Wednesday, November 26, 2014

The Benefits of Genetically Modified Crops

Opponents of genetically modified (GM) crops are quick to point out the potential risks involved in planting GM crops and in eating foods with GM ingredients. Some of the risks, such as the potential for encouraging the emergence of "superweeds" that are resistant to the herbicides used on GM crops, and the inadvertent cross-pollination of normal crops by GM crops in nearby fields, are real. Others, such as the potential for causing future unspecified human health problems, are as yet undocumented.

Are there any known benefits of GM crops, other than for the farmer? A recent meta-analysis published in PLOS one concludes that indeed there are. The authors of the analysis reviewed all of the previous reports of the economic and agricultural impacts of three GM crops (soybeans, maize, and cotton) published in English between 1995 and early 2014; 147 studies in all. They found that in addition to improving farmer's profits by 68%, the use of GM crops increased crop yields by 22% and decreased chemical pesticide use by 37%.

Increased profits for farmers is not a bad thing, for it means they pay more taxes and have more money to spend (stimulating the economy). Increased crop yields allows more people to be fed per acre of agricultural land; something to think about as Earth's human population continues to rise even as the amount of arable land remains constant. Finally, reducing chemical pesticide use by more than a third can only be good for the environment.

I'm not saying that GM crops are perfect. I'm well aware that there are risks, some of which may still be unknown. I'm just saying that in any dialogue about whether we should allow GM crops, we should consider both the risks and the benefits, and not just focus on one or the other. Do not be fooled into thinking that there is only one side (yours?) in this debate.

Saturday, November 8, 2014

Increasing Incidence of Colorectal Cancers in Young People

A review of the nearly 400,000 reported cases of cancers of the colon and rectum between 1975 and 2010 reveals some interesting trends. Overall, the incidence of colorectal cancers declined by just under 1% per year, due to a steady decline in persons 50 years of age or older. However, the incidence of colorectal cancers rose in the youngest age group; persons aged 20-34. Based on current trends, rates of colorectal cancers in this age group will nearly double by 2030.

The current study provides no information regarding the cause of the upward trend. But this is how science works; based on an observation, (a rising rate of colorectal cancers in young people) a hypothesis must be formed and further study undertaken to test it.

Perhaps by 2030 we'll know why colorectal cancers are increasing in young people, and also know what to do about it. The optimist in me hopes so.

Thursday, November 6, 2014

The FDA approves a Vaccine for a Rare Meningitis

Last fall an outbreak of a rare form of meningitis called serotype B occurred on the campus of Princeton University. Months later a similar outbreak occurred at the University of California Santa Barbara (UCSB). Although a vaccine against serotype B meningitis was available in Canada and Europe, it had not yet been approved in the U.S. Nevertheless, because of the dangerous nature of meningitis and the ease with which the disease might spread on college campuses (it's spread by close contact such as kissing or sharing eating utensils) the FDA granted emergency approval of the vaccine, just for students of Princeton and UCSB. The vaccine worked, the outbreaks subsided, and a greater crisis was averted.

Recognizing that the normal approval process for a vaccine or drug can take years, the FDA has developed a fast-track approval process for vaccines and drugs that meet certain criteria. Two competing vaccines against meningitis serotype B were fast-tracked under this program, and last week the FDA approved the first one, Pfizer's Trumenba.

And that's interesting, because the vaccine approved on an emergency basis for the students of Princeton and UCSB was the other vaccine, called Bexero, made by Novartis. We hope it's just that Pfizer just did a better (and faster) job of satisfying the FDA of its product's safety and effectiveness.

Now that a vaccine for meningitis serotype B is available, should it become part of the standard vaccination schedule for all children? That hasn't been decided yet, but the decision rests with the Centers for Disease Control and Prevention (CDC), not the FDA.

Saturday, November 1, 2014

New Uses for Wearable Skin Patches

Previously I talked about how wearable skin patches not much bigger than a Band-Aid that could be used to deliver drugs or vaccines (this blog, Mar. 13, 2014). Wearable skin patches are being developed for other uses as well, including monitoring a patient's vital signs and diagnosing specific diseases.

