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There have been a number of recent studies finding various harms from air pollution - both for children and adults.The following are all from Science Daily:

Living near major roads may increase risk of sudden cardiac death in women

Living near a major road was associated with an increased risk of sudden cardiac death in women. Environmental exposure may increase heart disease risk as much as smoking, poor diet or obesity.

In 523 cases of sudden cardiac death, living within 50 meters (164 feet) of a major road increased the risk of sudden cardiac death by 38 percent, compared to living at least 500 meters (.3 miles) away. Each 100 meters (328 feet) closer to roadways was associated with a 6 percent increased risk for sudden cardiac death.

Air pollution harmful to young brains, study finds

Pollution in many cities threatens the brain development in children. Findings from a recent study reveal that children living in megacities are at increased risk for brain inflammation and neurodegenerative changes, including Alzheimer's or Parkinson's disease.

The study found when air particulate matter and their components such as metals are inhaled or swallowed, they pass through damaged barriers, including respiratory, gastrointestinal and the blood-brain barriers and can result in long-lasting harmful effects..."We asked why a clinically healthy kid is making autoantibodies against their own brain components," Calderón-Garcidueñas said. "That is indicative of damage to barriers that keep antigens and neurotoxins away from the brain. Brain autoantibodies are one of the features in the brains of people who have neuroinflammatory diseases like multiple sclerosis."

High-pollution days linked to increased risk of cardiac arrest

Rates of out-of-hospital cardiac arrest are elevated after days with high levels of air pollutants, reports a Japanese study. For example, 48 to 72 hours after days with high levels of particulate air pollution, the risk of out-of-hospital cardiac arrest increased by 17 percent, the researchers report.

Strong link between higher levels of pollution, lung health of European citizens

New data has identified a clear link between higher levels of exposure to air pollution and deteriorating lung health in adult European citizens. This study confirms previous findings that children growing up in areas with higher levels of pollution will have lower levels of lung function and a higher risk of developing symptoms such as cough and bronchitis symptoms. The new study also identified that people suffering from obesity are particularly vulnerable to the negative effects of air pollution, possibly due to an increased risk of lung inflammation.

Air pollution linked to irregular heartbeat, lung blood clots

Air pollution is linked to an increased risk of developing an irregular heartbeat -- a risk factor for stroke -- and blood clots in the lung, finds a large study. The evidence suggests that high levels of certain air pollutants are associated with a higher risk of cardiovascular problems, but exactly how this association works has not been clarified.

Two articles which together point out that there are alternative approaches to the treatment of depression.

From Medscape: Patient Expectations Largely Dictate Antidepressant Response

People's expectations about how effective their antidepressant medication is going to be almost entirely predicts their response to it, such that giving patients a placebo pill as active therapy during an 8-week period results in very similar reductions in symptoms, new research shows.

Investigators at the David Geffen School of Medicine at the University of California, Los Angeles, found that patients assigned to either active antidepressant therapy or placebo pills had better clinical outcomes than supportive care alone and that there was little difference between outcomes for the medication and placebo groups.

"Supportive interaction with the subject helped them get better, and antidepressant therapy helped them get better, but I think our key finding was that patients' belief in the effectiveness of medication was a unique factor that contributed to them getting well. So belief in the power or effectiveness of the medication may be a contributor to placebo responses in the treatment of depression."

From Science Daily:

Sport, physical activity help against depression

Depression is the most frequently diagnosed mental illness. In the western industrial nations, at least every tenth person suffers from depression once in the course of their life. Depression influences physical health more than diabetes or arthritis, clinicians say. Treatment of depression traditionally occurs with antidepressants and psychotherapy. But as research has shown, sport and physical activity partially encounters the same neurophysiological changes as antidepressants. That is why a large number of meta-analyses showed a positive effect of sport and physical activity on depression.

