Sunday, March 19, 2017

Spiders are your friend, if you don't like all the other creepy-crawlies

So if you live in the Islands, you’ve got geckos in your house, and they’re annoying. But just how many insects are they removing to survive?

Probably a lot—and that’s a good thing for both your sanity and your health.

It turns out the spiders around your home, similarly annoying, are also removing insects from the environment—a lot of insects.

(Image: You won't find this one around your home. It's a sea spider, photographed by teacher Kaitlin Baird from a NOAA bottom trawl. Sea spiders are deep water creatures that tend to have very long legs and tiny bodies. Credit: Kaitlin Baird/NOAA.)

Globally, spiders are taking out 400 to 800 million tons of insects. A stunning amount.

That’s from calculations done by the authors of this paper

(Okay, we ought here to clarify that spiders are not themselves insects. Spiders are arachnids, and they have two main body parts and eight legs. Insects are six-legged creatures with three main body parts. There are other differences as well, but that should suffice for this discussion.)

Spiders have a much bigger impact in natural environments than disturbed or urban environments, but, still. They account for a lot of pest control.

One of the findings of the paper above is that if you remove spiders from the environment, you can expect a big rebound in insect populations.

“Our estimates are supported by the published results of exclusion experiments, showing that the number of herbivorous/detritivorous insects and collembolans increased significantly after spider removal from experimental plots.”

(Yeah, collembolans. Six-legged critters that used to be considered insects but no longer are. Commonly called springtails, for their prodigious jumping capacity.)

You may worry about predators like sharks and bears and snakes and mosquitoes, but spiders, say authors Martin Nyffeler and Klaus Birkhofer, are “the most common and abundant predators in terrestrial ecosystems.”

The Eurekalert press release on their study is here. 

If you have spiders in your garden, think twice before removing them. All spiders are carnivores—they eat other creepy-crawlies and only very rarely will one munch a plant.

Hawaii has lots of introduced spiders, but its native spiders are a fascinating bunch. The happy-faced spider is perhaps the most famous, but there are lots more. The Nature Conservancy’s Sam Gon writes about some of them here

If you’re interested in the tiny critters of the island, I can recommend “What’s Bugging Me,” by Gordon M. Nishida and Joann M. Tenorio. And "What Bit Me?" by the same pair.

© Jan TenBruggencate 2017

Monday, February 20, 2017

All the stuff that's in you makes you sick, and makes you well. The microbiome is a new frontier.

What you eat feeds not only what you think of as you, but also the millions upon millions of bacteria, yeasts and other microorganisms that are in you—effectively, part of you.

And increasingly researchers are finding that that mixture of gut bacteria and other stuff plays a massive role in what makes you you. This is a new frontier in nutritional and disease science.

Let’s talk a little about how big a deal is this association between us and our biological tenants.

“All organisms, including humans, exist within a sea of microorganisms. A select few microbes cause great harm, but most are benign, some essential,” wrote Caroline Ash and Kristen Mueller in an April 2016 article in the journal Science.

“The human microbiome is a source of genetic diversity, a modifier of disease, an essential component of immunity, and a functional entity that influences metabolism and modulates drug interactions,” wrote the authors Elizabeth Grice and Julia Segre in this paper

The University of Hawai`i at Manoa is active in the microbiome work.

Canadian researchers have found that babies with particular microscopic organisms in their systems in the first three months of life are more likely to have asthma later in life. They studied babies in Canada and babies in Ecuador and found the same pattern, although it was bacteria in Canadian kids and yeasts in Ecuadorian kids.  

A study in the journal Cell found that kids fed the same diets could be healthy or malnourished depending on what bacteria they had in their guts.

A study in the journal Research in Microbiology found that babies born by caesarian section end up with very different gut biota from those born vaginally—often with bacteria picked up in the hospital rather than those from their mothers.

There’s a whole industry, probiotics, that argues that by eating certain things, you can adjust your microbiome to favor microorganisms that keep you healthy and disfavor those that make you sick. But there are cautions.

“The probiotic industry currently faces huge challenges. These range from exaggerated health claims to the difficulties of developing rigorous testing protocols within existing regulatory frameworks. All the same, probiotic development shows great promise for rebuilding microbiotas and restoring health, certainly for some individuals,” wrote Ash and Mueller in Science.

