Compared to normal-length pregnancies, pregnancies that go on too long carry a slightly greater risk of fetal death at or near the time of birth. For that reason, physicians sometimes recommend that labor be induced when a pregnancy has gone on longer than normal. But induction of labor may also entail a small risk, especially if there is no sign of impending spontaneous labor. Which is the lesser risk?
To find out, researchers combed all the available data from previous studies of inducing, or not inducing, labor after unusually long gestation (usually 41 weeks). In all, they reviewed 30 studies involving a total of over 12,000 women in 14 countries.
The results? Inducing labor after 41 weeks resulted in fewer infant deaths. It also resulted in fewer caesarean deliveries, though on the other hand it did result in more assisted (operative) vaginal births. All in all, induction of labor after 41 weeks of gestation appeared to be a good choice. However, it was not determined in this study whether there is an optimal time of induction - should it be at 41 weeks, or 42, or even 43?
Based on this analysis, women who experience an extra-long gestation can safely consider induction of labor as an option.
Wednesday, June 20, 2018
Wednesday, June 13, 2018
Cinnamon-Flavored e-Cigarettes May Pose a Health Risk
The naturally occurring organic compound that gives cinnamon its characteristic flavor and odor is called cinnamaldehyde. It's approved by the FDA as a food additive and is considered to be completely safe in foods. More recently, it's also been used as a flavoring in e-cigarettes, but that just may be a problem. Recent preliminary research suggests that cinnamaldehyde may be harmful when inhaled, according to a report in HealthDay.
In the research, which must be considered preliminary because it has not yet been published in a peer-reviewed journal, human lung cells in cell cultures showed reduced cilia activity when exposed to cinnamaldehyde either in e-liquids and e-liquid vapors. In intact humans, lung cell cilia are responsible for helping to clear the lungs of mucus, dust, and bacteria. If cinnamaldehyde affects the activity of lung cell cilia in intact lungs the same way as it does in cell cultures, it's just possible that it could increase the risk of lung infections.
To be clear, though, an increased risk to your health of vaping cinnamon-flavored e-cigarettes has not yet been proven. So YOU have to decide whether the potential of risk is worth it, if you're ever choosing e-cigarette flavors.
In the research, which must be considered preliminary because it has not yet been published in a peer-reviewed journal, human lung cells in cell cultures showed reduced cilia activity when exposed to cinnamaldehyde either in e-liquids and e-liquid vapors. In intact humans, lung cell cilia are responsible for helping to clear the lungs of mucus, dust, and bacteria. If cinnamaldehyde affects the activity of lung cell cilia in intact lungs the same way as it does in cell cultures, it's just possible that it could increase the risk of lung infections.
To be clear, though, an increased risk to your health of vaping cinnamon-flavored e-cigarettes has not yet been proven. So YOU have to decide whether the potential of risk is worth it, if you're ever choosing e-cigarette flavors.
Tuesday, June 5, 2018
Not All Women With Breast Cancer Will Need Chemotherapy
Nearly 60,000 women a year will benefit from a recent study which shows that not all women with breast cancer should undergo chemotherapy, according to an article in the New York Times. The women who don't benefit from chemotherapy are a subset of women with breast cancer who: 1) are in the early stages of breast cancer, 2) are sensitive to estrogen, 3) test positive for a protein called HER2, and most importantly, 4) have a mid-range score on a genetic test that looks for various genes involved in cancer recurrence. The genetic test, which is now widely available, costs about $3,000.
Cancer is complicated. The newest findings are part of an ongoing effort to fine-tune cancer treatment to each patient's specific situation, so that the patient receives the very best treatment while reducing the risks associated with unnecessary chemotherapy.
Cancer is complicated. The newest findings are part of an ongoing effort to fine-tune cancer treatment to each patient's specific situation, so that the patient receives the very best treatment while reducing the risks associated with unnecessary chemotherapy.
Wednesday, May 23, 2018
California's Death With Dignity Law is Declared Unconstitutional
In 2015, California became the fourth state to pass legislation designed to allow terminally ill patients to end their own life under certain prescribed conditions (see this blog, Sept 17, 2015). The law, called the End of Life Option Act, has always been somewhat controversial. And last week, opponents of the law won a battle in court when a Superior court judge declared the law unconstitutional, according to an article in the LA Times.
