“Simply suggesting that people go on low-carb diets isn’t going to work because most people cannot adhere to such a diet.”

Will not. Fixed that.

Part of the point of Atkins-like diets is that it’s easier to stick to them than it is to low-fat diets, because fat sends your brain satiety signals faster than do carbs.

The US gov’t already subsidizes carb production, largely through corn subsidies, which translate into high fructose corn syrup, one of the main refined sugars consumed in the US. Simply removing those subsidies would decrease the amount of sugar being produced.

I drastically reduced the amount of refined carbs I eat about 3 years ago, and have stayed that way. I am not on a ‘diet’ (I am not looking to lose weight), but have just adopted better long-term eating habits. I don’t avoid *all* carbs (that would be very hard,) but I do not consume any juice, breakfast cereals, oatmeal, or sweets of any kind, and limit my bread and pasta.

Interestingly, my first two pregnancies, when I was eating a relatively ‘normal’ American diet, I gained 50 lbs each pregnancy (then lost it again before the next.) My most recent pregnancy, during which I had stopped drinking milk and cut most of my carbs (replaced with microwavable veggies, nuts, meat, butter, and fish,) I only gained 35 lbs.

Hardly scientific data, but we start somewhere.

Not as an example of great science, but I’ve made the observation that people who are more into ideas than actual experiences tend to stay lean. They don’t seem any more disciplined than the rest but simply less interested. Possibly due to high dopamine levels. Maybe we should put all the fatties on ADHD meds : )

It’s more than just IQ, again just in my experience. I’ve met several of this type who have been pretty average. Female journalists of this type seem very common for some reason. They are often very impulsive but it’s usually idea-oriented.

I have seen studies that fat people degenerate more quickly, mentally speaking, than thin people. There are a lot of obvious correlates, but I find it very strange that, for example, African Americans are more likely to develop Alzheimer’s than African Africans. Since we hear so much about the quest for genetic bases to these diseases, I’d expect a closer match. (I see three possibilities: 1. bad data, 2. black folks aren’t adapted to something in the environment here, eg, low sun levels, 3. something in the environment here which they are disproportionately exposed to, eg, stress.)

ADHD meds suppress appetite, so they might do something for folks who just over-eat.

jayman, you should read gcbc. it is an exceptional good book on food science.

even if he omits hbd, which he does, it is still a very good review of existing literature.

“but I find it very strange that, for example, African Americans are more likely to develop Alzheimer’s than African Africans.”

“Maybe because Africans in Africa don’t live as long as African Americans?”

Higher prevalence of Alzheimer’s disease in African American populations relative to African populations may be due to longer life expectancy in America versus Africa, and maybe environmental, lifestyle, and dietary factors also contribute (inflammation etc.?). However, it is well known that African American populations are partly admixed with Europeans. Previous studies have shown an association with Alzheimer’s disease and the HLA region. The paper below finds a link between Alzheimer’s and the HLA B7 allele in linkage with HLA Cw*0702 :-

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1764414/

If presence of the HLA Cw*0702 – B7 haplotype in human populations does confer susceptibility to Alzheimer’s, it is worth looking at the frequencies of this in different human populations worldwide:-

http://www.allelefrequencies.net/hla6003a.asp?hla_locus1=A_not&hla_locus2=B*07%3A02&hla_locus3=C*07%3A02&hla_locus4=DRB1_not&hla_locus5=DPA1_not&hla_locus6=DPB1_not&hla_locus7=DQA1_not&hla_locus8=DQB1_not&hla_population=&hla_country=&hla_dataset=&hla_region=&hla_ethnic=&hla_study=&hla_order=order_3&hla_sample_size_pattern=equal&hla_sample_size=&hla_sample_year_pattern=equal&hla_sample_year=&hla_loci=

Note the high frequency of this haplotype in North-West European derived populations [eg Northern Ireland 17.00%; USA Caucasians 11.10%]. Now contrast African American frequency [6.90%] with frequency in a native West African population [Mali Bandiagara 4.30%]. If African Americans are intermediate in frequency of HLA Cw*0702 – B7 between native West Africans and USA Caucasians, the data appears to support North West European ancestry being a component in higher rates of Alzheimer’s, alongside the other factors mentioned.

African Americans develop Alzheimer’s at a higher rate than whites (despite shorter life expectancies,) so a genetic factor which they possess less of than whites does not seem like a good theory. (http://www.ncbi.nlm.nih.gov/books/NBK25535/)

Thankfully the people doing these studies are not complete idiots, so very often they are not measuring ‘What is the most common cause of death in this population overall?’ but ‘Among members who are FOO years old, how prevalent is disease X?’ For example, one study I read compared the progression of atherosclerosis in the hearts of accident victims in their 30s-50s in the US and, I believe, Uganda. (The Ugandans had far, far less heart disease than their equally-aged American counterparts.) Or they will look at a population of people who have made it to 80 (even in the third world, there are some very old people,) and try to measure the rates of Alzheimer’s, heart disease, etc.

