The scientist who decided what you’ll eat and whether you’ll like it

Rose Marie Pangborn has almost certainly decided what you’re going to eat today. Possibly it’ll be a soda. Maybe it will be potato chips. It could be some candy. Whatever it was, her work made it possible to understand what you’ll taste, and how much you’ll like it.

Rose Marie Valdes Pangborn was born in 1932, when food science was mostly concerned with not poisoning people. She wound her way through New Mexico State University and Iowa State University before finally teaching at UC Davis - where her academic career really took off. She directed hundreds of grad students, taught one of the university’s most work-intensive classes to many hundred more undergraduates, and published over 180 papers. The subject of all that teaching and research? You’re probably nibbling on it right now. Pangborn was one of the first sensory researchers, to precisely measure a person’s responses to the food they eat.

The idea of such researchers conjures up images of tedious and cynical focus groups for a new line of soups marketed as “home style,” or the carefully edited taste tests shown in television commercials. Although Pangborn’s kind of research is worth a lot of money to companies, Pangborn’s interest was scholarly. Despite the bad press, the subject needs scholarly analysis. No one quibbles with the idea that it’s academically important to measure when a person first consciously or unconsciously responds to light, to pain, or to sound. It should be the same to measure a person’s first response to salt, or to sweet. If anything, as Pangborn discovered, the measuring of taste is a lot more complicated than the perception of light or sound.

One of the common themes running through Pangborn’s many papers is how taste is not an absolute, but depends on many different factors. She measured how body weight related to a person’s experience of milk fats. She tested how color affects a person’s experience of sweets - people tend to prefer blue and hate yellow-green. Most of all she related how a person’s regular diet caused them to react to new foods. Did someone who habitually tasted wine perceive a new kind of wine as more or less astringent than an infrequent drinker? How did someone who was accustomed to eating fats and sweets react to lemonade and milk fat compared to someone who rarely ate them? The data she got showed how complicated biochemistry and perception can be. In one paper she describes testing how regular sodium intake affects a person’s experience of salt. When salt was added to water, high-intake people recognized it first. In tomato juice, low-intake people noticed it first. Low-intake people added less salt to their food, but didn’t generally recognize when more was added. She concluded that showing that a person noticed, or liked, salt in one solution did not guarantee a better response when adding salt across the board. (She added, a little bit testily, that they needed to develop a better process to verify the salt intake of their subjects.)

Sadly, Pangborn died in 1990, but she left behind a science - sensory analysis - that she helped shape throughout its infancy. The Association for Chemoreception Sciences, which she co-founded, and the Sensory Reception Scholarship Fund, which she established, both continue to shape the science of sensory perception. Although few people will read their research, we all undoubtedly have tasted it. 

For Peat’s Sake - Peat is not a renewable resource. What does that mean for my favorite Scotch whiskies?

The peat that the Scotch industry burns by the ton to make peated whiskies isn’t renewable, but it’s not quite a fossil fuel either. A sort of proto-coal, peat is a mush of partially decomposed plant matter that lies on the surface of the Earth and accumulates imperceptibly, by about a millimeter a year. It only forms in places where a handful of climatic conditions are in balance. Soil chemistry, density of flora, precipitation, temperature, humidity, and average wind speed must be just so, yielding a habitat with more rainfall than evaporation can subsequently carry away. When all these variables line up, plants never fully decompose; an initial, brief round of decay produces a bath of weak acids that prevents any further decomposition. Over centuries, mummified plants pile up and get compressed into a carbon-rich gunk that resembles crumbly, wet Oreo cookies. Give it a few more million years, and this peat turns into coal.

“There’s some peat that’s 20,000 years old,” says Sandy Neuzil, a peat specialist with the United States Geological Survey. “But most of it’s between 4,000 and 8,000 years.”

In peat-rich regions, which are located mostly in Northern Europe, Canada, and Russia, people have long burned the gunk for heating and cooking. For most of human history, consumption was at the household level and without serious consequences. However, in at least one place, Ireland’s Blasket Islands, the peat resource was totally exhausted. (For this reason, the islands have been uninhabited since 1953.) In the past 150 years, peat consumption ticked up as it became a primary fuel in some power plants, though most of these plants are closing or reducing the amount of peat they burn.

Every year, about 25 million tons of peat are harvested and burned, by individuals, power utilities, and companies of various kinds (including, but not limited to, distilleries). Another 14 million tons are used by farmers, landscapers, and gardeners to amend deficient soil. Peat keeps golf courses looking sharp. As massive as these numbers are, they amount to about 0.1 percent of the global peat resource. An additional 10 percent of the global resource has been lost to real-estate development and agriculture.

Thankfully, the majority of the Earth’s peatlands remain undisturbed. Jean-Yves Daigle, outgoing chair of the Canadian National Committee of the International Peat Society, estimates that there are around 1.5 million square miles of peatland on Earth. This figure only scratches the surface: Square miles measure surface area, but peat deposits can be up to 60 feet deep. (Neuzil reported this anecdotal figure in a stage whisper, as if it were a shamefully tasty rumor.) So, Daigle says, call that between 5 trillion and 6 trillion tons. He reckons that we are using about 0.05 percent of this resource every year. If the trend holds, and if the incidence of peatland fires—such as one that burned uncontrollably in Minnesota last year—doesn’t increase dramatically, that works out to another 2,000 years of Scotch.

However, Neuzil told me that if peat were used only to make Scotch, its most noble purpose (my words, not hers), the supply would never run out. Accumulation would keep pace with consumption, and from now until the end of time there would be Scotch on Earth.

