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ACSH Dispatches Round-Up: PERC, Diabetes, Tea Parties, Salt, Sharks, More
By Elizabeth Wade
April 15, 2009
Diabetes, Prostate Cancer, and Recalling Food Recalls
By Elizabeth Wade
Diabetes dominates JAMA
The current issue of the Journal of the American Medical Association (JAMA) focuses on diabetes -- and brings some good news. According to their graph, death rates for diabetes are stable or decreasing among black females, white males, and white females in the United States. The death rate for diabetes among black males has gone up in recent years, but not by much. "People throw around the phrase 'diabetes epidemic,' but I don't see an epidemic here," says ACSH's Dr. Gilbert Ross.
But as Dr. Ruth Kava points out, "The graph shows the death rate, not the incidence rate. Perhaps we are treating the disease better. And if there has been an increase in younger people with type 2 diabetes, incidence might not correlate with the death rate."
Another study in JAMA shows that transplanting stem cells made from individual patients' bone marrow cells may help people with type 1 diabetes go for up to four years without needing to inject insulin. "It's a very small study -- only twenty-three patients -- and the technique sounds pretty labor-intensive. But it's certainly a big step forward for people who would otherwise need to inject insulin two or more times a day," Dr. Kava says. "I bet people will be lining up to participate in further trials."
A third study emphasizes the importance of blood sugar control in older people with type 2 diabetes, since it appears that they are more likely to develop dementia if their blood sugar drops so low that they must go to the hospital. Dr. Ross points out, "I think this study just measures the tip of the iceberg because many incidences of less extreme hypoglycemia probably occur without the patient or caregiver noticing." Diabetics are generally concerned with their blood sugar going too high, but an unusually low blood sugar can also be dangerous; this study encourages diabetics to aim for a middle ground.
They will have their Provenge
The prostate cancer "vaccine" Provenge may soon be approved by the FDA, two years after the agency first declined to do so. "Back then, the data were optimistic and suggestive, but not statistically significant," Dr. Ross explains. Now, the makers of Provenge claim that in a new study, the drug met the FDA's requirement of reducing the risk of death by 22% compared to a placebo.
"Provenge is the first drug of its kind," notes Dr. Ross. It aims to provoke an immune response against prostate cancer by infusing the patients with a mixture of their own white blood cells and a combination of an immune system stimulator and a protein found almost exclusively in prostate cancer cells. While not a traditional preventative immunization, it is referred to as a therapeutic "vaccine" because it trains the body's immune system to attack the cancer.
Understandably, many men with advanced prostate cancer have been clamoring for access to Provenge for years and were furious when the FDA did not approve the drug after the initial application. ACSH's Jeff Stier wrote about the difficulties of getting access to experimental cancer treatments in the Medical Progress Today editorial "Lessons Learned From a Last Battle."
Do you ignore food recalls?
While 84% of Americans report paying close attention to news about food recalls, only about 60% actually search their homes for recalled products, according to a Rutgers University study. Although, as Dr. Kava points out, "If I hear that some peanut products have been contaminated with salmonella, but I know I haven't bought any peanut products, I won't bother searching my kitchen."
ACSH's Dr. Elizabeth Whelan blames the problem in part on over-warning.
Dr. Ross agrees, "People can't tell the difference between a valid warning and an alarmist warning anymore."
April 14, 2009
Birth Defects, Cancer, Depression, Impotence -- and Comedy
By Elizabeth Wade
Pregnant women should stop fearing fish
Warnings about mercury in fish have scared many women away from eating seafood during pregnancy, but now some scientists are encouraging a reversal of this trend. Fish are rich in omega-3 fatty acids, which may aid in neural development and, therefore, be important during pregnancy. "Women who are pregnant should be eating more fish, but they are still safe avoiding those types of seafood that are known to be highest in mercury," says ACSH's Dr. Gilbert Ross.
