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Latest Articles

Is Red Light a Missing Nutrient for Our Health? Podcast with Dr. Michael Hamblin

Light is essential to life as we know it. Plants rely upon sunlight to generate chemical energy, which is stored in their tissues and fuels various life processes. In turn, animals like us convert the energy from the food that we eat into mechanical energy.

Given its fundamental role in our biology, perhaps it makes sense that specific types of light are connected to our health in some surprising ways, which research is only just starting to elucidate. For example, short-wavelength light (or blue light) has been shown to modulate blood pressure. And some studies have suggested that ultraviolet light might protect against weight gain and cardiovascular disease.

But another form of light exposure, which you’ve probably heard about before, and which we haven’t had the opportunity to address here, until now, is red light therapy.

Like hundreds of technological advances that we take for granted today, the medical application of red light therapy appears to have originated from NASA. Scientists developed red light-emitting diodes (LEDs) to help promote growth in plants on space shuttle missions. From there, red light was investigated for potential medical uses. These LEDs were shown to stimulate energy processes in mitochondria – the organelles from which our cell’s energy is generated. By augmenting mitochondrial function, and enhancing energy production, you would expect cells to be better able to repair and rejuvenate themselves. But is that indeed the case?

In this episode of humanOS Radio, Dan speaks with Michael Hamblin. Dr. Hamblin was (recently retired) Principal Investigator at the Wellman Center for Photomedicine at Massachusetts General Hospital, and an Associate Professor at Harvard Medical School.

There is perhaps no one alive with greater expertise in the health effects of red light therapy and near infrared light than Dr. Hamblin. He is a prolific researcher in photomedicine, having published over 400 peer-reviewed articles on the subject, as well as authored and edited 23 different textbooks.

In this interview, Dr. Hamblin explains:

What photobiomodulation is, and the molecular mechanisms through which it works its magic

What wavelengths and intensities of light are used for physiological effects

How photobiomodulation has been investigated for athletic performance, skin health and rejuvenation, and psychological conditions

When and how to use red light therapy for exercise performance and recovery

How red light functions as a healthy stressor to elicit anti-aging effects

And more!


Can We Beat Insomnia by Cooling the Racing Mind? Podcast with Dr. Eric Nofzinger

Insomnia is a uniquely vexing medical problem. It is the most common sleep-related issue, thought to affect around 10-40% of the population in the US. So it is a challenge that affects a whole lot of us.

Yet despite its prevalence, treatments for the condition are lackluster at best. Pharmaceutical interventions for insomnia are not helpful for many patients, and the chronic use of these medications comes with really nasty side effects.

Why is this the case? Perhaps because it remains poorly understood. Insomnia has been known and documented for thousands of years, but it has proven to be difficult to study for a number of reasons. It’s hard to develop good animal models for the condition, it’s difficult to objectively define, and symptoms manifest quite differently in individuals.

In order to address a complex disorder like insomnia, we need to get to the root cause. For most of us, it is clear that the origin lies within the brain. This has compelled some very clever researchers to take snapshots inside the heads of patients with insomnia (via positron emission tomography, or PET), and compare them to normal controls. The results of such studies have been enlightening.

And that brings me to our guest for this episode.

In this episode of humanOS Radio, Dan speaks with Eric Nofzinger. Dr. Nofzinger is a renowned expert in the science of sleep, and formerly the president of the Sleep Research Society. He spent more than 35 years practicing sleep medicine and studying the neurobiology of insomnia at the University of Pittsburgh School of Medicine.

As a researcher at Pittsburgh, Dr. Nofzinger frequently interacted with patients with insomnia. They would often attribute their inability to sleep to a “racing mind.” If you’ve ever had trouble falling asleep due to incessant rumination, that characterization probably sounds pretty relatable. Furthermore, they would often claim to have hardly slept at all, even when polysomnography showed that they had experienced normal sleep.

He, along with other scientists in the field, suspected that there was a biological basis for these commonly reported complaints. To gain meaningful insight into what was going on, he couldn’t just look at sleep patterns – he needed to look inside the brain. To that end, he started conducting functional imaging studies on patients with insomnia to examine patterns of brain activity and metabolism during sleep.