On what grounds is the law unconstitutional, you might ask? It turns out that the judge's decision had nothing to do with the law itself; his decision was based solely on the fact that the law was passed during a special session of the legislature devoted solely to health care issues. The judge declared that the law was not a health care issue, and so it was unconstitutional to pass it during the special legislative session.
Really? Not a health care issue when a terminally ill patient is in excruciating pain? California's Attorney General has already filed an appeal to the judge's ruling with the 4th District Court of Appeal. He's also asked that the law stay in place while the matter is under appeal.
The matter could end up with the Supreme Court. Or, the law might need to be considered all over again in a regular session of the legislature.
On what grounds is the law unconstitutional, you might ask? It turns out that the judge's decision had nothing to do with the law itself; his decision was based solely on the fact that the law was passed during a special session of the legislature devoted solely to health care issues. The judge declared that the law was not a health care issue, and so it was unconstitutional to pass it during the special legislative session.
Really? Not a health care issue when a terminally ill patient is in excruciating pain? California's Attorney General has already filed an appeal to the judge's ruling with the 4th District Court of Appeal. He's also asked that the law stay in place while the matter is under appeal.
The matter could end up with the Supreme Court. Or, the law might need to be considered all over again in a regular session of the legislature.
Monday, May 21, 2018
Ebola Outbreak Spreads to a Nearby City
Health officials at the World Health Organization (WHO) reported this week that the most recent Ebola outbreak, which began in a remote village of the Democratic Republic of the Congo (see this blog, May 12, 2018), has spread to a nearby city of over a million people. Only one case of Ebola has been reported in the city so far, but the fear is that the outbreak could spread more quickly now, making containment more difficult. In a city, tracking down and potentially vaccinating every individual who has been exposed to a patient becomes much more difficult.
Keep your fingers crossed. We'll be watching this outbreak closely.
Keep your fingers crossed. We'll be watching this outbreak closely.
Sunday, May 13, 2018
How DNA Analysis Led to the Golden State Killer
More than 30 years after his last crime, a suspect has finally been arrested in the infamous Golden State Killer case. The suspect, a 76-year-old former police officer named Joseph DeAngelo, is believed to have committed over 50 rapes and 12 murders in California between 1976 and 1986. How did police solve a crime spree that ended more than 30 years ago? (Drum roll, please.....) DNA analysis, that's how!
It turns out that police had DNA samples from the Golden State Killer, collected from several of his crimes many years ago. But they had no suspects to try to match them to. Companies like 23andMe have lots of DNA samples, but they are not searchable by the public or the police. However, there's a small company called GEDmatch that analyzes DNA samples and makes them available for free for research purposes. Police detectives searched the GEDmatch database recently, and identified a DNA sample that was close enough to the killer's DNA that it had to belong to a relative (for more on how that works, see this article). Studying that person's family tree led them to Joseph DeAngelo as a possible suspect in the Golden State Killer case.
To find out for sure, the police covertly collected a DNA sample from Mr. DeAngelo (it wouldn't be hard to do - we discard DNA every day on coffee cups and soda cans, for example). It was a match to the killer's DNA samples that they'd had on file for 30 years!
Case closed, finally.
It turns out that police had DNA samples from the Golden State Killer, collected from several of his crimes many years ago. But they had no suspects to try to match them to. Companies like 23andMe have lots of DNA samples, but they are not searchable by the public or the police. However, there's a small company called GEDmatch that analyzes DNA samples and makes them available for free for research purposes. Police detectives searched the GEDmatch database recently, and identified a DNA sample that was close enough to the killer's DNA that it had to belong to a relative (for more on how that works, see this article). Studying that person's family tree led them to Joseph DeAngelo as a possible suspect in the Golden State Killer case.
To find out for sure, the police covertly collected a DNA sample from Mr. DeAngelo (it wouldn't be hard to do - we discard DNA every day on coffee cups and soda cans, for example). It was a match to the killer's DNA samples that they'd had on file for 30 years!
Case closed, finally.
Saturday, May 12, 2018
Another Outbreak of Ebola
The Ebola virus that killed more than 11,000 people in four African countries in 2014-2015 has broken out again - this time in a remote village in the Democratic Republic of Congo. So far, 17 people have died from the newest outbreak, including one nurse who was caring for victims.
The 2014-2015 outbreak was so deadly because the countries involved and various medical aid agencies were slow to respond. This time around, health officials are taking no chances. The World Health Organization is mobilizing a rapid response force that includes medical experts, equipment, and medical supplies, including a new Ebola vaccine. The affected area is just three hours away by road from a city of over a million people. If the virus reaches the city, containment of the outbreak could become much more difficult.