ACSH's Jeff Stier adds, "I like the risk-benefit analysis aspect of this story, but I think they should have gone farther and encouraged everyone -- not just pregnant women -- to stop being afraid of eating fish."
ACSH chose the claim that "mercury in seafood causes neurological problems in humans" as one of our Top Ten Unfounded Scares of 2004. For more on evaluating risks versus benefits, check out our Riskometer.
Location trumps genetics in explaining cancer survival disparities
A new study indicates that modifiable factors may play more of a role than genetics in racial disparities in the incidence and survival rates of some types of cancer. In broad population studies of large geographic areas, African-Americans have higher incidence of and death rates from prostate cancer -- and poorer outcomes of breast cancer -- than whites. But when the study focuses on smaller geographic areas like neighborhoods, the racial disparity in these rates diminishes or disappears.
"Neighborhoods tend to be more homogenous in terms of lifestyle and socio-economic status, so the racial disparity in cancer survival we see in larger populations may be attributable not to genetics but to differences in lifestyle, diet, economic factors, access to medical care, and other modifiable factors," Dr. Ross explains.
Depression may increase risk of heart failure
Patients with coronary heart disease who develop depression may be at an increased risk for heart failure, a condition in which the heart gradually loses its ability to pump blood effectively. Heart disease patients are already at a greater risk for developing depression, and while anti-depressants may help relieve symptoms of the illness, they do not appear to affect the increased risk of heart failure. "Researchers found a four-and-a-half-fold increase in developing heart failure among those patients who had depression, which is a dramatic statistic," Dr. Ross says. "However, there is no comment in the story about a potential biological mechanism, so we should take this study with a grain of salt."
ED drugs don't impair vision
While some men who take the erectile dysfunction drugs Viagra and Cialis have reported vision problems (like seeing a "blue aura"), a new study concludes that the drugs do not significantly impair vision. "There is a biological hypothesis as to why these drugs might have an effect on the blood vessels in the eye -- they work by blocking the enzyme PDE5 in the genitals, and PDE5 may also affect blood vessels in the retina," Dr. Ross explains. "However, this study found no evidence of retinal arterial disease or any significant visual impairment among men taking these drugs."
ACSH on the Daily Show
ACSH has been extending its reach lately, getting our message out via all sorts of different news outlets, from Forbes.com to California's Orange County Register. But today we add an entirely new audience to the list -- ACSH's Jeff Stier is being interviewed about organic food for the Daily Show, Comedy Central's "news" program. The segment will probably air in late April or early May, and we will certainly let all our MD readers know about the exact date so you can tune in.
April 13, 2009
Multivitamins, Screenings, Vaccinations, Detailers, and Tea Parties
By Elizabeth Wade
Some multivitamins are not what they seem
ConsumerLab.com reports that 30% of the multivitamins it tested contained significantly more or less of an ingredient than the label claimed, while some others were contaminated with lead. Vitamin A levels appear to be particularly problematic, with several of the tested supplements containing too little or too much of the nutrient.
"I'm more worried about the ones that contain too much vitamin A, since it is one of the few vitamins that is actually stored in the body, and very high intake of this vitamin can be dangerous," says ACSH's Dr. Ruth Kava. While the body may store enough vitamin A to ward off deficiencies, too much of the vitamin can cause nausea and blurred vision in the short term and may lead to bone softening and liver problems over time.
Some of the multivitamins were short on folic acid as well, including one marketed as a prenatal vitamin. "Women who are planning to become pregnant should be taking folate to lower the risk of spina bifida in their newborns, so it is worrisome that these supplements may not be delivering enough of that important vitamin," notes ACSH's Dr. Gilbert Ross.
As always, we remind our MD readers that multivitamins and other dietary supplements are not regulated by the FDA. Talk to your doctor before you begin taking them, and check out ACSH's publication What's the Story? Drug-Supplement Interactions for more information.
