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FDA, Health Policy, Nutrition, Pediatrics, Public Health, Research, Stanford News

How much Bisphenol A is okay?

How much Bisphenol A is okay?


A new study came out this week that happened to remind me of one of my pet peeves about certain biomedical studies — choosing an “outcome” measure that doesn’t tell you what you really want to know. The study, which was led by Stanford postdoctoral fellow Jennifer Hartle, DrPH, and estimated the amount of BPA a child is exposed to in the course of a normal school day, was great. But her description of EPA safety tests on the plastics component Bisphenol A, or BPA — done back in the 1980s — made me think back to earlier work by University of California, Berkeley biologist Tyrone Hayes, PhD.

In the 1990s, the agricultural herbicide atrazine was safety tested by exposing frogs to low doses of atrazine as they developed from eggs to tadpoles to frogs. The adult frogs didn’t die or show obvious deformities such as extra legs, so the pesticide was deemed safe. But Hayes took a closer look and, in 2002, found that even at very low levels of atrazine exposure, male frogs were producing eggs instead of sperm.

So no gross deformities if you just looked at the frogs for 30 seconds. But in fact the animals had experienced a dramatic change in their health and biology. The lesson is that, in biology, sometimes the right outcome measure is something you have to really look for. There is a lot more to the Hayes-atrazine story.

But back to the current study: Hartle and her colleagues turned their attention to national school breakfast and lunch programs, which provide nutritious meals to 30 million kids every year but also deliver small amounts of BPA, an estrogen mimic that messes with hormones. Children’s meals are disproportionately packaged in tiny one-meal containers. Those tiny packages of apple sauce and juice have a greater BPA-emitting surface area than a big carton or can for the amount of food. And school kids often eat meals off plastic trays with plastic forks and spoons. For children who eat a lot of meals at school, it can add up.

According to Hartle’s paper, appearing today in the Journal of Exposure Science and Environmental Epidemiology, the question isn’t whether the kids are getting BPA in their meals — they are — but whether any of them are getting doses of BPA that could affect their long-term health. Based on those 1980s studies, the EPA estimates that BPA is safe at chronic exposure levels below 50 μg per kilogram of body weight per day. Happily, Hartle and her colleagues found that children are getting far less than that — as little as 0.0021 μg for a low-BPA breakfast to 0.17 μg for a high-BPA lunch. Everything should be hunky-dory, right?

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Autoimmune Disease, Chronic Disease, FDA, Immunology, Pediatrics, Research, Stanford News

Can a safe, cheap pill prevent type 1 diabetes?

Can a safe, cheap pill prevent type 1 diabetes?

happy pillType 1 diabetes, an autoimmune disorder once known as juvenile diabetes because it tends to strike during adolescence or earlier, affects one in every 300 people. With the diagnosis comes the certainty of a lifetime of insulin injections, made necessary due to the destruction of insulin-producing cells in the pancreas by a misguided immune system.

Insulin is a hormone that alerts the body to the presence of glucose in the blood, typically after a meal. In insulin’s absence, the body’s tissues fail to take up glucose, a key energy source. Without several-times-daily insulin shots, type 1 diabetes patients’ blood sugar levels can shoot up to dangerous heights – a condition called hyperglycemia.

There’s never been any way to prevent type 1 diabetes, although it can be predicted based on the detection of self-targeting antibodies in a blood test. But screening for type 1 diabetes this way hasn’t been particularly useful, because there’s been nothing to be done for patients diagnosed in the asymptomatic phase except wait for them to become hyperglycemic and put them on insulin.

Now, an elaborate mouse study by Stanford immunologist and structural biologist Paul Bollyky, MD, PhD, shows that it might be possible to intervene during the asymptomatic stage of type 1 diabetes – using a pharmaceutical compound that’s been on the global market for more than 40 years and has a terrific safety record – thereby stopping the immune system’s stupid but relentless destruction of the pancreas’s vital insulin-producing cells, and stave off hyperglycemia indefinitely.

