Mandy Oaklander

There's a veritable fish pharmacy in your freezer

When we think about food raised with antibiotics, we probably picture oversized chickens and plumped-up cows. But they’re also in our fish—both farmed and wild, finds a new study published in the Journal of Hazardous Materials.

Antibiotics are used in fish largely to treat and prevent disease, not to promote growth, says study leader Hansa Done, a PhD candidate at Arizona State University’s Center for Environmental Security. They’re dispersed into the water in fish farms and are sometimes injected into fish directly. And once they get into the fish, they generally stay there, even though their concentration diminishes over time.

MORE: Obama Plan to Fight Antibiotic Resistance ‘Disappointing,’ Critics Say

The study looked at 27 fish from 11 different countries, all bought at an Arizona supermarket. Researchers used a meat grinder to pulverize the fish and tested the meat for 47 types of antibiotics. They found residues of five antibiotics, some of which are also used to treat human diseases. Residues of a kind of tetracycline, for instance, showed up in farmed tilapia, farmed salmon and farmed trout. It was also present in wild-caught shrimp from Mexico—probably due to wastewater treatment plant runoff, Done says. Even fish marketed as antibiotic-free wasn’t off the hook: researchers found virginiamycin in one sample of farmed salmon bearing the label.

All traces of the drugs were within legal limits of what’s allowed—which is a victory for our food supply, says Done, but there is a caveat: “For there to still be something in there”—after untold stages of processing and months in Done’s freezer—“means that at one point, it was injected or fed a lot more,” she says. “We just don’t know how much.”

The problem with low-dose antibiotics isn’t that they’re immediately harmful to human health, Done says. It’s that high or low levels in our food supply can breed antibiotic resistance. “Antibiotics present at levels well below regulatory limits still can promote the emergence of drug resistant microorganisms,” the researchers write in the study. In a related meta-analysis of studies on antibiotics and seafood, Done found that antibiotic resistant bacteria in seafood has grown more than 8-fold in the past three decades.

Beyond fending off disease, it’s not clear what antibiotics are doing to the fish themselves. “There’s this rumor that high levels of [the antibiotic] oxytetracycline could lead to spinal deformities in rainbow trout if it’s fed to them during their growth stages,” Done says, though she notes a definite lack of research on the matter. In the six fish she tested, the group with normal spines didn’t have detectable levels of oxytetracycline, but the three with deformed spines did—though only very slightly detectable levels, she says.

More research is needed.

The best brew for your heart

Recent research has come down squarely on the side of caffeinated morning beverages, suggesting that coffee can protect against cancer and type 2 diabetes. Tea has enjoyed a healthy reputation for years as a heart-protector, and a study published in the October issue of British Journal of Nutrition suggests it might even help lower blood pressure.

Researchers were intrigued by the inconclusive link in studies so far regarding blood pressure and tea intake, so they analyzed 25 randomized controlled trials—the gold standard of scientific research—to further explore on the association.

They found that in the short term, tea didn’t seem to make a difference for blood pressure. But long-term tea intake did have a significant impact. After 12 weeks of drinking tea, blood pressure was lower by 2.6 mmHg systolic and 2.2 mmHg diastolic. Green tea had the most significant results, while black tea performed the next best.

Those might not seem like big numbers, but small changes in blood pressure can have a significant impact on health, the study authors write. Reducing systolic blood pressure by 2.6 mmHg “would be expected to reduce stroke risk by 8%, coronary artery disease mortality by 5% and all-cause mortality by 4% at a population level,” they write.

Tea is thought to offer endothelial protection by helping blood vessels relax, allowing blood to flow more freely. It’s a high source of antioxidants that have been linked to better cardiovascular health.

The researchers weren’t able to pinpoint the optimal number of cups to drink to get the benefit, but other studies have shown protective effects at 3-4 daily cups. The researchers said they didn’t see a difference in caffeinated tea vs. decaf.

“These are profound effects and must be considered seriously in terms of the potential for dietary modification to modulate the risk of CVD [cardiovascular disease],” the authors write.

Read next: 6 Ways to Lower Your Blood Pressure Naturally

How to eat the superfood safely

Chia, the superseed du jour, is all the rage for its abundant fiber and plant-based protein and fat. But swallowing chia seeds, warns new research presented at the American College of Gastroenterology Annual Scientific Meeting, should also come with a note of caution.