Barbershops offer blood pressure screenings
In an effort to reach African-American men, hospitals and other health organizations have partnered with nursing students to set up blood pressure screening stations in barbershops. "This sounds like an excellent outreach idea, although the article doesn't include any statistics about its success," Dr. Ross says. Black men tend to have higher rates of hypertension than white men, but they are also less likely to regularly visit a doctor. In addition to being convenient, screening for high blood pressure in barbershops provides a relaxed and open atmosphere to discuss health issues with people who may have otherwise fallen under the radar.
New vaccines keep kids out of hospitals
ACSH spends a lot of time contending with anti-vaccine scaremongers, so it was refreshing to hear some good news about childhood immunizations. Prevnar, Wyeth's vaccine against certain pneumococcal bacteria, and Rotateq, Merck's vaccine against rotavirus that ACSH Advisor Dr. Paul Offit helped develop, have dramatically reduced the number of children visiting emergency rooms.
"This is really great news -- a true success story," says ACSH's Dr. Elizabeth Whelan. The potential benefits of these vaccines extend far beyond the United States, particularly in the case of Rotateq. As Dr. Ross points out, "Serious rotavirus disease is not a major problem in this country, but it is a huge problem in less developed regions." For more on the benefits and safety of vaccines, check out ACSH's What's the Story? Childhood Immunizations. And keep an eye out for our new report on adult immunizations, which we will be publishing in the coming months.
NYC dispatches health detailers
The New York City Health Department has started sending "detailers" to doctors' offices in low-income areas to encourage doctors to provide their patients with information about health issues such as domestic violence, vaccines, smoking cessation, and cancer screening. The program was inspired by the detailers who work for pharmaceutical companies and visit doctors' offices to promote certain drugs.
"The issues the New York City detailers are raising are mainly important ones," Dr. Ross says. "I'm especially glad to see that they're not harping on the dangers of trans fat or the importance of lowering sodium levels in prepared foods."
Todd Seavey defends Tea Parties
We often note that government prioritizes irrationally, so ACSH's Director of Publications Todd Seavey is unsurprised by the big turnouts at the recent "Tea Party" protests going on across the country denouncing government spending. Check out Todd's letter to the New York Times defending the protests.
April 9, 2009
Brown Fat, Beverage-Induced Fat, Grade-F Fat, and Smoke
By Elizabeth Wade
Calorie-burning brown fat found in adult humans
Brown fat was all over the news this morning, as three studies report that the calorie-burning substance has been found in adult humans for the first time. "We knew that brown fat was found in animals (particularly ones that hibernate) and infants, and that it burned energy when activated by cold," explains ACSH's Dr. Ruth Kava. Scientists believed that brown fat disappeared in humans once they grew old enough to shiver effectively, but it appears that small pockets remain in most people in the upper back, on the side of the neck, between the collarbone and shoulder, and along the spine.
The studies found that lean people tend to have more brown fat than obese people, and its calorie-burning properties are particularly intriguing to those looking for pharmacological treatments for obesity. "Potentially, researchers could figure out a way to use a pharmacological agent to stimulate brown fat's ability to burn calories," Dr. Kava says. "It's important to remember that these studies are super, super preliminary, but I expect they will inspire an explosion of research in this field."
Should we tax sugary drinks?
In the New England Journal of Medicine, New York City Health Commissioner Dr. Thomas Frieden and Yale professor Dr. Kelly Brownell call for a tax on sugar-sweetened beverages, including soda, sports drinks, and fruit juice with added sugar. Ironically, this comes after New York Governor David Paterson dropped his idea for a similar soda tax in the face of overwhelming opposition from residents of his state. "Taxing sugary beverages is just not the way to go," says ACSH's Dr. Elizabeth Whelan.
Soda and other drinks that contain added sugar are currently taking much of the blame for the obesity epidemic -- even though, as ACSH knows, nutrition is too complicated to be boiled down to a single factor. "For example, orange juice naturally contains a lot of calories and a lot of sugar -- which is metabolized exactly the same way added sugar is," Dr. Kava points out.