In one such trial, subjects completed regional cerebral glucose metabolic assessments while awake and while asleep using the FDG PET method. These scans were telling. During normal healthy sleep, there are typically substantial reductions in brain activity, particularly in the frontal cortex. But imaging for individuals with insomnia painted a very different picture. Their brains remained comparatively active during sleep, particularly in the frontal cortex, and they exhibited greater cerebral glucose metabolism during sleep and while awake. So, when these people claimed that their minds were racing throughout the night – when their brains should have been resting – that was actually a remarkably accurate assessment.

These kinds of studies demonstrate that insomnia is, in essence, a disorder of hyperarousal of the brain. With this revelation, what can be done to slow down the racing mind?

Cooling it down.

It has been known for some time that application of a cooling stimulus to the head can lower the brain temperature in the underlying cortex, and in turn reduce brain metabolism. This insight led to the development of Ebb, a sleep therapy unlike any other that has yet been invented. Here’s how it works: the device is comprised of a headband attached to a bedside unit. Cold fluid circulates through the forehead pad from the bedside unit, keeping your forehead at a cool temperature throughout the night. In this way, Nofzinger and his colleagues hope to target the root cause of insomnia, calming the mind and body.

To learn more about Ebb and Dr. Nofzinger’s research, check out the interview!


Flavonoids in Edible Plants and Heart Health. Podcast with Dr. Nicola Bondonno

It has become axiomatic that fruits and vegetables are protective against disease.

Humans have intuitively recognized the link between edible plants and health for thousands of years. However, it is only very recently in our history as a species that we have been able to identify these benefits through empirical methods. Over the past decades, countless scientific studies have investigated the relationship between consumption of fruits and vegetables and human health and disease, and compelling evidence has emerged.

But why specifically are plant foods so good for you? What exactly makes them special?

We now believe that biologically active constituents within plants are in large part responsible for their disease-fighting power.

On this episode of humanOS Radio, we welcome Nicola Bondonno to the show. Her research has been examining the effects of bioactive compounds occurring naturally in plant-based foods and beverages, and how they are linked to the cardiovascular health benefits associated with a plant-rich diet.

Nicola’s work has zeroed in on the health-promoting effects of flavonoids, a large class of polyphenolic compounds found in fruits and vegetables. They carry out a variety of important functions in plants, and they affect our bodies as well when we eat them. Just as one example, flavonoids have been shown to enhance bioavailability of nitric oxide, a molecule that regulates vascular tone. Specifically, nitric oxide relaxes the walls of blood vessels, which in turn reduces blood pressure and improves blood flow. With respect to cardiovascular health, you can imagine that this would be a very good thing.

In a recent study, Nicky and colleagues analyzed data from the Danish Diet, Cancer and Health cohort. This study assessed the diets of 53048 middle-aged Danish residents over the course of up to 23 years. The researchers estimated the flavonoid content of the foods and beverages that these subjects reported consuming, and compared this dietary intake to the medical outcomes and cause of death (if applicable) of the participants.

From this data, a number of important questions could be addressed:

Did flavonoid intake affect mortality, when adjusting for other potential confounders?

What dose of flavonoids is required for benefits to be achieved?

Are certain subclasses of flavonoids responsible for observed benefits?

And do flavonoids have different effects in individuals who drink or smoke?

To hear what Nicky and her team found, and to learn more about dietary flavonoids and their role in health and disease, please check out the interview!


Sleep Tracking and Sleep Enhancement. Podcast with Dr. Daniel Gartenberg

Sleep is essential and universal, and has been so for our entire existence as a species. Yet there is so much about it that we still do not understand, and in many respects it remains one of the great mysteries of science.

One reason, perhaps, why sleep remains such a puzzle lies in the way that it is measured.