From past experience, health officials believe that by attacking viral disease outbreaks early and hitting them hard, outbreaks can be stopped in their tracks before they can spread very far. It worked (minus the new vaccine) in stopping a previous Ebola outbreak in the Democratic Republic of Congo in 2017. Let's hope it works again.
The 2014-2015 outbreak was so deadly because the countries involved and various medical aid agencies were slow to respond. This time around, health officials are taking no chances. The World Health Organization is mobilizing a rapid response force that includes medical experts, equipment, and medical supplies, including a new Ebola vaccine. The affected area is just three hours away by road from a city of over a million people. If the virus reaches the city, containment of the outbreak could become much more difficult.
From past experience, health officials believe that by attacking viral disease outbreaks early and hitting them hard, outbreaks can be stopped in their tracks before they can spread very far. It worked (minus the new vaccine) in stopping a previous Ebola outbreak in the Democratic Republic of Congo in 2017. Let's hope it works again.
Sunday, May 6, 2018
Testing Zika Vaccines
Here's a question for you. Suppose that you had been working on a vaccine for the Zika virus, and now you have what you think might be a good one. How are you going to prove its safety and effectiveness?
Testing your vaccine for safety would be relatively easy; you'd give it to just a few people at first, and then to dozens, then hundreds of volunteers until you could prove that it was free of dangerous side-effects. But the real difficulty would be to prove that it is effective; that is, that it actually would prevent a Zika virus infection. Zika infections are relatively rare, even in Zika-infections regions. And you can't just test the vaccine on the persons who do become infected; vaccines have to be given before an infection occurs, not after.
So here are your options: 1) Administer the vaccine (or a placebo) to tens or even hundreds of thousands of healthy people in a Zika-infected region, so that just by chance you will have vaccinated a few people who will contact Zika at some time in the future, and then wait, or 2) administer the vaccine (or a placebo) to perhaps a few hundred volunteers and then deliberately infect them with the Zika virus.
Because Zika infections are relatively rare, the first approach is likely to be prohibitively expensive, time-consuming, and might never achieve the desired result. That's why researchers are proposing the second approach; deliberately infecting vaccinated and unvaccinated volunteers with Zika. The researchers argue that a Zika infection, like the flu or a cold, is a relatively minor illness for an adult. The real danger is to a woman who is pregnant, because a Zika infection during pregnancy can lead to serious birth defects in an infant. For that reason, the researchers say that any women in the proposed study would have to agree to avoid pregnancy for the duration of the study.
Still, some ethicists are queasy about the proposed study. Accidents (including unplanned pregnancies) happen. And this study would be of no benefit whatsoever to the persons who would choose to volunteer; they'd have to be doing it solely out of altruism.
What do YOU think?
Testing your vaccine for safety would be relatively easy; you'd give it to just a few people at first, and then to dozens, then hundreds of volunteers until you could prove that it was free of dangerous side-effects. But the real difficulty would be to prove that it is effective; that is, that it actually would prevent a Zika virus infection. Zika infections are relatively rare, even in Zika-infections regions. And you can't just test the vaccine on the persons who do become infected; vaccines have to be given before an infection occurs, not after.
So here are your options: 1) Administer the vaccine (or a placebo) to tens or even hundreds of thousands of healthy people in a Zika-infected region, so that just by chance you will have vaccinated a few people who will contact Zika at some time in the future, and then wait, or 2) administer the vaccine (or a placebo) to perhaps a few hundred volunteers and then deliberately infect them with the Zika virus.
Because Zika infections are relatively rare, the first approach is likely to be prohibitively expensive, time-consuming, and might never achieve the desired result. That's why researchers are proposing the second approach; deliberately infecting vaccinated and unvaccinated volunteers with Zika. The researchers argue that a Zika infection, like the flu or a cold, is a relatively minor illness for an adult. The real danger is to a woman who is pregnant, because a Zika infection during pregnancy can lead to serious birth defects in an infant. For that reason, the researchers say that any women in the proposed study would have to agree to avoid pregnancy for the duration of the study.
Still, some ethicists are queasy about the proposed study. Accidents (including unplanned pregnancies) happen. And this study would be of no benefit whatsoever to the persons who would choose to volunteer; they'd have to be doing it solely out of altruism.
What do YOU think?