Sport and physical activity bring about various changes in the brain which are otherwise achieved only through drugs. Similar to sport and physical activity, drugs for treatment of depressions act on the brain's capacity to absorb serotonin. They strengthen the epinephrine activity and ensure the release of various factors for nerve growth. These factors promote cell growth in the brain and prevent the death of cells in the hippocampus which is otherwise caused by depression. Together with these changes, sport and physical activity also lead to a reduced activity of the stress hormone cortisol and therefore have an effect similar to psychotropic drugs.

Research finding benefits from various foods. From Science Daily:

Drinking decaf or regular coffee maybe good for the liver

Researchers report that decaffeinated coffee drinking may benefit liver health. Results show that higher coffee consumption, regardless of caffeine content, was linked to lower levels of abnormal liver enzymes. This suggests that chemical compounds in coffee other than caffeine may help protect the liver. Previous studies found that coffee consumption may help lower the risk of developing diabetes, cardiovascular disease, non-alcoholic fatty liver disease, cirrhosis, and liver cancer.

From Science Daily:

Did fruit contribute to Apple's success?

Steve Jobs swore by a fruit diet, as he believed it improved his ideas. And he wasn't wrong: food with high levels of tyrosine, like bananas, peaches and almonds, allow us to think harder and more creatively.

The researchers found that the test subjects who drank orange juice with added tyrosine were better at solving puzzles than those who were administered a placebo. Tyrosine is an amino acid that increases the production of dopamine in the brain, which positively influences our ability to think creatively. It can be found in various kinds of fruit, but also in soybeans, spinach, eggs and cottage cheese.

Done in mice, but interesting. And think of all the people who have promoted grapefruit diets over the years. From Science Daily:

Grapefruit juice stems weight gain in mice fed a high-fat diet, study finds

Mice fed a high-fat diet gained 18 percent less weight when they drank clarified, no-pulp grapefruit juice compared with a control group of mice that drank water, a new study demonstrated. Juice-drinking mice also showed improved levels of glucose, insulin and a type of fat called triacylglycerol compared with their water-drinking counterparts.

Different than my usual post, but oh so interesting. From Science Daily:

Near-death experiences? Results of the world's largest medical study of the human mind and consciousness at time of death

The results of a four-year international study of 2060 cardiac arrest cases across 15 hospitals concludes the following. The themes relating to the experience of death appear far broader than what has been understood so far, or what has been described as so called near-death experiences. In some cases of cardiac arrest, memories of visual awareness compatible with so called out-of-body experiences may correspond with actual events. A higher proportion of people may have vivid death experiences, but do not recall them due to the effects of brain injury or sedative drugs on memory circuits. Widely used yet scientifically imprecise terms such as near-death and out-of-body experiences may not be sufficient to describe the actual experience of death. The recalled experience surrounding death merits a genuine investigation without prejudice.

In 2008, a large-scale study involving 2060 patients from 15 hospitals in the United Kingdom, United States and Austria was launched. The AWARE (AWAreness during REsuscitation) study, sponsored by the University of Southampton in the UK, examined the broad range of mental experiences in relation to death. Researchers also tested the validity of conscious experiences using objective markers for the first time in a large study to determine whether claims of awareness compatible with out-of-body experiences correspond with real or hallucinatory events.

Dr Sam Parnia, Assistant Professor of Critical Care Medicine and Director of Resuscitation Research at The State University of New York at Stony Brook, USA, and the study's lead author, explained: "Contrary to perception, death is not a specific moment but a potentially reversible process that occurs after any severe illness or accident causes the heart, lungs and brain to cease functioning. If attempts are made to reverse this process, it is referred to as 'cardiac arrest'; however, if these attempts do not succeed it is called 'death'. In this study we wanted to go beyond the emotionally charged yet poorly defined term of NDEs to explore objectively what happens when we die."

Thirty-nine per cent of patients who survived cardiac arrest and were able to undergo structured interviews described a perception of awareness, but interestingly did not have any explicit recall of events"This suggests more people may have mental activity initially but then lose their memories after recovery, either due to the effects of brain injury or sedative drugs on memory recall," explained Dr Parnia, who was an Honorary Research Fellow at the University of Southampton when he started the AWARE study.

