You might be interested in listening to the podcast at http://www.thelivinl...re-episode-302/
It's about using a calorie restricted ketogenic diet to treat brain cancer. Not exactly what you're looking for, but interesting to hear about the research.
That was interesting, yes. Would love to drag Dr. Seyfried into this discussion.
PRAL score is thought to be a good indicator of whether ones diet is acidic or not. That said, I've seen some conflicting research on whether PRAL score really indicates potential bone health issues.
PRAL =
0.49 * protein (g) +
0.037 * phosphorus (mg) -
0.021 * potassium (mg) -
0.026 * magnesium (mg) -
0.013 * calcium (mg)
Fat is essentially neutral and should comprise the bulk of your diet. If you balance calcium with magnesium and ensure adequate intake, bone loss shouldn't be too crazy either. Especially if you do weight bearing exercises and supplement vitamin D. One thing is for certain, many hunter gather cultures eat a lot of animal foods (50%+) and have no skeletal degeneration. Likewise, the Inuit also seem to have excelent skeletal health.
Regarding CR, with such low caloric intake, you will need to choose your foods very carefully to ensure adequate micro-nutrient intake. One benefit to a CR ketogenic diet might be:
http://www.proteinpo...eans-our-cells/
I'm not familiar with the PRAL score but from the looks of it, it's measured on acidic content of foods. What I think scottknl is suggesting is that the ketones induced by the diet would be acidic enough to leach calcium from the bones. I haven't yet discovered whether or not this is true, but it sounds very plausible. If it is, I will probably have to drop spinach and cacao beans due to their oxalate content. And I was actually starting to really like the addition of cacao beans.
About the nutrient intake, I definitely have to pick my foods carefully but I don't see how that separates me from a standard ketogenic diet. Both diets are limited to their carb restriction, this is just a little less excessive on fat intake.
Thank you, that was a very interesting read. There definitely are a lot of benefits that keeps tilting the risk/benefit ratio for me (brain health being one of the big ones).
Just now, I stumbled upon this intriguing study:
Acute oxidative stress and systemic Nrf2 activation by the ketogenic diet.
Milder JB, Liang LP, Patel M.
Graduate Program in Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
Abstract
The mechanisms underlying the efficacy of the ketogenic diet (KD) remain unknown. Recently, we showed that the KD increased glutathione (GSH) biosynthesis. Since the NF E2-related factor 2 (Nrf2) transcription factor is a primary responder to cellular stress and can upregulate GSH biosynthesis, we asked whether the KD activates the Nrf2 pathway. Here we report that rats consuming a KD show acute production of H(2)O(2) from hippocampal mitochondria, which decreases below control levels by 3 weeks, suggestive of an adaptive response. 4-Hydroxy-2-nonenal (4-HNE), an electrophilic lipid peroxidation end product known to activate the Nrf2 detoxification pathway, was also acutely increased by the KD. Nrf2 nuclear accumulation was evident in both the hippocampus and liver, and the Nrf2 target, NAD(P)H:quinone oxidoreductase (NQO1), exhibited increased activity in both the hippocampus and liver after 3 weeks. We also found chronic depletion of liver tissue GSH, while liver mitochondrial antioxidant capacity was preserved. These data suggest that the KD initially produces mild oxidative and electrophilic stress, which may systemically activate the Nrf2 pathway via redox signaling, leading to chronic cellular adaptation, induction of protective proteins, and improvement of the mitochondrial redox state.
© 2010 Elsevier Inc. All rights reserved.
PMID: 20594978 [PubMed - in process]