Bollyky and his colleagues first showed that a particular substance, hyaluronan, builds up near insulin-producing cells in mice developing the murine equivalent of type 1 diabetes, confirming earlier findings in postmortem human pancreatic tissue that had been supplied to Bollyky’s team by the Juvenile Diabetes Research Foundation.

“We wondered what would happen if we prevented that buildup,” Bollyky told me when I interviewed him for my news release on the study. “And we knew a drug that does that.”

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FDA, Media, Research, Science Policy, Sexual Health, Women's Health

“A historic moment for women”: FDA approves the first drug to treat hypoactive sexual desire disorder

"A historic moment for women": FDA approves the first drug to treat hypoactive sexual desire disorder

20705116491_5351758c67_zRoughly 16 million women over the age of 50 suffer from low sex drive. Yet, until recently, there were no FDA-approved medications to treat the lack of sexual thoughts and desire experienced by women with hypoactive sexual desire disorder (HSDD).

That’s why the U.S. Food and Drug Administration’s recent approval of the drug flibanserin (sold under the brand name Addyi™) to treat women with HSDD, is such big news.

“It’s a historic moment for women,” said Leah Millheiser, MD, director of Stanford’s Female Sexual Medicine Program, in a story published today in the San Francisco Chronicle. HSDD, Millheiser explains, is more than the occasional loss of sexual desire that can result from changes in hormones, stress and discontent in a relationship. “These are women who want to have sex with their partner, they’re attracted to their partner and used to love having sex,” Millheiser said. “It’s as if someone turned off the lightbulb.”

It’s tempting to equate flibanserin to Viagra (the drug approved to treat erectile disfunction in men), but this is clinically inaccurate. As explained in the article, Viagra treats erectile dysfunction by increasing blood flow to the penis, while flibanserin works on the brain.

From the story:

The drug [flibanserin] was first developed as an antidepressant. Like other antidepressants, it works on the brain’s serotonin levels, but researchers say it works on different serotonin receptors than other similar antidepressants.

It didn’t work to relieve depression, as it turned out, but patients reported increased sexual desire.

In clinical trials, researchers said 53 percent of women who took the drug reported an increased desire for sex and 29 percent said the drug decreased their level of distress over their condition. In the trials, the number of “satisfying sexual events” reported by participants essentially doubled from an average of 2.5 per month before they received flibanserin to five while taking it.

Millheiser credits Viagra for helping to pave the way for this new approved treatment for HSDD.  “As a result of Viagra, there was an explosion in research and understanding into what sexual dysfunction is and how we treat it,” she said. “It took 17 years to … get to this day,” she said.

Previously: When hormonal issues interfere with mental healthFemale sexual health expert responds to delay in approval for “Viagra for women and Speaking up about female sexual dysfunction
Photo by Day Donaldson

FDA, Health and Fitness, In the News, Nutrition, Public Health

“They might be slightly healthier, but they’ll still be junk foods”: Expert comments on trans-fat ban

"They might be slightly healthier, but they'll still be junk foods": Expert comments on trans-fat ban

4345026096_35defbf6b0_zAs you’ve probably heard, the FDA ruled last week to ban trans-fats and phase them out of all food products over the next three years. This news has been widely covered, both heralded for its health implications and critiqued for being too long in coming. Yet either way, it is not a panacea, as Stanford Medicine professor Christopher Gardner, PhD, explained when he shared his opinion with me over the weekend:

The true impact of the FDA ban on trans-fats will not be known until we find out what substitutes the food industry finds, and what that does to the sale of junk food and the health of Americans in response to the switch. It could be beneficial. But it isn’t as if trans-fats will be gone and everyone will eat an extra two servings of vegetables in their place.

