Evolutionary Study Shows Human Bodies Were Partially Shaped By Climate Change 

As humans evolved, it’s become common knowledge that our body’s and brain’s have both increased in size as we developed into the Homo Sapiens we are today. The original Homo genus emerged about 300,000 years ago, and today we are much larger and have a brain three times as big as our human ancestors who lived a million years ago. 

Scientists have long debated why humans evolved the way that they did. There’s a multitude of potential explanations for why our bodies and minds grew into what they are today, but one of the newer possibilities has to do with climate change, and the role it’s played in our evolution overall. 

Embed from Getty Images

A research team led by Cambridge University and Tübingen University in Germany have combined data on more than 300 human fossils from the Homo genus alongside climate models to establish a direct connection between the Earth’s climate and our evolutionary journey.

The study, published in Nature Communications, explained “what temperature, precipitation and other climate conditions each of the fossils, spanning the last million years, would have experienced when it was a living human. We found a strong link between temperature and body size, showing that climate was a key driver of body size during that period.”

The colder it gets, the bigger the humans are. If you’re bigger, you have a bigger body – you are producing more heat but losing relatively less because your surface is not expanding at the same rate,” said Dr. Manuel Will, a Tübingen University researcher and author on the study.

“It’s not completely surprising, but it’s interesting to see that in this respect our evolution isn’t that different from other mammals. We face similar problems when it comes to gaining and losing heat, so we seem to have evolved in similar ways,” said Dr. Nick Longrich.

Embed from Getty Images

The study also linked changes in climate to brain size among the Homo genus species, however, it found that the environment has a much greater impact on body size than brain size. 

“This phenomenon shows that body and brain size are under different selective pressures. This study really manages to detangle the fact that both brain and body size are increasing, but increasing for very different reasons.”

“The more stable [the climate] is, the larger brains are. You need a lot of energy to maintain a big brain – in stable environments, you find more stable food, so you likely have sufficient nutrition to give you that energy,” said Dr. Will.

Dr. Will also pointed out that evolution is ongoing, “but there are different drivers now to a million years ago. The past gives us clues about the future; we can learn from it. But we cannot simply extrapolate from it. While we are currently seeing that the climate is getting warmer, we cannot assume that our bodies will get smaller as a result.”

Covid-19 Mutation

Majority Of Covid-19 ‘Long-Haulers’ Experiencing Multiple Brain-Related Symptoms 

According to a new study, 85% of Covid-19 “long-haulers” are experiencing at least four lingering neurological symptoms even if they weren’t hospitalized for their initial illness. The lingering symptoms include brain fog, headache, and the loss of smell and/or taste. 

The study was published in the journal Annals of Clinical and Translational Neurology earlier this week. Researchers claimed to analyze information from 100 Covid-19 long haulers from 21 states. All participants were seen in person or over video conference at the Neuro Covid-19 Clinic at Northwestern Memorial Hospital in Chicago. The study went from May-November of 2020, and none of the participants were hospitalized when initially infected with the virus. 

Embed from Getty Images

All participants claimed to experience Covid symptoms for more than six weeks, and on average they were seen for four to five months after their initial infection. Half of the participants had previously tested positive while the other half had tested negative but were still experiencing consistent Covid symptoms. The researchers of the study believed that all the participants who tested negative in the study likely did have the virus, but got it at the point in the pandemic when getting a test was nearly impossible.

“85% of participants reported at least four neurological symptoms. The most common symptom was ‘brain fog’ or trouble thinking, reported by 81% of participants; followed by headaches, reported by 68%; and numbness or tingling, reported by 60% of participants. More than half reported problems with their sense of taste or smell; 47% reported dizziness; 30% reported blurred vision; and 29% reported ringing in the ears,” according to the article. 

According to a previous study posted by Live Science Magazine last year, “‘long COVID-19’ is an important emerging entity requiring multidisciplinary expertise and care. It’s unclear how many people have long COVID, but some studies suggest that about 30% of people with COVID-19 experience lingering symptoms up to nine months after their diagnosis.”

