4 ms·

Blindly encouraging a ketogenic diet can actually be damaging. While the average person slightly benefits from a high-fat, low-carb diet, a small group of peopl

by gavazzy 11y ago

Blindly encouraging a ketogenic diet can actually be damaging. While the average person slightly benefits from a high-fat, low-carb diet, a small group of people (who have the APOE4 allele) are unable to properly digest fat and thus are greatly harmed by it. Similarly, light alcohol consumption seems to slightly benefit the majority of people. But, for those with APOE4, it causes significant harm. So, tonic for one group is toxic to another. It is far better if Alzheimer's treatment is prescribed on a case-by-case basis, based on genetic, environmental, and familial factors. This maximizes the outcomes for all, and not just the average.

mrfusion 11y ago
Do you have sources for those? I've never heard that.
mrfusion 11y ago
So you think apoe4's should eat a high carb diet?
- gavazzy 11y ago
  Not necessarily high in sugar, since the insulin causes just as much damage as high fat. But a lower-fat diet would be beneficial
einarvollset 11y ago
You seem to have those the exact wrong way around, or? I have never heard any evidence that people with APOE mutations are "greatly harmed" by eating a ketogenic diet. Link? Ditto for alcohol.
- gavazzy 11y ago
  My original post is correct. APOE 4/4 is sensitive to dietary fat; high fat diets cause large LDL [0]. Further, fat causes atherosclerosis in APOE 4/4 individuals more quickly than others [1]. It would make sense that APOE 4/4 would have this effect, because it is the "defective" form of APOE. Individuals with APOE 4/4 do not clear oxidized fats from the brain as quickly as APOE 2 or 3 individuals. [0] http://jn.nutrition.org/content/134/10/2517.full http://jn.nutrition.org/content/134/10/2517.full [1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674716/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674716/
  - gavazzy 11y ago
    Update to previous post: A study on diet and APOE genotype showed that fat content affects APOE 4 and APOE 2 or 3 people differently. "No diet can be recommended unequivocally without knowing more about those being targeted. Even though a MUFA-rich diet increases LDL size compared with a CHO-rich diet, this effect is dependent on apoE genotypes. Thus, the replacement of a CHO diet by a MUFA diet increases LDL-size in apoE 3/3, whereas it decreases it in apoE 4/3 subjects" http://jn.nutrition.org/content/134/10/2517.full.pdf+html http://jn.nutrition.org/content/134/10/2517.full.pdf+html
tptacek 11y ago
Isn't this a little like saying that blindly encouraging the consumption of healthful tree nuts is damaging to people who are allergic to tree nuts? True, that is, but not at all interesting?
- gavazzy 11y ago
  The effects of tree nut allergies are acute and visible, but the effects of APOE genotype are chronic and insidious. Further, genetic testing is readily available and cheap ($99), so that the cost of determining whether someone should have a low-fat or high-fat diet is far outweighed by the benefits of: a) lowered risk of alzheimer's b) lowered risk of calcified deposits c) lowered risk of stroke
rhinoceraptor 11y ago
Of course, a ketogenic diet is quite the shock to the system for the average sugar burner. If you're otherwise healthy, it's usually not a big deal. But if you're using insulin for T2D, blood thinners, etc. and it could be pretty dangerous. People who are on medications should definitely find a good doctor who knows the full ramifications of a ketogenic diet, and how to taper off medications that treat symptoms reversed by a ketogenic diet.
austinjp 11y ago
I'd be very interested to see specific references for this. I'll have a look for myself later, but if you have some to hand, that would be much appreciated.

by gavazzy 11y ago

mrfusion 11y ago

Do you have sources for those? I've never heard that.

mrfusion 11y ago

So you think apoe4's should eat a high carb diet?

gavazzy 11y ago
Not necessarily high in sugar, since the insulin causes just as much damage as high fat. But a lower-fat diet would be beneficial

einarvollset 11y ago

You seem to have those the exact wrong way around, or? I have never heard any evidence that people with APOE mutations are "greatly harmed" by eating a ketogenic diet. Link? Ditto for alcohol.

gavazzy 11y ago
My original post is correct. APOE 4/4 is sensitive to dietary fat; high fat diets cause large LDL [0]. Further, fat causes atherosclerosis in APOE 4/4 individuals more quickly than others [1]. It would make sense that APOE 4/4 would have this effect, because it is the "defective" form of APOE. Individuals with APOE 4/4 do not clear oxidized fats from the brain as quickly as APOE 2 or 3 individuals. [0] http://jn.nutrition.org/content/134/10/2517.full http://jn.nutrition.org/content/134/10/2517.full [1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674716/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674716/
- gavazzy 11y ago
  Update to previous post: A study on diet and APOE genotype showed that fat content affects APOE 4 and APOE 2 or 3 people differently. "No diet can be recommended unequivocally without knowing more about those being targeted. Even though a MUFA-rich diet increases LDL size compared with a CHO-rich diet, this effect is dependent on apoE genotypes. Thus, the replacement of a CHO diet by a MUFA diet increases LDL-size in apoE 3/3, whereas it decreases it in apoE 4/3 subjects" http://jn.nutrition.org/content/134/10/2517.full.pdf+html http://jn.nutrition.org/content/134/10/2517.full.pdf+html

tptacek 11y ago

Isn't this a little like saying that blindly encouraging the consumption of healthful tree nuts is damaging to people who are allergic to tree nuts? True, that is, but not at all interesting?

gavazzy 11y ago
The effects of tree nut allergies are acute and visible, but the effects of APOE genotype are chronic and insidious. Further, genetic testing is readily available and cheap ($99), so that the cost of determining whether someone should have a low-fat or high-fat diet is far outweighed by the benefits of: a) lowered risk of alzheimer's b) lowered risk of calcified deposits c) lowered risk of stroke

rhinoceraptor 11y ago

Of course, a ketogenic diet is quite the shock to the system for the average sugar burner. If you're otherwise healthy, it's usually not a big deal. But if you're using insulin for T2D, blood thinners, etc. and it could be pretty dangerous. People who are on medications should definitely find a good doctor who knows the full ramifications of a ketogenic diet, and how to taper off medications that treat symptoms reversed by a ketogenic diet.

austinjp 11y ago

I'd be very interested to see specific references for this. I'll have a look for myself later, but if you have some to hand, that would be much appreciated.