CR May Make Your Kids Chill Out

[Dean Pomerleau]

I thought this new study [1] that James Cain posted in his great weekly CR research update (thanks James!) was well worth promoting to its own post/thread. And without a little digging & careful reading, it wasn't clear to me what it was saying. So here is my interpretation.

 

These researchers subjected adult male rats to 25% CR prior to breeding them. They then raised the male offspring of these CR'ed rats to adulthood, and subjected them to a battery of tests to measure their anxiety-related behavior. What they found across a variety of metrics was that the male offspring of CR'ed rats were less anxious than the male offspring of rats fed ad lib. One test where the offspring of CR'ed rats weren't less anxious / cautious was the alarm they exhibited when exposed to signs of a predator (cat urine).

 

So in a sense, the offspring of CR'ed rodents were more mellow, but no less sensitive to real danger. Overall, it seemed like a good result to me, and one that I wouldn't have necessarily expected. My intuition would say that hardship of CR in dad might make his kids more neurotic, rather than less.

 

The authors suggest the influence of CR in one generation on the psychological tendencies of offspring in the following generation is potentially mediated epigenetically. To me it seems hard to imagine how it would happen otherwise, since I don't believe the male parent rats were involved in the rearing of their offspring in this study (i.e. it was a one-night-stand with mom after which the dads were out of the kids' life).

 

So this study did not address the influence of practicing CR in the presence of children on the children's psychological health, attitude towards food, etc. I think that would be at least as interesting a topic to investigate.

 

--Dean

 

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[1] Psychoneuroendocrinology. 2015 Oct 30;64:1-11. doi:

10.1016/j.psyneuen.2015.10.020. [Epub ahead of print]

Paternal calorie restriction prior to conception alters anxiety-like behavior of
the adult rat progeny.

Govic A(1), Penman J(2), Tammer AH(3), Paolini AG(4).


The maternal environment influences a broad range of phenotypic outcomes for
offspring, with anxiety-like behavior being particularly susceptible to maternal
environmental perturbations. Much less is known regarding paternal environmental
influences. To investigate this, adult male rats were exposed to 25% calorie
restriction (CR) or glucocorticoid elevation (CORT; 200μg/ml of corticosterone in
drinking water) for ∼6 weeks prior to breeding. Elevated plus maze (EPM), open
field (OF), predator odor (cat urine), and acoustic startle/pre-pulse inhibition
(AS/PPI) were characterised in the adult male offspring. Plasma concentrations of
corticotrophin-releasing hormone (CRF), adrenocorticotropin hormone (ACTH), and
serum lepin were characterised in both sires and offspring. Maternal care
received by litters was additionally observed. Expectedly, CR and CORT treatment
attenuated weight gain, whilst only CR induced anxiolytic behavior in the EPM.
The adult offspring sired by CR males also demonstrated a reduction in weight
gain, food intake and serum leptin levels when compared to controls. Moreover, CR
offspring demonstrated an anxiolytic-like profile in the EPM and OF, enhanced
habituation to the AS pulse, reduced PPI, but no alteration to predator odor
induced defensiveness compared to control. CORT offspring failed to demonstrate
any behavioral differences from controls, however, exhibited a trend towards
reduced ACTH and leptin concentration. Collectively, the results indicate that a
reduction in calories in males prior to conception can affect the behavior of
adult offspring. The phenotypic transmission of CR experiences from fathers to
the progeny could potentially be mediated epigenetically. The role of
glucocorticoid elevation and maternal care are also discussed.

Copyright © 2015 Elsevier Ltd. All rights reserved.

PMID: 26571216