Overweight and Low Mortality

Last week the Journal of the American Medical Association (JAMA) published a meta-analysis documenting that being “overweight was associated with significantly lower all-cause mortality.” (here).  The study was authored by Dr. Katherine Flegal of the U.S. Centers for Disease Control and Prevention (CDC) and colleagues at the National Cancer Institute and the University of Ottawa. 

 

This post will focus on the study’s scientific findings and the reaction to same, which is not dissimilar to the research and backlash surrounding tobacco harm reduction.

Dr. Flegal and colleagues conducted an extensive search for population studies reporting all-cause mortality according to categories of the body mass index (BMI), which is weight in kilograms divided by height in meters squared.  They used the following standard categories: 

Table 1. BMI Ranges for Weight Categories in the Flegal Meta-Analysis
BMI Range	Weight Category
Under 18.5	Underweight
18.5 to less than 25	Normal
25 to less than 30	Overweight
30 to less than 35	Grade 1 Obesity
35 to less than 40	Grade 2 Obesity
40+	Grade 3 Obesity

 

Dr. Flegal’s literature search initially identified 7,036 articles, of which 97 met the criteria for their study, which included adequate adjustment for age, gender and smoking.  The results were reported as hazard ratios (HRs), which are similar to relative risks.

Table 2. Hazard Ratios (HRs) for All-Cause Mortality According to Weight Categories in the Flegal Meta-Analysis
Weight Category	HR (95% Confidence Interval)
Underweight	Not Reported
Normal Weight	Referent Group
Overweight	0.94 (0.91 – 0.96)
Grade 1 Obesity	0.95 (0.88 – 1.01)
Grade 2-3 Obesity	1.29 (1.18 – 1.41)
All Obesity	1.18 (1.12 – 1.25)

 

 

The major finding is remarkable: Overweight people had a LOWER risk of mortality than people of normal weight.  In addition, Grade 1 obesity (up to BMI < 35) was also associated with lower mortality risk, although this was not statistically significant.  

The results run counter to the dominant public health message that overweight and obesity are killers, which is why the study was immediately denounced by many.  As Christopher Snowdon pointed out (here), extensive media coverage of the attacks gave credence to the notion that the analysis was flawed and unreliable.  Walter Willett, professor of public health at Harvard, declared: “This study is really a pile of rubbish and no one should waste their time reading it.” (here). 

This high-profile assault is similar to that which has been waged against tobacco harm reduction findings over a 20-year period.  In the 1990’s, Philip Cole and I published numerous scientific articles on the gaping difference in health risks associated with smokeless tobacco use and smoking.  We were sometimes ignored and often reviled; ad hominem attacks routinely obscured our important findings.

 

I have long had a professional interest in population studies of weight and health. In 2004, I published the first and only study showing that Swedish men who quit smoking by switching to snus avoided the weight gain usually seen with smoking cessation (abstract here).  My research experience provides some insights into the Flegal/CDC study.

Why are overweight people at less risk of dying than those of normal weight?  It’s possible that the normal-weight group included people who had lost weight because they were ill and were close to death, thereby raising the death rate in the reference group to which all other categories were compared.  In other words, an artificially higher death rate in the normal-weight group resulted in an artificially lower rate among overweights.  Although this is one of the more common criticisms discussed in the media, it is not likely to be a major factor, because the vast majority of the normal-weight population are healthy.

A more likely explanation for Dr. Flegal’s surprising result is that many in her “overweight” population belong in a properly defined “normal” weight category.

In my weight research I had to establish BMI categories.  A literature review revealed that major health organizations had changed the definition of overweight.  Up to the late 1990s, researchers had defined overweight as a BMI of 27+, which meant that normal weight went from 18.5 up to 27.  Dr. Flegal agreed with this definition, as she published a study using this classification in 1994 (here).

 

For reasons that I was never able to pin down, the definition of overweight changed in the late 1990s to a BMI of 25+.  Suddenly, people with a BMI from 25 to 27, who were previously normal weight, were now overweight.  The prevalence of overweight skyrocketed.

Since the newly-classified overweights continued to die at normal-weight rates, this reclassification might help explain Dr. Flegal’s finding of low mortality in the overweight category. 

 

One unresolved problem with Dr. Flegal’s analysis is that she defined three distinct obesity categories (1, 2 and 3 in Table 1), but then combined the mortality results for the highest two categories, and failed to report any results for the underweight category.  These are important omissions which Dr. Flegal needs to explain.