The best book I can recommend on this subject is Food and Western Disease: an Evolutionary Perspective, by Lindberg. (http://www.amazon.com/Food-Western-Disease-Evolutionary-Perspective/dp/1405197714/ref=la_B002P8YG9G_1_1?ie=UTF8&qid=1366572545&sr=1-1)

(To cut to the chase, I think our bodies have evolved to handle/process certain foods, get a certain amount of exercise of specific sorts, receive certain amounts of sunlight, etc., store certain amounts of fat, etc., and when you radically change that over a very short time period, the body has trouble.

The Paleo Diet supporters often go a bit overboard in their claims (hunter-gatherers did eat grain, for example, when they could find it growing in their environment–how else could they have gotten the idea to plant it?) but the idea that we should pay attention to what we’re adapted to eat is not a bad one. (And basically none of us is adapted to highly *refined* carbs, because refining technology is very recent and its widespread use even more recent. Most grain has been eaten straight or as slightly fermented porridge for most of agricultural history, because grinding flour and making bread is a lot of work.)

When we get a result which doesn’t square with genetics (Africans in Africa having much lower obesity rates than Africans in America, for example,) then environment is a likely culprit. )

As for intelligence and obesity, there’s an obvious chicken and egg problem: stupid people, for many reasons, end up fatter, and fatter people have conditions (eg, diabetes, atherosclerosis,) which kill brain cells.

“Researchers in another study compared MRI-assessed manifestations of cerebral degeneration in 89 non-demented subjects with type-2 diabetes to 438 age-matched healthy controls over a three-year period. Individuals with diabetes displayed increased progression of brain atrophy, and performed less well on tests of cognitive performance and learning. The investigators concluded that “our data show that elderly patients with [type-2 diabetes] without dementia have accelerated progression of brain atrophy with significant consequences in cognition compared to subjects without [type-2 diabetes]. Our findings add further evidence to the hypothesis that diabetes exerts deleterious effects on neuronal integrity.” ”

“Mid-life obesity was strongly linked to later-life dementia in over 1,000 participants in a longitudinal study carried out over a 36 year period. Subjects with the greatest waist diameters at baseline were nearly three-fold more likely to develop dementia over the following three decades. The investigators in this study concluded that “central obesity in midlife increases risk of dementia independent of diabetes and cardiovascular comorbidities.””

“Adipose tissue secretes molecules that directly influence multiple functions within the brain.114 There is a clearly established reciprocal relationship between adiposity (amount of body fat) and overall brain volume and cognitive function. In other words, as bodyweight increases, brain volume drops and cognitive function worsens.”

http://www.lef.org/protocols/neurological/age_related_cognitive_decline_01.htm

Chickens, eggs.

I must admit that my theory is flawed, I didn’t know that Alzheimer’s rates are higher in african americans than in US caucasians.

You know, Cochran/Harpinding’s book raises this point briefly about carb consumption, agricultural and HBD. If you look at certain disease rates, like obesity, heart-disease and alcoholism, those who have practiced agriculture the longest tend to have gene variants that help in the digestion of the altered diet. People who had never eaten a grain or sipped alcohol in their entire evolutionary history suffer horribly from adopting a western diet. Australian Aboriginals are a prime example.

I have a Vietnamese friend who, amazingly, does best when eating a traditionally Vietnamese diet. Lactose intolerance + celiac disease is really annoying when living in Western society, but what can you do?

Jay, I agree that stupidity sets in earlier than diabetes, but my original comment was about brain degeneration, which does appear to happen faster in fat people, and is very likely exacerbated by conditions like type II diabetes, which skyrockets in incidence as countries “develop”, especially in populations which did not historically eat things like refined wheat. (Also, obesity sets in pretty darn early, if “Epidemic of overweight 6 month olds” means anything. Babies born to fat people are over-fed in the womb, making the chicken and egg problem pretty pernicious.)

Farmers fatten cattle on corn, but only at the ends of their lives–too much too early will make the cow grow fat instead of big, hit puberty early, and generally mess up their lifecycle. Cows aren’t people, but it’s difficult to devise effective, ethical human experiments on food and growth with the same scientific rigor as animal husbandry. Humans may explain away their obesity as ‘lack of willpower’, but a farmer facing lost profits has an incentive to be honest.

Of course, I don’t know if anyone has tried feeding the cows refined fats 🙂

I’m not saying there isn’t a genetic component. Of course there is. But people are much fatter now than a hundred years ago, and environmental changes (including food) to which we aren’t adapted (and some folks are less adapted than others,) are likely culprits.

Mind and body exist together, one and the same, and the idea that the one influences the other is only sensible; inducing faster growth in an organism likely triggers faster brain maturation simply because growth and maturation have always been physiologically linked, thus leading to the “prematurely aged” brains of fatter people. Intelligent species always develop more slowly and have extended childhoods for brain growth. Short-circuiting this through feedlot-style fattening of children is probably a bad idea.

[quote]ADHD meds suppress appetite, so they might do something for folks who just over-eat.[/quote]

For a time. Like other effects, that tends to diminish over time without an increase in dose.