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Published on Leave a comment on Male Infertility Linked to Other Chronic Medical Conditions

A recent study found that men with infertility have a much higher risk for a variety of other chronic medical conditions, including diabetes, heart disease, renal disease, alcohol abuse, and drug abuse. Thus, it appears that male infertility may be a symptom or a clue that there may be other health problems. One example is that male infertility is linked to an 81% greater risk of diabetes, and the greatest risk for renal disease occurred among men with azoospermia (zero sperm counts, the most severe form of male infertility). From Medscape:

Infertility in Men Tied to Heart Disease, Chronic Conditions

Men with infertility have a higher risk for a variety of other chronic medical conditions, including diabetes, heart disease, alcohol abuse, and drug abuse, according to a retrospective cohort study published online December 7 in Fertility and Sterility."The results suggest that male factor infertility has more than just reproductive implications," write Michael Eisenberg, MD, assistant professor of urology and director of male reproductive medicine and surgery at Stanford University School of Medicine in California, and colleagues.

The researchers used insurance claims data from 2001 to 2008 from the Truven Health MarketScan to identify more than 115,000 patients for the study population. They compared outcomes among 13,027 men diagnosed with male factor infertility (average age, 33 years), with outcomes among 23,860 men (average age, 33 years) who received semen or infertility testing and with outcomes among 79,099 men who had received vasectomies.

The authors looked for 16 conditions: hypertension, diabetes, hyperlipidemia, renal disease, chronic pulmonary disease, liver disease, depression, peripheral vascular disease, cerebrovascular disease, ischemic heart disease, other heart disease, injury, alcohol abuse, drug abuse, anxiety disorders, and bipolar disorder.

The men with infertility had higher rates of obesity and smoking, but even after adjustment for these covariates and for age, follow-up time, and healthcare use, men with infertility had a higher risk for multiple conditions compared with vasectomized men or those receiving only fertility testing. Specifically, compared with the men who received fertility testing, men with infertility had a 30% increased risk for diabetes (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.10 - 1.53), a 48% increased risk for ischemic heart disease (HR, 1.48; 95% CI, 1.19 - 1.84) and for alcohol abuse (95% CI, 1.07 - 2.05), a 67% increased risk for drug abuse (HR, 1.67; 95% CI, 1.06 - 2.63), and a 19% increased risk for depression (HR, 1.19; 95% CI, 1.04 - 1.36).

Compared with men who received vasectomies, those with infertility had a 9% higher risk for hypertension (HR, 1.09; 95% CI, 1.02 - 1.17), a 14% greater risk for hyperlipidemia (HR, 1.14; 95% CI, 1.07 - 1.22), a 41% greater risk for ischemic heart disease (HR, 1.41; 95% CI, 1.19-1.67), and a 16% greater risk for other heart disease (HR, 1.16; 95% CI, 1.04 - 1.29). Further, men with infertility, compared with vasectomized men, had an 81% greater risk for diabetes (HR, 1.81; 95% CI, 1.57 - 2.08), a 60% greater risk for renal disease (HR, 1.60; 95% CI, 1.14 - 2.24), a 53% greater risk for liver disease (HR, 1.53; 95% CI, 1.31 - 1.80), and a 52% greater risk for peripheral vascular disorders (HR, 1.52; 95% CI, 1.12 - 2.07).

Published on Leave a comment on Sense of Purpose In Life May Be Good For Health

Of course! Makes sense that people who have a higher sense of purpose in life are at lower risk of death and cardiovascular disease!. From Science Daily:

Sense of purpose in life linked to lower mortality and cardiovascular risk

People who have a higher sense of purpose in life are at lower risk of death and cardiovascular disease, reports a pooled data analysis."Possessing a high sense of purpose in life is associated with a reduced risk for mortality and cardiovascular events," according to the study by Drs. Randy Cohen and Alan Rozanski and colleagues at Mt. Sinai St. Luke's-Roosevelt Hospital, New York. While the mechanisms behind the association remain unclear, the findings suggest that approaches to strengthening a sense of purpose might lead to improved health outcomes.

Using a technique called meta-analysis, the researchers pooled data from previous studies evaluating the relationship between purpose in life and the risk of death or cardiovascular disease. The analysis included data on more than 136,000 participants from ten studies -- mainly from the United States or Japan. The US studies evaluated a sense of purpose or meaning in life, or "usefulness to others." The Japanese studies assessed the concept of ikigai, translated as "a life worth living."