Among those who reported a perception of awareness and completed further interviews, 46 per cent experienced a broad range of mental recollections in relation to death that were not compatible with the commonly used term of NDE's. These included fearful and persecutory experiences. Only 9 per cent had experiences compatible with NDEs and 2 per cent exhibited full awareness compatible with OBE's with explicit recall of 'seeing' and 'hearing' events.

One case was validated and timed using auditory stimuli during cardiac arrest. Dr Parnia concluded: "This is significant, since it has often been assumed that experiences in relation to death are likely hallucinations or illusions, occurring either before the heart stops or after the heart has been successfully restarted, but not an experience corresponding with 'real' events when the heart isn't beating. In this case, consciousness and awareness appeared to occur during a three-minute period when there was no heartbeat. This is paradoxical, since the brain typically ceases functioning within 20-30 seconds of the heart stopping and doesn't resume again until the heart has been restarted. Furthermore, the detailed recollections of visual awareness in this case were consistent with verified events.

Thus, while it was not possible to absolutely prove the reality or meaning of patients' experiences and claims of awareness, (due to the very low incidence (2 per cent) of explicit recall of visual awareness or so called OBE's), it was impossible to disclaim them either and more work is needed in this area.

Two related stories that look at children, exercise, and academic performance. Boys, in general, have higher activity levels than girls, and they need exercise and recess to be able to get through the rest of the school day. Sitting quietly in class and doing classwork is hard when one has lots of excess energy. In fact, sitting still for hours on end is NOT healthy in any way for anyone! Fidget, fidget, fidget... From Science Daily:

High levels of physical activity linked to better academic performance in boys

Higher levels of physical activity are related to better academic achievement during the first three school years, particularly in boys, research shows. For instance, boys with higher levels of physical activity, and especially walking and bicycling to and from school, had better reading skills than less active boys....The findings of the present study highlight the potential of physical activity during recess and participation in organized sports in the improvement of academic achievement in children

 Instead of medicine, why aren't doctors prescibing exercise? From The Atlantic:

Exercise Is ADHD Medication

Physical movement improves mental focus, memory, and cognitive flexibility; new research shows just how critical it is to academic performance.

...More insipid but also more clearly critical to addressing what's being called the ADHD epidemic is plain old physical activity.

This morning the medical journal Pediatrics published research that found kids who took part in a regular physical activity program showed important enhancement of cognitive performance and brain function. The findings, according to University of Illinois professor Charles Hillman and colleagues, "demonstrate a causal effect of a physical program on executive control, and provide support for physical activity for improving childhood cognition and brain health." If it seems odd that this is something that still needs support, that's because it is odd, yes. Physical activity is clearly a high, high-yield investment for all kids, but especially those attentive or hyperactive. This brand of research is still published and written about as though it were a novel finding, in part because exercise programs for kids remain underfunded and underprioritized in many school curricula, even though exercise is clearly integral to maximizing the utility of time spent in class.

Earlier this month, another study found that a 12-week exercise program improved math and reading test scores in all kids, but especially in those with signs of ADHD.

Last year a very similar study in the Journal of Attention Disorders found that just 26 minutes of daily physical activity for eight weeks significantly allayed ADHD symptoms in grade-school kids. The modest conclusion of the study was that "physical activity shows promise for addressing ADHD symptoms in young children." 

"If physical activity is established as an effective intervention for ADHD," they continued, "it will also be important to address possible complementary effects of physical activity and existing treatment strategies ..." Which is a kind of phenomenal degree of reservation compared to the haste with which millions of kids have been introduced to amphetamines and other stimulants to address said ADHD. The number of prescriptions increased from 34.8 to 48.4 million between 2007 and 2011 alone. The pharmaceutical market around the disorder has grown to several billion dollars in recent years while school exercise initiatives have enjoyed no such spoils of entrepreneurialism. 

Over all, the pandemic of physical inactivity, as Hillman and colleagues put it in their Pediatrics journal article today, is "a serious threat to global health" responsible for around 10 percent of premature deaths from noncommincable diseases. 