While cutting calories from drinks can help people lose weight, ACSH believes that targeting one type of beverage for a tax is a bad strategy -- not to mention an untested one. Click here to read Dr. Kava's testimony against New York's proposed soda tax.
A, B, C, D...Obese?
Massachusetts plans to start calculating students' BMIs and sending the numbers home to their parents every few years in an effort to combat obesity in the state. "I have mixed feelings about this," Dr. Whelan says. "While parents should be aware if their child is overweight or obese, most parents won't have a clue what to do when they get this information. And what about the emotional implications for the child?"
There was some debate at our breakfast table over the merits of using BMI to determine if a child has weight problems, but Dr. Kava says, "Sending BMI reports home could be useful if it's done confidentially and if they are accompanied by an explanation of what this information means so the parents could respond appropriately."
Second-hand smoke attacks New York
More New Yorkers appear to be exposed to second-hand smoke than most people nationwide, but ACSH staffers are skeptical of the significance of this report. "If you live in a big city, you're exposed to a lot of different things," Dr. Kava remarks. "Just because a blood test signals exposure to 'toxic chemicals' doesn't mean they can be found at a level that would actually harm our health."
The study measured blood levels of cotinine, which indicates exposure to nicotine. But, as Dr. Whelan reminds us, "You can find trace levels of anything in everything if you look hard enough."
April 8, 2009
PharmaScolds, Fat Kids, Liquid Losses, Perc-secution
By Elizabeth Wade
Taking on the "PharmaScolds"
ACSH Advisor Dr. David A. Shaywitz and ACSH Trustee Dr. Thomas P. Stossel, who is also a professor at Harvard Medical School and a fellow at the Manhattan Institute, have an impressive op-ed in today's Wall Street Journal entitled "It's Time to Fight the 'PharmaScolds."
They write, "The goal of medical research is not to publish papers but to develop new treatments for people suffering from disease. And translating laboratory research into new therapies, in the words of Robert Beall, president of the Cystic Fibrosis Foundation, is something 'academics are really not good at.'" The pharmaceutical industry, they say, fills the gaps by using basic research to develop new drugs, devices, and treatments. Drug companies' important role in this process should be admired rather than vilified, they argue.
"The op-ed defends the importance of the dynamic relationship between academics and industry and points out that this partnership has led to the development of life-saving drugs," says ACSH's Jeff Stier. "It's a necessary and beneficial relationship for medical progress, but it has been demonized by people like FDA deputy commissioner Joshua Sharfstein." For more on this topic, read ACSH's publication Scrutinizing Industry-Funded Science: The Crusade Against Conflicts of Interest.
Obesity epidemic reaches four-year-olds
A new study reports that nearly 20% of four-year-olds in the United States are obese, with even higher numbers found among Native Americans and Hispanics. "I suppose most of it boils down to a combination of not having a low calorie diet and not exercising enough, but it's hard to believe the obesity rate is already so high at age four," says ACSH's Dr. Elizabeth Whelan.
ACSH's Cheryl Martin agrees, "It's hard to imagine a four-year-old not running around enough to burn some of those calories."
Surprise! Cutting liquid calories leads to weight loss
ACSH staffers find it obvious that people who cut back on sugar-sweetened beverages lost weight in a new study, but we know it's not the whole story. "What you drink as well as what you eat contributes to your caloric intake, so if you cut back on calories from liquids, of course it will help you lose weight," Dr. Whelan says. "But there is a tendency to zoom in on one food category as the cause of obesity, and these days, soda is that category." She points out that orange juice, for example, also packs a lot of calories -- while diet soda contains none.
EPA reconsiders possible perc ban
The EPA is once again considering banning perchloroethylene, a dry cleaning chemical commonly known as "perc."