The study participants, average age 67 years, were followed up for an average of seven years. During this time, more than 14,500 participants died from any cause while more than 4,000 suffered cardiovascular events (heart attack, stroke, etc).

The analysis showed a lower risk of death for participants with a high sense of purpose in life. After adjusting for other factors, mortality was about one-fifth lower for participants reporting a strong sense of purpose, or ikigai. A high sense of purpose in life was also related to a lower risk of cardiovascular events. Both associations remained significant on analysis of various subgroups, including country, how purpose in life was measured, and whether the studies included participants with pre-existing cardiovascular disease..

There is a well-documented link between "negative psychosocial risk factors" and adverse health outcomes, including heart attack, stroke, and overall mortality. "Conversely, more recent study provides evidence that positive psychosocial factors can promote healthy physiological functioning and greater longevity," according to the authors.

While further studies are needed to determine how purpose in life might promote health and deter disease, preliminary data suggest a few basic mechanisms. The association might be explained physiologically, such as by buffering of bodily responses to stress; or behaviorally, such as by a healthier lifestyle.

Published on Leave a comment on Amazing Paper Sculptures of Microbes

Just saw some of  Rogan Brown's amazing paper sculptures of microbes. He designs, then cuts by hand or laser thousands of paper microorganisms, including tree moss, cell structures, bacteria, coral, and diatoms. Absolutely gorgeous! From :

Paper Life – The artist Rogan Brown cuts thousands of microorganisms in paper

The following article was from April 2015, and it described the work of various artists contributing to a permanent exhibit of the human microbiome. Go to the article and check out the various fascinating artworks. From Wired (UK edition): Eden Project's 'Human Biome' is a gross, musical microbe showcase

The great domed biomes of the Eden Project are to play host to a new permanent exhibition that will focus on one of nature's most important and complex ecosystems: the human body. Invisible You: The Human Biome will explore the community of microbes that live in and on each and every one of us. Artistic and interactive displays will show bacteria, fungi and viruses, with 11 artists commissioned to create works for the exhibition.

"These trillions of microbes outnumber our cells ten to one and, in the main, work together to keep us healthy -- whether it’s the bacteria in the gut helping to digest our food or the microbes on our skin working to keep it soft. This fascinating new exhibition is one of the most compelling and important we have ever staged," said Jo Elsworthy, the Eden Project's interpretation director. Among the artists commissioned to create work for the exhibition is Rogan Brown, who creates beautifully intricate, hand-cut paper artworks, including microbes. 

Published on Leave a comment on Beneficial Foods: Blackberries, Red Raspberries, and Black Raspberries

It seems that a lot has been written about the health benefits of some berries, such as blueberries, while other berries have been neglected. This study focused on red raspberries, black raspberries, and blackberries. While the study was done in Poland, it was pointed out that these berries are also commonly grown in the USA. Red raspberry, black raspberry, and blackberry fruits are abundant in dietary phytochemicals such as flavonols, phenolic acids, ellagitannins, vitamins C and E, folic acid, and β-sitosterol. Many of these bioactive compounds exhibit antioxidant activity. Anthocyanins and other phenolic compounds such as ellagitannins and ellagic acid, which distinguish raspberry from other berries, occur in high levels and are mainly responsible for their broad beneficial health properties (including anti-inflammatory, antimicrobial, and antiviral activities).

For these reasons, the researchers said that "raspberry and blackberry fruits can be regarded as natural functional foods". Another term for functional foods is nutraceutical, which is a food containing health-giving additives and having medicinal benefit. From Science Daily:

Looking for the best antioxidant fruit? Search no further than black raspberries

As far as healthy foods go, berries make the top of the list. They contain potent antioxidants, which decrease or reverse the effects of free radicals -- natural byproducts of energy production that can play havoc on the body and that are closely linked with heart disease, cancer, arthritis, stroke or respiratory diseases.

Unsurprisingly, the benefits of berries are extoled in one study after another....The research published now in Open Chemistry suggests that black raspberries grown in Central Europe show greater health benefits than their better known cousins -- raspberries or blackberries.

A group of researchers led by Anna Małgorzata Kostecka-Gugała measured the content of phenolics and anthocyanins in black raspberries, red raspberries and blackberries, assessing their antioxidant potential and health benefits. They were able to confirm that the antioxidant activity of natural products correlates directly with their health promoting properties.

