Skepticism about science and medicine

In search of disinterested science

Anti-obesity surgery: Weight loss prevents Alzheimer’s? (Anti-obesity fuss IV)

Posted by Henry Bauer on 2014/09/05

Being obese is bad for you, so everyone is saying just now; everyone including professional societies, official agencies, and drug companies who sell mind-altering drugs to curb your appetite that may also cause “potentially life-threatening serotonin syndrome . . . . confusion, Cognitive Impairment, disturbances in attention or memory . . . , Psychiatric Disorders including euphoria and dissociation, . . . depression or suicidal thoughts” [emphasis added] as well as priapism (erections lasting longer than 4 hours) [1].

Lest this possibility of literally fatal harm suggests that the possible benefit is not worth the risk and dissuades potential customers for these drugs, we’re now told that the drugs might not only harm the brain, they could actually do the very opposite too:

“Weight-loss surgery can boost brain power and ‘cut the risk of developing Alzheimer’s’”

  • Scientists in Brazil found gastric bypass surgery can affect brain activity
  • Found the operation curbed changes in the brain associated with obesity
  • They noted improvements in planning, strategising and organising
  • Researchers also found evidence operation could reduce risk of Alzheimer’s

All this from a study of just 17 obese women, comparing them before bariatric surgery and 24 weeks after surgery.

“[S]ome areas of their [obese women’s] brains metabolised sugars at a higher rate than normal weight women. . . . in a part of the brain linked to the development of Alzheimer’s disease . . . . Since bariatric surgery reversed this activity, we suspect the procedure may contribute to a reduced risk of Alzheimer’s disease and other forms of dementia. . . .

The new research focused on a procedure known as a Roux-en-Y gastric bypass (RYBG) which combines the two types of bariatric surgery.

Brain scans and a range of psychological tests were used to assess its effect over a period of six months. . . .
bariatric surgery seemed to improve the performance of the obese women in a test of ‘executive function’. . . . the brain’s ability to connect past experience and current action . . . involved in planning, organising and making strategic decisions. Other tests measuring various aspects of memory and thinking ability showed no change after bariatric surgery”.

 

The original article on which this account is based is Marques et al., “Changes in neuropsychological tests and brain metabolism after bariatric surgery”, Journal of Clinical Endocrinology and Metabolism, 26 August 2014: jc.20142068. Its 6 pages are replete with speculation and do nothing to decrease my skepticism that lack of improvement in “various aspects of memory and thinking ability” could accompany improved performance in “planning, organising and making strategic decisions”.

This speculation is without any reasonable basis at all because Alzheimer’s Disease (AD) is far from well understood. It is simply not known that there is “a part of the brain linked to the development of Alzheimer’s disease”. There is considerable evidence against the mainstream hypothesis that AD is characterized by amyloid plaques [2].

TV’s 60 Minutes of 31 August 2014 reported results of continuing research with cohorts of old (≥90 years) people, observing their behavior and cognitive abilities together with in vivo recording of brain activity. The researchers expressed surprise that the amyloid plaques and tau tangles thought to be the cause of AD were present in some people who showed no signs of dementia; while some individuals with dementia had no sign of amyloid plaques or tau tangles. Instead, there were indications that tiny strokes had effectively killed small parts of the brain, strokes so small that the affected individual would have had no immediate indication of their occurrence.

 

Lay people might regard those findings as further evidence that amyloid and tau have nothing to do with AD, or indeed with dementia in general.
Those who believe that science rejects hypotheses when the evidence contradicts them might also imagine that the mainstream is now discarding the notion that AD is caused by accumulation of plaques of amyloid protein.

But that’s not what happens in the real world. The researchers suggested on 60 Minutes that maybe the brains of non-demented individuals with tau tangles and amyloid plaques had found some way or other to “get around” those indications of AD . . . . They didn’t try to explain why some AD victims had no tau tangles or amyloid plaques.

 

Those of us who are familiar with the ignoring of evidence that contradicts mainstream dogmas recognize this as routine, cognitive dissonance in the service of mainstream denialism.

 

————————————————————

[1] Belviq®, revised 08/2012

[2]  Pp. 108-9 in Dogmatism in Science and Medicine: How Dominant Theories Monopolize Research and Stifle the Search for Truth, McFarland (2012)

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s