A lot of scientific studies are done in the field of nutrition, often with conflicting or misleading results. It’s important for people to know the difference between a well-designed study and one that’s not. It’s also important that people be able to determine the validity of conclusions drawn from a study. Most important of all, don’t trust others to interpret a study—read it for yourself.

To illustrate, I’ll take two studies—both done at Harvard. Let’s start with the colony collapse disorder study overseen by biologist Chensheng Lu. He starts with the question: Why are honeybee colonies suddenly collapsing? He proceeds to review the scientific literature on the subject. That’s good science. Then comes the hypothesis: Colony collapse disorder is caused by honeybee exposure to imidacloprid, an insecticide used on corn and transferred to bees in high fructose corn syrup fed to them by beekeepers. Next step: Design a study to test the hypothesis.

In this case new honeybee colonies populated by healthy bees were established in central Massachusetts. Some were fed HFCS containing various concentrations of imidacloprid, and some received HFCS that was free of the pesticide. All the bees were treated the same except for one variable—the pesticide dose. None of the field workers knew the concentrations of pesticides the bees were getting. Good science. The experiment is described in the final report in such detail that anyone who doubts the results could replicate it. Good science.

The results supported the hypothesis. The greater the pesticide dosage, the faster a colony collapsed, and all of the pesticide-exposed colonies eventually failed. Three out of four of the control hives (no pesticide) survived. So the data collected strongly support the hypothesis. That’s what scientists hope for but don’t always get. Next, the authors suggest questions raised and avenues of study for other scientists researching the same topic. Good Science. Finally, the study is published in a reputable scientific journal where other scientists can learn from it and possibly challenge it. Good science

Here we have the elements of a good scientific study whose results we can take seriously. In the next post we’ll take a look at a bad nutrition study done at the same university.

If you missed the recent youth gardening webinar, you can hear the presentations using this link.

Ken Olsen of Ground Works talks about laying the groundwork for a school garden so that people work as a team and keep the garden going in the long term. One Sioux Falls school garden he describes has been going for four years.

Chris Zdorovtsov of SDSU discusses various kinds of raised beds, why raised beds work so well, and how to design them for kids, adults, and people in wheelchairs.

“This webinar is perfect for school teachers and afterschool and summer garden program leaders – basically anyone who works with youth and would like to see youth step outside and embrace gardening,” said Chris Zdorovtsov, SDSU Extension Community Development Field Specialist.

This Webinar will be April 25 from 3:45 to 4:45 p.m. CDT. An additional Webinar will run during the growing season. Webinars are an hour long and will typically have two presentation topics running 15 to 20 minutes each with about 20 minutes for a question answer session at the end.

Presentation 1: Resourcing the Garden Program: People and Money by Tim Olsen, Director, Ground Works

Presentation 2: Building Raised Beds by Chris Zdorovtsov, Community Development Field Specialist, SDSU Extension

Discussion Time: Are You Organized?–The Season Is Starting!

Click here to join the webinar. You can join the session up to 30 minutes before it starts.

The Rodale website is an ongoing source of good information for organic gardeners. Here’s a post that will be of interest to beginning gardeners who have limited space. You’ll learn where to buy containers, how to fill them, and what seeds to purchase for an early crop. In our climate the watering is especially important. Planter soil dries out faster than ground soil and should be tested for moisture twice a day—unless it’s raining.

Here’s one of my basic life principles: Every technological ‘advance’ brings with it one or more negative effects.

Example: The car is a wonderfully convenient machine for travel and carrying stuff. But it pollutes the air, injures and kills people, and makes cities crowded and dangerous.

So what does this have to do with honeybee colony collapse? Maybe everything. In the early 1990s nicotine-containing pesticides called neonicotinoids were developed that would kill insects but be minimally harmful to humans and other mammals. That was, so to speak, the good part. The really bad part is that this class of insecticides is now believed to be a major contributor to the death and disruption of honeybee colonies. These chemicals affect bee nervous systems and in small doses cause bees to neglect their eggs and larvae and to become disoriented, unable to find the hive after collecting nectar or pollen. Large doses mean death.

The connection between neonicotinoids and honeybee deaths has been suspected since 1995. While other nations have banned or restricted their use, they are still common in the US, where they are applied to corn seeds to prevent damage from corn rootworm. The seed coatings turn to dust as the corn is mechanically planted, and this dust is highly toxic. Once airborne, it can be inhaled by bees. The insecticides are also found to persist in the soil. Because neonicotinoids are water soluble, they can be taken up by roots, move through a plant’s vascular system, and become part of the flower’s pollen and nectar which is then collected and ingested by bees. Yet another pathway for the pesticides to reach bees is high fructose corn syrup fed to bee colonies by beekeepers. HFCS is, of course, made from corn kernels, and if that corn has been nicotine treated, the pesticide will reach the kernels.

A new study released April 5 again points the finger at the neonicotinoids and, as expected, Bayer, the chemical company that produces them, goes on the offensive and tries to discredit the research. If you want to read the study and decide for yourself if it is an example of good science or bad science, here it is.

Chief biologist of the study Chensheng Lu, when asked about the criticism, refers to the book “Silent Spring” and wonders how long it will take for Americans to wake up to the dangers of pesticides.