Humans Can Use Smell to Detect Levels of Dietary Fat

New research from the Monell Center reveals humans can use the sense of smell to detect dietary fat in food. As food smell almost always is detected before taste, the findings identify one of the first sensory qualities that signals whether a food contains fat. Innovative methods using odor to make low-fat foods more palatable could someday aid public health efforts to reduce dietary fat intake.

"The human sense of smell is far better at guiding us through our everyday lives than we give it credit for," said senior author Johan Lundström, PhD, a cognitive neuroscientist at Monell. "That we have the ability to detect and discriminate minute differences in the fat content of our food suggests that this ability must have had considerable evolutionary importance."

As the most calorically dense nutrient, fat has been a desired energy source across much of human evolution. As such, it would have been advantageous to be able to detect sources of fat in food, just as sweet taste is thought to signal a source of carbohydrate energy.

Although scientists know that humans use sensory cues to detect fat, it still remains unclear which sensory systems contribute to this ability. The Monell researchers reasoned that fat detection via smell would have the advantage of identifying food sources from a distance.

While previous research had determined that humans could use the sense of smell to detect high levels of pure fat in the form of fatty acids, it was not known whether it was possible to detect fat in a more realistic setting, such as food.

In the current study, reported in the open access journal PLOS ONE, the researchers asked whether people could detect and differentiate the amount of fat in a commonly consumed food product, milk.

To do this, they asked healthy subjects to smell milk containing an amount of fat that might be encountered in a typical milk product: either 0.125, 1.4 or 2.7 %.

The milk samples were presented to blindfolded subjects in three vials. Two of the vials contained milk with the same percent of fat, while the third contained milk with a different fat concentration. The subjects' task was to smell the three vials and identify which of the samples was different.

The same experiment was conducted three times using different sets of subjects. The first used healthy normal-weight people from the Philadelphia area. The second experiment repeated the first study in a different cultural setting, the Wageningen area of the Netherlands. The third study, also conducted in Philadelphia, examined olfactory fat detection both in normal-weight and overweight subjects.

In all three experiments, participants could use the sense of smell to discriminate different levels of fat in the milk. This ability did not differ in the two cultures tested, even though people in the Netherlands on average consume more milk on a daily basis than do Americans. There also was no relation between weight status and the ability to discriminate fat.

"We now need to identify the odor molecules that allow people to detect and differentiate differentiate levels of fat. Fat molecules typically are not airborne, meaning that they are unlikely to be sensed by sniffing food samples," said lead author Sanne Boesveldt, PhD, a sensory neuroscientist. "We will need sophisticated chemical analyses to sniff out the signal."

This study reveals an important applicsation of chemistry that may contribute to improve the live expectancy if we are able to make healthy food more appealing.

Thinking hard weighs heavy on the brain

Balance measures tiny changes in force due to blood flow behind thoughts

When the mind is at work, the brain literally gets heavier. That fact may be surprising, but it isn’t new: In the late 1880s, Italian scientist Angelo Mosso built an intricate full-body balance and reported that mental activity tips the scales. Now, a modern-day version of Mosso’s “human circulation balance” backs him up. Compared with a brain at rest, a brain listening to music and watching a video is indeed heavier, David Field and Laura Inman of the University of Reading in England January 9 report in Brain.

While teaching a course about brain-imaging techniques, Field grew curious whether Mosso’s general approach would work. So he and some students decided to find out. “It was a bit of a mad idea, to be honest,” Field says.

At the heart of both balances lies a simple seesaw lever. As weight shifts in a body, presumably from blood moving, the lever tilts the head or the feet downward, Mosso observed. Field and Inman’s contraption doesn’t actually tip. The researchers put a sensitive scale under the head end, which would register changes in force.

After lots of troubleshooting, which involved eliminating signals created by bodily processes that move blood such as breathing and heart beats, Field and Ingram were able to test mental tasks. Fourteen participants were asked to lie still on the lever, and listen to music or listen to music and simultaneously watch a video of colorful geometric shapes. The part of the brain that detects sound is relatively small, Field says, so the audio plus video test was used to activate a wider swath of the brain and increase the chances of a measurable blood shift.

Right after a two-second blip of either audio or audio and video, blood leaves the brain, as measured by a drop in force, Field and Inman found. This quick dip in blood volume, a phenomenon that’s also seen in functional MRI, may represent the brain preparing for work by shunting waste-ridden blood out via the jugular vein. Seconds after that, a surge of new blood enters the brain, increasing the force measured by the scale.

These changes in force were very small — about 0.005 newtons — and most prominent in the people who both listened to music and watched a video, Field says. It’s hard to calculate how much blood rushes into the brain with each mental task. To know that value, scientists would need to know the distance of the head from the lever’s fulcrum, which could be easily measured, and exactly where the blood came from, which is nearly impossible to know.  

In his original experiments, Mosso found that tasks that required more mental energy made the brain heavier. Reading a page from a mathematics manual seemed to tip the balance more than reading a page from a newspaper. Strong emotions also tipped the scales: When a subject read a letter from an angry creditor, Mosso wrote, “the balance fell at once.”

Until recently, Mosso’s scientific manuscripts had not been described in detail. But Stefano Sandrone of King’s College London unearthed Mosso’s papers in archives and published a description in Brain in 2013.

