Obesity May Accelerate Brain Aging

natehoy writes "According to the US News and World Report, a recent study has shown a link between obesity and the loss of neurological tissue. The brains of elderly patients who were obese had on average 8% less tissue than their trimmer counterparts. Overweight patients had brains lighter by about 4%. This could have implications for the onset of dementia illnesses such as Alzheimer's. Just one more risk factor to add to the growing body (no pun intended) of reasons to try and stay trim."

Now I get it

[mcgrew]

Fat women have always hit on me. Now I know why -- they're stupid!

However, from TFA:

Dr. Jonathan Friedman, an associate professor of surgery and neuroscience and experimental therapeutics at the Texas A&M Health Science Center College of Medicine noted that the causal relationship here is not clear.

Another possibility is that The brains of overweight people have more receptors for the neurotransmitter serotonin than those of people of normal weight, suggesting that being overweight may be down to more than just eating habits and may have an origin in brain chemistry. [newscientist.com] Clearly, more study is warranted.

From the New Scientist article on the ssubject of big people with little brains:

In an as yet unpublished study, Thompson's team has shown that exercise, which improves cardiovascular health and blood flow, protects the very brain regions that had shrunk in the current study. "The most strenuous kind of exercise can save about the same amount of brain tissue that is lost in the obese," he says. This indicates that it is blood flow that drives brain health, not the other way round. As these areas undergo the most remodelling throughout adult life, they may be more sensitive to any changes in oxygen supply and nutrients, Thompson suggests.

But Deborah Gustafson at the University of Gothenburg in Sweden, who previously found that overweight women had less brain tissue than their leaner counterparts, questions whether obesity is driving brain atrophy or vice versa. She points out that brain atrophy in the frontal and temporal lobes, which also control eating behaviour and metabolism, could cause weight gain. "There are not enough longitudinal data available for us to know which is the chicken and which is the egg."

Possible Viral Link

[TheNarrator]

Perhaps this has something to do with the virus / obesity link: http://www.sciencedaily.com/releases/2006/01/060130031548.htm [sciencedaily.com]

There is accumulating evidence that certain viruses may cause obesity, in essence making obesity contagious, according to Leah D. Whigham, the lead researcher in a new study, "Adipogenic potential of multiple human adenoviruses in vivo and in vitro in animals," in the January issue of the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology published by the American Physiological Society. The study, by Whigham, Barbara A. Israel and Richard L. Atkinson, of the University of Wisconsin, Madison, found that the human adenovirus Ad-37 causes obesity in chickens. This finding builds on studies that two related viruses, Ad-36 and Ad-5, also cause obesity in animals. Moreover, Ad-36 has been associated with human obesity, leading researchers to suspect that Ad-37 also may be implicated in human obesity. Whigham said more research is needed to find out if Ad-37 causes obesity in humans. One study was inconclusive, because only a handful of people showed evidence of infection with Ad-37 -- not enough people to draw any conclusions, she said. Ad-37, Ad-36 and Ad-5 are part of a family of approximately 50 viruses known as human adenoviruses.

Re:These morally chiding "correlation" studies

[CannonballHead]

Is it any coincidence that the medical profession was once closely linked to the idea [thinkquest.org] that all illness was caused by immoral behavior?

Interestingly enough, in the Old Testament, Job's three friends made this mistake and were actually reprimanded for it. Calamity and "bad stuff" (including illness) does not, even in the Old Testament, mean judgment from God for immoral behavior.

Re:These morally chiding "correlation" studies

[b0ttle]

... the fact that the obese are often geographically concentrated in areas (like the American South) where public education is shit and poverty is high.

"American obesity rates are the highest in the world with 64% of adults being overweight or obese"
http://en.wikipedia.org/wiki/Obesity_in_the_United_States

actual paper

[flynt]

Here is a link to the actual publication.

http://www3.interscience.wiley.com/cgi-bin/fulltext/122539667/HTMLSTART [wiley.com]

It always bothers me that these aren't provided, we can read the the actual results and not the news version!

