I Wish I Were Far From the Madding Crowd

August 6, 2010

A chemical pot pourri

This is a real hodge-podge of items.

Bisphenol A

The Environmental Working Group (EWG) recently announced the findings of a study that found BPA in a large percentage of paper receipts it had collected.  http://ewg.org/BPA_Found_In_Receipts

Chemicals in cosmetics

Another resource EWG maintains is the Skin Deep cosmetic safety database.

http://www.cosmeticsdatabase.com/

Speaking of cosmetics, Annie Leonard (“The Story of Stuff”) has come out with “The Story of Cosmetics”, a look at chemicals in cosmetics and personal care products.  The Story of Stuff blog looks at the cosmetics industry’s reaction.

Learning and developmental disabilities and other diseases and conditions

The Collaborative on Health and the Environment (CHE) covers a wide range of topics, from learning and developmental disabilities to the CHE Toxicant and Disease Database, a searchable database that summarizes links between chemical contaminants and approximately 180 human diseases or conditions, to the Metabolic Syndrome Discussion Group.

BP (not just oil spills)

The CHE site also includes news items like:

6 Aug Thousands sign on for $10 billion BP suit. The revelation that BP’s Texas City refinery emitted toxic benzene for more than a month has ignited a furor in the port community that has suffered its share of deadly industrial accidents and toxic spills. Houston Chronicle.

Yes, before the BP oil spill there was the BP Texas City refinery explosion.  The U.S. Chemical Safety Board conducted an investigation.  I believe that they are looking into whether these incidents show that BP fostered a culture of cutting corners.

Chemicals and depression?

Was reading Peter Kramer’s Against Depression, where he argued that depression is a true illness.  (At least that’s what I’m getting out of it.)  He makes a couple of points that struck me.  One, on p. 156 he states that there is a connection between diabetes and depression.  Unfortunately, he doesn’t cite a source for that.  And if true, it’s not clear which caused which.  That is, does having diabetes make it more likely that you would be depressed?  Or does depression in some way connected to the development of diabetes.  Or could diabetes and depression be caused by the same agent?  (Or some combination of the above.)

He also talks about how long-term stress can result in increased levels of corticotropin and that such stress can lead to depression and illness.  Of course, corticotropin is but one element of the neuroendocrine system.  And with many of these things, there are feedback loops that get out of whack if enough recovery time is not available.  That’s actually why some scientists have proposed that a chronic lack of sleep can cause obesity over the long haul.  The International Agency for Research on Cancer and NIOSH are looking at whether “shift work” (along with a number of chemicals) can be considered carcinogenic.

Leptin: An example of what we didn’t know

Leptin, the appetite hormone, was not discovered until 1994 (though its effects had been observed much earlier).  (Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman JM (December 1994). “Positional cloning of the mouse obese gene and its human homologue”. Nature 372 (6505): 425–32. doi:10.1038/372425a0. PMID 7984236.) I mention that because chemical industry apologists seem to ignore the fact that we’ve learned a lot about the human body in the last 15-20 years.  And the more we learn, the more we discover how chemicals can mess up our systems.

Regarding leptin, I found the following using the National Library of Medicine’s MedlinePlus service.

A National Cancer Institute fact sheet on physical activity and cancer states that “increasing physical activity may influence insulin and leptin levels and influence breast cancer prognosis.”

An EPA report, “A Decade of Children’s Environmental Health Research:  Highlights from EPA’s Science to Achieve Results Program,” cites an EPA-funded study that found that “autistic children showed higher levels of leptin (a hormone that affects the regulation of body weight, metabolism, and reproductive function, and influences the immune system) in their blood when compared to typically developing children (Ashwood et al. 2007; R829388C002).”

Citation: Ashwood P., Kwong C., Hansen R., Hertz-Picciotto I., Croen L., Krakowiak P., Walker W., Pessah I.N., and Van de Water J. 2007. “Brief report: Plasma leptin levels are elevated in autism: association with early onset phenotype?” J. Autism Dev. Disord. Advanced online publication (DOI 10.1007/s10803-006-0353-1).  Abstract

So our bodies are these incredibly complex systems.  Some chemical companies would have you believe that the stuff they make, even the synthetic chemicals that human beings have never been exposed to before, have absolutely NO effect on our health.

Truth is, despite the Environmental Defense Fund saying that we’re not guinea pigs, we all are.  (See previous post: “Tired of being a guinea pig?“)

“Would you like BPA with those fries?”