John Ratey, an associate professor of psychiatry at Harvard, suggests that people think of exercise as medication for ADHD. Even very light physical activity improves mood and cognitive performance by triggering the brain to release dopamine and serotonin, similar to the way that stimulant medications like Adderall do

I mentioned these studies earlier in July, but this write-up (from Sept. 17, 2014) gives the reader some new information. From Gut Microbiota Watch:

Studies uncover 500 “hidden” microbes in the gut

Over the last few years, scientists have found that the microbes hosted in the digestive tract (the gut microbiota or gut flora) perform key functions for health. Digestion, immunity and even mental health are extremely dependent on tasks carried out by the gut bacteria.

Now, two studies have found that the human gut hosts five hundred species of microbes – and seven million microbial genes – that were unknown until now. The proportion of the gut flora that had been hidden until now may hold essential information on the origin of a range of diseases (IBD and metabolic syndrome, among others), as well as the clues on how to cure them.

The two studies were published in Nature Biotechnology in July, and come from the efforts of the MetaHIT(METAgenomics of the Human Intestinal Tract) project, a European consortium working to explore the composition of human gut microbiota.

The first of the two studies focuses on expanding the catalogue of genes that belong to microbes of the gut flora....As a result, the catalogue has increased to 10 million genes. The next step for the scientists is to find what these genes do, in order to have a better understanding of the functions performed by the microbiota.

The second of the two studies pursues an even more ambitious goal: identifying new organisms in the microbiota, rather than identifying new genes....By applying this method, the authors have found 500 species whose existence in the microbiota was previously unknown.

Interestingly, some of the subjects analysed in the study had very few of these new species. By checking who these individuals were, the authors found that they all had Crohn’s disease, ulcerative colitis, or metabolic syndrome with an inflammatory component. These findings suggest that there is a correlation between suffering from these diseases and having less diversity in these unknown species. “These species, unknown until now, will possibly make the difference between healthy and unhealthy people”, said Guarner.

This information may open the door to new strategies aimed at recovering the presence of these species through nutritional intervention. In particular, providing patients with probiotics or prebiotics,  that may help to balance their microbiota.

Well DUH ! Of course children need to run, run, run or somehow exercise to get rid of excess energy. That's why recess is so important (but unfortunately so many schools are eliminating it). It is incredibly hard for children to quietly sit for many, many hours straight like little robots working tirelessly on schoolwork, especially those with high energy levels to start with. From Medscape:

Before-School Exercise May Reduce ADHD Symptoms

Moderate to vigorous aerobic exercise in the morning may reduce symptoms of attention-deficit/hyperactivity disorder (ADHD) in young children at risk for the illness, new research suggests.

A randomized study of 202 kindergarteners, 1st graders, and 2nd graders showed that those who completed 12 weeks of before-school physical activity had significantly higher reductions in inattention and moodiness than those who completed a sedentary classroom-based intervention.In addition, the subgroup of children with elevated ADHD symptoms who went through the before-school exercise program showed reduced impairment associated with ADHD risk in both their school and home settings.

"We need more studies to replicate the results, but I think the take-home message is that aerobic exercise is a health-producing activity ― and there are really no negative side effects from it," added Dr. Hoza.

Past research has shown some positive effects from exercise on patients with ADHD, providing evidence that it may be "a viable strategy for improving symptoms, behavior, achievement, inhibitory control, and neurocognitive function in youth with elevated ADHD symptoms," write the investigators.

In the current study, the researchers enrolled 94 children at risk for ADHD and 108 children deemed "typically developing" to act as their control group....The physical activity involved continuous movement requiring children to breathe hard and included a variety of age-appropriate activities and games.

"Although our findings indicated that all participants showed improvements, children with ADHD risk receiving exercise benefited across a broader range of outcomes than those receiving the sedentary activities," said coinvestigator Alan Smith, PhD, chair of the Department of Kinesiology at Michigan State University in East Lansing, in a release.