Embed from Getty Images

Study author Dr. Igor Koralnik claimed in a news conference that it’s likely millions of people are experiencing long Covid symptoms, so these studies are important. He also noted that more than 40% of the participants claimed to have struggled with anxiety and depression throughout their lives pre-pandemic, so more research is currently being done to see if there’s a link to mental illness and the long-Covid symptoms. 

“About 70% of participants were women, which matches the sex ratio seen in some other autoimmune disorders, such as rheumatoid arthritis, which affects three times more women than men,” the authors wrote.

The authors also noted that this study was extremely preliminary and small, pointing out that a majority of the patients were white, and there’s a chance a lot of the long-haulers with negative Covid tests may have never had the virus to begin with. Researchers are planning on continuing these research efforts and are starting with analyzing how certain immune systems respond to Covid-19 proteins.

Couple Exercising

How Exercise Improves Brain Health

The various benefits of regular exercise on the human body are well-known. But fewer people realize that exercise benefits not just the body, but the mind as well. Indeed, recent studies have revealed that the connection between physical fitness and psychological health runs deeper than previously assumed, both in people with mental illnesses and in psychologically healthy people. Exercise not only improves brain performance in the short term, sharpening memory and information processing, but can also help maintain the health of the brain in the long term by lessening the impact of dementia in old age. While a lifelong routine of exercise is most likely to protect the brain against the worst effects of age-related psychological problems, exercise has also been shown to improve brain function immediately after as few as one workout. As such, when it comes to preserving and improving mental health, physical exercise plays a more substantial role than most of us likely assume.

Embed from Getty Images

Several studies were reported on in 2019 that represent substantial breakthroughs in medical understanding of the relationship between the brain and body. A study published in July, for instance, looked at the performance of semantic memory, or the portion of long-term memory involving ideas and concepts not related to personal experience, in older adults immediately following exercise. It found that after a single session of exercise, regions of the brain associated with semantic memory were more active, though this effect did not apply throughout the entire brain. While scientists used to believe that the human brain was fully formed and fixed by the time a person reaches adulthood, recent evidence has shown that the brain actually remains somewhat malleable throughout life. As semantic memory is often one of the first aspects of brain function to deteriorate with age, these findings give hope to people who are entering old age and are concerned about preserving their brain function through the end of their lives.

The results of this study are supported by other studies that examine how, at a molecular level, exercise changes the brain. Specifically, in a study published in January, scientists found that the hormone irisin may play a key role in preserving brain function, even in people experiencing age-related cognitive impairment. The study involved mice, but nevertheless provides insights about the function of the human brain, as all mammals are fairly genetically similar to one another. Irisin is a hormone that is released during exercise and helps the body metabolize energy while working out, improving the function of the body as well as the brain. It is thought to be involved in the development of Alzheimer’s disease, as the brains of people who did not have Alzheimer’s were found to contain irisin whereas the brains of people with Alzheimer’s had none. In the study, mice that were bred to develop dementia performed better on memory tests after being given a dose of irisin, and mice whose production of irisin was artificially blocked were prone to developing dementia.

Embed from Getty Images

Another study published in 2019 looked at how different forms of exercise affect the brain in different ways. While scientists have determined that aerobic exercise can improve memory and cognition by creating new neurons and reducing inflammation in the brain, less has been determined about the impact of weight training. As such, the researchers in this study developed a weight training program for rats, some of which had been given a substance that causes the development of dementia in animals, to determine whether weight training has the same positive effects on the brain that aerobic exercise does. The scientists found that the rats involved in the weight training program more successfully navigated a maze than those that weren’t, even for the rats with induced cognitive impairment. In fact, an examination of the rats’ brain tissue found that the rats who trained with weights were actually able to restore lost brain function, as their brains reshaped themselves to more closely resemble the brains of healthy rats. The results suggest that all forms of exercise, whether they focus on improving cardiovascular health or muscle mass, may support overall brain health.