"The New York Times refers to perc as a 'likely human carcinogen,' but in reality, there is no evidence that it has ever caused any harm to human health," Dr. Whelan notes. "Perc has always been an easy target for the anti-chemical movement, but there's no science supporting the EPA's possible ban." For more information, read ACSH's publication What's the Story? The Dry-Cleaning Chemical Perc.
April 7, 2009
Salt Experiments, Combo Therapy, McDonald's Famine, Inside Edition
By Elizabeth Wade
Salt plan turns New Yorkers into lab rats
While ACSH and others have been vocal in our opposition to New York City Mayor Michael Bloomberg’s plan to pressure companies to reduce the amount of salt in food, New York Times columnist John Tierney frames the issue in a new way -- calling it an experiment from which there is no escape, nor any consent required.
Mayor Bloomberg and the Health Department run by Dr. Thomas Freiden are convinced that lowering the amount of salt in food will help control people’s blood pressure and prevent cardiovascular disease, such as heart attack and stroke; however, Tierney points out that cutting back on salt could have many different consequences -- from worsening moods to even raising blood pressure for some. In fact, when heart disease patients were put on various diets in a randomized clinical trial, those in the low-sodium group were more likely to be rehospitalized and die.
“You just don’t know what reaction people will have on a large scale,” says ACSH’s Dr. Elizabeth Whelan. “If the city were serious about controlling hypertension, it would put resources into widespread blood pressure screening and pharmaceutical intervention as necessary -- which is a much more cost effective way of dealing with the problem.”
ACSH’s Jeff Stier wonders, “Couldn’t Mayor Bloomberg respond to these criticisms by saying that the city is simply trying to lower salt intake to the recommended dietary allowance (RDA), which is not an untested number?” But ACSH’s Dr. Ruth Kava points out, “It’s very hard to compare the average current salt intake to that in the past, especially before we ate a lot of canned food, because so many other things have changed. There is a lot going on with our diets and health other than changes in salt intake.”
ACSH’s Dr. Gilbert Ross adds, “The real tragedy is that less than one fourth of people with high blood pressure have been correctly diagnosed and adequately treated. Public health officials should be thinking of ways to find and treat those at risk, which amounts to millions of Americans.”
Read more about New York’s plan to cut back on salt in Dr. Whelan’s New York Postop-ed “NYC Food Cops’ National Agenda.”
Combo therapy and counseling help more people quit smoking -- but still not enough
Two new studies evaluate quit rates for smokers utilizing different cessation methods. The first shows that smokers with chronic illnesses are more likely to quit if they use a combination of a nicotine patch, a nicotine inhaler, and an antidepressant -- but at six months, the quit rate even for those receiving such intensive combination therapy reached just 35%, and we anticipate even lower numbers after a year and beyond.
The second study indicates that smokers who receive the most counseling are the most likely to successfully quit. “Doctors need to encourage their smoking patients to quit, and explain to them that the more attempts they make to quit, the more likely they are to be successful,” Dr. Ross says. “But then of course you run up against the brick wall of the low quit rate -- and the fact that only slightly more than half of smokers report being counseled by their doctors to quit during a routine check up.” (For more on doctors’ responsibility to advise their patients to quit smoking, read Dr. Ross’s Medscape article “Smoke Out Doctors Who Neglect Their Smoking Patients.”)
These dismal numbers are certainly not helped by what Dr. Ross calls “the anti-science campaign against smokeless tobacco as a smoking cessation tool.” The latest device that has the potential to be used as harm reduction is the e-cigarette, which journalist and former smoker Richard Leiby evaluates in the Washington Post today.
“While he doesn’t come out and endorse the e-cigarette, he goes further in recognizing its potential benefits than most anti-smoking groups,” Stier notes.
Could McDonald’s be in for a potato famine?