Earlier this month, the University of Hawai`i hosted the author of the book, “Let Them Eat Dirt:
Saving Your Child from an Oversanitized World.” In it, Michael Finlay, with co-author Marie-Clair Arrieta, argue that early exposure to a range of microscopic life can be beneficial.

A lot of folks eat yogurt for its effect on gut bacteria. And University of Hawai`i researchers have studied the effects of poi as a non-dairy player in changing the mix of your internal biology. They didn’t find much impact from fresh poi, but they suggested that sour poi might have a different impact.

That paper includes a detailed review of probiotics, and it’s interesting reading. The authors are Amy C. Brown and Anne Shovic, of the Department of Human Nutrition, Food and Animal Sciences at the University of Hawaii at Manoa, Salam Ibrahim, of the Food Microbiology and Biotechnology Laboratory, Department of Human Environment and Family Sciences, North Carolina A&T State University, Peter Holck, of the John A. Burns School of Medicine, and Alvin Huang, of the Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa. Their paper is here

They wrote, in part, that “The probiotic theory is supported by the fact that a disruption in the intestine’s delicate balance may contribute to diarrhea, gastroenteritis, constipation, irritable bowel syndrome, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), food allergies, and certain cancers. On the contrary, a balanced or “normal” enteric flora may competitively exclude possible pathogenic organisms and stimulate the intestinal immune system.”

So what all is in there? “The human microbiome is composed of bacteria, archaea, viruses and eukaryotic microbes that reside in and on our bodies. These microbes have tremendous potential to impact our physiology, both in health and in disease,” wrote the authors of this paper

Clearly, we’re learning a lot, but there are vast amounts left to learn. Hawai`i will be part of the information gathering, in part through the university’s involvement in the National Microbiome Initiative.

© Jan TenBruggencate 2017

Thursday, February 9, 2017

Children at risk from poisons at home

A new study has once again confirmed that children are at risk from pesticides used in the home.

Hawai`i's  statewide hue and cry about agricultural pest control products appears to miss the real danger, which is caused by home pest control products.

Not agricultural pesticides, but the pesticides used on pets are identified as a specific threat to infants and older kids.

The new probe is the first study into unintentional exposure to animal medications by children. It is entitled “Pediatric Exposures to Veterinary Pharmaceuticals,” and was performed by researchers from Nationwide Children’s Hospital.

The study was published online in the journal Pediatrics

Science Daily’s Feb. 6, 2017, review of the study notes that kids can be exposed in numerous ways, including eating the medication directly, eating medicated pet food, and coming into contact with fur of treated pets. 

“When you have kids and pets in the home, sometimes things get a little busy. Thinking about how your pet's medicines could be a risk for your family might not even cross your mind" said Kristi Roberts, of the Center for Injury Research and Policy at Nationwide Children's Hospital.

While the Hawai`i Legislature continues to express angst about risks from farmers’ use of agricultural chemicals, for which there is limited evidence, it’s arguable that it ignores the actual threats. 

Agricultural pesticide use is on a downturn, and actually peaked 30 years ago, as we wrote in 2015. 
That said, it's a mixed bag. The kinds of agricultural chemicals have changed—more herbicides and less insecticides—and has trended over time to less hazardous chemicals.

But actual health impacts from exposure to the chemicals used closest to home and in the home--those threats appear to be real.

When a Kaua`i mother subjected her child’s hair to testing for chemicals a few years go, it turned out most of the pesticides found at the highest levels were chemicals used in the home—including ones used to control insects on pets. We covered that here

The Nationwide Children’s Hospital study in Pedatrics looked at actual hospital admissions for children suffering from pesticide poisoning from 1999 to 2013, in data collected by the Central Ohio Poison Center. It found 1,431 cases, 88 percent of them involving kids aged 5 or less.

“Exploratory behavior was the most common exposure-related circumstance (61.4%) and ingestion accounted for the exposure route in 93% of cases,” the study says.

“Substances commonly associated with exposures included: veterinary drugs without human equivalent (17.3%), antimicrobial agents (14.8%), and antiparasitics (14.6%).”

The authors argue that parents and child care services may not recognize the risks of exposure to young children who are constantly exploring their environments.