Re:The link between carbohydrate consumption and A

[dogmatixpsych]

If I may offer my opinion as someone who researches cognitive aging and the brain, I think the link (without actually reading the article) is likely due to cerebrovascular factors. People who are overweight often have high or highly varying blood pressure. They also often have arterosclerosis and all sorts of plaque build-up in the blood vessels. Basically their cardiovascular systems in general do not work as efficiently.

The brain is very power hungry. It needs virtually uninterrupted blood flow to function well. People who have reduced blood flow (efficiency) could have lower blood perfusion in the brain. Their neurons may just be slowly starved of enough oxygen and nutrients. People who are overweight are at increased risk for developing strokes, particularly so-called "silent strokes" that might not have apparent effects at first but could over time.

I don't think it's the obesity as much as the cardiovascular issues that are associated with it. I've seen the brains of older adults who have (uncontrolled or long-term) high blood pressure and by and large, they are not pretty. Their white matter is often pretty messed up. They often have larger ventricles (more brain atrophy) and do worse on cognitive tests.

In any case, being overweight is one of the worst things you can do to your overall health. Maybe not now, but in old age overweight (particularly obese) people are going to have a lot of problems - physical and cognitive. Again, I deal not with individuals as much as with groups of people so everything I say should be taken as "on average."

Re:These morally chiding "correlation" studies

[Darkness404]

http://healthyamericans.org/reports/obesity2009/ [healthyamericans.org]

The most obese states are located in the south. Look at the childhood obesity too and you will find even a higher concentration in the south.

Re:I also noticed a link

[Entropius]

You can do perfectly good statistics on 94 people.

Any good scientific study includes both the effect ("8% brain loss") alongside an estimation of the error ("8% +/- 4%"). Over in the life sciences, when comparing the results from two groups (fat/normal, say) they like to give the probability that any difference they saw was due to chance, with suitably small values of this probability meaning that the result is considered "statistically significant".

Having a limited sample size makes it less likely that a small effect will be above this threshhold for significance (since you can't distinguish it from the noise), but it does nothing to impair the validity of the statistics themselves, so long as all the errors are estimated correctly (which they should be, if you do your math honestly).

Now, of course, the article linked in the summary doesn't actually give the significance level or the error estimates or any of those other things that are crucial to a scientific result actually meaning anything. But this is a condemnation of the shitty state of science reporting, not of the study itself.

Re:These morally chiding "correlation" studies

[SBrach]

I want to haul plywood, bags of cement, tile, etc from home depot when I work on my house, tow my trailer full of dirt bikes or quads when I go camping, go off-roading occasionally, carry many passangers occasionally, go on a cross country trip with my wife, kids, and 2 weeks worth of luggage and I can't afford to have multiple vehicles for every task. Which type of vehicle is versatile enough to suit my (and the average American family's) needs.

Re:These morally chiding "correlation" studies

[Anonymous Coward]

http://www.gladwell.com/2004/2004_01_12_a_suv.html

Re:These morally chiding "correlation" studies

[natehoy]

I had the same shock when I went to France and spent a week in Orleans. At the time, I weighed 205 and I'm 6'3", so I didn't stand out amongst the French population. I walked around Paris for a day, then spent most of my time in Orleans (when I wasn't working) walking down the pedestrian district trying French food.

I saw three people who were heavy enough to stand out, and all three were Americans.

When I got back to JFK Airport in the US, it was almost shocking to see how many people were large.

The things we get used to and don't even realize it...

The funny part was that I ATE LIKE AN EFFING KING in France. I denied myself NOTHING, and ate cheese by the ton. And came back 2 pounds lighter. I'm sure it helped that I only used my car to go back and forth to work, and the rest of my time was spent walking (4-5 miles a day, minimum).

I'm sure it also helped that there was very little sugar in what I ate in France, and it was all food prepared by people who care about the quality of what they were serving. Even the cafeteria food at the company I was working for ran circles around the nicer restaurants here in the US, and the restaurants? Oh. My. God. I have never eaten anything like it.