March 19, 2010

Update on fructose – Dr. Lustig on Nightline

From post by Michelle Burton – “Dr. Robert Lustig on ABC’s Nightline”

Check out Dr. Robert Lustig on ABC’s Nightline discussing sugar and the damage it is taking on American’s Health.  (See post for link to video.)

March 14, 2010

The toxic effects of … sugar

UCSF Lecture on Sugar & Obesity Goes Viral as Experts Confront Health Crisis

March 10, 2010 UCSF news release (University of California San Francisco)

Background

Metabolic syndrome (from National Library of Medicine) – a group of conditions that put you at risk for heart disease and diabetes. These conditions are

See also Metabolic Syndrome from the Nemours Foundation.

Connection between sugar and the metabolic syndrome

The news release includes a presentation by Dr. Robert H. Lustig, UCSF, on “Sugar: The Bitter Truth” (approx. 1h, 30min.)

Dr. Lustig explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin. Series: UCSF Mini Medical School for the Public [7/2009].  (In case you don’t have an hour and a half to spare, I found a basic version of Lustig’s presentation on the NIEHS website.  Also includes a QuickTime version of the presentation Lustig gave at that workshop.)

I’m still convinced that environmental chemicals could be contributing to occurrence of metabolic syndrome, but Dr. Lustig’s presentation was eye-opening.  I don’t understand all the biochemistry, but he makes what I think is a convincing argument that fructose, whether from high fructose corn syrup (HFCS) or from refined sugar (sugar = fructose + glucose), is responsible for the development of metabolic syndrome.

The basic reason is not because we’re taking in too many calories, but that fructose is metabolized differently than glucose is.

Lustig goes through the history of sugar in drinks and food and the production of HFCS before diving into biochemistry.  He compares the metabolism of glucose, ethanol, and fructose, covering all the metabolic pathways for each.

All of the cells in the body can metabolize glucose, some ethanol is absorbed bv the gastrointestinal tract, then metabolized by the brain and liver.

Fructose is primarily metabolized by the liver.  I won’t go into the details here, but fructose increases the level of triglycerides, messes with the insulin and leptin processes, makes the pancreas work harder, and has other negative effects on your body.

Dr. Lustig makes a very convincing argument that overconsumption of fructose has causes metabolic syndrome and had led to the obesity epidemic.

Some people argue that it’s Americans’ eating habits and lack of exercise that have caused the obesity epidemic.  Lustig asks, if that’s true, how do you explain the epidemic of obese six-month-olds? (Lustig looks at the amount of sugar contained in many formulas.)

Lustig also notes that the role of exercise isn’t really to burn calories, but to keep our bodies’ metabolic processes running smoothly and discusses the important role of fiber in fructose metabolism.

From the NIEHS website (a basic version of Lustig’s presentation)

(presented at a workshop on “Children’s Environmental Health Research: Past, Present & Future,” Jan. 2007) – this workshop had sessions focusing on lead and neurotoxicity, asthma, metabolic disorders, and ADHD)

Summary

Fructose (sucrose or HFCS) consumption has increased in the past 30 years, coinciding with the obesity epidemic

  • Fructose is everywhere
  • Fructose is not glucose

• Hepatic fructose metabolism leads to all the manifestations of the Metabolic Syndrome:

      • hypertension
      • de novo lipogenesis, dyslipidemia, and hepatic steatosis
      • inflammation
      • hepatic insulin resistance
      • obesity
      • CNS leptin resistance, promoting continuous consumption

• Fructose ingestion interferes with obesity intervention
• Fructose is a chronic toxin (it’s metabolized like ethanol)

Links (from UCSF)

UCSF Center for Obesity Assessment, Study & Treatment (COAST)

WATCH Clinic
UCSF Children’s Hospital

Adult Weight Management Program
UCSF Medical Center

New Center to Focus on Effects of Stress, Socioeconomic Status on Obesity
UCSF Today, August 11, 2009

Sugar is a Poison, Says UCSF Obesity Expert
Science Café, June 25, 2009

The Biology of Fat (or Why Literally Running Away from Stress Is a Good Idea)
Science Café, July 6, 2007

Note: A much briefer (and less rigorous) discussion of the harmful effects of HFCS can be found at High-Fructose Corn Syrup Truth, Still Not Sexy, HFCS.

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