“We have been neglecting Mosso and his work for so many years. It’s good that someone has begun to find interest in the papers that he wrote,” Sandrone says of the modern-day experiment. He and his colleagues are working on an exhibition of Mosso’s original balance.

Many neuroscientists use functional MRI to detect changes in blood flow in the brain. Usually, fMRI spots regional differences, as when a little blood moves from one part of the brain to another. In contrast, the balance describes overall changes in brain workload, Field says.

The balance is not going to replace modern neuroimaging as a way to see what happens inside the brain. But with refinements, it might ultimately prove to be useful, Sandrone says. “The more measures we have, the more we can approximate the complexity of the brain.” 

Europe's financial support to 20 scientific projects

Europe supports scientific projects of 20 Spanish high-level researchers

Those who consider themselves scientists need some proof of their scientific careers. Therefore, they must publish their results and communicate their foundings. However no science can be made without founding. Having financial support for a purposed scientific project is the key to develope it. Indeed, it is the key fot industrial development. We scientists must do research and try to solve, in a nearer or further future, society's demands. 

Good news are that Europe is going to support some of the best-considered spanish scientific projects. More concretely, 20 Spanish scientists would be given the well-known European Reserach Council (ERC) grant. Their investigations involve hot topics such as new treatments for neurodegenerative illnesses and cancer, new methods and interactions in the mathematical singularity theory and the collateral macroeconomy.

Spain has rise up untill the sixth position as a receiver of these grants -with six more grants than the last call-, then comes United kingdom, Germany, France, The Netherlands, Switzerland and finally Italy.

ERC is going to support an amount of 312 projects of well-considered European scientists with 575 millions of euros. Each of these grants give 1.84 millions of euros as an average and they can rise up to 2.7 millions of euros each.

This organisation claimed that in this last call, they selected a wide range of topics that start from the exploration of the black matter effects and the black energy in the gravitational theory in the use of a geochemical watch to predict volcanic eruptions, and finish with the study of the role of the genetic and environmental factors in the brain connexions of the embryos.

All these topics are of high importance to society. However there are still a few if we want to develop this country and fight agains ignorance. More scientific projects should be supported. There is a huge need of doing research. It is the key of success. 

May you be addicted to your smartphone?

Six disorders have been discovered due to the use of smartphones

The unavoidable need of using the mobile evrytime and everywhere highlights the existent addiction to it. Phil Reed, which is a phycology professor in the Swansea University, reported that the addiction to smartphones can provoque depression and social isolation. Time after time we become more dependent on technology. However, these technologic items can produce different addictions or illnesses. Some of the most known disorders are the following:

1. Nomophobia: is the fear that a person feels when leaving the mobile away. It provoques a feeling of anxiety. One of tis symptoms is the impossibility of being without your phone.

2. Cybersickness: it is a secondary effect of the excessive use of the mobile apps. In this occasion the person feels tired and has a strong headache.

3. iPosture: many mobile users tend to bend theirselves when using the phone. This can cause a huge pressure in the spine and also provoque headache and pain in neck and shoulders.

4. Phantom vibration syndrome: it is a symptom due to the dependence on the mobile. The user thinks that it is vibrating although it is not doing so, or even if it is swithced off. 

5. Dry eye syndrome: the high levels of concentration that a person dedicates to his/her mobile reduces in one third the number of eye blinkings causing eye problems.

6. Finger pain: the massive use of the phone can cause cramps in the fingers, wrists and forearms.

Technology can be really helpful and, indeed, it is. However you have to be aware and make an intelligent use of it. You must keep in mind that a mobile phone is just a thing, just a tool and that you cannot let it take the control of your life and your health.

The first edition of the scientific divulgation event "Desgranando la ciencia" fired on all cylinders

The scientific divulgation event "Desgranando la ciencia" that took place the last 14th and 15th of December in the "Parque de las ciencias" in Granada had a big success

Fortunately, step by step, science is arriving to everyone

I could not find a better new to start this blog, which aims to talk about science and arrive to everybody! The scientific divulgation event "Desgranando la ciencia" had a great succes. It took place in the "Parque de las ciencias" in Granada (Spain) between the 14th and 15th of December. It was organized by the scientific divulgation platform "Hablando de Ciencia" and patrocinated by the "Descubre" Fundation. In addition, several local and national experts particepated in it.

There were several conferences and parades about astrophysiscs, environment, physics, biology, economy, divulgation...with the aim of showing people what is being done in the laboratories. All of them were very attractive to children because they could intract with the scientists and they could even do some experiments too.

"New technologies and alimentation" and "Physics and Egineering" were the topics of the first session of the first day. "Medicine and Future" was the topic of the afternoon. One of the most important things they talked about was the Alzheimer. The latest investigations related to this disease were introduced by Javier Burgos, which is the scientific director of Neuron BioPharma.

On Sunday, they talked about the environment. Moreover there was a session about "Science, Education and Critic thinking" in which Juan Soler, from the Society for the Advance of the Critic thinking, made a demonstration of how to bend spoons with the aim of showing people the importance of being critic with what they see on TV or on the other media. Finally, there was a session about "Science and Society" in which young researchers and women had the main role.

These kind of events are very common nowadays and, from my point of view, they should be even more common as one of our objectives as scientists must be to approach science to people and to promote it to get funds whether from public or private entities to keep investigating and developing new projects and ideas. This would be the key for the succes of any country.