Saturday, May 5, 2018
Hawaii Passes a Death With Dignity Law
Hawaii becomes the sixth state (plus Wash. D.C.) to pass a Death With Dignity law, permitting terminally ill persons to choose to end their own life in certain situations. Like the laws in other states, Hawaii's law requires agreement of two doctors that the patient is mentally sound and has less than six months to live. If such conditions are met, the patient is prescribed a lethal dose of a medication (usually a powerful barbiturate) that they may use (or not) at their own discretion.
Death With Dignity laws continue to gain traction. One reason is that both a majority of Americans and a majority of doctors now support them. High-profile cases such as that of Brittany Maynard (see Johnson's Human Biology; Concepts and Current Issues, 8e. p. 480) have kept end-of-life issues in the public eye. And it helps that there has been no evidence of misuse or abuse of such laws in the first few states that passed them.
The number of people who choose to take advantage of Death With Dignity laws remains small. In Oregon, which has had a Death With Dignity law since 1997, only 218 people requested lethal prescriptions in 2017 and only 143 people used their prescriptions to end their lives. Most were cancer patients over the age of 65.
Death With Dignity laws continue to gain traction. One reason is that both a majority of Americans and a majority of doctors now support them. High-profile cases such as that of Brittany Maynard (see Johnson's Human Biology; Concepts and Current Issues, 8e. p. 480) have kept end-of-life issues in the public eye. And it helps that there has been no evidence of misuse or abuse of such laws in the first few states that passed them.
The number of people who choose to take advantage of Death With Dignity laws remains small. In Oregon, which has had a Death With Dignity law since 1997, only 218 people requested lethal prescriptions in 2017 and only 143 people used their prescriptions to end their lives. Most were cancer patients over the age of 65.
Thursday, April 26, 2018
The FDA Tackles the Marketing of e-Cigarettes to Youths
The FDA announced this week that it is initiating a multi-pronged approach to try to curb the illegal sales of e-cigarettes to underage youths. That includes Juul, a vaping product popular with teens that looks like a flash drive (see this blog Apr. 14, 2018).
The FDA's current multi-pronged approach includes; 1) Identifying retailers that are selling e-cigarettes to minors and sending them warning letters, 2) working with e-bay to remove listings for Juul on its website, and 3) working to hold manufacturers of Juul and other e-cigarettes accountable for how their products are marketed and used.
Publicly, at least, Juul claims it is opposed to the use of its products by minors. But that claim is hard to square with Jull's youth-friendly product design and the kinds of flavors that the nicotine-containing "pods" come in.
It will be hard to curtail what many people might see as a relatively minor crime. We'll see how far the FDA gets with this.
The FDA's current multi-pronged approach includes; 1) Identifying retailers that are selling e-cigarettes to minors and sending them warning letters, 2) working with e-bay to remove listings for Juul on its website, and 3) working to hold manufacturers of Juul and other e-cigarettes accountable for how their products are marketed and used.
Publicly, at least, Juul claims it is opposed to the use of its products by minors. But that claim is hard to square with Jull's youth-friendly product design and the kinds of flavors that the nicotine-containing "pods" come in.
It will be hard to curtail what many people might see as a relatively minor crime. We'll see how far the FDA gets with this.
Wednesday, April 25, 2018
First FDA-Approved Drug Derived from Marijuana
An FDA advisory committee has recommended the approval of a new drug, called Epidiolex, for the treatment of several types of epilepsy in children . If the FDA accepts the recommendation, Epidiolex will be the first FDA-approved drug to contain cannabidiol (CBD), a non-psychoactive substance purified from marijuana (cannabis).
Following the discovery that CBD had certain medical benefits, a number of states (30 at last count) legalized marijuana for certain medical purposes. Several other states legalized just the CDB extract. Relatively pure CBD is now widely sold over the internet for a host of medical and quasi-medical conditions, including as a sleep aid, an anti-anxiety treatment, an anxiety reliever, and even as a cure for certain types of cancer. But while some of these alleged benefits of CBD may be true, none has been proven by rigorous scientific studies. In addition, the purity and consistency of non-FDA-approved drugs sold over the internet can be suspect.
What makes Epidiolex different is that its developer and manufacturer has gone through the necessary testing to prove its medical efficacy. As a result, Epidiolex is poised to receive FDA approval for the treatment of two rare types of epileptic seizures. A distinct advantage of FDA approval is that patients with the forms of epilepsy targeted by the drug can be assured of the drug's purity and consistency of dose from one prescription to the next, because the drug will be produced according to best pharmaceutical practices.
