Nurses Frequently Attending Church Live Longer

The Harvard-based Nurses' Health Study has been a remarkably productive longitudinal health study.

My wife has been a subject in this study and frequently completes interval questionnaires regarding her health status.

A recent publication looked at the relationship between religious service attendance and mortality in the Nurses's Health Study cohort.

This manuscript tried to provide a more valid look at the relationship between religiosity/spirituality and health. Previous studies have found a link between church attendance and longer life but these studies were vulnerable to reverse causation confounding.

Mortality rates over a 20 year period were reduced in a scaled manner compared to those control subjects who id not attend church by the following amounts:

• Attends church less than once per week: 13% lower mortality
• Attends church once per week: 26% lower mortality
• Attends church more than once per week: 33% lower mortality

Potentially confounding factors that were controlled included diet, physical activity, smoking status and body mass index.

The research team suggests church attendance rates may be a proxy for social support, a factor known to influence mortality risk.

Read more about this study at the ScienceDaily website HERE.

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Photo of willet birds on seashore is from the my files.

Li, S., Stampfer, M., Williams, D., & VanderWeele, T. (2016). Association of Religious Service Attendance With Mortality Among Women JAMA Internal Medicine DOI: 10.1001/jamainternmed.2016.1615

Do Baseball Players Live Longer?

The Major League Baseball (MLB) playoffs begin today. I did a PubMed search for recent research related to baseball.

One interesting abstract examined the body of research related to elite athletes and longevity.

This review article examined 54 peer-reviewed manuscripts that addressed the mortality and longevity of elite athletes. Sixteen of these studies examined longevity in MLB players.

I will summarize some of the conclusions from this review.

• MLB players tended to have longer lifespan than controls by up to an average of around 4.5 years
• Players with longer MLB careers tended to have the most extended lifespans
• Some studies found evidence for slighter shorter lifespans for left-handed players than for right-handed players. A handedness effect was not found in some studies.
• Years of education contributed to longevity in MLB players, a finding that has been reported in the general population
• Position played and body weight of MLB players contributed to extended life expectancy with lower weight players showing the greatest mortality benefit
• MLB players were similar to NBA and NFL players in showing an extended longevity compared to the general population. However, NFL players showed higher rates of death due to neurodegenerative disorders including amyotrophic lateral sclerosis and Alzheimer's disease

The authors note there are some significant research design issues including potential confounders in this type of research. First, athletic participation at the elite level selects individuals with the highest levels of fitness and health. Additionally, athletes are required to maintain high fitness levels during their playing careers. Many may continue to participate in fitness activities following the end of their career. 

Elite athletic participation appears to be associated with increased longevity, although this effect may be tempered if high body weight is required for the sport and the position played.

Readers with more interest in this research can access the free full-text manuscript by clicking on the PMID link in the citation below.

Follow the author on Twitter WRY999

Photo of MLB spring training game is from the author's files.

Lemez S, & Baker J (2015). Do Elite Athletes Live Longer? A Systematic Review of Mortality and Longevity in Elite Athletes. Sports medicine - open, 1 (1) PMID: 26301178

Nuts, Booze, Soy and Cardiovascular Mortality

I have previously published several posts related to diet, cardiovascular mortality and cognitive function.  A recent post looked at the relationship of fiber intake and mortality.  Another post examined adherence to a Mediterranean style diet with reduced risk of cognitive decline.  Now there is another important study published examining diet and risk of cardiovascular mortality and all-cause mortality. 

Cardiovascular disease and mortality are important issues for many of the clinical neuroscience diseases.  Heart disease is often the first issue that comes to mind when thinking about cardiovascular disease.  However, here is just a partial list of clinical neuroscience disorders linked to vascular function and health:

• Stroke
• Vascular and Alzheimer's dementia
• Transient ischemic attacks
• Vascular neuropathy

A study Akbaraly et al published in The American Journal of Clinical Nutriton examined dietary history and mortality in those participating in the Whitehall II epidemiologic study.  The Whitehall II study is a study of Londoners who worked in one of 20 civil service occupations.  The baseline data was first collected in 1985 through 1988 (when subjects were 35 to 55 years old) but nutritional information was not collected until 1991-1993.  At that time subjects were scored on a composite index of healthy eating called the Alternative Healthy Eating Index (AHEI) composed of the following subscale categories:

• Vegetables
• Fruits
• Nuts and soy
• Ratio of white meat to red meat
• Total fiber
• Trans fat
• Ratio of unsaturated fats to saturated fats
• Duration of multivitamin use
• Alcohol intake

A composite score is calculated from this index with higher scores indicating presumed healthier diet.  The study subjects were grouped in three groups--low AHEI , intermediate AHEI and high AHEI each group representing a third of the sample.  


After 18 years of follow up, approximately 10% of the low AHEI subjects had died compared to 7% of the high AHEI subjects.  Cardiovascular mortality was 42% less for those in the high AHEI group.  All estimates were made after controlling for a variety of potential confounding sociodemographic variables, i.e. gender, BMI, smoking status).


There were two findings that caught my attention from this study.  One was some of the inflammatory and clinical differences in the groups.  The high AHEI group:

• Had lower serum levels of inflammatory markers C-reactive protein (CRP) and interleukin-6 (IL-6)
• Had lower levels of dyslipidemias (elevated cholesterol or triglycerides)
• Had no lower risk of having hypertension or diabetes

A second finding in the study was the examination of the contribution of individual categories to correlation with lower cardiovascular mortality risk.  Only two of the categories correlated with reduced cardiovascular death rates: nuts and soy AHEI scale score and alcohol intake scale score.  Total fiber intake had the next largest individual contribution but failed to be statistically correlate with reduced mortality.


