating behaviors. And those eating changes only make the brain chemistry worse. It becomes a vicious cycle that can become incredibly difficult to break out of.
Both diet approaches operate on the assumption that the brain is intact and functioning completely normally. If that were the case, I argue, the client wouldn't be asking for help with an activity that should be primarily intuitive and without thinking too much about it. My clients often demonstrate signs and symptoms that the above described imbalance exist, which sets them up to fail with commonly endorsed nutrition counseling approaches.
Wednesday I'll continue with how changes in these brain regions interfere with nutrition counseling. For now, suffice it to say that a fatal error nutrition and exercise counselors make is to assume that their clients have the brain power and function that allows them to make the changes we advise them to make. And in doing so, we work against their ability to change. If we understand what's going on in the brain, we can develop therapies that harness their potential to succeed!
Elizabeth Sublette M, Milak MS, Hibbeln JR, Freed PJ, Oquendo MA, Malone KM, Parsey RV, John Mann J. Plasma polyunsaturated fatty acids and regional cerebral glucose metabolism in major depression. Prostaglandins Leukot Essent Fatty Acids. 2009 Jan;80(1):57-64. Epub 2009 Jan 6.