With further testing, the FDA could expand the approved use of CBD to include other medical conditions. In the meantime (even if the FDA does eventually approve CBD, or even marijuana, for other uses), I doubt that marijuana-users will give up their favorite form of self-medication.
Following the discovery that CBD had certain medical benefits, a number of states (30 at last count) legalized marijuana for certain medical purposes. Several other states legalized just the CDB extract. Relatively pure CBD is now widely sold over the internet for a host of medical and quasi-medical conditions, including as a sleep aid, an anti-anxiety treatment, an anxiety reliever, and even as a cure for certain types of cancer. But while some of these alleged benefits of CBD may be true, none has been proven by rigorous scientific studies. In addition, the purity and consistency of non-FDA-approved drugs sold over the internet can be suspect.
What makes Epidiolex different is that its developer and manufacturer has gone through the necessary testing to prove its medical efficacy. As a result, Epidiolex is poised to receive FDA approval for the treatment of two rare types of epileptic seizures. A distinct advantage of FDA approval is that patients with the forms of epilepsy targeted by the drug can be assured of the drug's purity and consistency of dose from one prescription to the next, because the drug will be produced according to best pharmaceutical practices.
With further testing, the FDA could expand the approved use of CBD to include other medical conditions. In the meantime (even if the FDA does eventually approve CBD, or even marijuana, for other uses), I doubt that marijuana-users will give up their favorite form of self-medication.
Saturday, April 14, 2018
Juul Vaping Product Appeals to Minors
The latest fad among teenagers: Juul, a nicotine-containing vaping product that looks like a flash drive. Teachers report that some students take them to school and have been caught smoking them in class.
Juul cannnot be sold legally to persons under the age of 21. Juul is intended for adults who want curb their smoking habit, according to Juulvapor.com. But if that's so, why did they design the device to look like a flash drive? One has to believe that there is a reason for their strange design choice. And why sell nicotine-containing "Juulpods" in flavors that appeal to kids, such as mango and fruit medley?
Aftermarket sellers of Jull-compatible pods containing nicotine were quick to see the kids potential in Juul; they now sell pods in flavors such as strawberry, blueberry, and watermelon. Does anyone really believe that this product was designed solely for adults?
Juul cannnot be sold legally to persons under the age of 21. Juul is intended for adults who want curb their smoking habit, according to Juulvapor.com. But if that's so, why did they design the device to look like a flash drive? One has to believe that there is a reason for their strange design choice. And why sell nicotine-containing "Juulpods" in flavors that appeal to kids, such as mango and fruit medley?
Aftermarket sellers of Jull-compatible pods containing nicotine were quick to see the kids potential in Juul; they now sell pods in flavors such as strawberry, blueberry, and watermelon. Does anyone really believe that this product was designed solely for adults?
Tuesday, April 10, 2018
Non-Antibiotic Drugs May Contribute to Antibiotic Resistance
We've discussed on this site a number of times the role that antibiotics play in the development of antibiotic resistance. But it turns out that that's just the half of it; new research shows that some non-antibiotic drugs, including painkillers, antipsychotics, and drugs to combat high blood pressure, can also contribute to antibiotic resistance.
These findings are going to make efforts to combat antibiotic resistance harder than previously thought. Many drugs, such as those to combat high blood pressure, are meant to be taken for the rest of the patient's life; one can't just stop taking them because they may affect the bacteria in your gut. What to do?
If there is any good news in this latest research, it is that the tests revealed that a few drugs used to treat other diseases actually turned out to have some antibiotic activity as well, according to an article in the popular press on the subject. Perhaps some of these drugs could be tested further and then used to combat the increasing number of antibiotic resistant bacteria. But it's a long shot.
These findings are going to make efforts to combat antibiotic resistance harder than previously thought. Many drugs, such as those to combat high blood pressure, are meant to be taken for the rest of the patient's life; one can't just stop taking them because they may affect the bacteria in your gut. What to do?
If there is any good news in this latest research, it is that the tests revealed that a few drugs used to treat other diseases actually turned out to have some antibiotic activity as well, according to an article in the popular press on the subject. Perhaps some of these drugs could be tested further and then used to combat the increasing number of antibiotic resistant bacteria. But it's a long shot.