Gardner, who has spent the past 20 years researching the health benefits of various nutrition components, pointed out that “a lot of good people and excellent scientists worked on this for a long time” and “it took a great deal of effort to assemble the science to demonstrate that this is something so harmful in the American diet that it should be removed with an FDA ban.” He also offered more specifics on what food companies might do following the ban:

The companies making those products are unlikely to remove those junk food products entirely from the shelves of grocery stores across America. Instead, it is most likely that they will look for an alternate form of fat that will serve as closely as possible the same role that trans-fats served. Trans-fats act like saturated fats in terms of being solid rather than liquid at room temperature. This can help the icing on a cupcake stay solid, and it can give a “mouth feel” of solid fat that people like to taste in their food. The goal of the food industry will be to replace the trans-fat with another fat that is solid at room temperature, which likely means the replacement could very well be as bad as the trans fats themselves.

For example, palm oil or esterified stearic acid are likely to be options. For the palm oil, this will mean destruction of rain forests and biological diversity. For esterified stearic acid, this will mean another reason to grow more monocultures of soybeans from which to extract the oil. Both of these will likely have a negative environmental impact. There are likely other choices to consider.

After all this, will those junk foods now be health foods? Absolutely not. They might be slightly healthier junk foods, but still junk foods.

Previously: Want to curb junk food cravings? Get more sleep, Talking to kids about junk food ads, and Trans-fat still lurks in packaged foods
Photo by Kevin

FDA, In the News, Nutrition, Public Health

FDA changes regulation for antibiotic use in animals

FDA changes regulation for antibiotic use in animals

8756885685_0ebc1c75ce_zLivestock can no longer be fed antibiotics “preventatively” or to help them grow bigger. The FDA has ruled to change their regulations of how drugs can be administered to food animals, including those used to make animal feed.

After this ruling, livestock producers can only use antibiotics to treat animals that actually have an infection, and only under the supervision of a veterinarian. These new rules are aimed at decreasing the risk of developing drug-resistant bacteria, sometimes called “super bugs.” According to the Centers for Disease Control and Prevention, drug-resistant bacteria cause 2 million illnesses and about 23,000 deaths in the United States each year.

According to an article from The Hill, the Department of Health and Human Services is moving forward with new regulations for hospitals, and President Obama has called on government cafeterias to prioritize meat that has been raised with responsible antibiotic practices.

Previously: Paradox: Antibiotics may increase contagion among salmonella-infected animals, and Healthy gut bacteria help chicken producers avoid antibiotics
Photo by Chiot’s Run

Cancer, Dermatology, FDA, Health Policy, In the News, Public Health

Experts call on FDA for a “tanning prevention policy”

Experts call on FDA for a "tanning prevention policy"

6635416457_a62bfeb09d_zIndoor UV tanning beds are known carcinogens that are responsible for many cases of skin cancer, which is the most commonly diagnosed form of cancer in the U.S. A recently issued Call to Action to Prevent Skin Cancer from the U.S. Surgeon General states that “more than 400,000 cases of skin cancer [8% of the total], about 6,000 of which are melanomas, are estimated to be related to indoor tanning in the U.S. each year” while “nearly 1 out of every 3 young white women engages in indoor tanning each year,” making indoor tanning a serious public health issue.

In a JAMA opinion piece published yesterday, Darren Mays, PhD, MPH, from the Georgetown University Medical Center‘s Department of Oncology, and John Kraemer, JD, MPH, from Georgetown’s School of Nursing and Health Studies, argued that the FDA needs to step up its regulatory approach and restrict access to this technology – due to its limited therapeutic benefits and known damaging effects.

In 2011, California was the first state to ban access to indoor UV tanning beds to minors. The authors assert that “state-level policies restricting a minor’s access to indoor tanning devices are effectively reducing the prevalence of this cancer risk behavior among youth,” but argue that regulation at the federal level is in order:

Like tobacco products, a national regulatory framework designed to prevent and reduce indoor tanning could reduce public health burden and financial costs of skin cancer. …from a public health perspective the indoor tanning device regulations are not commensurate to those of other regulated products that are known carcinogens with very little or no therapeutic benefit.

However, the likelihood of this regulation taking place is questionable:

FDA did not leverage its authority last year to put a broader regulatory framework in place, which could have included a national minimum age requirement and stronger indoor tanning device warning labels… Critical factors seem to be aligning for such policy change to take place, but additional momentum is needed to promote change at a national scale. The US national political environment makes more expansive regulation by either FDA or Congress seem unlikely in the near future.

