Why are we growing corn to fuel our cars? Three reasons why ethanol is a bad idea.

Most of us are driving around right now in cars powered by a combination of gasoline and ethanol. Ethanol is a fuel alternative produced from corn (mostly), and it has been touted for years as cleaner, carbon-neutral alternative to gas.

The problem is that ethanol’s benefits have been greatly exaggerated, leading to Congressional regulations that required ever-increasing amounts of ethanol in our gasoline supply. The government requirement goes back to 2005, when gas prices were much higher and the U.S. was in the midst of the Iraq war. Ethanol was supposed to be a clean way to reduce our dependence on foreign oil. The growing mandate for ethanol has instead created an enormous, artificial demand that has had unintended consequences, many of them bad.

Some background: Congress requires automakers to meet fuel economy (“CAFE”) standards for all their cars and light trucks. To encourage ever-greater use of ethanol, Congress modified the CAFE standards in 2005. As a result of that law, this year the EPA will require refiners to use 18.1 billion gallons of ethanol to fuel our cars.

Politicians still love ethanol. In the 2016 presidential campaign, several candidates came out in support of continuing the corn-based fuel program, hoping this position would win them votes in the Iowa caucuses. Iowa is a big corn state.

Unfortunately for the rest of us, mandating the use of ethanol is a terrible policy. Here are three reasons why.

1. Ethanol lowers your gas mileage–a lot. Ethanol only has about 2/3 the energy content of gasoline, meaning it simply cannot provide the same amount of power per gallon (or liter) as gas. E85 fuel, which uses 85% ethanol and 15% gasoline, is widely available, and some gas stations now offer no alternative. Consumer Reports put E85 to the test, and found that highway mileage decreased by 29% and city mileage by 22%. Car and Driver ran their own tests and found a 30% drop in mileage on E85. According to the Union of Concerned Scientists, nearly all gas sold in the US today has 10% ethanol–much less than in E85, but still providing lower fuel efficiency than straight gasoline.

Making things worse, ethanol attracts water and is more corrosive to some metals and rubber than gasoline. So it's bad for your car.

2. Using ethanol doesn’t reduce carbon emissions. The main argument for using ethanol is that because the carbon contained within it was recently put in the ground, burning ethanol (and releasing that carbon) is carbon neutral. Compared to extracting oil, which has lain in the ground for millions of years, growing corn and extracting ethanol puts far less carbon back in the atmosphere.

This argument makes sense, but only in a very narrow context. In an article published in Science in 2008, Timothy Searchinger and colleagues pointed out that previous analyses

“failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels.” 

When the scientists accounted for these land-use changes, they found that using corn to produce ethanol will double greenhouse emissions over a 30-year period. Switchgrass is only slightly better, increasing emissions by 50%. As the Union of Concern Scientists explains that “sustainable production is possible” only if we stop making ethanol from corn.

Admittedly this is a complex topic, but it seems that ethanol-from-corn simply doesn't reduce carbon emissions. Thus the entire justification for using ethanol to fuel our cars is unsound.

3. Increasing fuel efficiency means we’ll never be able to meet Congress’s mandated levels of ethanol usage, not unless we sacrifice even more gas mileage. Automakers have made great progress in producing more fuel-efficient cars, and the growing electric car market (Tesla!) mean that we’re using less and less fuel each year. This is terrific for reducing carbon emissions, but it means that Congress’s original mandate to use more ethanol becomes far harder to satisfy.

What happened was that back in 2005, Congress told us how to solve a problem (carbon emissions from our cars), instead of just encouraging us to solve it using innovative new ideas. Corn producers and their government representatives—governors, Senators, Representatives—all got behind the ethanol “solution” because they saw increased profits in it. Now we are stuck with a non-solution that, as the NY Times recently put it, is “a boon for Iowa and a boondoggle to the rest of the country.” It’s long past time to end the ethanol mandate.

Long term antibiotic use for Lyme disease doesn't work, according to new study

Fifteen years. That's how long scientists have been trying to prove a negative: that "chronic Lyme disease" does not exist, and that long-term antibiotic usage does not help with symptoms that include joint pain and fatigue. This past week, a study in the New England Journal of Medicine showed that long-term antibiotic usage–the favorite treatment prescribed by doctors who call themselves "Lyme literate"–is a failure. Will it convince any of those doctors to change their practice? I doubt it.

