Breast Self Examination

Women; have you been feeling guilty because you haven’t been doing regular breast self-examinations to make sure you aren't developing breast cancer? Well, here’s good news for you. The U.S. Preventive Services Task Force (USPSTF), which makes recommendations about preventive care services for people who do not yet have any signs or symptoms of disease, is now recommending against breast self-examination (BSE) as a way to detect breast cancer. (The USPSTF’s previous position on the usefulness of BSE was “insufficient evidence” either for or against).

The USPSTF systematically reviews of the benefits and harms of a preventive care services, and then tries to come up with a net assessment. In the case of BSE, the USPSTF reviewed the latest published data and concluded that; a) regular BSE does not lower the mortality rate from breast cancer, and b) women who perform BSE tend to have more imaging procedures and biopsies than women who don’t. These procedures are expensive and are themselves associated with minor health risks, such as infection and increased exposure to radiation. Overall, the net risk/benefit ratio for BSE is on the side of net risk.

The recommendation against BSE is only for women who are not at increased risk for breast cancer. Women who are at increased risk should consult their physician.

Reference: U.S. Preventive Task Force. Screening for Breast Cancer: U.S. Preventive Services Task Force Recommendation Statement. Ann. Int. Med. 151:716-726, 2009.

Stress Reduction and Heart Attacks

It has long been suspected that a risk factor for heart attacks, in addition to lack of exercise, poor diet, high cholesterol, genetic makeup, and so on, is the level of stress in one’s life. Scientists have hypothesized for years that relaxation techniques such as yoga and meditation might have a positive effect on disease outcome, but it’s been difficult to prove.

Now a team of researchers claims to have proved it, according to a news article. They report that just 20 minutes of transcendental meditation per day significantly lowers the risk of heart attack by 47% in a group of high-risk patients (African American patients with narrowed coronary arteries.)

The results have not yet been published in a peer reviewed medical journal, the point at which they generally are accepted by the scientific community. Personally, I’d feel better if one of the researchers were not from the Maharishi University of Management, an institution founded by the Indian guru who popularized transcendental meditation back in the 1960s. In addition, it’s not clear whether the results in this one group of high-risk patients would translate to other types of high-risk patients, or to persons at lower risk. Time will tell whether the findings can be duplicated by other researchers and whether other stress relaxation techniques have a similar effect.

Caffeinated Alcoholic Beverages Under Scrutiny

This week the Food and Drug Administration (FDA) notified 27 manufacturers of caffeinated alcoholic beverages that they must either explain to the FDA why they believe that the addition of caffeine to alcoholic beverages is “generally recognized as safe” (GRAS) or take their products off the market. According to the FDA, for caffeine to be allowed as an additive to an alcoholic beverage “there must be evidence of its safety at the levels used and a basis to conclude that this evidence is generally known and accepted by qualified experts.” If the companies cannot provide such data within 30 days, the FDA will “take appropriate action” to ensure that the products are taken off the market.

Caffeinated alcoholic beverages are marketed primarily to young people under such names as Max Vibe, Torque, and Evil Eye. Some promotional campaigns depict consumption of multiple drinks in conjunction with high-risk sports such as snowboarding and motocross biking. The action by the FDA comes after the agency received a letter from 18 state Attorneys General asking that the FDA use its authority to see that the products are removed from the market. The Attorneys General argue that caffeine can mask the effects of alcohol and could lead to increased risk-taking behavior.

The two largest manufacturers have already agreed to remove their products from the marketplace. It would not be surprising to see the others follow suit within 30 days.

Energy Sustainability in 20 years?

Would it be possible to get 100% of our energy needs from renewable resources such as wind, water, and the sun in just 20 years? In theory, yes, but for practical reasons it's not likely to happen that soon. With current technologies it would require almost 4 million wind turbines, nearly 90,000 concentrated solar and photovoltaic power plants, and rooftop photovoltaic systems on nearly every rooftop – 1.7 billion, to be exact. Other challenges include a projected critical shortage of certain materials that would be needed, including rare earth metals (found primarily in China), lithium for lithium-ion batteries (half of the world’s reserves are in Bolivia and Chile) and platinum for fuel cells. In addition, we’d have to shift to shift to electric vehicles for transportation.

Fortunately, the technologies for harnessing energy from renewable resources continue to improve each year. It may take some time and effort, but what choice do we have? At current rates of consumption, known reserves of the non-renewable energy resources (coal, oil, and gas) will run out in less than a century.

Reference: Jacobson, Mark Z. and Mark A. Delucchi. A Path to Sustainable Energy by 2030. Scientific American pp. 58-65, Nov. 2009.

I Don't Hear You...

How does the public respond when a published scientific report shows that a dietary supplement is ineffective, or even worse, potentially harmful? To find out, scientists at the National Institutes of Health examined the sales trends of five different dietary supplements before and after the publication of negative research results. There were no significant declines in sales for four of the five supplements (saw palmetto, Echinacea, glucosamine, and St. John’s wort) after published reports that the supplement was ineffective. But sales of the fifth supplement (Vitamin E) declined about 33% after a report suggested that high doses of Vitamin E might actually be harmful.

Why did consumers ignore the reports that supplements just didn’t work, but responded to a report of potential harm? Researchers speculate that reports of harm might have higher impact because of greater news coverage, or that some supplements (such as Vitamin E) might be recommended more often by physicians who are more likely to read and understand scientific reports, or even that it depends on the type of person who takes a particular kind of supplement, the purpose of the supplement, and the availability of alternatives.

Still, it must be discouraging for public health officials to learn that consumers aren’t getting the message, don’t believe the message, or just don’t care whether their supplements work or not.

Water versus Ethanol

In 2007 the U.S. Congress passed the Energy Independence and Security Act, which calls for a five-fold increase in fuel-grade ethanol production by 2022. Most of the ethanol would come from corn produced in the Corn Belt states of the Midwest. It sounds good for the economy of those states, but there’s a catch; growing the corn and producing the ethanol would require nearly 100 gallons of water per gallon of ethanol, by some estimates. Eventually we might have to choose between water and ethanol, or between ethanol and higher food prices.

There would be winners and losers in an ethanol-based biofuels economy, because water generally must be used locally, whereas ethanol is more easily transported. Agricultural communities with plenty of irrigation water and the ability to grow corn would benefit from an ethanol-based biofuel economy. Agricultural communities with marginal water supplies would be forced to choose how best to use their dwindling water supplies – for agriculture or for people? City dwellers generally would be in favor of ethanol production for fuel by others; they don’t use much water for agriculture anyway and so have nothing to give up. However, they are likely to react negatively to a run-up in food prices.

What do you think about producing ethanol from corn?