“Prevention and education efforts should focus on appropriate product dispensing, home storage practices, and proper medication delivery to help reduce the risk of veterinary pharmaceutical exposure to young children,” they write.

This threat was earlier identified in a 2012 pesticide statement in the Journal of the American Academy of Pediatrics. While it said the data at that time was limited, it expressed serious concern.

“Children encounter pesticides daily in air, food, dust, and soil and on surfaces through home and public lawn or garden applications, household insecticide use, application to pets, and agricultural product residue,” the statement says. 

A 2015 study, “Residential Exposure to Pesticide During Childhood and Childhood Cancers: A Meta-Analysis,” also in Pediatrics, also found that indoor use of insecticides was a risk. 

“Children exposed to indoor insecticides would have a higher risk of childhood hematopoietic cancers. Additional research is needed to confirm the association between residential indoor pesticide exposures and childhood cancers. Meanwhile, preventive measures should be considered to reduce children’s exposure to pesticides at home,” the study said.

"We found that childhood exposure to indoor but not outdoor residential insecticides was associated with a significant increase in risk of childhood leukemia ... and childhood lymphomas," wrote the authors of the 2015 pesticide/cancer study.

There is lots of data out there, and making sense of it can be challenging. But a number of studies is now suggesting the need for serious attention to home pesticide use.

© Jan TenBruggencate 2017

Thursday, January 26, 2017

Hawaiian chocolate--hoo da good! And how you process it makes a difference.

Immature cacao fruit.

A lot of Hawaii residents are growing chocolate—either for a hobby or commercially.

And if you’re growing Theobroma cacao, the cacao tree, from which chocolate is made, chances are you’ve experimented with making some.

It turns out there’s a lot of disagreement about how best to process this magical fruit. 

Traditionally, the fruit is harvested and the cocoa-producing seeds removed along with their white fleshy pulp. All of that is then fermented, normally with the bacteria and yeasts that show up naturally.

Later, the fermented beans are cleaned, dried, roasted, processed to remove the seed coat, and then the resulting nibs are ground into chocolate liquor. After that you can make chocolate milk, add the stuff to cake, or even make chocolate bars.

It’s a whole lot of work. There are dozens of Hawai`i companies marketing Hawaiian-grown chocolate. I’ll list a few, and apologize to those left out. 

Manoa Chocolate on O`ahu has a quick video on production.
The Moloa`a Bay Coffee folks on Kaua`i do excellent chocolate. I've tried it.
The Original Hawaiian Chocolate Farm does tours in Kona 
There’s Waialua Estate on O`ahu. 
And Steelgrass Farm on Kaua`i.
You can take the Maui Chocolate Tour

It goes on and on. Do your own search to find more.

And it turns out, there are different theories about which processing method for chocolate is best.

For example, the fermenting is supposed to bring out a better flavor, but it can also remove some of the valued anti-oxidants. 

“Substantial decreases (>80%) in catechin and epicatechin levels were observed in fermented versus unfermented beans,” says this paper in the Journal of Agriculture and Food Chemistry. Catechin and epicatechin are anti-oxidant flavonoids. They’re also found in green tea. 

Of course, we really don’t eat chocolate because of its health benefits, do we?

Fermenting can also increase the likelihood that rot will set in during the fermentation. (I lost a whole season that way once.)

There is a small movement marketing non-fermented cacao. I tried doing that. Just drying the beans without fermenting and then roasting them. Still tastes like chocolate to me, but I haven’t done proper testing to see whether it’s inferior to fermented beans.

There are studies that argue that the specific type of yeast used in fermenting makes all the difference. 

“Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics.,” wrote the authors of this paper

But wait, the Mars candy company has announced a patent for a fermentation-free chocolate. No yeast at all. It uses an ethanol soak for a couple of days instead of the fermentation. And it insists that it’s the ethanol, not the microbes, that causes the great chocolate flavor. 

You’d assume the Mars people know something about chocolate. Here is the link to Oliver Neiburg’s article in Confectionery News on the subject of the new Mars technique.

There’s more on the Hawaiian chocolate industry at the website of the industry organization, Hawaii Chocolate and Cacao Association..

© Jan TenBruggencate 2017