There is a principle in physics known as the observer effect, which broadly states that the mere observation of some feature of a system will inevitably change that phenomenon – often as a result of instruments that alter the state of what they measure. This principle is evident, to some extent, in sleep medicine. Accurately measuring aspects of sleep and capturing sleep pathology involves multi-parametric testing equipment in a lab setting, requiring around 22 wire attachments. Needless to say, this setup is not what most people imagine when they envision an ideal sleeping environment.

Perhaps more importantly, this equipment is not practical for the average person who wants to better understand their own sleep. That is a pretty big problem if you are one of the many people out there who isn’t getting the sleep that you need – it’s pretty hard to change something if you’re not able to measure it.

Fortunately, technology is gradually promising to solve this by developing smaller and less intrusive sensors. In recent years, zillions of tracker apps and devices have emerged that purport to be able to gauge the duration and architecture of your sleep.

But this brings us back to the original problem: the value of the information that we receive from these trackers is limited by their precision. How accurate are these devices really? Can we rely on them for useful feedback to inform our future behavior?

And that brings me to our guest. On this episode of humanOS Radio, we welcome Daniel Gartenberg to the show. Daniel has a Ph.D in Human Factors and Applied Cognition from George Mason University, and is an adjunct assistant professor at Penn State University.

His current research is focused upon accurately tracking sleep quality through wearable technology. But he doesn’t just want to measure it – he wants to make it better. Dan is particularly interested in using technology to enhance slow wave sleep (also known as deep sleep), by manipulating temperature, light, and sound.

In this interview, the two Dans discuss how sleep is studied in a clinical study, how sleep monitoring devices have advanced over the past ten years, potential pitfalls in how these devices are used, ways to augment deep sleep and REM sleep, and much more. To learn about the future of consumer technology and sleep enhancement, check out the podcast below!


Seasonal Changes, Sunlight, and Metabolic Health. Podcast with Dr. Sander Kooijman

When we talk about diseases of civilization, there is perhaps no condition that is more emblematic of this concept than insulin resistance.

Normal glucose regulation is exquisitely orchestrated. When you eat food, that food is broken down into molecules of glucose, and that glucose goes into circulation to be transported throughout the body. Your pancreas detects the rise in blood sugar, and releases the hormone insulin to help shuttle glucose from the blood into cells, where it can be used for energy.

So, in a healthy individual, this is a fairly harmonious and smooth-running system. Blood sugar rises, insulin rises in parallel, blood sugar goes back down.

However, in the context of insulin resistance, cells throughout the body cease to respond efficiently to insulin. Consequently, cells fail to take up glucose from the blood, and circulating blood sugar remains high.

So why exactly does this happen? The etiology of insulin resistance is mind-bogglingly complex, and frankly is still not fully understood. We do know, of course, that both diet and exercise play a crucial role. Changes in our dietary patterns, as well as our physical activity patterns, are a major reason why insulin resistance has become so much more common.

But researchers are gradually revealing some other factors that are key to insulin sensitivity – factors that may be within our control.

And that brings me to our guest for today.

In this episode of humanOS Radio, Dan speaks with Sander Kooijman. Sander is a post-doctoral researcher at Leiden University Medical Center, where he is investigating brown adipose tissue activation as a therapeutic target to attenuate obesity, type 2 diabetes, and atherosclerosis in humans.

He and his colleagues recently published a paper examining how light exposure and environmental temperature affect measures of glucose and lipid metabolism in two large population-based European cohorts.

Why? Well, observational evidence suggests that light exposure – particularly sun exposure – may be beneficial for glucose metabolism. For example, a cohort study found that participants who received a lot of sunlight exposure during the day had a 30% lower risk of developing type 2 diabetes, compared to those who didn’t get much sun.

A number of studies have also suggested that ambient temperature may influence insulin sensitivity. One analysis compared county level data for diabetes prevalence across the United States to county level environmental temperature, and found that ambient temperature explained 12.4% of variation in prevalence of type 2 diabetes, after accounting for obesity, poverty, and race.

