Category Archives: Discoveries

Artificial Sweeteners: Tied to Stroke & Dementia

A new study published in the American Heart Association’s journal Stroke suggests that artificial sweeteners, found in diet sodas, have considerable health risks for both the body and the brain.

The data was collected from the Framingham Heart Study, a project of the National Heart, Lung, and Blood Institute and Boston University, and involved data on 2,888 adults older than 45 and 1,484 adults older than 60 from Framingham, Massachusetts. In the group aged 45-and-older, researchers measured for increased risk of stroke; in the group aged 60-and-older, researchers measured for dementia.

The statistics analyzed how many sugary beverages and artificially sweetened soft drinks each person in the two different age groups drank, between the years 1991 and 2001. That data was than compared against the number of people who suffered from stroke or dementia in the next decade.

Researchers found that—juxtaposed against people who never drank artificially sweetened soft drinks—those who drank one per day were almost three times as likely to have an ischemic stroke. Those who drank one per day were also almost three times as likely to be diagnosed with dementia.

Previous studies have shown a strong association between the intake of sugar-sweetened beverages and a host of adverse health effects, including type 2 diabetes, obesity, and cardiovascular disease. Professor and chair of neurology at the University of Miami Miller School of Medicine Dr. Ralph Sacco confirms that this article “provides further evidence on artificially sweetened beverages and their possibly effects on vascular health…we believe the pathways of which artificially sweetened beverages would affect the brain are probably through vascular mechanisms.”

Moreover, artificial sweeteners have been shown to cause glucose intolerance in mice by altering gut microbiota, and have been associated with dysbiosis and glucose intolerance in humans. The cumulative research strongly indicates that there is no benefit to using artificial sweeteners, or drinking diet soda, compared to regular sucrose or sugary drinks.

To learn more about the gut-immune-brain connection, and the different ways in which various types of inflammation can affect the body and brain, register for Module VII: Autoimmune Disease & Inflammation, from August 10-12.

Human Umbilical Cord Blood: The Secret to Memory?

A recent study indicates that a specific protein in human umbilical cord blood plasma has the potential to improve learning and memory in aging, older mice.

In 1972, research demonstrated that when pairs of rats were surgically attached, older rats had increased lifespan when sharing a bloodstream with young rats. This particular study spearheaded a scientific effort surrounding the understanding and consensus of aging: certain materials from younger bodies or organisms can often improve or rejuvenate older ones, when transplanted.

Further findings produced exciting research; scientists have previously shown that young blood can restore cell activity in the muscles and livers of aging mice, and that linking older mice to young when helped reverse heart muscle thickening.

Although many of the findings have not been successfully replicated, there is a unanimous agreement that—like humans—as mice and rats age, their bodies and behavior change on profoundly fundamental levels. Joe Castellano, a neuroscientist at Stanford University School of Medicine, saw that older mice tended to stop building nests, and became increasingly forgetful.

Castellano and his colleagues collectively hypothesized that young human blood might produce beneficial effects for aging mice; in a report published in the journal Nature, they state that they have located a protein in human umbilical cord blood that can improve both learning and memory in aging mice—a significant and exciting finding in the field of regenerative medicine.

The team collected plasma, the ‘watery part of blood,’ from people of different ages, in addition to plasma from human umbilical cords. They then injected human plasma from those different age groups, and from umbilical cord blood, into mice continuously over several weeks. The mice were aged 12 and 14 months, which is calculated to be approximately the mouse equivalent of being in late 50s or 60s.

When the mouse brains were dissected and the hippocampi were inspected, it was found that certain genes linked to the creation of new memories had been turned on in some of the mice. “So, we had a hint early on that one of these donor groups, specifically the [umbilical] cord plasma, might be having an effect on the brain itself,” Castellano says.

Castellano and his team then injected more aging mice with human plasma, and tested the animals’ ability to remember things. They found that after cord plasma treatment, mice escaped from a maze more rapidly; the performance in most areas was increased and improved. Similarly, mice treated with human umbilical cord performed better on memory tests.

A series of further experiments led Castellano and his colleagues to conclude that one specific protein—TIMP2—in human umbilical cord blood was responsible for the improvements. “The really exciting thing about this study, and previous studies that have come before it, is that we’ve sort of tapped into previously unappreciated potential of our blood — our plasma — and what it can do for reversing the harmful effects of aging on the brain,” says Castellano.

The research potentially hints at possible treatments and therapies that might ultimately work to prevent age-related illnesses from developing, including Alzheimer’s disease.

The Gut Microbiome & Its Influence

While scientists remain uncertain about the specific causes of rheumatoid arthritis, an emerging body of research has led many to suspect that the microbiome—the bacteria that live in the gastrointestinal tract—may be to blame.

Rheumatoid arthritis occurs when the body attacks its own joints: several recent studies have found additional correlations between gut microbes and other diseases in which the body’s immune system goes ‘awry,’ and begins to attack its own tissue.

In 2013, Jose Scher, a rheumatologist at New York University, published a study that found people with rheumatoid arthritis were far more likely to have a bug called Prevotella copri in their intestines than people without the disease. Another study two years later indicated that aptients with psoriac arthritis, another type of autoimmune joint disease, had significantly lower levels of other types of intestinal bacteria.

Scher’s work is part of a growing effort by researchers across the globe to understand the ways in which the microbiome affects overall health. The gut contains up to one thousand different species of bacteria, which collectively weight between one and three pounds. This mass contains trillions of cells, more than the number of cells that make up our bodies. Throughout the past several years, scientists have compiled a growing collection of evidence that confirms links between these bugs and overall wellness.

These microbes can directly affect the immune system, even with diseases not located in the gut. An immunologist at the Mayo Clinic, Veena Taneja, has found striking differences in the bacterial populations of mice bred to be genetically prone to rheumatoid arthritis. Scher, director of NYU’s Microbiome Center for Rheuamtology and Autoimmunity, believes this is “frontier stuff…a shift in paradigm. By including the microbiome, we’ve added a new player to the game.”

Other research has focused on the influence of these bacteria on the immune system, as recent decades have seen a spike in the incidence of many autoimmune diseases. Several researchers state that this rise is, at least partially, due to changes in our bacterial ecosystem: altered diet, the proliferation of antibiotic use, and decreasing contact with the ‘microbe-packed natural world of animal plants’ have transformed the bacteria. NYU microbiologist Martin Blaser argues that because we lose microbes with each generation, “They are going extinct. These changes have consequences.”

Blaser’s own research has pinpointed the gut bacteria of U.S. children, finding that a specific species of bacteria thought to reduce the risk of asthma was very low. The decline of this bacteria in the West, as opposed to its appearance in the vast majority of the developing world, could have medical consequences. Blaser suspects that asthma is one of the primary illnesses affected by the changing microbiome; rates have escalated in the U.S. for the past three decades, growing over 28 percent between 2001 and 2011.

Dozens of researchers are looking into a range of potential strategies to use bacteria as medicine for immune disorders. Scher believes that eventually, it will be possible to treat arthritis, and other immune disorders, by adjusting the microbiome. At the Mayo Clinic, Taneja has found that a species of bacteria can prevent or halt the mouse versions of both rheumatoid arthritis, and multiple sclerosis—an autoimmune disease of the brain and nerves. Harvard University microbiologist Dennis Kasper, who discovered a targeted compound in the gut that protects mice from certain autoimmune diseases, including MS, is optimistic: “In 10 or 15 years, I think the microbiome will be a key therapeutic option for some of these diseases. There will be challenges, but I don’t see why it can’t happen. This isn’t science fiction.”