Thursday, April 5, 2018
A Cancer Warning on Coffee?
Responding to a lawsuit from a non-profit toxic chemicals watchdog group, a superior court judge in California has issued a preliminary judgment that may ultimately require coffee roasters and sellers to post warnings that coffee may pose a cancer risk. How did it come to this?
Well, it turns out that during the coffee roasting process, a miniscule amount of a chemical called acrylamide is created. Acrylamide is on California's list of cancer-causing or toxic chemicals. And back in 1986, California voters passed Proposition 65, a law requiring businesses and sellers to inform consumers about any possible exposure to toxic or cancer-causing agents in their products. An exception to this requirement can be granted only if the seller can prove that the exposure (in this case, to coffee) poses "no significant risk". But how would Starbucks, for example, ever be able to prove a negative (a complete lack of risk, over a lifetime)? Do you think Starbucks is up to that task?
It's true that there's acrylamide in coffee, but the levels are orders of magnitude below levels that have ever been shown to be a risk factor for cancer. So is the judge's ruling an example of regulatory overreach? Is Proposition 65 functioning as intended? Where do we draw the line between protecting the public and scaring them needlessly? For more on this controversy, read an article by NPR here.
What do you think?
Well, it turns out that during the coffee roasting process, a miniscule amount of a chemical called acrylamide is created. Acrylamide is on California's list of cancer-causing or toxic chemicals. And back in 1986, California voters passed Proposition 65, a law requiring businesses and sellers to inform consumers about any possible exposure to toxic or cancer-causing agents in their products. An exception to this requirement can be granted only if the seller can prove that the exposure (in this case, to coffee) poses "no significant risk". But how would Starbucks, for example, ever be able to prove a negative (a complete lack of risk, over a lifetime)? Do you think Starbucks is up to that task?
It's true that there's acrylamide in coffee, but the levels are orders of magnitude below levels that have ever been shown to be a risk factor for cancer. So is the judge's ruling an example of regulatory overreach? Is Proposition 65 functioning as intended? Where do we draw the line between protecting the public and scaring them needlessly? For more on this controversy, read an article by NPR here.
What do you think?
Thursday, March 29, 2018
Fitness and Dementia
More than 5 million people in the U.S. are living with Alzheimer's disease, the most common form of dementia. There is no cure or prevention for Alzheimer's disease, despite all the research into its causes.
Now a new study spanning 46 years offers some tantalizing clues. Way back in 1968, researchers in Sweden enrolled 191 women 38-60 years old into a study of cardiovascular fitness, as measured by their capacity to exercise on a bicycle until they became so fatigued that they had to stop. Based on their workload achieved, they separated the women into "low", "medium" and "high" fitness groups. Then they followed the women for the next 44 years, looking for signs of dementia, among other health issues. Surprisingly, they found that compared to the "medium" fitness group, those in the "high" fitness group were 88% less likely to develop dementia. Among those who did develop dementia, high fitness delayed the time to onset of dementia by 5 years, compared to the medium fitness group.
A word of caution; these results show a correlation only; they do not prove that high fitness per se is what is reducing the risk of dementia. Perhaps the high fitness group also has a better diet, or just better genetics to begin with. Nevertheless, the results are intriguing, and may point the way to additional research to tease out the actual cause. Anything we can do to solve this baffling and debilitating disease would be welcome.
Now a new study spanning 46 years offers some tantalizing clues. Way back in 1968, researchers in Sweden enrolled 191 women 38-60 years old into a study of cardiovascular fitness, as measured by their capacity to exercise on a bicycle until they became so fatigued that they had to stop. Based on their workload achieved, they separated the women into "low", "medium" and "high" fitness groups. Then they followed the women for the next 44 years, looking for signs of dementia, among other health issues. Surprisingly, they found that compared to the "medium" fitness group, those in the "high" fitness group were 88% less likely to develop dementia. Among those who did develop dementia, high fitness delayed the time to onset of dementia by 5 years, compared to the medium fitness group.
A word of caution; these results show a correlation only; they do not prove that high fitness per se is what is reducing the risk of dementia. Perhaps the high fitness group also has a better diet, or just better genetics to begin with. Nevertheless, the results are intriguing, and may point the way to additional research to tease out the actual cause. Anything we can do to solve this baffling and debilitating disease would be welcome.