In today’s Canada Free Press, ACSH advisor and senior fellow at the Hudson Institute Dennis Avery criticizes McDonald’s decision to “pursue pesticide-free potatoes for its restaurants.” As Dr. Whelan says, “The potato is a very vulnerable crop, and if the decision to go organic puts the viability of one of the company’s main products at risk, I just can’t believe they would take that chance.”
Dr. Kava adds, “McDonald’s must use a phenomenal amount of potatoes, which I doubt they can get from only organic farmers. Plus, organic doesn’t mean ‘pesticide-free.’ There are approved organic pesticides, including the highly toxic copper sulfate.”
McDonald’s pesticide issue could be mitigated with the development of potatoes that have been genetically modified to resist particularly dangerous pests and devastating diseases, but, ironically, testing of this new crop did not receive approval in, of all places, Ireland.
Inside Edition consults ACSH
Jeff Stier’s interview on Farrah Fawcett’s reported used of shark cartilage to treat her cancer aired on Inside Edition across the country last night and this morning in New York. “In going through the results of our donor survey that so many of our MD readers responded to, we’ve heard from many of you that we should get our message out more broadly,” Jeff says. “The interview on Inside Edition helped us reach people who weren’t necessarily looking for policy issues but who came away with more knowledge about health and about ACSH.”
April 6, 2009
Tobacco Legislation, Vaccine Exemption, plus HIV, FDA, Fat, and Sharks
By Elizabeth Wade
ACSH argues against misguided tobacco legislation
ACSH’s Dr. Elizabeth Whelan has an op-ed in the New York Post criticizing the Kennedy-Waxman tobacco regulation bill, while ACSH’s Jeff Stier takes on the legislation in the Washington Times. As Dr. Whelan writes, “The bill would give the FDA regulatory authority over tobacco -- but in the process, it gives cigarettes a virtual government stamp of approval, while impeding consumers’ access to less-harmful alternative forms of tobacco.”
Stier’s op-ed was even picked up by ABC’s blog The Note as one of today’s must-read stories about Congress. “This is a continuation of our ability to get our message out to different audiences through a variety of venues,” Stier says.
Unfortunately, the Kennedy-Waxman bill passed the House last week, while Rep. Steven Buyer’s (R-IN) amendment promoting harm reduction was voted down. The bill will soon move to the Senate, where many expect a tighter vote. Sen. Richard Burr (R-NC) plans to introduce alternative legislation that would ensure that smokers receive truthful information about smokeless tobacco and harm reduction.
ACSH’s Dr. Gilbert Ross says, “The forces arrayed to promote the anti-health Kennedy-Waxman bill try to paint all opposition to it as ‘pro-tobacco.’ In fact, it is the current bill which is anti-public health, while the Burr substitute would allow easier access to lower-risk products that may help addicted smokers quit, saving lives.”
Lax vaccine exemption endangers children in California
Since the now-debunked hypothesis that childhood vaccines cause autism took hold among scared parents in the late 1990s, vaccination rates have dropped dramatically in Europe and the United States. The Los Angeles Times recently analyzed the trend to opt out of childhood vaccinations in California, finding that unvaccinated children tend to be concentrated in affluent areas and their public charter schools and private schools.
“It’s ironic that California goes to such pains to warn people about every possible ‘toxic chemical,’ but because of the state’s very lax vaccine exemption, many children go unprotected against diseases like measles, mumps, and rubella -- which can be deadly,” says ACSH’s Dr. Gilbert Ross.
We especially appreciate ACSH advisor and chief of infectious diseases at Children’s Hospital of Philadelphia Dr. Paul Offit’s take on the issue: “I think it’s hard to unscare people.” For more on the safety of childhood immunizations, check out ACSH’s special report The Promise of Vaccines: The Science and the Controversy.