  

Despite these issues, CDC scientists should be commended for publishing this profoundly important finding: Compared with normal-weight individuals, overweight and slightly obese people have LOWER mortality.  It’s a shame that their colleagues at the CDC Office of Smoking and Health aren’t equally forthcoming about the minuscule risks for smokeless tobacco use.  For example, the first entry on the smokeless tobacco fact sheet from the CDC (available here) is - inexplicably – a webpage for gutka, a southeast Asian tobacco product that is rarely used in the U.S.  The rest of the CDC document conflates information regarding the health risks from smokeless tobacco use with those from smoking.

Like tobacco use, overweight and obesity are the objects of revulsion among some health advocates.  Scientific evidence, however, clearly shows that overweight or minimally obese people have lower mortality risks than those of normal weight, placing them at risk only for misguided, unscientific public health interventions like fat taxes (here) or soda restrictions (here).  Like tobacco users, the overweight and obese deserve health policies based on scientific facts, not fanaticism. 

High School Seniors’ Tobacco Use Pales in Comparison to Alcohol

Smoking by teens has declined to record-low levels, according to the latest University of Michigan annual Monitoring the Future Study, which examines youth tobacco, alcohol and drug use in 2012 (data tables here).  The figure at left, which shows the percentage of high school seniors using alcohol, marijuana, cigarettes and smokeless tobacco in the past 30 days over the period 1975-2012, is highly informative. 

Cigarette use continued a long-term decline, reaching 17%, the lowest prevalence since the survey’s introduction in 1975.  Cigarette use was lower than marijuana use (23%) for the fourth consecutive year.  Smokeless tobacco use among boys declined for the third consecutive year to 13.5%; use among girls was 1.6%. 

As I noted in 2009, (here), anti-tobacco forces have a brilliant strategy for dealing with tobacco use research: If it’s good, take credit; if it’s bad, blame the industry.  In a press release, the Campaign for Tobacco Free Kids did a little of both.  It implied that the gains were attributable to FDA regulation and tax increases, but it claimed that “…the tobacco industry still spends $8.5 billion a year — nearly $1 million every hour — to market its deadly and addictive products …that entice youth.”

If the tobacco industry is responsible for youth smoking, which industry is responsible for marijuana use?

For high school seniors, alcohol is by far the drug of choice.  While alcohol prevalence declined substantially from over 70% around 1980, it remains far too high.  In 2012, more than 40% of high school seniors had an alcoholic drink in the past 30 days; 28% of them had been drunk.  This is astounding, given that the legal age to consume alcohol is 21 years.  It is especially worrisome when considering how many teens and young adults die in auto accidents.  With the exception of the elderly, this age group (15-24 years) has by far the highest death rates from auto accidents.  It comprises 14% of the U.S. population but accounts for 27% of auto deaths (2,498 in 2009).

Any use of drugs among children is a problem that should concern every American. We need to better understand the social and behavioral reasons why children experiment with and adopt substance use, in order to develop prevention strategies.  But we need to prioritize limited resources based on the relative impact of each substance on children’s health. Cigarettes and smokeless tobacco should not be ignored, but the MTF survey documents that alcohol is the major threat.

FDA Inaction Strengthens Cigarette Market Supremacy

Two weeks ago AP writer Michael Felberbaum published an interesting story, “FDA review of tobacco products grinds to a halt,” about how the FDA has failed to review 3,500 product applications required by the 2009 Tobacco Act (here).   

Felberbaum notes, “The reviews, which are supposed to take 90 days, has [sic] dragged on for years in some cases. About 90 percent of applications have lingered for more than a year.”

The story’s title is not entirely accurate, since it implies that the FDA review had been active.  In fact, the agency has not completed any reviews.

The number of applications is large, primarily because the Tobacco Act requires manufacturers to submit them even for minor product changes, and even if the new product is “substantially equivalent” to those already on the market.  I wrote in March 2011 that the FDA would “Require tobacco manufacturers to spend millions of dollars to keep their existing tobacco products on the market, and prevent the introduction of new products.” (here).

The accuracy of my prediction is confirmed by Felberbaum: “For example, [Lorillard CEO Murray] Kessler said that under the FDA's guidelines, if the nation's third-biggest tobacco company wanted to take a Kent brand cigarette and rename it ‘Newport,’ it would be subject to review even though ‘it's not substantially equivalent — it's exactly equivalent.’”  

At first glance, this FDA bottleneck looks like a win for public health, as it effectively blocks new cigarette introductions.  But as I noted almost two years ago, this process would result “in a regulatory nightmare for tobacco harm reduction by threatening existing smokeless products and completely inhibiting new-product innovation.”  