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Iridescence With My Tea

As a cup of tea was steeping one morning in my sun-filled kitchen, I noticed the colorful patterns shown here.

Sunlight scattered through the steamy mist just above the surface of the hot tea, produced an iridescent mix. The similarly sized lipids (perhaps 0.01 mm in diameter) on the surface of the tea deflect sunlight in such a way to produce the pastel colors.

Color intensity results from minuscule variations in the size of the droplets. Photo taken on April 1, 2012. — Photographer: Hans Juergen Heyen // Summary Authors: Hans Juergen Heyen; Jim Foster

It’s fun to know we can science even when doing something as simple as drinking tea. Strangely satisfying :)

The Secret to Olive Oil’s Anti-Alzheimer’s Powers:

People living in the Mediterranean have a much lower risk of contracting Alzheimer’s disease than those of us stuck in other parts of the world. Researchers looking for an explanation nailed down an association between extra virgin olive oil and low rates of the disease. They attributed olive oil’s disease-fighting power to high amounts of monounsaturated fats. But now, however, new research shows that a natural substance found in olive oil called oleocanthal is the real hero, Phys.org writes.

Past studies have identified oleocanthal as the likely candidate behind olive oil’s protective effects, but this study helped fill in the blanks of how specifically it bestows that advantage. In trials with mice, oleocanthal protected nerve cells from the kind of damage that occurs from Alzheimer’s disease. It decreased the accumulation of beta-amyloids—the amino acid–based plaques that scientists believe cause Alzheimer’s—in the brain and boosted production of the proteins and enzymes that researchers think play roles in removing those same plaques. 

In their paper, published in ACS Chemical Neuroscience, the researchers write:

This study provides conclusive evidence for the role of oleocanthal on Aβ degradation as shown by the up-regulation of Aβ degrading enzymes IDE and possibly NEP. Furthermore, our results show that extra-virgin olive oil-derived oleocanthal associated with the consumption of Mediterranean diet has the potential to reduce the risk of AD or related neurodegenerative dementias.

As if deliciousness and protection against Alzheimer’s were not enough to recommend it, other researchers have found that extra virgin olive oil helps to clarify thinking and improve memory.

Raw Food Not Enough to Feed Big Brains

Eating a raw food diet is a recipe for disaster if you’re trying to boost your species’ brainpower. That’s because humans would have to spend more than 9 hours a day eating to get enough energy from unprocessed raw food alone to support our large brains, according to a new study that calculates the energetic costs of growing a bigger brain or body in primates. But our ancestors managed to get enough energy to grow brains that have three times as many neurons as those in apes such as gorillas, chimpanzees, and orangutans. How did they do it? They got cooking, according to a study published online today in the Proceedings of the National Academy of Sciences.

“If you eat only raw food, there are not enough hours in the day to get enough calories to build such a large brain,” says Suzana Herculano-Houzel, a neuroscientist at the Federal University of Rio de Janeiro in Brazil who is co-author of the report. “We can afford more neurons, thanks to cooking.”

Humans have more brain neurons than any other primate — about 86 billion, on average, compared with about 33 billion neurons in gorillas and 28 billion in chimpanzees. While these extra neurons endow us with many benefits, they come at a price — our brains consume 20 percent of our body’s energy when resting, compared with 9 percent in other primates. So a long-standing riddle has been where did our ancestors get that extra energy to expand their minds as they evolved from animals with brains and bodies the size of chimpanzees?

One answer came in the late 1990s when Harvard University primatologist Richard Wrangham proposed that the brain began to expand rapidly 1.6 million to 1.8 million years ago in our ancestor, Homo erectus, because this early human learned how to roast meat and tuberous root vegetables over a fire. Cooking, Wrangham argued, effectively predigested the food, making it easier and more efficient for our guts to absorb calories more rapidly. Since then, he and his colleagues have shown in lab studies of rodents and pythons that these animals grow up bigger and faster when they eat cooked meat instead of raw meat — and that it takes less energy to digest cooked meat than raw meat.

In a new test of this cooking hypothesis, Herculano-Houzel and her graduate student, Karina Fonseca-Azevedo, now a neuroscientist at the National Institute of Translational Neuroscience in São Paulo, Brazil, decided to see if a diet of raw food inherently put limits on how large a primate’s brain or body could grow. First, they counted the number of neurons in the brains of 13 species of primates (and more than 30 species of mammals). The researchers found two things: one, that brain size is directly linked to the number of neurons in a brain; and two, that that the number of neurons is directly correlated to the amount of energy (or calories) needed to feed a brain.

After adjusting for body mass, they calculated how many hours per day it would take for various primates to eat enough calories of raw food to fuel their brains. They found that it would take 8.8 hours for gorillas; 7.8 hours for orangutans; 7.3 hours for chimps; and 9.3 hours for our species, H. sapiens.

These numbers show that there is an upper limit on how much energy primates can get from an unprocessed raw diet, Herculano-Houzel says. An ape’s diet in the wild differs from a modern “raw food diet,” in which humans get sufficient calories from processing raw food in blenders and adding protein and other nutrients. In the wild, other apes can’t evolve bigger brains unless they reduce their body sizes because they can’t get past the limit of how many calories they can consume in 7 hours to 8 hours of feeding per day. But humans, she says, got around that limit by cooking. “The reason we have more neurons than any other animal alive is that cooking allowed this qualitative change — this step increase in brain size,” she says. “By cooking, we managed to circumvent the limitation of how much we can eat in a day.”

This study shows “that an ape could not achieve a brain as big as in recent humans while maintaining a typical ape diet,” Wrangham says.