Unfortunately the first article doesn't list the herbal supplements causing liver problems, but the earlier NY Times article mentions green tea extracts as one of them. From Science Daily:

Liver injury caused by herbals, dietary supplements rises in study population

Liver injury caused by herbals and dietary supplements increased from 7% to 20% in a U.S. study group over a ten-year period, research shows. According to the study, liver injury caused by non-bodybuilding supplements is most severe, occurring more often in middle-aged women and more frequently resulting in death or the need for transplantation than liver injury from bodybuilding supplements or conventional medications.

In response to the need for research in this area, the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK) supported the establishment of the Drug-Induced Liver Injury Network (DILIN) in 2003 to track cases of liver injury caused by medications (excluding acetaminophen (Tylenol®)), herbals, and dietary supplements. Herbals and dietary supplements were identified as the second most common cause of liver injury in the first DILIN report.

The present study examines hepatotoxicity due to supplements compared to medications, enrolling 839 patients with liver injury from 8 U.S. DILIN referral centers between 2004 and 2013 While bodybuilding supplements caused prolonged jaundice (median 91 days) in young men, no fatalities or liver transplantations occurred. Death or liver transplantation occurred more frequently among cases of injury from non-bodybuilding supplements, 13%, than from conventional medications, 3%. Liver injury from non-bodybuilding supplements was more common in middle aged women.

From NY Times (Dec. 2013):

Spike in Harm to Liver Is Tied to Dietary Aids

But the supplement business is largely unregulated. ... But a federal law enacted in 1994, the Dietary Supplement Health and Education Act, prevents the Food and Drug Administration from approving or evaluating most supplements before they are sold. Usually the agency must wait until consumers are harmed before officials can remove products from stores. Because the supplement industry operates on the honor system, studies show, the market has been flooded with products that are adulterated, mislabeled or packaged in dosages that have not been studied for safety.

The new research found that many of the products implicated in liver injuries were bodybuilding supplements spiked with unlisted steroids,and herbal pills and powders promising to increase energy and help consumers lose weight.

 More popular supplements like vitamins, minerals, probiotics and fish oil had not been linked to “patterns of adverse effects,” he said.

Since 2008, the F.D.A. has been taking action against companies whose supplements are found to contain prescription drugs and controlled substances, said Daniel Fabricant, the director of the division of dietary supplement programs in the agency’s Center for Food Safety and Applied Nutrition. For example, the agency recently took steps to remove one “fat burning” product from shelves, OxyElite Pro, that was linked to one death and dozens of cases of hepatitis and liver injury in Hawaii and other states.

A second trend emerged when Dr. Navarro and his colleagues studied 85 patients with liver injuries linked to herbal pills and powders. Two-thirds were middle-aged women, on average 48 years old, who often used the supplements to lose weight or increase energy. Nearly a dozen of those patients required liver transplants, and three died

But one product that patients used frequently was green tea extract, which contains catechins, a group of potent antioxidants that reputedly increase metabolism. The extracts are often marketed as fat burners, and catechins are often added to weight-loss products and energy boosters. Most green tea pills are highly concentrated, containing many times the amount of catechins found in a single cup of green tea, Dr. Bonkovsky said. In high doses, catechins can be toxic to the liver, he said, and a small percentage of people appear to be particularly susceptible.

An interesting article that discusses research that finds advantages to being dyslexic. Perhaps think in terms of cognitive diversity. From Scientific American:

The Advantages of Dyslexia

With reading difficulties can come other cognitive strengths.

In our laboratory at the Harvard-Smithsonian Center for Astrophysics we have carried out studies funded by the National Science Foundation to investigate talents for science among those with dyslexia. The dyslexic scientist Christopher Tonkin described to me his sense of this as a sensitivity to “things out of place.”  He’s easily bothered by the weeds among the flowers in his garden, and he felt that this sensitivity for visual anomalies was something he built on in his career as a professional scientist.  Such differences in sensitivity for causal perception may explain why people like Carole Greider and Baruj Benacerraf have been able to perform Nobel prize-winning science despite lifelong challenges with dyslexia.