It turns out that the amount of antioxidants in black raspberries was three times higher than the other fruits under investigation. Remarkably, the number was even higher for phenolics or the amount of anthocyanines -- with black raspberries topping their humble cousins by over 1000%. But most interestingly, black raspberries seem to be characterized by a higher content of secondary metabolites, which have been proved beneficial for human health.

Published on Leave a comment on Can Cruciferous Vegetables Fight Cancer?

Reading this recent study, I was struck by how the results are evidence for eating sulforaphane containing foods, such as kale, cauliflower, brussels sprouts, broccoli, and cabbage for health and preventing cancer (due to anti-tumor activity). It is debatable whether it is support for taking supplements (here a sulforaphane supplement called BSE), even though the researchers were testing the supplement. Seven days of taking a supplement without "serious adverse events" (but they did have minor ones such as "mild abdominal discomfort") is too short a length of time for any support for a product. The real test would be seeing what health effects, both positive and negative, are after a year or two of taking the supplement.

Numerous other studies have found that eating foods are linked to good health, while taking supplements are linked to various health problems. Some scientists speculate that it's because the doses in supplements are too high - that they're much higher than what is found in foods. Also, supplements may be missing important nutrients that are found in foods. Bottom line: eat real foods for health and and cancer prevention, including several servings a week of cruciferous vegetables (cauliflower, cabbage, garden cress,bok choy, broccoli, brussels sprouts and similar green leaf vegetables). From Futurity:

Can A Broccoli Sprout Pill Fight Cancer?

A compound in broccoli sprouts may not only help prevent cancer but also treat it. Sulforaphane is found in vegetables such as kale, cauliflower, and cabbage—and in particularly high concentrations in young broccoli sprouts. Sulforaphane also is available as a dietary supplement called BSE.

Researchers at the Texas A&M Health Science Center Institute of Biosciences and Technology, along with collaborators in Oregon, had previously found that sulforaphane could inhibit colon and prostate cancer cells in the laboratory. They’ve now shown that it seems to help humans as well. A paper published in the journal Clinical Epigenetics hints at the biological pathways involved and suggests BSE is generally safe.

“We have not seen any serious adverse events in healthy volunteers who consumed BSE pills for seven days,” says Praveen Rajendran, an assistant professor at Texas A&M University, although some people did experience mild abdominal discomfort.

In a separate clinical study, 28 human volunteers over the age of 50, who were undergoing routine colonoscopies, were surveyed for their cruciferous vegetable-eating habits. When their colon biopsies were examined, those who ate more servings were found to have higher levels of expression of the tumor suppressor gene p16 than those who ate few or no cruciferous vegetables.

This effect on p16 held even for people who didn’t eat these vegetables every single day, which may seem strange, as a single serving of sulforaphane is generally cleared from the body in less than 24 hours. “This hints at the possibility that epigenetic mechanisms are initially triggered by sulforaphane and its metabolites, and downstream mechanisms could be sustained, at least in the short-term, even after compounds are eliminated from the body.” In other words, eating vegetables containing sulforaphane may change your genes and help your body fight tumor growth.

However, it’s not all good news. In animal models, sulforaphane was shown to generally inhibit the development of colon cancer, but it’s a bit of a two-edged sword. Sulforaphane induces a protein called Nrf2, which has beneficial antioxidant and detoxifying effects—and is obviously good for fighting cancer. Later in the development of cancer, though, Nrf2 can also have a role in tumor growth and can even enhance the buildup of plaque in the arteries.

Published on Leave a comment on Early Pesticide Exposure Linked to Poorer Lung Function

 Just a few years ago the type of pesticide (organophosphate, for example chlorpyrifos) looked at in this study was commonly used everywhere - in schools, homes, agriculture. It was easy to buy in stores (e.g., Raid spray), and was considered "safer" than older pesticides. Over time problem after problem has been found with them - with the latest being decreased lung function in children exposed to organophosphates early in life.