The authors concluded with a call for organizations other than governments to help build momentum on toward a “national indoor tanning prevention policy.” For example, they said, universities could implement “tan-free” campus policies similar to the “tobacco-free” campaign.

Previously: More evidence on the link between indoor tanning and cancers, Medical experts question the safety of spray-on tanning productsTime for teens to stop tanning?, Senator Ted Lieu weighs in on tanning bed legislation and A push to keep minors away from tanning beds
Photo by leyla.a

FDA, Medicine and Society, Men's Health, Research, Science, Women's Health

Sex matters: Why we shouldn’t conduct basic research without taking it into account

Sex matters: Why we shouldn't conduct basic research without taking it into account

2593063816_9a4eaba16e_zIn a PNAS opinion piece (.pdf) published last week, two Stanford faculty are among the authors arguing that sex shouldn’t be overlooked in basic research studies. Londa Schiebinger, PhD, director of the Gendered Innovations in Science, Health & Medicine, Engineering, and Environment program, and Marcia L. Stefanick, MD, director of the Stanford Center for Health Research on Women and Sex Differences in Medicine, take issue with the fact that much of the research that leads to drugs, devices, and our conclusions about biology comes from studies conducted on non-human animals and cell cultures without considering their sex.

Evolutionarily speaking, sex is one of the most well-conserved biological differences, of fundamental importance to 100 percent of the population. Paying more attention to it, the authors claim, would help biomedical research disaggregate data and explain heterogenous outcomes. While some think it would create unnecessary duplication to account for sex earlier in the research process, before drugs and treatments are tested on humans, the authors argue that such practices would save money and be more efficient in the long run. Early tests are far less expensive than removing something from the market because it has adverse effects on half the population. Moreover, preventing such adverse outcomes would keep people of both sexes safer and healthier.

The article states that the FDA is beginning to reconsider whether unisex dosing is accurate and safe for many drugs, and cites that “about 80% of rodent drug studies are conducted only on males, and 8 of 10 drugs withdrawn from the US market from 1997 to 2000 posed greater health risks for women than for men.”

Previously: Stanford professor encourages researchers to take gender into account, A look at NIH’s new rules for gender balance in biomedical studies and Why it’s critical to study the impact of gender differences on diseases and treatments
Photo by Rick Eh?

FDA, In the News, otolaryngology, Public Health, Science Policy

With e-cigarettes, tobacco isn’t the only danger

With e-cigarettes, tobacco isn't the only danger

20879247991_a1ef02a28e_zE-cigarettes are far from safe, Robert Jackler, MD, writes in a strongly worded op-ed that appeared over the weekend in the San Jose Mercury News.

Most at risk are teens and tweens, enticed by flavors ranging from cotton candy, gummy bear and root beer to peanut butter cookie. (An aside: Can you imagine a hardened, pack-a-day smoker deciding to curb his or her harmful habit by switching to cotton candy-flavored e-cigarettes?)

Interestingly, these flavors, which are thought to be safe in foods may be upping the harmfulness of the e-cigs; after all, the lungs process chemicals much differently than the stomach does. (Remember popcorn lung? In the early 2000’s, a group of workers at a microwave popcorn plant fell ill after inhaling too much of the flavoring agent, diacetyl, used to give popcorn its buttery taste.)

From Jackler’s piece:

In 2009, to reduce youth smoking, the FDA banned flavors (other than menthol) from traditional cigarettes. Fearing regulatory action, the e-cigarette industry response has echoed the playbook of the tobacco industry. One brand went so far as to commission a study which, not surprisingly, arrived at the improbable finding that flavors do not appeal to the young. The industry argues that flavored e-cigarettes should be allowed because they have not been proven unsafe.

Jackler goes on to warn of the progressive nature of lung damage — e-cigarette smokers may be accumulating harm well before they notice a problem.

