Category: science

The unfiltered truth about caffeine

Coffee! If you're not shaking, you need another cup.

Photo by Flickr user Timothy Appnel [timaoutloud], used under a Creative Commons license (CC BY-NC-ND 2.0)

Journalist Murray Carpenter has a new book out next week titled Caffeinated: How Our Daily Habit Helps, Hurts, and Hooks Us. As Scientific American summarizes, “His book examines the caffeine industry, the coffee and other products it churns out, and the complex effects the chemical has on our bodies.” Kirkus Reviews says that “Carpenter blends intriguing historical episodes with interviews, accounts of treks to caffeine-related locations and a multitude of test results.”

For a preview of some of the book’s themes, Maddie Oatman of Mother Jones interviewed Carpenter. Take the following as just one example of the lessons learned in his research:

There’s no standard amount of caffeine in each cup of coffee—even within the same brand.

“Starbucks gives an approximation of 20 milligrams per ounce. One 16-ounce cup of Starbucks puts you at about 320 milligrams of caffeine. One 16-ounce cup of Starbucks is for many Americans a good daily dose of caffeine.

“One researcher found that a 16-ounce cup had 560 milligrams of caffeine. The researcher, Bruce Goldberger, went to the same Starbucks and ordered the same blend of coffee for six days, and found that the levels varied more than twofold. He’s not the only one to have found those things. Even espresso shots, which are much more regimented, can vary.”

Check our her full post here.

Deftly deployed, salt can work magic

104/365 - Salt

Photo by Flickr user Dennis Wilkinson [djwtwo], used under a Creative Commons license (CC BY-NC-SA 2.0)

A few weeks ago, The Guardian posted a piece by Amy Fleming about some of the unlikely chemical (and even psychological) effects that a bit of salt can have as food is prepared, smelled, and tasted. For example, she considers how salt can neutralize bitterness:

The bitter-reducing ability of salt is a marvel. It is why coffee aficionados add an undetectable pinch to their grounds before brewing, says Barry Smith of London University’s Centre for the Study of the Senses…. But it is not easy to uncover the precise mechanics of this culinary godsend, what with it occurring on a molecular level. We do know that it is a physiological phenomenon, rather than cognitive. Even if there isn’t enough salt in our mouths for us to consciously taste it, the effect will still happen. And if you stimulate one side of the tongue with salt, and then put something bitter such as quinine on the other side, the salt will generally not suppress the bitterness. The two tastes have to be hitting the same receptors for it to work. Put very simply, we think that sodium ions turn down bitter responses in the receptors.

For more, including two distinct ways that salting can influence aroma, head here.

Vitamins may offer less (or more) than you expect


Photo by Flickr user mike lietz, used under a Creative Commons license (CC BY-NC-SA 2.0)

Science writer Beth Skwarecki recently penned a piece for the PLOS Public Health Perspectives blog about vitamins. As she begins,

Bad news for athletes this week: two studies show that vitamin supplements can interfere with the benefits of exercise. While vitamins are safer and cheaper than many other supplements sold to athletes, these studies add to the growing body of evidence that more of a good thing isn’t necessarily better. And even though we think we understand what vitamins do, their real-world effects highlight how murky our understanding of human biology really is.

Skwarecki goes on the detail the findings of the two studies, and then notes the following:

In December, an Annals of Internal Medicine editorial cried out: Enough is enough: Stop wasting money on vitamin and mineral supplements. The authors concluded that multivitamins don’t prevent dementia, heart disease, or cancer; but certain vitamins can be harmful in large doses. The jury is still out on Vitamin D, they wrote, but for all the rest, taking them on top of a reasonable diet carries no benefit and may be harmful.

For the full piece, head here.

Then, for news that many vitamins targeted at the youngest children contain levels far in excess of recommended daily allowances, check out this piece from Malanie Haiken at Forbes.

Digital tracking and drones (we’re talking bees, not the NSA and DOD)

Photo by CSIRO

Todd Woody recently wrote a piece about a new research effort to understand the behavior of bees doing the essential work of pollinating plants in our food supply. As he writes at Quartz,

Australian scientists have devised a way to pinpoint the causes of the global die-off of bees that pollinate a third of the world’s crops: Attach tiny sensors to 5,000 honey bees, and follow where they fly.

The sensors, each measuring 2.5 millimeters by 2.5 millimeters (0.1 inch by 0.1 inch), contain radio frequency identification chips that broadcast each bee’s location in real-time. The data is beamed to a server, so scientists can construct a three-dimensional model of the swarm’s movements, identifying anomalies in their behavior.

Worker bees tend to follow predictable daily schedules—they don’t call them drones for nothing—leaving the beehive at certain times, foraging for pollen, and returning home along well-established routes. Variations in their routines may indicate a change in environment, such as exposure to pesticides.

For the full story and links, head here, and check out the press release and accompanying audio clips from CSIRO, the Commonwealth Scientific and Industrial Research Organisation, Australia’s national science office. For some of my earlier posts about bees and the challenges they’re facing, check out these links.