Why are there advantages in dyslexia?  Is it something about the brains of people with dyslexia that predisposes them to causal thinking? Or, is it a form of compensation, differences in the brain that occur because people with dyslexia read less? Unfortunately, the answer to these questions is unknown.

One thing we do know for sure is that reading changes the structure of the brain. An avid reader might read for an hour or more a day, day in and day out for years on end. This highly specialized repetitive training, requiring an unnaturally precise, split-second control over eye movements, can quickly restructure the visual system so as to make some pathways more efficient than the others.

My colleagues and I suggested that one reason people with dyslexia may exhibit visual talents is that they have difficulty managing visual attention⁠. It may at first seem ironic that a difficulty can lead to an advantage, but it makes sense when you realize that what we call “advantages” and “disadvantages” have meaning only in the context of the task that needs to be performed.

For example, imagine you’re looking to hire a talented security guard. This person’s job will be to spot things that look odd and out of place, and call the police when something suspicious —say, an unexpected footprint in a flowerbed— is spotted. If this is the person’s task, would you rather hire a person who is an excellent reader, who has the ability to focus deeply and get lost in the text, or would you rather hire a person who is sensitive to changes in their visual environment, who is less apt to focus and block out the world?

Tasks such as reading require an ability to focus your attention on the words as your eyes scan a sentence, to quickly and accurately shift your attention in sequence from one word to the next.  But, to be a good security guard you need an opposite skill; you need to be able to be alert to everything all at once, and though this isn’t helpful for reading, this can lead to talents in other areas.

A series of studies by an Italian team led by Andrea Facoetti have shown that children with dyslexia often exhibit impairments in visual attention. In one study,Facoetti’s team measured visual attention in 82 preschool children who had not yet been taught to read. The researchers then waited a few years until these children finished second grade, and then examined how well each child had learned reading. They found that those who had difficulty focusing their visual attention in preschool had more difficulty learning to read.

These studies raise the possibility that visual attention deficits, present from a very early age, are responsible for the reading challenges that are characteristic of dyslexia. If this theory is upheld, it would also suggest that the observed advantages are not an incidental byproduct of experience with reading, but are instead the result of differences in the brain that were likely present from birth.

If this is indeed the case, given that attention affects perception in very general ways, any number of advantages should emerge.  While people with dyslexia may tend to miss details in their environment that require an attentional focus, they would be expected to be better at noticing things that are distributed more broadly.  To put this another way, while typical readers may tend to miss the forest because its view is blocked by all the trees, people with dyslexia may see things more holistically, and miss the trees, but see the forest.

Among other advantages observed, Gadi Geiger and his colleagues at MIT found that people with dyslexia can distribute their attention far more broadly than do typical readers, successfully identifying letters flashed simultaneously in the center and the periphery for spacings that were much further apart. They also showed that such advantages are not just for things that are visual, but that they apply to sounds as well. In one study, simulating the sounds of a cocktail party, they found that people with dyslexia were able to pick out more words spoken by voices widely-distributed in the room, compared with people who were proficient readers.

Whether or not observations of such advantages —measured in the laboratory— have applications to talents in real life remains an open question. But, whatever the reason, a clear trend is beginning to emerge: People with dyslexia may exhibit strengths for seeing the big picture (both literally and figuratively) others tend to miss.  Thomas G. West has long-argued that out-of-the-box thinking is historically part and parcel of dyslexia, and more recently physicians Brock and Fernette Eide have advanced similar arguments. Sociologists, such as Julie Logan of the Cass Business School in London agree.  Logan found that dyslexia is relatively common among business entrepreneurs; people who tend to think differently and see the big picture in thinking creatively about a business.

Whatever the mechanism, one thing is clear: dyslexia is associated with differences in visual abilities, and these differences can be an advantage in many circumstances, such as those that occur in science, technology, engineering and mathematics. It’s only when everything is all the same that nothing productive can get done. Neurological differences similarly drive the engine of society, to create the contrasts between hot and cold that lead to productive work. Impairments in one area can lead to advantages in others, and it is these differences that drive progress in many fields, including science and math.