That’s because the seeds can absorb 27 times their dry weight in water—expanding in size so much that the thickened, gel-like mass got lodged in a man’s esophagus, sending him to the ER. The 39-year-old man swallowed a tablespoon of dry chia seeds and then chased them with water. When he did, he discovered he couldn’t swallow any of his own saliva. The man had a history of intermittent dysphagia—or the sensation of things getting stuck as he’s swallowing them.

How could a seed so tiny actually cause a blockage? “It got to be this sort of almost Play-Doh-like consistency, very hard in terms of a liquid but also sort of soft,” says Dr. Rebecca Rawl, MD, the gastroenterology fellow at Carolinas HealthCare System who helped treat the patient. None of her regular tools worked at dislodging it, so using a tiny endoscope meant for babies, she broke of little chunks of chia until it got small enough to push the whole thing through. “It was labor intensive,” she says.

MORE: The Truth About 6 “Superfood” Seeds

Rawl has seen plenty of things get stuck in the esophagus, but the obstructions are usually meat: things like steak, chicken and hot dogs. “Generally, vegetative matter and seeds at least can get broken down and slide through,” Rawl says, and the chia case was the first she’s heard of. “The popularity of chia seeds is growing, and I think this will come up more frequently,” she says.

You don’t have to swear off the smoothie-enhancer for good: just let them expand fully in liquid before eating or drinking them, Rawl recommends.

New research presented at the European College of Neuropsychopharmacology Congress in Berlin sheds light on what happens in the brains of gamblers.

Pathological gambling is a difficult condition to classify. Though the Diagnostic and Statistical Manual of Mental Disorders (DSM) formerly classified it as an impulse control disorder, the most recent version, the DSM-5, made the switch to defining it as an addictive disorder because of the growing research finding that “gambling disorder is similar to substance-related disorders in clinical expression, brain origin, comorbidity, physiology, and treatment,” the DSM website says.

But this new small study shows that it might be unique in some neurologic ways, too. Researchers performed Positron Emission Tomography (PET) scans on 14 male pathological gamblers and 15 non-gambling volunteers to measure their levels of opioid receptors, the parts of the brain activated by pleasure-inducing endorphins. People with addictions like alcoholism or drug addiction have been found to have more opioid receptors. In problem gamblers, however, the researchers saw no difference from healthy volunteers, a finding that surprised them.

Then, participants took an amphetamine capsule, which unleashes endorphins with similar effects to the rush you get from exercise or alcohol, the study says. An additional PET scan revealed that pathological gamblers responded differently to the drug. They released fewer endorphins than those who didn’t gamble, and they also reported lower levels of euphoria on a questionnaire afterward. This might help explain the addictive part of pathological gambling: to get pleasure from the act, problem gamblers might need more of it or to work harder for it.

“These findings suggest the involvement of the opioid system in pathological gambling and that it may differ from addiction to substances such as alcohol,” says lead researcher Dr. Inge Mick of the Imperial College London in a press release. “We hope that in the long run this can help us to develop new approaches to treat pathological gambling.”

Changing your circadian clock messes with your microbes

Working the night shift has long been linked to an increased risk of obesity, heart attack and breast cancer. One 2011 study even showed that shift work lasting a decade or more boosts your risk for type-2 diabetes by 40%. And new study published in the journal Cell looked at why.

Researchers led by Eran Elinav, MD, PhD, senior scientist in the immunology department at the Weizmann Institute of Science in Israel, suspected the gut microbiome, which he calls “the neglected organ,” might be affected by a disrupted circadian rhythm. It wasn’t an obvious choice. Microbes hang out in the dark of our guts, so they’re never directly exposed to light and dark cycles, he says. That’s why it was surprising to find out that the microbiome is very much affected by disruptions to our bodies’ inner clocks.

Elinav started by making mice work the graveyard shift, subjecting them to a state that would be the equivalent of jet lag from an 8-hour time difference in humans. Mice are nocturnal, so in this case, they stayed awake during the day. “We saw that in the presence of jet lag, their microbes were completely messed up,” he says. The bugs changed in composition and function, losing their circadian rhythm and becoming far less efficient at tasks like cell growth, DNA repair and detoxification. Like humans, mice microbes perform housekeeping and repair functions while they sleep, and growth and energy-promoting functions when they’re awake. But in the study’s graph of these functions in jet-lagged mice, the tasks hardly vary throughout the day and are performed at much lower levels.