Lyme disease is a serious illness, caused by bacteria that are transmitted through tick bites. Although the disease has been infecting humans for centuries, it got its name relatively recently, in 1975, when two Yale doctors, Stephen Malawista and Allen Steere, investigated a cluster of illnesses near the town of Lyme, Connecticut. The symptoms included joint pain that resembles arthritis, so much so that Malawista initially called it "Lyme arthritis." A few years later, biologist Willy Burgdorfer discovered the true cause, and the bacterium Borrelia burgdorferi was named after him. As deer have spread through the suburbs of modern society, ticks traveling with them have spread Lyme disease far and wide; the NIH reported over 36,000 cases in the U.S. in 2013. (Note that the CDC estimates the true number of cases may be closer to 300,000, ten times the number actually reported to health authorities.) Lyme is also common in Europe.

Luckily for most of us, a brief course of antibiotics usually cures people completely of Lyme disease. For some people, though, symptoms including fatigue and joint pain can linger for up to six months. The cause of these longer-term symptoms remains a mystery, and is an active area of current research. One possible explanation from the CDC is that

"the lingering symptoms are the result of residual damage to tissues and the immune system that occurred during the infection."

Unfortunately, the lack of a scientific explanation has opened the door to wildly speculative treatments, based on little or no evidence, by doctors who think they know the answer. These doctors, some of whom have adopted the label "Lyme literate," insist that their patients suffer from what they call Chronic Lyme Disease. Among other things, they've formed an association called ILADS that claims that:

"Most cases of chronic Lyme disease require an extended course of antibiotic therapy to achieve symptomatic relief" and "many patients with chronic Lyme disease require prolonged treatment until the patient is symptom-free."

Not only do these treatments cost far more than the 2-week course of treatment recommended by the Infectious Disease Society of America, but they also have the potential to cause harm: it's just not good for you to be on antibiotics for months or years. Indeed, one of the first studies (in 2001, by Mark Klempner and colleagues) to look at the efficacy of long-term antibiotic use explained its motivation as follows:

"Case reports and uncontrolled trials describe success with prolonged antibiotic therapy, often with a recurrence of the symptoms after the discontinuation of therapy. In view of the substantial morbidity and even death associated with prolonged parenteral antibiotic treatment of Lyme disease, it is important to determine the efficacy of such therapy."

"Substantial morbitity and even death": clearly, long-term antibiotic treatment is not something to be prescribed lightly. The 2001 study found no benefit from long-term versus short-term antibiotic usage for the treatment of Lyme disease.

Despite the science, some doctors persist in prescribing–against the advice of professional societies–long-term courses of antibiotics. Because the practice continues, a European group conducted a new study of long-term antibiotic use in patients who claim to have persistent symptoms from Lyme disease. Anneleen Berende and colleagues reported the results of this well-designed double-blind, placebo-controlled study in the New England Journal of Medicine just last week. Their findings matched those of the 2001 study: long term antibiotic use has no benefits for patients.

The study had three arms: a placebo group and two different treatment groups, who were given two different antibiotics. Everyone got a two-week treatment with real antibiotics, followed by 12 more weeks of either antibiotics or placebo. The pills were created just for this study to look identical, so that neither the doctors nor the patients knew who was getting the placebo.

In an editorial accompanying the article, my Hopkins colleagues Michael Melia and Paul Auwaerter explain that the take-home message is that

"Patients with subjective, vexing symptoms attributed to Lyme disease should not anticipate that even longer courses of antibiotics will produce relief, a finding that is in concert with results from previous trials."

I doubt that "Lyme literate" doctors will accept the latest results and stop prescribing long-term antibiotic use; their websites indicate that they already know that they are right. I hope, though, that patients will start to question doctors who put them on long-term, possibly harmful antibiotic regimens that don't provide any benefit.

(For more information, see this excellent video by Dr. Auwaerter about Lyme disease and its treatment.)