Previously: Raising the age for tobacco access would benefit health, says new Institute of Medicine report, How e-cigarettes are sparking a new wave of tobacco marketing, E-cigarettes and the FDA: A conversation with a tobacco-marketing researcher and E-Cigarettes: The explosion of vaping is about to be regulated
Photo by Hachim.Pi

Applied Biotechnology, Clinical Trials, FDA, Research, Stanford News

An inside look at drug development

An inside look at drug development

B0008664 Assorted pills, tablets and capsules

How are drugs born? If you’re really curious about this, you’d be fascinated by the weekly meetings of industry experts and academic researchers taking part in Stanford’s drug-development training program known as SPARK.

A recently published book, A Practical Guide to Drug Development in Academia, crystallizes the sessions. Even if you’re not a scientist dreaming of curing cancer with your latest discovery, you might find it interesting.

In his recent review of the book for Nature Chemical Biology, industrial medicinal chemist Derek Lowe, PhD, writes:

I would actually welcome it if this book’s intended audience were broadened even more. Younger scientists starting out in the drug industry would benefit from reading it and getting some early exposure to parts of the process that they’ll eventually have to understand. Journalists covering the industry (especially the small startup companies) will find this book a good reality check for many an over-hopeful press release. Even advanced investors who might want to know what really happens in the labs will find information here that might otherwise be difficult to track down in such a concentrated form.

Lowe also wrote about the book last week on his blog, In the Pipeline, where an interesting discussion has begun.

Previously: SPARK program helps researchers cross the “valley of death” between drug discovery and development and Accelerating the translation of biomedical research into clinical applications.
Photograph from Wellcome Images

Addiction, FDA, Health Policy, Pediatrics, Public Health

Raising the age for tobacco access would benefit health, says new Institute of Medicine report

Raising the age for tobacco access would benefit health, says new Institute of Medicine report

cigarette packToday, the Institute of Medicine released a new report evaluating the public health effects of reducing teenagers’ access to cigarettes and other tobacco products. Right now, in most places in the United States, you must be 18 years old to buy cigarettes and other tobacco products. But a few states and cities have higher minimums, and in 2013, the IOM convened a committee, at the request of the U.S. Food and Drug Administration, to examine the potential effects of a higher minimum legal age for tobacco access across the country.

The committee, which was led by Richard Bonnie of the University of Virginia and included Stanford adolescent medicine expert Bonnie Halpern-Felsher, PhD, reviewed the existing scientific literature on tobacco use in teens. They also devised mathematical models to predict what would happen if the federal minimum legal age were 19, 21 or 25.

The report brief (.pdf) says, in part:

Based on its review of the literature, the committee concludes that overall, increasing the MLA [minimum legal age] for tobacco products will likely prevent or delay  initiation of tobacco use by adolescents and young adults. The age group most impacted will be those age 15 to 17 years. The committee also concludes that the impact of raising the MLA to 21 will likely be substantially higher than raising it to 19. However, the added effect of raising the MLA from 21  to 25 will likely be considerably less.

The parts of the brain most responsible for decision making, impulse control, sensation seeking, and susceptibility to peer pressure  continue to develop and change through young adulthood, and adolescent brains are uniquely vulnerable to the effects of nicotine. In  addition, the majority of underage users rely on social sources—like family and friends—to get tobacco. Raising the MLA to 19 will therefore not have much of an effect on reducing the social sources of those in high school. Raising the MLA to 21 will mean that those who can legally obtain tobacco are less likely to be in the same social networks as high school students.

Although it can take time to fully realize the benefits of reduced smoking, since heart disease, lung cancer and other diseases linked to smoking take decades to develop, the payoff would ultimately be significant, the report adds:

…if the MLA were raised now to 21 nationwide, there would be approximately 223,000 fewer premature deaths, 50,000 fewer deaths from lung  cancer, and 4.2 million fewer years of life lost for those born between 2000 and 2019.

Previously: How e-cigarettes are sparking a new wave of tobacco marketing, To protect teens’ health, marijuana should not be legalized, says American Academy of Pediatrics and UN’s top health official: Anti-tobacco efforts can lead to better health “in every corner of the world”
Photo by Thomas Lieser

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