Sunday, March 25, 2018
The Origin of Sickle Cell Trait
Tens of millions of people have a genetic mutation in a single allele (one of a pair of genes) that by itself has no outward effect on the person's health, called sickle cell trait. Unfortunately, persons who inherit two copies of the allele (one from each parent) suffers from sickle cell disease, a debilitating condition in which red blood cells cab change shape, or sickle, impeding blood flow and damaging organs.
Typically, a genetic mutation that leads to health problems would be selected against over time by normal evolutionary processes. However, that's not the case for sickle cell trait, because it turns out that inheriting just one copy of the abnormal gene is protective against another disease, malaria. As a result the abnormal gene is selected for, not against, by evolutionary processes, especially in places such as Africa where malaria is common.
But where and when did the mutation arise? The genetic mutation comes in five different haplotypes, or forms, leading some scientists to speculate that the mutation arose independently perhaps as many as five different times. Others have suggested that it arose just once.
In attempt to resolve the dispute, researchers recently studied the genomes of nearly 3,000 people. 156 of them had the mutated gene for sickle cell trait. On close examination of their genomes (the details are beyond the scope of this blog), the researchers concluded that all 156 people had inherited the mutated allele from a single person who lived around 7,300 years ago. That person probably lived in western or central Africa. Case closed, it seems.
Typically, a genetic mutation that leads to health problems would be selected against over time by normal evolutionary processes. However, that's not the case for sickle cell trait, because it turns out that inheriting just one copy of the abnormal gene is protective against another disease, malaria. As a result the abnormal gene is selected for, not against, by evolutionary processes, especially in places such as Africa where malaria is common.
But where and when did the mutation arise? The genetic mutation comes in five different haplotypes, or forms, leading some scientists to speculate that the mutation arose independently perhaps as many as five different times. Others have suggested that it arose just once.
In attempt to resolve the dispute, researchers recently studied the genomes of nearly 3,000 people. 156 of them had the mutated gene for sickle cell trait. On close examination of their genomes (the details are beyond the scope of this blog), the researchers concluded that all 156 people had inherited the mutated allele from a single person who lived around 7,300 years ago. That person probably lived in western or central Africa. Case closed, it seems.
Thursday, March 22, 2018
Rates of STD Infection in the U.S. Continue to Rise
The rates of infection of most STDs rose again in 2016, according to the CDC. Compared to 2015, chlamydia infections were up 4.7%, syphilis infections increased 17.6%, and gonorrhea was up by 18.5%. The increases are part of a trend that started about a decade or so ago.
The only good news is that rates of HIV infection have been trending slightly downward over the past five years. Compared to 2015, the rate of HIV infection declined by 0.1% in 2016.
The dramatic increases in syphilis and gonorrhea infections in 2016 are cause for concern, of course. Sexually active individuals should be aware of these trends and seek to protect themselves accordingly.
The only good news is that rates of HIV infection have been trending slightly downward over the past five years. Compared to 2015, the rate of HIV infection declined by 0.1% in 2016.
The dramatic increases in syphilis and gonorrhea infections in 2016 are cause for concern, of course. Sexually active individuals should be aware of these trends and seek to protect themselves accordingly.
Wednesday, March 21, 2018
Exercise Can Turn Back Time on a Middle-Aged Heart
So... you didn't take care of your body when you were young, and now at middle age you're feeling out of shape and over the hill. You're motivated to make a lifestyle change if it would help, but will it actually do any good at this point?
The good news is that perhaps it will. According to a report in Circulation, just two years of high-intensity exercise improves heart health. In the study, sedentary middle-aged men (mean age 53 years) participated in either a moderate to high intensity aerobic exercise program for two years (the experimental group), or only non-aerobic exercise such as yoga or balance training (the control group). At the end of two years, those who had exercised showed signs of improved heart health, including improved oxygen uptake and a reduced stiffness of the left ventricle. It's as if the clock was turned back on the heart aging process.
Middle age may be the last time that one can improve heart function, however. According to an NPR article, the same improvement is not possible by the time one reaches seventy years of age. The time to get moving is now, not later.
The good news is that perhaps it will. According to a report in Circulation, just two years of high-intensity exercise improves heart health. In the study, sedentary middle-aged men (mean age 53 years) participated in either a moderate to high intensity aerobic exercise program for two years (the experimental group), or only non-aerobic exercise such as yoga or balance training (the control group). At the end of two years, those who had exercised showed signs of improved heart health, including improved oxygen uptake and a reduced stiffness of the left ventricle. It's as if the clock was turned back on the heart aging process.