In the study discussed on this show, the researchers collected data from a combined cohort of more than 10,000 healthy middle-aged subjects enrolled in the Oxford Biobank study (OBB) and the Netherlands Epidemiology of Obesity study (NEO). Participants in these studies have provided body composition measurements (weight, body mass index, body fat percentage) as well as bloodwork (fasting glucose, insulin, fasting lipid concentrations, insulin resistance, etc). Sander and his team very cleverly collected data on mean outdoor temperature and hours of bright sunlight (defined as global radiation >120 W/m2) from local weather stations. From this information, they were able to calculate mean outdoor temperature and bright sunlight duration during a 7-day and 30-day period before the date of blood sampling.

Sure enough, increased bright sunlight exposure was found to be associated with lower fasting insulin (−1.27% per extra hour of bright sunlight), lower triglyceride levels (−1.28%), and reduced insulin resistance (HOMA-IR; −1.36%).

After adjustment for bright sunlight, there was no association between outdoor temperature and measures of glucose and lipid metabolism, suggesting that it was indeed the light that was responsible here. But why?

To find out why Sander thinks bright sunlight might enhance cardiometabolic health, and more about his fascinating work, check out the podcast below!


Flavonoids and Brain Health. Podcast with Dr. Pamela Maher

More than 2000 years ago, the Roman poet Virgil wrote, “Time robs us of all, even of memory.” Humans have long recognized the insidious toll that aging takes on the body – including the brain. But it is only very recently in our history as a species that we have been able to conceive of plausible ways to halt or even reverse it. As we gradually unveil the fundamental mechanisms of biological aging, we are starting to develop interventions that directly combat the diseases emanating from this process.

And there is no target of this research that is more important than the brain. Your brain, after all, is what truly makes you who you are. The threat of losing our memories, our personality, and our connections to one another is perhaps more frightening than anything else. It is also a daunting challenge. Modern medicine has enabled us to repair or even wholly replace many other parts of the body, including vital organs. But how do you regrow or replace an aging mind?

Indeed, research into medical interventions to address problems associated with aging in the brain has been particularly disappointing. Just as one example, pharmaceutical drugs designed to treat Alzheimer’s disease have the highest failure rate of any disease area (99.6%). Why is this? One reason, perhaps, is that the brain is terribly complicated, and a constellation of different factors have been implicated in age-related decline in the function of the brain. Consequently, using a drug to target a single aspect of the disease process is unlikely to be completely successful. To have any chance for solving this monumental problem, it is thought that we will need to identify molecules that have multiple biological activities and ameliorate multiple aspects of aging. And that brings me to our guest for today.

In this episode of humanOS Radio, Dan speaks with Pamela Maher. Dr. Maher has a Ph.D. in biochemistry from the University of British Columbia, and currently works as a research scientist at the Salk Institute for Biological Studies.

Her research has centered on understanding responses of nerve cells to oxidative stress, and how chemical compounds can modulate these responses to enhance nerve cell function and survival. Her current work is focused on using natural products such as flavonoids to maintain nerve cell function in the presence of toxic insults. Flavonoids are a diverse class of secondary metabolites found in almost all fruits and vegetables. One of the great advantages of these phytochemicals is that they are tiny molecules – small enough to cross the blood-brain barrier. This has been convincingly demonstrated in studies of rodents. For instance, when rats are fed blueberries for ten weeks, and then dissected, anthocyanins from the fruit can actually be found distributed inside the brain!

Maher and her colleagues have been focusing their attention particularly on a few of these flavonoids as potential neuroprotective agents. One of these is fisetin, a flavonoid that is most highly concentrated in strawberries. Maher and her group have been developing more potent and more bioavailable versions of the flavonoid that might protect nerve cells and even promote learning and memory. Good stuff!

The other phytochemical we’ll be discussing on the show is sterubin. Sterubin is a flavonoid found in Yerba santa, a plant that native tribes in California have long prized for its medicinal properties. When Dr. Maher screened for plant extracts that could act on toxicity pathways relevant to age-associated degenerative disease, sterubin emerged as one with broad protective effects in cell assays.

To learn more about the power of flavonoids and the future of anti-aging research, please check out the interview!