Starting therapy for HIV early may save lives
New research suggests that HIV-positive patients could benefit from starting antiretroviral therapy as early as possible, rather than waiting until the count of their CD4+ white blood cells drops below a certain number. “It is tradition to stall beginning antiretroviral therapy because it is basically a lifelong commitment and the drugs are not entirely benign,” Dr. Ross explains. “But this study found that the patients’ risk of death was much higher if they waited to begin the therapy until after their CD4+ counts fell below whatever arbitrary cut-off their doctors used.”
Stier adds, “This new information moves the fulcrum for weighing the benefits and risks of antiretroviral therapy.” For more on this topic, read ACSH’s publication Weighing Benefits and Risks in Pharmaceutical Use: A Consumer’s Guide -- and don’t forget to check out our Riskometer!
The wrong path to FDA reform
Predictably, ACSH staffers disagreed with most of Dr. Marcia Angell’s recommendations for the next FDA commissioner. Her arguments condemning “me-too drugs,” financial conflicts of interest, direct-to-consumer advertising of pharmaceuticals, and the “user fees” paid by drug companies to the FDA were of particular discussion at our breakfast table. “Marcia Angell’s Boston Globe op-ed is a nice synopsis of all the bad arguments about how to ‘fix’ the FDA,” Stier remarks.
Gov. Patterson proposes pointless trans fat ban
New York Governor David Paterson is proposing legislation to ban trans fats throughout the state and ensure that students have access to healthier foods at school – both with the stated aim of fighting obesity. “We’re all in favor of healthy food being served in schools, but just because food is healthier does not mean that it is going to fight obesity,” ACSH’s Dr. Ruth Kava points out. “And banning trans fats certainly has nothing to do with obesity.”
Dr. Whelan agrees, “Demonizing trans fats is misleading and ultimately a marketing issue.” Click here for ACSH’s arguments against the New York City trans fat ban, and don’t miss our publication Trans Fatty Acids and Heart Disease.
Should you be taking shark cartilage?
This morning Jeff Stier did an interview with Inside Edition debunking the supposed health benefits of shark cartilage. “Farrah Fawcett is reportedly using shark cartilage to ‘treat’ her cancer, so there is a question about whether other people will follow her example,” he says.
See our FactsAndFears blog for more of Jeff’s take on celebrities’ impact on science and medicine, and check out Dr. Kava’s article debunking the shark cartilage myth. Inside Edition will air in most places across the country tonight but will reach New York and a few other places tomorrow morning. Check out their website for more information.
Elizabeth Wade is a research intern at the American Council on Science and Health (ACSH.org, HealthFactsAndFears.com).
A SAMPLE REACTION:
The following exchange occurred in reaction to the April 9, 2009 item above regarding Body Mass Index (BMI):
Mike Richey wrote:
BMI is mathematically flawed. It's equal to the person's weight in kg, divided by the square of the person's height in meters. But if I'm 10% taller than you, I'd expect to be 10% wider and 10% thicker as well, so the formula should be the cube of the height instead of the square.
Here's an example: If a 5' tall person weighs 100 pounds, is that equivalent to a 6' tall person who weighs 144 pounds or 173? In real life (not based on the math above), I would say that 6'-144 is extremely skinny, whereas 5'-100 and 6'-173 are not.
Of course BMI has other flaws too, including failure to distinguish between very muscular and fat people.
ACSH's Dr. Ruth Kava responded:
1. I think the BMI index was empirically derived--by Quetelet. He found it to best represent body's fat content--in SEDENTARY people. So the whole argument about athletes is not useful.
2. Re: ht 2 or ht3: see # 1: apparently wt per area conformed better than wt per volume. The example below makes little sense to me. Sorry, but the 5' person is pretty slim, has a BMI of 19.5 ( which is probably underweight). The 6' person who weighs 144 is also quite slim--same BMI of 19.5. If the 6' person weighed 173, he or she would have a BMI of 23.5 and, if not an athlete, would be better padded. Also, if you're 10% taller, you're not necessarily 10% wider or thicker, just as you're not necessarily 10% heavier.
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