Keep in mind that with all current pesticides we know very little about long-term effects, especially on developing fetuses and children, and so we should be very, very careful about using them and avoid unnecessary use. Yes, that means using them for harmless lawn weeds is an unnecessary use. Common lawn weeds can not give a person cancer, birth defects, health problems, or illnesses, but pesticides can. From Medical Xpress:

Weaker breaths in kids linked to early pesticide exposure

Taking a deep breath might be a bit harder for children exposed early in life to a widely used class of pesticides in agriculture, according to a new paper by researchers at the University of California, Berkeley. A new study has linked the levels of organophosphate pesticide metabolites in the urine of 279 children living in California's Salinas Valley with decreased lung function. Each tenfold increase in concentrations of organophosphate metabolites was associated with a 159-milliliter decrease in lung function, or about 8 percent less air, on average, when blowing out a candle. The magnitude of this decrease is similar to a child's secondhand smoke exposure from his or her mother.

"Researchers have described breathing problems in agricultural workers who are exposed to these pesticides, but these new findings are about children who live in an agricultural area where the organophosphates are being used," said study senior author Brenda Eskenazi, a professor of epidemiology and of maternal and child health. "This is the first evidence suggesting that children exposed to organophosphates have poorer lung function."

The children were part of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal study in which the researchers follow children from the time they are in the womb up to adolescence. The researchers collected urine samples five times throughout the children's lives, from age 6 months to 5 years, and measured the levels of organophosphate pesticide metabolites each time. When the children were 7 years old, they were given a spirometry test to measure the amount of air they could exhale.

"The kids in our study with higher pesticide exposure had lower breathing capacity," said study lead author Rachel Raanan, who conducted the research while she was a postdoctoral scholar in Eskenazi's lab. "If the reduced lung function persists into adulthood, it could leave our participants at greater risk of developing respiratory problems like COPD (chronic obstructive pulmonary disease)."

The study did not examine the pathways for the children's exposure to pesticides, but the researchers did recommend that farmworkers remove their work clothes and shoes before entering their homes. They also suggested that when nearby fields are being sprayed with pesticides, children be kept away and, if indoors, windows should be closed. Pesticide exposure can also be reduced by washing fruits and vegetables thoroughly before eating.

The authors noted that although organophosphate pesticides are still widely used, most residential uses of organophosphate pesticides in the United States were phased out in the mid-2000s. In California, use of organophosphates in agriculture has also declined significantly from 6.4 million pounds in 2000, when the study began, to 3.5 million pounds in 2013, the year with the most recent pesticide use data. 

Published on Leave a comment on What is “Seeding” the Microbiomes of Babies Born By C-section?

The mother is an important source of the first microbiome for infants by "seeding" the baby's microbiome - from the vaginal birth and then breastfeeding. However, research finds that infants born by C-section acquire bacteria commonly found on skin (Staphylococcus, Corynebacterium, and Propionibacterium) rather than the bacteria acquired during a vaginal birth.

This study examined the source of the skin-type bacteria found on C-section babies. The researchers analyzed the dust from operating rooms (which they collected right after C-sections) and found that it contains deposits of human skin bacteria and human skin flakes. The researchers point out that "Humans shed up to 37 million bacterial genomes into the environment per hour." Operating rooms are occupied by humans, lack natural ventilation, and even though they are regularly cleaned, the humans using the operating rooms shed bacteria and skin flakes. From Microbiome:

The first microbial environment of infants born by C-section: the operating room microbes

Newborns delivered by C-section acquire human skin microbes just after birth, but the sources remain unknown. We hypothesized that the operating room (OR) environment contains human skin bacteria that could be seeding C-section born infants. To test this hypothesis, we sampled 11 sites in four operating rooms from three hospitals in two cities. Following a C-section procedure, we swabbed OR floors, walls, ventilation grids, armrests, and lamps....The bacterial content of OR (operating room) dust corresponded to human skin bacteria, with dominance of Staphylococcus and Corynebacterium. Diversity of bacteria was the highest in the ventilation grids and walls but was also present on top of the surgery lamps. 

We conclude that the dust from ORs, collected right after a C-section procedure, contains deposits of human skin bacteria. The OR microbiota is the first environment for C-section newborns, and OR microbes might be seeding the microbiome in these babies. 

In the present study, we used 16S rRNA gene sequencing to show that OR dust, collected right after a C-section procedure, contains bacteria similar to human skin microbiota. Previous studies using culture-dependent methods also showed that over 85 % of air samples from ORs had skin-like bacteria which were mostly coagulase-negative staphylococci and Corynebacterium. These airborne skin-bacteria could be from individuals present during C-section but could also be shed by cleaning personnel between operations.