Carbohydrate Availability, Energy Balance, and Exercise. Podcast with Dr. Javier Gonzalez.

Why is losing weight – and keeping weight off – such a puzzle? At the individual level, the problem seems to be quite simple: it is chronic positive energy balance.

Simple, perhaps, but not easy. Changes in energy intake or energy expenditure can activate ancient feedback mechanisms that have evolved to preserve energy balance. And unfortunately for us, this system doesn’t seem to be biased toward supporting our beach body goals – it is adapted for survival.

This is one reason why exercise interventions often do not result in as much weight loss as would be predicted based on the projected energy expenditure produced by the activity. Changes in hormones, which are elicited by the energy deficient, cause hunger to ramp up. Consequently, many people who participate in structured exercise interventions wind up eating more food to partially or wholly compensate for the calories burned by that activity.

So, does this mean that exercise is a futile endeavor for managing weight? Actually…no. Not at all.

Research has shown that people who are highly physically active tend to be leaner than counterparts with a sedentary lifestyle. And oddly enough, it may be due to improved appetite regulation. For example, when scientists present blinded subjects with meals of varying caloric content, the participants who are habitually active do a better job of adjusting their subsequent energy intake.

How do we reconcile these seemingly contradictory observations?

In this episode of humanOS Radio, Dan speaks with Javier Gonzalez. Dr. Gonzalez is a professor at the Department for Health at the University of Bath in the UK. He and his colleagues recently published a hypothesis suggesting that carbohydrate availability plays a key role in the regulation of energy balance, and explains both why exercise increases hunger and why people who are highly active exhibit better appetite regulation.

What do I mean by carbohydrate availability? Well, our storage capacity for carbohydrates is relatively minuscule, compared to fat stores – even on a very lean individual. These stored carbs can be depleted much faster, and several studies suggest that alterations in carbohydrate availability may be carefully monitored by the body.

Importantly, physical activity alters carbohydrate availability by expending muscle glycogen. This may be why exercise has been shown to acutely lower fasting leptin concentrations. Reductions in carbohydrate availability resulting in a drop in leptin levels may explain, for instance, why individuals who utilize carbs faster during exercise seem to be more prone to increased appetite after exercise.

But high physical activity levels – and accompanying high physical fitness – produces relevant changes in carbohydrate and fat metabolism, that might make them better able to rein in their appetite after a bout of exercise or after a larger-than-normal meal. To learn about these changes, and more about his fascinating hypothesis, check out the podcast!


Is Modern Work Draining Our Attention Spans? Podcast with Dr. Gloria Mark

We live in an era of unprecedented access to information.

Technology has endowed us with the ability to immediately retrieve whatever we want to see or whatever we want to read, just by tapping on a screen a few times. Perhaps even more importantly, we have never had so much instant access to one another, even when we are very far away from one another.

In turn, other people – as well as our devices – have the ability to reach out to us. And they can seize our attention, literally 24 hours per day, seven days per week.

But how does this intimate and constant relationship with technology affect our brains?

Some researchers have begun to examine the impact of digital tools on how we think and perform. Perhaps unsurprisingly, the results are not entirely rosy.

In this episode of humanOS Radio, Dan speaks with Gloria Mark, who is a professor in the department of informatics at UC Irvine. She studies multi-tasking behavior in information workers, and technology use in disrupted environments. Her work examines how interaction with information technology affects attention, mood, and stress.

Much of this research has investigated what we commonly refer to as “multi-tasking.” You already know this: when you are rapidly switching between two different activities, typically your performance on both tasks markedly declines.

This area of research has also examined the impact of interrupted work, which often manifests itself in the form of digital notifications, like from email, text, or phone apps. For most of us, this is a normal aspect of our daily life. But you might not appreciate the full impact that this has on you.

For instance, in one study in which she and her colleagues continuously tracked employees at a tech company, they found that office workers who are interrupted take about 25 minutes to return to whatever task they were working on. And impaired productivity may not be the only price we pay. Gloria’s research has revealed that these kinds of disruptions also ramp up physiological stress levels, as well as increase subjective feelings of stress and frustration.