Middle age may be the last time that one can improve heart function, however. According to an NPR article, the same improvement is not possible by the time one reaches seventy years of age. The time to get moving is now, not later.
Tuesday, March 20, 2018
Herbicides Can Alter the Nutritional Content of Food Crops
Herbicides are widely used commercially to improve crop yields and to reduce the need for hoeing and weeding. But do herbicides affect the nutritional content of food crops? Are organic foods nutritionally different from non-organic foods, and if so, are they better for you? Surprisingly, very little research has been done on this subject.
A research paper published last month in the Journal of Agricultural and Food Chemistry suggests that some common herbicides can indeed change the nutritional content of a food crop (sweet corn). The research team exposed sweet corn to four different herbicides, with or without a commonly used "safener", which helps to protect the corn from herbicide damage. All of the herbicides increased the protein content of the corn slightly, and some of them increased the content of certain minerals (phosphorus, magnesium, manganese, and iron) as well. Several of the herbicides also altered the balance of sugars (fructose/glucose/sucrose) and the amounts of fatty acids.
Whether the effects of herbicides on nutritional content are good or bad is still an open question. All that can be said at the moment is that herbicides can affect the nutritional content of food plants in a myriad of ways.
A lot is still unknown about the effects of agricultural chemicals on food crops, including whether herbicides affect the food's taste. Further research is warranted.
A research paper published last month in the Journal of Agricultural and Food Chemistry suggests that some common herbicides can indeed change the nutritional content of a food crop (sweet corn). The research team exposed sweet corn to four different herbicides, with or without a commonly used "safener", which helps to protect the corn from herbicide damage. All of the herbicides increased the protein content of the corn slightly, and some of them increased the content of certain minerals (phosphorus, magnesium, manganese, and iron) as well. Several of the herbicides also altered the balance of sugars (fructose/glucose/sucrose) and the amounts of fatty acids.
Whether the effects of herbicides on nutritional content are good or bad is still an open question. All that can be said at the moment is that herbicides can affect the nutritional content of food plants in a myriad of ways.
A lot is still unknown about the effects of agricultural chemicals on food crops, including whether herbicides affect the food's taste. Further research is warranted.
Friday, March 9, 2018
Australia May Become the First Country to Eradicate Cervical Cancer
If the current trend continues, Australia may become the first country to virtually eradicate the HPV virus that causes cervical cancer. How did they do it? Health officials credit an aggressive government-financed vaccination campaign begun in 2007 that targeted 12-13 yr.-old girls, combined with a catch-up program to vaccinate older girls and women up to the age of 26 that was completed in 2009. By 2015, 53% of women in the now 18-35-yr.-old age group had been vaccinated. More importantly, rates of HPV infection have dropped from 22.7% to less than 1.5%. That's a 93% decline in HPV infection rates!
Why did HPV infection rates drop so dramatically when only 53% of the women have been vaccinated so far? It's the well-known "herd effect" - when enough people in a population are immune to a transmissible disease organism, it's much harder for the organism to be transmitted from person to person, even though some people are not yet immunized.
Although health officials have not yet seen a dramatic decrease in the number of cases of cervical cancer, that's because it can take years for cervical cancer to develop after HPV infection. At the moment, the number of cases of cervical cancer is just beginning to decline. Nevertheless, officials are confident that with continued aggressive vaccination against HPV, within 30-40 years cervical cancer will be a thing of the past in Australia.
The full HPV vaccination regimen costs about $400 per person in the U.S.; probably less in a country like Australia with a government-sponsored program. Sounds like a pretty good deal to me.
Why did HPV infection rates drop so dramatically when only 53% of the women have been vaccinated so far? It's the well-known "herd effect" - when enough people in a population are immune to a transmissible disease organism, it's much harder for the organism to be transmitted from person to person, even though some people are not yet immunized.
Although health officials have not yet seen a dramatic decrease in the number of cases of cervical cancer, that's because it can take years for cervical cancer to develop after HPV infection. At the moment, the number of cases of cervical cancer is just beginning to decline. Nevertheless, officials are confident that with continued aggressive vaccination against HPV, within 30-40 years cervical cancer will be a thing of the past in Australia.
The full HPV vaccination regimen costs about $400 per person in the U.S.; probably less in a country like Australia with a government-sponsored program. Sounds like a pretty good deal to me.
Topics:
cancer,
infectious disease,
reproductive system
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