In our study, 30 % of samples failed to yield sufficient DNA sequences to be analyzed. While there are no published data on the microbiota in operating rooms using 16S rRNA gene sequencing, very few bacteria (average 3.3–3.5 CFU/10 cm2) were detected in ORs after regular decontamination using standard culturing methods, consistent with the low sequence numbers in our study.

In addition, we found that the microbiota of OR samples was more similar to human skin microbiota than oral microbiota and that OR dust contains deposits of human skin flakes. These results reveal that while the use of surgical masks has limited effectiveness at curtailing oral microbial shedding, skin flakes from individuals present during C-section and/or from cleaning personnel between operations could be a more influential factor contributing to the structure of OR microbiota.

Our SourceTracker analysis results suggest that the OR microbes could play a role in seeding infants born by C-section. C-section born infants, in particular, may be solely receiving this inoculum, while vaginally born infants have exposure to vaginal bacteria. The results of these further studies could be relevant to the possible effects on the priming of the immune system by skin bacteria from environmental sources as the primordial inoculum seeding the infant microbiome. This might be relevant to the increased risk of immune diseases observed in C-section born infants.

Published on Leave a comment on When Do Football Players Recover From Concussions?

New research showed that eight days after a concussion, the concussed athletes (football players) looked and felt like they had recovered (clinical recovery), but MRIs showed that there were still neurophysiological abnormalities (significant blood flow decrease) in their brains. They did not look at if and when the blood flow returned to normal, but that research also needs to be done.

It is very disturbing to look at both this research and also the finding that the off-season is not enough for high school football players to recover from the repeated hits (not concussions, but sub-concussive hits) that they receive during the football season (Nov. 24, 2015 post). Do student football players really know and understand the dangers to their brains from the repeated hits and also concussions that occur in football? From Medical Xpress:

Reduced blood flow seen in brain after clinical recovery of acute concussion

Some athletes who experience sports-related concussions have reduced blood flow in parts of their brains even after clinical recovery, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA). The results suggest a role for MRI in determining when to allow concussed athletes to return to competition.

Decisions to clear concussed athletes to return to action are typically based on symptoms and cognitive and neurological test results. However, there is increasing evidence that brain abnormalities persist beyond the point of clinical recovery after injury. To find out more, researchers from the Medical College of Wisconsin in Milwaukee studied concussed football players with arterial spin labeling, an advanced MRI method that detects blood flow in the brain.

Dr. Wang and colleagues studied 18 concussed players and 19 non-concussed players. They obtained MRI of the concussed players within 24 hours of the injury and a follow-up MRI eight days after the injury and compared results with those of the non-concussed players. Clinical assessments were obtained for both groups at each time point, as well as at the baseline before the football season.

The concussed players demonstrated significant impairment on clinical assessment at 24 hours post-injury, but returned to baseline levels at eight days. In contrast to clinical manifestation, the concussed players demonstrated a significant blood flow decrease at eight days relative to 24 hours post-injury, while the non-concussed players had no change in cerebral blood flow between the two time points.

"In eight days, the concussed athletes showed clinical recovery," Dr. Wang said. "However, MRI showed that even those in clinical recovery still had neurophysiological abnormalities. Neurons under such a state of physiologic stress function abnormally and may become more susceptible to second injury." "For years, we've relied on what athletes are telling us," Dr. McCrea said. "We need something more objective, and this technology may provide a greater measurement of recovery."

Published on Leave a comment on The Appendix Has A Purpose

This new study gives further support for the role of the appendix as a "natural reservoir for 'good' bacteria". The researchers found that a network of immune cells (innate lymphoid cells or ILCs)  safeguard the appendix during a bacterial attack and help the appendix "reseed" the gut microbiome. They also said that a person's diet, such as the proteins in leafy green vegetables, could help produce ILCs. Note that while it is thought that this applies to humans, the research was done on mice. From Medical Xpress:

Immune cells make appendix 'silent hero' of digestive health

New research shows a network of immune cells helps the appendix to play a pivotal role in maintaining the health of the digestive system, supporting the theory that the appendix isn't a vestigial—or redundant—organ.

The research team....found that innate lymphoid cells (ILCs) are crucial for protecting against bacterial infection in people with compromised immune systems. By preventing significant damage and inflammation of the appendix during a bacterial attack, ILCs safeguard the organ and help it to perform an important function in the body, as a natural reservoir for 'good' bacteria.