So what can we do about this? Fortunately, Gloria has come up with some plausible ideas for how individuals and organizations can reduce the cognitive costs associated with digital distractions. To learn more, check out the interview below!


Sunlight for Weight Control? Podcast with Scott Byrne

When we talk about sunlight in the context of health, the picture is usually quite negative. This is because of the well-understood link between ultraviolet light and skin cancer. Ultraviolet radiation penetrates deeply into the skin and generates DNA-damaging molecules. Over time, this can result in mutations and ultimately in cancer.

There is no doubt that excessive exposure to sunlight can be harmful. But research increasingly suggests that too little sun may be just as detrimental. A host of studies have shown, for instance, that living further from the equator is associated with increased risk of multiple sclerosis, and perhaps other autoimmune conditions. Lack of sunlight has also been linked to greater risk of cardiovascular disease and type 2 diabetes. Why is this? Some very clever researchers are starting to investigate this, including our guest for today.

In this episode of humanOS Radio, Dan speaks with Scott Byrne. Scott is a professor at the University of Sydney School of Medicine. He is a cellular immunologist who is studying how the ultraviolet part of the solar spectrum activates regulatory pathways that result in immune suppression and tolerance.

When Scott and his team were investigating skin cancer development in mice, they happened to notice that mice receiving ultraviolet radiation gained less weight than counterparts. At the same time, other researchers also pointed to interesting links between sunlight exposure and cardiometabolic disease.

These observations inspired Scott and his team to perform a series of experiments examining how regular exposure to physiologically relevant doses of solar ultraviolet radiation (like an amount that you could realistically get on a sunny day) influences weight gain and cardiovascular disease. And the findings were pretty eye-opening, especially if you are someone who routinely shrinks away from the sun (like me). To learn what they found, and more about the far-reaching effects of sun exposure on human health, check out this interview!


The Role of Advanced Glycation End Products in Aging and Disease. Podcast with Pankaj Kapahi

Have you ever wondered what makes cinnamon rolls so irresistible? I don’t know about you, but whenever I walk past a Cinnabon, I am bombarded by an unmistakable and mouth-watering aroma.

But what exactly makes them smell and taste so wonderful? The ingredients alone don’t explain it. Like, if I put white flour, hydrogenated oil, artificial flavors, cinnamon, and sugar (a lot of sugar) in a bowl, it wouldn’t produce that characteristic Cinnabon fragrance, nor would it taste particularly good.

You can see where I’m going with this. Obviously, the cooking process is the mediating factor here. More specifically, I am referring to the Maillard reaction. When amino acids and reducing sugars are exposed to high heat, hundreds of flavor compounds are generated. Food generally becomes browner, and it tastes and smells extra enticing. And this feature is obviously not exclusive to cinnamon rolls. The scent and flavor of roasted coffee, toasted marshmallows, fried bacon, grilled burgers, freshly baked bread, are all results of this chemical reaction.

Humans almost universally gravitate to foods that have been exposed to this process. However, our affinity for these compounds is a bit of a paradox, because of the negative long term effects that they seem to have on our health.

On this episode of humanOS Radio, we welcome Pankaj Kapahi to the show. Pankaj is a professor at the Buck Institute, an independent biomedical research institute that is devoted solely to research on aging. He and his team have also begun to investigate the role of advanced glycation end products (also known as AGEs) in the aging process. Advanced glycation end products are compounds that are formed when proteins or lipids become glycated, as a result of being exposed to sugars.

As I mentioned above, this has been carefully studied and exploited by the food industry for decades, because of its appealing effects on sensory qualities of food. However, it was only recognized comparatively recently that AGEs may impair our health and function over time.

Aptly enough, the formation and accumulation of AGEs is a hallmark of age. AGEs wreak havoc by binding with cell surface receptors and cross-linking with body proteins, altering their structure and function. This produces a range of deleterious effects throughout the body.

So, how can we reduce our exposure to advanced glycation end products in the food that we eat? And how can we control the formation of AGEs inside the body? To learn more, check out the interview below!