Monthly Archives: September 2014

Pollution Messes with Metabolism

Air pollution is not good for lungs. Just ask anyone in Beijing where surgical masks are a fashion accessory.

How bad is air pollution? The World Bank reported in 2010 that 16 of the world’s top 20 most polluted cities are in China. Linfen City in Shanxi Province, China, which is known for its coal industry, was the world’s most polluted.

Developed countries are polluted too.

Despite decades of cleanup measures, the American Lung Association State of the Air 2012 revealed that nearly half the population of the United States still suffers pollution levels that are often dangerous to breathe. The report found that unhealthy air posed a threat to the lives and health of more than 127 million people—roughly 41 percent of the nation. Even cities like Salt Lake City, Utah, and North Pole, Alaska, which sound pristine, are choking with pollution—the first from automobiles and industry and the latter from burning coal and wood for warmth. At times the air quality readings in North Pole are twice as bad as that of Beijing, according to Kim Murphy writing in the Los Angeles Times in 2013.

Air is judged by ozone and particulate matter. Greenhouse gases including carbon dioxide, methane, and nitrous oxide are bad for respiratory systems, according to the EPA. But a new slyer villain has emerged: the small bits, called particulate matter (PM).

According to the World Health Organization, PM affects more people than any other pollutant. PMs are a jumble of solids, liquids, and organic and inorganic matter: mostly sulfate, nitrates, ammonia, sodium chloride, carbon, mineral dust, and water. The smaller ones at 2.5 µm are most dangerous because they easily invade the lungs.

And as you may have guessed by the recipe, these PM2.5s, which emerge from burning fuels, are linked to asthma, lung cancer and other respiratory diseases. People exposed to pollution don’t live as long. The mortality in cities with high levels of pollution exceeds that observed in relatively cleaner cities by 15 to 20 percent.

The link to obesity is new. How could this happen? The idea is that PM contributes to insulin resistance and adipose inflammation. In one experiment, mice exposed to PM2.5 showed insulin resistance and more visceral fat and inflammation among other defects.

In a new study published in Particle and Fibre Toxicology journal, special mice susceptible to Type 2 diabetes were exposed to either ambient PM2.5 or filtered air for 5 to 8 weeks.


  • O2, Co2, respiratory exchange and thermogenesis were all changed.
  • More insulin resistance
  • More visceral fat
  • More inflammation in spleen and visceral fat
  • Leptin levels increased
  • Gene expression in brown adipose tissue changed.

Air pollution may be adding to our obesity and diabetes numbers. Choking  on this epidemic is not an option.




Wasted Wealth of Fruits and Vegetables

Eat your vegetables!  It’s not a new message but one that is more urgent today given the soaring numbers of obese children. An innovative push in the United States focuses on Farm to School (F2S) activities where locally-grown fruits and vegetables (FV) find a place on cafeteria menus.

Great idea. Yet many millions of tons of food are wasted every year—much of it tossed in the trash from a student’s tray. (See the April 2014 article in the Los Angeles Times newspaper about $100,000 worth of food wasted in Los Angeles Schools every DAY).

Are student’s benefiting at all?

Research done at the University of Wisconsin in Madison asked if a F2S program would change knowledge, attitudes, or consumption of fruit and vegetables as well as short-term BMIs.

Third through fifth-grade pupils at 12 schools were tested. The researcher found:

  • Small increases in dietary knowledge and attitudes toward eating fruits and vegetables
  • Increased FV access and consumption in school lunch.
  • No change in total energy intake.
  • Increase in energy from fruits and vegetables, indicating calorie displacement.
  • No change in BMIs.

The author concluded that F2S programs could play a part in supporting community health.

Lowering obesity rates will take a while. But putting more beans and berries in a child’s tummy has rewards far beyond weight loss.

Fruits and vegetables are rich in phytochemicals, prebiotics, fibers both soluble and insoluble, antioxidants, flavonoids and of course vitamins and minerals. Potato chips and soda look bankrupt in comparison.