While more work certainly has to be done to understand the full extent of the relationship between exercise and brain health, it is abundantly clear that frequent exercise is a key component of a healthy life. Anyone who is physically able to exercise is likely to benefit from a regular workout routine in any number of ways, some of which may not have even been discovered yet.

Pills 2

Nootropics: Scientific Breakthrough or Snake Oil?

It sounds like a concept straight out of a science fiction film: pills or drinks that improve your brain’s ability to focus, concentrate, remember, and learn, improving your capacity for productivity. For centuries, people have sold products that claim to offer these and other benefits, and nearly all of them are now widely understood to cause a placebo effect at best and harmful side effects at worst. But nootropics, marketed by brands such as Trubrain and Neurohacker, differ from these products as their manufacturers claim that their formulations are derived from the cutting edge of neuroscience. That being said, consumers should exercise care when selecting a drug or supplement, particularly ones that were not prescribed by a doctor for treatment of a medical condition. As such, it’s a good idea to do some research before investing money and potentially your health into a cognitive-enhancing supplement.

As the category of nootropics, which simply refers to substances that may improve cognitive function, is a broad one, it is useful to understand the differences between various drugs and supplements that fall under this category. You may be surprised to learn that caffeine, which most people consume every day, is considered a nootropic, as are Adderall and Ritalin, prescription drugs used to treat ADHD and other mental illnesses. As such, some nootropics are clearly quite safe while others can be very dangerous when used improperly. While many nootropics are only legally available with a prescription, most reputable doctors won’t write a prescription for a drug to improve a patient’s cognitive ability if they have no underlying illness. Modafinil, for instance, is a prescription drug used to treat narcolepsy which is thought by nootropics enthusiasts to improve executive functioning, attention and memory, and has been shown to have mild efficacy in these areas, though more research needs to be done to determine whether taking modafinil is safe in the long term.

Embed from Getty Images

Other nootropics are available off-the-shelf or online without a prescription, and while these products are more likely to be safe, their effectiveness has not been demonstrated to the degree of scientific rigor necessary to satisfy the medical community. These products tend to feature a blend of widely available supplements, like taurine, l-theanine, and l-tyrosine, and claim to “fuel cognition while supporting long-term brain health,” in the case of Neurohacker’s Qualia Mind product. Oftentimes, these nootropic blends will include caffeine and a wide range of vitamins in addition to ingredients derived from herbs like ashwagandha and ginkgo biloba. While the marketing associated with popular nootropics sounds enticing, it’s worth noting that because they are classified as supplements rather than as drugs, most commonly available nootropics are not approved by the FDA, and as such the manufacturer’s claims are not legally held to a high scientific standard. 

Most people are probably best off sticking to caffeine as their performance-enhancing drug of choice

In fact, some studies show that many common nootropics are not effective whatsoever. A 2015 meta-analysis found that actual mental performance was not improved when taking many popular nootropics, particularly in healthy people, and another study found that nootropics could even cause psychological damage, especially in people who have some form of mental illness or who are taking certain prescription drugs which can interact with nootropics destructively. As a result of an overall lack of scientific support, most doctors will not recommend their patients try nootropics, and instead point to other things that could improve mental performance. Having a good, balanced diet, getting enough sleep, and exercising have all been shown to improve various aspects of life, including cognitive performance, and as such anyone considering trying nootropics should first evaluate whether they can improve these areas of their life instead.

Given the general lack of strong scientific support for nootropics, their recent explosion in popularity seems surprising. One possible explanation for this is the placebo effect, which causes people who expect a particular result from a drug to believe they are experiencing this result. Given the highly subjective nature of the experiences in question, the placebo effect could be particularly potent among nootropics proponents, as all of the changes one expects to observe from nootropics are mental, not physical. Another explanation is that some nootropics do in fact work, but science has yet to catch up with the results. In any case, it’s always a good idea to talk to a doctor before introducing changes that could affect your health. Most people are probably best off sticking to caffeine as their performance-enhancing drug of choice and making sure they are living a healthy lifestyle.