Re:Best Reason So Far

[HonestButCurious]

More power to you. If you want a geek-friendly diet plan, I've seen people here recommend the Hacker's Diet [fourmilab.ch]. It's a diet with widgets!

Avoiding Obesity is Difficult

[erroneus]

Once upon a time, obesity was a sign of wealth. Food was different in those days and only by consuming large quantities of it could you hope to gain the wealthy appearance of obesity.

These days, the opposite is true. Our food is different in its content and in its richness. Average portion offered for sale are larger. And while it's true that people do less physical work, doing some basic calculation associated with calorie intake versus calorie burn and the increase of calorie burn with added exercise will reveal that exercise is not as effective at controlling weight as is controlling intake.

It is my observation that reducing the intake of food is the most significant thing anyone can do when attempting weight control and what's more, there is no "I have no time for it" excuse when attempting to do so. It is also my observation that reducing the intake of food is extremely difficult for a variety of reasons. Our habits and expectations are hard to change when ordering or preparing food. (for example, don't we all feel like a cheap-ass for not ordering that double-quarter-pounder meal deal instead of ordering from the dollar menu to get smaller portions?) Further, the content of our most available foods are a lot higher in calories than they have been in the past and this is largely due to increases in highly processed ingredients and preservatives and the like. While other nations have outlawed many of the more offensive ingredients, the U.S. has failed to issue as many restrictions which I believe is one of the most significant reasons that the U.S. is one of the most obese nations in the world today.

So what can we do? The best thing is to buy less and eat less. It takes a lot of effort to eat less, but in time your stomach will shrink and it will actually become difficult to eat as much as you are now accustomed to eating. This helps a lot, but it's the best answer for everyone and often leads to feelings of hunger and tiredness even after the adjustment in intake is made. (Keep in mind that the purpose of expensive and elective gastric alteration surgical is to serve this exact cause but people prefer to make these changes in their bodies rather than to make changes in their self-discipline.) Another thing is to start sending comments to your government representatives about fixing healthcare by fixing the problems with our food! (Imagine national healthcare costs plummeting because we aren't getting diabetes or any of the other health problems associated with obesity with the same frequency. That's what we see in nations with better controls over food content and since we're all the same species, we can expect similar results by enforcing similar rules.)

And before anyone start the criticism or attacks, let me just say that I am obese. I am working on it, but it's damned hard. I'm 200lbs (+/- 5lbs) when I should be 180lbs or less. I own more clothes that I cannot wear than clothes that I can. (I don't want to buy more "fat clothes" because that merely feeds the problem. I want to wear my old clothes.) And to better tie my commentary in with the original story, I feel a LOT less smart than I was when I was operating at my prime weight. And since I have been losing weight, I am feeling a lot more alert and aware than I have in a while and I sleep better and need less sleep as well. The benefits are obvious. And when the main course of action is simply to do less of what is causing the problem, it's not unreasonable or even expensive to pull off. I sure as hell haven't stopped eating at McDonald's... I just eat slightly more than the contents of a kid's meal instead of super-sizing everything.

Re:These morally chiding "correlation" studies

[Chosen Reject]

Both the Honda Odyssey and the Toyota Sienna can tow more than 3500 lbs. Even the Hyundai Elantra has a towing capacity of 2000 lbs. If you have a trailer for your four wheelers, I assume you can put some plywood and concrete on that trailer from Home Depot. Also, you might have missed the part where I talked about Home Depot renting you a truck. $19.95 for the first 75 minutes. Let me know of any other problems you have so I can find more solutions for you.

I said you might very well have a valid excuse, but with you not knowing that a minivan has towing capacity of "more than a thousand pounds or so", maybe you really haven't thought your needs or your options through.

Bogus stats, however.

[mikehoskins]

I saw this quote: "the researchers studied brain images of 94 people in their 70s who had participated in an earlier study looking at cardiovascular health and cognition."