Reading this article, I kept thinking of vampires and Transylvania. But the million dollar question is - will it work? From New Scientist:

Young blood to be used in ultimate rejuvenation trial

 In October, people with Alzheimer's disease will be injected with the blood of young people in the hope that it will reverse some of the damage caused by the condition.

The scientists behind the experiment have evidence on their side. Work in animals has shown that a transfusion of young mouse blood can improve cognition and the health of several organs in older mice. It could even make those animals look younger. The ramifications for the cosmetics and pharmaceutical industries could be huge if the same thing happens in people.

Disregarding vampire legends, the idea of refreshing old blood with new harks back to the 1950s, when Clive McCay of Cornell University in Ithaca, New York, stitched together the circulatory systems of an old and young mouse – a technique called heterochronic parabiosis. He found that the cartilage of the old mice soon appeared younger than would be expected.

It wasn't until recently, however, that the mechanisms behind this experiment were more clearly understood. In 2005, Thomas Rando at Stanford University in California and his team found that young blood returned the liver and skeletal stem cells of old mice to a more youthful state during heterochronic parabiosis. The old mice were also able to repair injured muscles as well as young mice (Nature, doi.org/d4fkt5). Spooky things seemed to happen in the opposite direction, too: young mice that received old blood appeared to age prematurely. In some cases, injured muscles did not heal as fast as would be expected.

Several other experiments have shown similar effects. In 2012, Amy Wagers at Harvard University showed that young blood can reverse heart decline in old mice.

Once the researchers had ruled out the effect of reduced blood pressure on the older mice, they identified a protein in the blood plasma called growth differentiation factor 11 (GDF11) that appeared to fall with age. To see if it was linked to the rejuvenating effects, the team gave old mice with enlarged hearts daily injections of GDF11 for 30 days. Their hearts decreased in size almost as much as they had in the parabiosis experiments (Cell, doi.org/q2f).

In both mice and humans, GDF11 falls with age. We don't know why it declines, but we know it is involved in several mechanisms that control growth. It is also thought to mediate some age-related effects on the brain, in part by activation of another protein that is involved in neuronal growth and long-term memory.

So the billion-dollar question is: would a GDF11 boost have the same effect in humans? Wyss-Coray thinks it will, having taken the next step of injecting young human blood plasma into old mice. His preliminary results suggest that human blood has similar rejuvenating benefits for old mice as young mouse blood does.

"We saw these astounding effects," he says. "The human blood had beneficial effects on every organ we've studied so far."

Now, the final step – giving young human blood plasma to older people with a medical condition – is about to begin. Getting approval to perform the experiment in humans has been relatively simple, says Wyss-Coray, thanks to the long safety record of blood transfusions. So in early October, a team at Stanford School of Medicine will give a transfusion of blood plasma donated by people under 30 to older volunteers with mild to moderate Alzheimer's.

Following the impressive results in animal experiments, the team hopes to see immediate improvements in cognition, but Wyss-Coray cautions that it is still very experimental. All researchers involved in the work agree that GDF11 is unlikely to be the only factor that keeps organs youthful. "It's too optimistic to think there would be just one factor," says Francesco Loffredo, who studies the effects of young blood in old animals at Harvard University. "It's much more likely to be several factors that exert these effects in combination."

Alessandro Laviano at the Sapienza University of Rome in Italy says that the research on diseases of ageing certainly holds promise, but he is more interested in the potential use of young blood in chronic disease. ...Before moving to clinical trials in people with cancer we need to learn more about the dynamics of the beneficial factors in blood, says Laviano, such as when they are at their peak. Do we reach a peak at 5 or 35 years? "We just don't know," he says.

An earlier related exciting study (from May 2014) in which it was found that "the blood of young mice has the ability to restore mental capabilities in old mice". From Science Daily:

Infusion of young blood recharges brains of old mice