Turnip seeds heading to the moon


Turnip photo by Flickr user Nicholas Noyes [niznoz], used under a Creative Commons license (CC BY-NC-SA 2.0)

Thanks to a recent piece at NPR’s The Salt, I learned that the humble turnip (or its seeds, anyway) will be rocketing to the moon as part of a planned NASA mission in 2015. Here’s how NASA describes it:

Can humans live and work on the moon? Not just visit for a few days but stay for decades? A first step in long term presence is to send plants. As seedlings, they can be as sensitive as humans to environmental conditions, sometimes even more so. They carry genetic material that can be damaged by radiation as can that of humans. They can test the lunar environment for us acting as a “canary in a coal mine”.

As Maanvi Singh explains in the NPR post,

growing plants on the moon won’t be easy. The moon has one-sixth the gravity of Earth — and the plants that NASA sends up there will have to deal with that, as well as facing extreme temperatures and harsh radiation….

The plant habitat that [mission scientist Bob] Bowman and his colleagues have designed contains seeds, as well as a nutrient-rich paper and enough air and water for the seeds to germinate and grow. The canister also has features that regulate light and temperature, and cameras that the researchers will use to track the plants’ progress over five to 10 days.

The entire thing is about the size of a coffee canister, and it weights only one kilogram.

How will it work? As Jon M. Chang details for ABC News,

When the garden lands on the moon, it will automatically trigger a small reservoir to squirt water on nutrient-rich filter paper. The dissolved nutrients will trickle down to the seeds, prompting the seeds to start growing.

A week or so obviously won’t yield full-grown “moon turnips,” but the scientists are dreaming big. As NASA outlines,

After LPX-0 demonstrates germination and initial growth in lunar gravity and radiation, we anticipate follow on experiments that expand the biological science. These include: 1) long term, over-lunar-night experiments, 2) multi-generation experiments, 3) Diverse plants.

Survival to 14 days demonstrates plants can sprout in the Moon’s radiation environment at 1/6 g. Survival to 60 days demonstrates that sexual reproduction (meiosis) can occur in a lunar environment. Survival to 180 days shows effects of radiation on dominant & recessive genetic traits. Afterwards, the experiment may run for months through multiple generations, increasing science return.

In other words, a lunar CSA is a long, long way off.

TTBOOK on fermentation

Home Brew Day - Reedsburg Fermentation Fest

A home brewing demonstration at the 2010 Fermentation Fest. Photo by Flickr user Nic Stage [Analog Weapon], used under a Creative Commons license (CC BY-SA 2.0)

Yesterday I caught the latest episode of To The Best of Our Knowledge on my local public radio station. The topic this time? Fermentation. As their intro describes,

Something’s bubbling in American kitchens: a resurgence of interest in cultured and fermented foods. Fermentation revivalists share a slow food philosophy, a DIY approach to foodcraft, and a deep interest in the health of the American gut. Today, we explore fermentation culture in food, technology, art and science.

Guests include Sandor Katz, author of The Art of Fermentation; Michael Paterniti, author of The Telling Room: A Tale of Love, Betrayal, Revenge, and the World’s Greatest Piece of Cheese; designer Suzanne Lee on growing fabric via microorganisms; and human microbiome expert Rob Knight. The episode also features a visit to Fermentation Fest right here in Wisconsin and a funny short story by John Scalzi called “When the Yogurt Took Over.”

Check out audio of the full episode (or any of its parts) here. If you’d rather read than listen, you can find Scalzi’s story here at his blog (though the audio version with reader Adam Hirsch is swell).

The “mule” of summer

Ada Park Playground June 05, 2010

Photo by Steven Depolo via Flickr, used under a Creative Commons license (CC BY 2.0)

It’s the time of year when mules start showing up at grocery stores, farmers’ markets, and produce stands. Not actual mules, nor the refreshing Moscow Mule popularized by Oprah Winfrey*. No, I’m talking about seedless watermelons. Ever wonder how a plant with no seeds came to be? Or where those hard black seeds went? Well, the seeds got stopped before they could start, thanks to a little chemical intervention and some careful breeding.

As this “Ask a Scientist!” post from Cornell University explains,

Producing a seedless watermelon involves three steps. First, a plant is treated with colchicine, a substance that allows chromosomes to duplicate, but prevents the copies from being distributed properly to dividing cells. As a result, a plant with four sets of chromosomes is created, a “tetraploid.” In the second step, a tetraploid plant is crossed with a [regular] diploid to produce offspring that are … triploid, with three sets. They get half the number of chromosomes from each parent. Finally, the triploid seeds are grown into plants.

The triploid abnormality means that the watermelons can’t reproduce, so their seeds never mature and develop the hard black exterior like a diploid watermelon. As NPR’s Andrea Seabrook says in this piece, “it’s the watermelon version of a mule…. It can’t reproduce but it exists.”

For all the details, including why you still need diploid watermelon plants around for seedless triploids to bear fruit, check out the NPR story (audio or transcript) or the Cornell post. And if, like me, you find the average watermelon to be less flavorful than you’d like, keep an eye out for varieties like the wonderful Yellow Doll.


* If you haven’t yet learned the best way to squeeze a lime when there’s no juicer on hand, check out this video of Oprah in Yosemite making Moscow Mules with Gayle for their campsite neighbors. Honestly, J swears by her technique! (You can skip to minute mark 1:20 if you don’t want to first watch her comically try to figure out how to open a bottle of ginger beer.)

The Conscientious Omnivore is away. This is an encore presentation of a post that originally appeared in slightly edited form on July 26, 2012.