There is additional evidence of FDA inaction.  On December 17 the agency held a public hearing “to obtain comments …on FDA consideration of applicable approval mechanisms and additional indications for nicotine replacement therapies (NRTs), and to request input on a report to Congress examining the regulation and development of innovative products and treatments for tobacco dependence.” (here). 

Officials heard surprisingly consistent testimony – from advocates of tobacco harm reduction and e-cigarettes, strident anti-tobacco groups and tobacco and drug companies – that smoking, not nicotine and tobacco, is the public health problem and that the current federal government obsession with tobacco and nicotine abstinence is an utter failure.  The agency was encouraged to give smokers truthful information about the comparative risks of all tobacco products and, most importantly, to implement sensible regulations that would enhance smokers’ awareness of and access to vastly safer and satisfying cigarette substitutes that are already on the market. 

There is little reason to expect that the hearing will have any impact on FDA behavior.  Over two years ago the agency held a public workshop entitled “Risks and Benefits of Long-Term Use of Nicotine Replacement Therapy (NRT) Products” (here).  The consensus among experts was that long-term nicotine use has negligible risks and considerable benefits, but the hearing had no appreciable effect on the abstinence-only agenda.

In the past, the FDA has frequently been criticized for its regulatory actions, but hardly ever for regulatory inaction, which may partially explain its behavior.  Lars Erik Rutqvist, senior vice president of scientific affairs at snus manufacturer Swedish Match, thinks there is an industry focus: “I think there's suspicion within industry that this is how it's going to be in the future and this is more or less a way of punishing the industry.”

The FDA is not just punishing the industry.  By failing to review applications for new smoke-free products, the agency becomes an enabler of cigarette consumption, assuring continued market domination of the deadliest of nicotine delivery systems.  That is a public health tragedy.

The E-Cigarette Revolution

Richard Craver, a writer for the Winston-Salem Journal, recently described the growing popularity of e-cigarettes (here).  Bonnie Herzog, a Wells Fargo security analyst who has followed the tobacco industry for many years, described e-cigarettes as “here to stay,” suggesting that sales would reach $1 billion within a few years.  In an August research note to investors (here), Herzog predicted that e-cigarette sales could surpass combustible cigarettes within ten years.

These predictions are based on impressive increases in e-cigarette sales since 2008.  The chart illustrates UBS data presented by NJOY CEO Craig Weiss during a conference call with Goldman Sachs on December 14.  U.S. e-cigarette sales totaled $20 million in 2008; they have doubled each subsequent year, to $500 million in 2012.  As Weiss noted, the explosive growth occurred even as the category was inundated with low-quality products that provided a suboptimal experience to smokers.  That problem is being resolved by substantial investment in quality improvement.  NJOY, which has a 40% share of convenience store e-cigarette sales, introduced King (here), describing it as “the first electronic cigarette with the look, feel and flavor of the real thing.”

 

Product improvements can be expected because cigarette manufacturers are also investing in the category.  In April, Lorillard purchased Blu (here), and Craver reports that the company has invested $40 million in a marketing campaign.  In July, Craver reported that RJ Reynolds launched e-cigarette Vuse in limited test markets in Virginia and North Carolina (here). 

British American Tobacco announced on December 19 that it had purchased CN Creative (here).  This company makes the Intellicig e-cigarette brand (here) and Ecopure nicotine solution (here), which it says is produced with pharmaceutical- and food-grade products and undergoes stringent testing.  BAT also owns Nicoventures (here), a company devoted to providing “…a new choice to smokers looking for a safer alternative to cigarettes.  Nicoventures will focus exclusively on the development and commercialization of innovative regulatory approved nicotine products that provide a consumer-acceptable alternative to cigarettes without the serious risk to health of smoking.  We want to explore the development of innovative nicotine products that, subject to regulatory approval, will provide smokers with an alternative to cigarettes and a product they actually want to use.”

Wells Fargo’s Herzog also notes that the steep decline in cigarette consumption will affect state payments from the 1998 Master Settlement Agreement.  While cigarette manufacturers promised to pay the 46 MSA states about $206 billion over more than 20 years, their payments will be reduced if cigarette sales decline.  This could lead state governments to impose excise taxes on e-cigarettes to cover those losses. 

So far, e-cigarettes have avoided excise taxes because they are not classified as tobacco products.  However, in 2011, federal courts ruled that e-cigarettes are tobacco products (here), so the “excise tax honeymoon” that e-cigarettes and their users have enjoyed won’t last forever.    

The tobacco harm reduction revolution is unstoppable, and e-cigarettes are poised to play a major role.  State legislators can facilitate smokers’ switch to healthier e-cigarettes by keeping excise taxes low, or nonexistent.