Monday, April 4, 2011

Follow Up on Set-Point Theories: Could Royal Jelly Help With Obesity / Diet Induced Structural Brain Changes?

The colleagues over at dug up a 2009 study (Narita. 2009) on the endocrine effects of royal jelly supplementation on rats. You may now wonder "Why is he suddenly beginning to writing off information about old studies on other sites?" Well, my interest in this study relates to my recent appearance on Carl Lenore's Super Human Radio show (I know, I promised a write-up /just have to find the time ;-) and diverges from the original interpretation the anonymous author over at ergo-log provided.

As you may have heard on the podcast, the most significant finding of the Ravussin study (Ravussin. 2011) was the down-regulation of pro-opiomelanocortin [POMC] neurons in the hypothalamus, which went hand in hand with weight gain and weight loss and is associated with a reduction of the metabolic rate to levels at which further weight loss or even weight maintenance become a significant challenge. Here, the findings of the aforementioned study on royal jelly, "a honey bee secretion that is used in the nutrition of larvae, as well as adult queens" (Wikipedia), come into play. As can be seen from in figure 1, 7 months supplementation with 5% Royal Jelly produced profound effects on the expression of the rats' pituitary hormone genes, one of which (you will have guessed that) is POMC.
Figure 1: Expression of Pituitary Hormone Genes in Middle-Aged Female Rats Fed a 5% Royal Jelly Diet for 7 Months. (Narita. 2009)
Now, one could speculate that despite the fact that a ~10% increase in POMC expression could not compensate for the obesity induced loss of 50% of excitatory POMC neurons observed by Ravussin et al., the combined effect of increased POMC expression and a rise in thyroid stimulating hormone TSH could eventually turn out to be beneficial for someone, who has maneuvered him or herself in a metabolic state, where effective weight loss, i.e. the loss of body fat and conservation of muscle mass, is nigh on impossible.
Yet, before you break into the next beeyard, you should consider that...
  1. the amount of royal jelly the rats consumed in the study, i.e. 5% of their daily food intake is almost impossible to achieve without plundering beeyards all over the country (for the same reason it is no practical alternative to medications for "rejuvinating the pituitary" which the author of the ergo-log post seems to imply in the headline of his post)
  2. an upregulation in gene expression alone does not guarantee an increase in metabolic rate (the increase in the thyroid (pre-)hormone T4, for example, was non-significant, despite a significant increase in TSH related gene expression)
Basically, this means that you should get accustomed to the idea that the damage years of overeating and/or crash- & yoyo-dieting has inflicted to your body are unlikely to be repaired within weeks or even months by just popping pills or eating some kind of superfood, no matter how "royal" it may be. In the end, it will come down to making a decision to change your life (nutrition and exercise) and to stick to this decision, no matter how hard it may seem.