At that point, I said, "Stop. What a useless study." Look at the sample size again... 94?!?!? That has a roughly 10% margin of error built in to the sample size (at a 95% confidence interval). At least they included the sample size! ...and then there's the operative word "study...." That, word (in the singular, no less), gives me all sorts of warm fuzzies.

So, is that 8% (+/- 10%) less brain mass for obese elderly people or a range from 7.2% to 8.8% for obese elderly people, based on this sample and a 95% confidence interval? I'm thinking the former.

In statistics class, this was called by the name "statistical deception." Just because a single study of 94 people says so, don't believe it. It has a roughly 50% chance of being right -- or wrong (at a 100% confidence interval) but so do psychics, horoscopes, and fortune cookies.

Junk science prevails in the popular press. Anything sensational gets front-page headlines -- it gets grant money and sells news. It doesn't matter that the next study contradicts it, the next supports it, the next contradicts that one, and on and on the tennis match goes....

Once this has been peer reviewed numerous times with tens of thousands of people per study, call me. I'll be getting a snack, in the mean time.

Here's a couple of links to refresh people with the term "margin of error:"
    http://en.wikipedia.org/wiki/Margin_of_error [wikipedia.org]
    http://www.isixsigma.com/library/content/c040607a.asp [isixsigma.com]

Re:These morally chiding "correlation" studies

[Chosen Reject]

I don't understand you. If you have real and valid reasons for driving an SUV, then by all means do so. I have an uncle that does. I don't consider him an idiot. But why do you feel the need to vindicate yourself so much? The way you put down minivans indicates that you have more of an image issue than a real need issue.

The vast majority of four wheelers weigh about 500 lbs or less. 3500 pound towing capacity is already 5 or 6 ATVs + the trailer. Are you really suggesting you need double that?

Concrete is about 150 lbs per cubic foot. Are you really hauling more than 22 cubic feet of concrete to your home once a week, or even once a month?

I am an American home owner, in addition to being an American home landlord. I own one car. It's a Honda Fit. It's been more than enough the vast majority of the time. Had I bought a truck or SUV it would have been more expensive to buy, operate, insure, maintain, etc in every conceivable way even when I include all the times I've rented another vehicle. Also, I could sell it for nearly as much as I paid for it. I don't have to climb up to get in. The fact is, for the average American home owner, a small car is more practical, efficient, convenient and less expensive. When you include non-homeowners, it becomes even more so.

Re:The link between carbohydrate consumption and A

[brian0918]

The idea that you can make a couple of simple changes and lose lots of weight is great for building a money milking industry on top of

Well, actually it was pretty easy for me, and everyone I've recommended this diet to has had similar results - 15-20 lbs dropped in under a month. I myself lost 40 lbs and have kept it off for a year. My weight loss was all without exercise - I didn't want to confound the data, so I avoided all exercise. I also didn't starve myself - I ate whenever I was hungry, and even then was eating 1400-2200 Calories a day. The diet was simply meats, fish, eggs, bacon, cheeses, dairy, some vegetables, minimal low-carb fruits (e.g. berries). For beverages: dry red wine, tea, coffee. Very simple.

I had been taking blood pressure medication for a couple years before this - my highest was 145/95. I eventually had to stop taking the medication - after about 20 lbs weight loss - because I was getting light headed and my blood pressure was dropping too low. Now I'm at normal blood pressure.

After a couple weeks on the diet, you lose all interest in bread and pasta. I don't remember the last time I had a slice of bread, or even bought a loaf of bread.

As for why it's so hard for everyone else to lose weight - all I can say is they're following bad advice. It's kind of disturbing that whether or not you are successful in weight loss can depend on which doctor you happen to have. I have seen doctors recommend the usual AMA/AHA/NIH nonsense about eating low-fat, and I have seen doctors who actually know what they're talking about, know all about the connection between carbohydrate (specifically fructose) ingestion and insulin resistance, ketosis, etc, and make good recommendations.

I have personally gotten both my parents on this diet, and at least three of my friends, and they've all had the same results - minimum 20 lbs dropped in a maximum of a month. Weight loss is actually pretty easy.