These mice were also more susceptible to obesity and diabetes, and when Elinav transferred their gut bacteria into sterile, germ-free mice, they also transferred the heightened risk for disease, “proving that it’s actually their microbes driving this susceptibility,” he says.

Such a theory is much harder to test in humans, of course, but Elinav studied two people traveling from the U.S. to Israel, which induced an 8-hour jet lag similar to the mice. He sampled their gut bacteria three times over two weeks, capturing the main stages of jet lag, and found that their microbes indeed changed in composition, and in ways that were startlingly similar. Elinav even transferred the humans’ jet-lagged bugs into germ-free mice. “We could very nicely see that transferring the gut microbes from the point where jet lag was at its highest induced much more obesity and glucose intolerance,” he says.

Thankfully, the gut microbes of the travelers had returned to normal two weeks after their flight, and transferring their bugs into mice no longer led to increased obesity and glucose intolerance. But the implications of the findings are troublesome for frequent travelers and especially shift workers, whose work demands a consistent disruption of circadian rhythms.

New rat research raises health questions for researcher

“Low T” therapy is a fast-growing trend for men who want to jack up testosterone—which declines naturally with age but which can also be clinically low in some people—and the testosterone therapy industry is predicted to reach $5 billion by 2017. The long-term safety effects of supplementing with the hormone is still in question, however—especially in light of a study earlier this year that found double the heart attack risk in certain men after starting testosterone treatments. Other research suggested there was no meaningful increase in heart risk, adding to the confusion. But a new rat study published in the journal Endocrinology raises some alarming questions about the increasingly popular drugs.

Maarten Bosland, PhD, study author and professor of pathology at the University of Illinois at Chicago’s College of Medicine, devised an animal model to test the tumor-promoting effects of testosterone in rats. He exposed a group of rats to a carcinogen, which would put them at risk of developing cancer. He also gave some of the rats testosterone, but no carcinogen. In a third group, he administered both the carcinogen and the testosterone. Then, he measured tumor growth among the two groups.

None of the rats developed prostate cancer when they were just exposed to the carcinogen, but 10-18% of them did when they were just given testosterone. When the rats were exposed to the carcinogen and then given testosterone—even at very low doses—50-71% developed prostate cancer. “I was totally amazed about how strong testosterone can work to promote the formation of prostate cancer in these animals,” he says.

Of course, an animal model can’t determine what will happen in men, but Bosland thinks a similar effect is possible. “Absent of having solid human studies, we won’t be able to say that—it’s just an extra warning signal,” he says. “But I think it’s a clear indication that there is risk.”

Black diabetics are much more likely to face amputation

Black type-2 diabetes patients are three times more likely to lose a leg to amputation as non-black patients, finds a new report from the Dartmouth Atlas Project. That’s partly because they’re also far less likely to get preventative care like foot exams, cholesterol testing and blood sugar testing.

Researchers looked at Medicare claims from 2007-2011 from patients diagnosed with diabetes and peripheral arterial disease, a condition in which plaque builds up in the arteries and blocks blood flow, primarily in the legs. They found significant disparities, both racial and regional: black patients and the rural Southeast region of the U.S. both saw elevated amputation rates.

Diabetes-related amputation, a last resort, generally results from wounds on the feet and poor circulation. Foot exams and testing for blood sugar and cholesterol levels can help lower the risk of having to resort to extreme measures. But in 2010, 75% of diagnosed black diabetics received a a blood lipids test, while 82% of non-black patients had the test.

An average of 2.4 leg amputations for every 1,000 Medicare patients with diabetes and peripheral arterial disease happen nationally, but regionally, the situation is much more grim. Mississippi, which currently ties West Virginia for the most obese state, also has some of the highest amputation rates—6.2 per 1,000 patients in the city of Tupelo. It’s not just racial: For every 1,000 black Medicare beneficiaries with diabetes, 14.2 amputations occurred in the Mississippi city of Meridian, but only 2.1 occurred among black patients in San Diego.

“The resources needed to prevent amputation are currently severely misaligned,” says co-author Philip Goodney, MD, director of the Center for the Evaluation of Surgical Care at Dartmouth Hitchcock Medical Center. “While we must look for opportunities to expand education and preventive care for all patients at risk for amputation, it seems clear to us that we can make the greatest gains by focusing on African-American patients in the highest risk regions, typically in the poor rural regions of the Southern United States, where the highest amputation rates remain.”