"Popular belief tells us the appendix is a liability," she said. "Its removal is one of the most common surgical procedures in Australia, with more than 70,000 operations each year. However, we may wish to rethink whether the appendix is so irrelevant for our health. "We've found that ILCs may help the appendix to potentially reseed 'good' bacteria within the microbiome—or community of bacteria—in the body. A balanced microbiome is essential for recovery from bacterial threats to gut health, such as food poisoning."

Professor Belz said having a healthy appendix might even save people from having to stomach more extreme options for repopulating—or 'balancing out'—their microbiomes. "In certain cases, people require reseeding of their intestines with healthy bacteria by faecal transplant—a process where intestinal bacteria is transplanted to a sick person from a healthy individual," Professor Belz said. "Our research suggests ILCs may be able to play this important part in maintaining the integrity of the appendix.

"We found ILCs are part of a multi-layered protective armoury of immune cells that exist in healthy individuals. So even when one layer is depleted, the body has 'back ups' that can fight the infection. "In people who have compromised immune systems—such as people undergoing cancer treatment—these cells are vital for fighting bacterial infections in the gastrointestinal system. This is particularly important because ILCs are able to survive in the gut even during these treatments, which typically wipe out other immune cells."

Professor Belz has previously shown that diet, such as the proteins in leafy green vegetables, could help produce ILCs."ILCs are also known to play a role in allergic diseases, such as asthma; inflammatory bowel disease; and psoriasis," she said. "So it is vital that we better understand their role in the intestine and how we might manipulate this population to treat disease, or promote better health."

Drawing of colon seen from front (appendix is colored red). From Wikipedia.

Published on Leave a comment on Loneliness Is a Health Risk

Loneliness or social isolation is a health risk that can increase the risk of chronic illness and premature death. Why?  Loneliness leads to fight-or-flight stress signaling, which can ultimately affect the production of white blood cells. Essentially, lonely people had a less effective immune response and more inflammation than non-lonely people. The study was part of the Chicago Health, Aging, and Social Relations Study (CHASRS) and followed 144 people over 10 years. From Science Daily:

Loneliness triggers cellular changes that can cause illness, study shows

Loneliness is more than a feeling: For older adults, perceived social isolation is a major health risk that can increase the risk of premature death by 14 percent.

Now a team of researchers, including U Chicago psychologist and leading loneliness expert John Cacioppo, has released a study shedding new light on how loneliness triggers physiological responses that can ultimately make us sick. The paper.... shows that loneliness leads to fight-or-flight stress signaling, which can ultimately affect the production of white blood cells. The study examined loneliness in both humans and rhesus macaques, a highly social primate species.

Previous research from this group had identified a link between loneliness and a phenomenon they called "conserved transcriptional response to adversity" or CTRA. This response is characterized by an increased expression of genes involved in inflammation and a decreased expression of genes involved in antiviral responses. Essentially, lonely people had a less effective immune response and more inflammation than non-lonely people.

For the current study, the team examined gene expression in leukocytes, cells of the immune system that are involved in protecting the body against bacteria and viruses. As expected, the leukocytes of lonely humans and macaques showed the effects of CTRA--an increased expression of genes involved in inflammation and a decreased expression of genes involved in antiviral responses. But the study also revealed several important new pieces of information about loneliness' effect on the body.

Next, the team investigated the cellular processes linking social experience to CTRA gene expression in rhesus macaque monkeys at the California National Primate Research Center, which had been behaviorally classified as high in perceived social isolation. Like the lonely humans, the "lonely like" monkeys showed higher CTRA activity. They also showed higher levels of the fight-or-flight neurotransmitter, norepinephrine.

Previous research has found that norepinephrine can stimulate blood stem cells in bone marrow to make more of a particular kind of immune cell--an immature monocyte that shows high levels of inflammatory gene expression and low levels of antiviral gene expression. Both lonely humans and "lonely like" monkeys showed higher levels of monocytes in their blood.

Taken together, these findings support a mechanistic model in which loneliness results in fight-or-flight stress signaling, which increases the production of immature monocytes, leading to up-regulation of inflammatory genes and impaired anti-viral responses. The "danger signals" activated in the brain by loneliness ultimately affect the production of white blood cells. The resulting shift in monocyte output may both propagate loneliness and contribute to its associated health risks.