Swedish researchers are developing a wearable skin patch called the Bio-patch, with embedded wireless micro-sensors and a small battery. The Bio-patch could be used to monitor a patient's vital signs and send them wirelessly to a smartphone or to the patient's doctor. The Bio-patch would permit 24-hour monitoring of a patient, enabling a physician to know exactly when a patient's condition has changed. Sensors have been developed to monitor body temperature and the electrical activity of the heart (an electrocardiogram; ECG) and brain (an electroencephalogram; EEG).

An Australian group is developing a wearable skin patch with tiny micro-needles that penetrate the outer layer of the skin and sample the intradermal fluid. The tiny micro-needles are coated with antibodies that detect the presence of antigens from the malaria parasite, Plasmodium falciparum. The device can detect malaria in a patient without the need for a blood sample and blood analysis. So far the device has only been tested on mice, and only to detect malaria. But in theory, it should also work in humans and it could conceivably be used to test for nearly any disease in which disease antibodies are present in interstitial fluid.

It's a pretty good bet that within the next decate you'll see some of these products come to market.

Monday, October 27, 2014

Recalled Dietary Supplements Return to the Shelves

Unlike pharmaceutical drugs, dietary supplements do not have to be proven safe and effective before they can be sold. All the FDA can do is to force specific products to be pulled from store shelves (recalled) after it receives complaints about the product's safety.

A study published in JAMA shows how ineffective the FDA's recall power really is. The authors of the study examined 27 dietary supplement products that had been recalled by the FDA. Some of the products were recalled for containing anabolic steroids or prescription drugs such as Viagra and Prozac. Several weight-loss products contained an amphetamine-like drug not approved in the U.S. The authors found that within an average of three years after recall, approximately 2/3 of the products were being sold again - under the same name and with the same ingredients. Even the manufacturers and distributors were the same! Most of the manufacturers are U.S.-based.

Why can't the FDA put a stop to this? In part, their hands are tied because dietary supplement manufacturers have the right to sell their products without any proof that they are safe and effective. Tainted products are only identified after they have hit store shelves and after complaints are received. And even then, recall can be difficult because many of these products are sold over the internet from unknown physical addresses.

Until the dietary supplements regulatory environment changes and the FDA is given more power to punish unscrupulous companies, it remains "buyer beware" when it comes to dietary supplements. Unfortunately for us, the authors did not name the manufacturers, distributors, or products in their study. That's a shame.

Wednesday, October 22, 2014

Canada Opens First Carbon Capture Power Plant

Canada recently completed the first commercial-scale coal-fired power plant designed to capture and sequester greenhouse gases. The plant will capture around 90% of the CO2 that the plant generates - about a million tons a year. The CO2 will either be sold to a nearby oil company to enhance oil production or buried deep underground.

The new plant, called Boundary Dam, demonstrates that it is possible to burn coal without damaging the environment in the process. But don't expect the more than 1,000 coal-fired power plants in the planning stages worldwide (most of them in China) to adapt the technology any time soon. The technology is economically feasible at the Boundary Dam plant because the plant received substantial subsidies from the Canadian government and because the plant is located in an area in which the CO2 could be sold to oil producers, who use the CO2 to enhance oil production.

And there's the irony. Some of the CO2 not released into the atmosphere by the coal-fired power plant will be used to enhance the production of oil, which of course is also a fossil fuel that releases CO2 when it is burned. I suppose there's still a net reduction in CO2 released into the atmosphere, but it's not the full million tons a year.

Sunday, October 19, 2014

Another Artificial Sweetener

There's a new artificial sweetener about to hit the market that's more than 30 times sweeter than saccharine (Sweet-n-Low), aspartame (Nutrasweet and Equal), or sucralose (Splenda). The new sweetener, called advantame (it does not have a catchy brand name yet), is made by Ajinomoto, a Japanese company.

Although it's entering a crowded and competitive field, Advantame will probably find a niche in the marketplace because it doesn't break down as readily as other sweeteners under heat. That means that it'll probably become the artificial sweetener of choice in baked goods.

The FDA approved the new sweetener in May. It's not clear how long it'll be before it's found in the products you buy.