Maximum scores in the nuts and soy category were reached with only one serving per day.  Maximum scores in the alcohol intake category were reached with two drinks per day for men and one drink per day for women. 


This study adds impetus to further study of what are the most important contributing factors of a "healthy diet" when health is measured as reduce risk of mortality from cardiovascular disease and all other causes.


Photo of Carlos Zambrano pitching for the Chicago Cubs courtesy of Yates Photography.
  
Akbaraly TN, Ferrie JE, Berr C, Brunner EJ, Head J, Marmot MG, Singh-Manoux A, Ritchie K, Shipley MJ, & Kivimaki M (2011). Alternative Healthy Eating Index and mortality over 18 y of follow-up: results from the Whitehall II cohort. The American journal of clinical nutrition, 94 (1), 247-53 PMID: 21613557

Aerobic Exercise, Resistance Training and Mortality

The research support for regular exercise to be associated with reduced risk of death is growing.  However, there is limited research that focuses on effects of aerobic versus strengthen (resistance) training.  Additionally, there is limited data comparing mortality in those with and without a general medical condition. 

Schoenborn and Stommel recently published a study addressing these issues in teh American Journal of Preventive Medicine.  They examined a large sample of U.S. adults and assessed whether they met  the 2008 USDHHS Activity Guidelines for Americans:

• 150 minutes per week of moderate intensity aerobic activity
• OR 75 minutes per week of high intensity aerobic activity
• Encourage two days per week of weight training of 7 large muscle groups

The study examined exercise levels and mortality by linking data from the 1997-2004 National Health Interview Survey and death registry data from 1997-2006.  Mortality examined in groups with no chronic medical conditions compared to those with one or more medical conditions including: diabetes, hypertension, vascular problems, lung disease (asthma/bronchitis), one or more functional limitations (any difficulty walking, climbing steps, standing, sitting, stooping, reaching, grasping, or lifting/pulling or pushing large objects).

This study was informative because it looked at the effect of aerobic versus strength versus both aerobic and strength on mortality.  Additionally, it examined the effect of exercise on mortality in four age categories: 18 and younger, 18 to 44 years of age, 45 to 64 years of age and 65 and older age groups.

>The key findings from the study were:

• Strength training alone was not associated with decrease mortality risk
• Aerobic exercise was linked to reduced mortality risk aerobic exercise with over 150 minutes per week somewhat better than less than 150 minutes per week ( although going above 300 minutes per week did not correlate with additional mortality reduction)
• Among those meeting aerobic exercise guidelines, adding strengthening showed a trend for correlation with an additional beneficial  mortality effect
• Older adults  with one or more chronic conditions appeared to have the strongest association between exercise and lower mortality risk

The chart below summarizes the magnitude of association between exercise levels and lower mortality rates in those in the 45 to 64 age category and those aged 65 and older with one or more medical conditions.  To aid in interpretation of the numbers the SMR for those 65 and older with one medical condition meeting both aerobic and strengthening exercise guidelines was .52.  This means during follow up they were 48% (1-SMR) less likely to die than those not meeting exercise guidelines for either aerobic or strengthening types.

This study is a correlational study and not a prospective controlled trial so the data need to be interpreted cautiously.  It may be that individuals with chronic medical conditions die not because they don't exercise but because their illness is so severe they are unable to exercise.  Nevertheless, this study adds to our knowledge of the relative correlation of aerobic and resistance training and mortality.  Additionally, it suggests that exercise may have a significant beneficial role in older adults who have one or more medical conditions.

Figure by author adapted from data provided in manuscript.

Schoenborn, C., & Stommel, M. (2011). Adherence to the 2008 Adult Physical Activity Guidelines and Mortality Risk American Journal of Preventive Medicine, 40 (5), 514-521 DOI: 10.1016/j.amepre.2010.12.029

Suicide Tops Death List for Meth Heads

Methamphetamine Chemical Structure

Methamphetamine dependence can lead to an early death.  The magnitude and mechanism of this effect is not well understood.  One way to better understand effects of drug abuse/dependence on mortality is the prospective outcome study.  These types of studies tend to be costly and may require many years to yield research results.   That’s why there are not many published studies to answer the question of this post.

A recent study from Taiwan provides some valuable insight into this issue.  This study followed a cohort of 1254 individuals with a history of methamphetamine abuse and a psychiatric admission for treatment between 1990 and 2007.  National death records were queried and the methamphetamine abuse cases were compared to an age- and gender- matched control group.  One hundred thirty methamphetamine users died during follow up with the following leading categories of death:  

• Suicide n=42 (32.3%)
• Accidents n=26 (20.0%)
• Undetermined unnatural deaths n=14 (10.8%)
• Cardiovascular disease n=13 (10.0%)
• Undetermined natural deaths n=9 (6.9%)
• Liver disease n=6 (4.6%)

In this Taiwanese sample, methamphetamine abuse carried an overall six fold increase in mortality.  Unnatural deaths (suicides, accidents, homicides, undetermined natural deaths) were particularly elevated.  Male amphetamine abusers had about a 10-fold increase in unnatural deaths while female methamphetamine abusers had a remarkable 26-fold increase in unnatural death during follow up.

Being married appeared to reduce the risk of death from unnatural and natural causes in this cohort.  Use of other substances in addition to methamphetamine increased risk of death.

I would suspect that in the United States, homicide would be a greater contributor to mortality in those with a history of methamphetamine dependence.  Overall homicide rates in Taiwan are much lower than in the United States and may reduce risk for this type of unnatural death.

Interestingly, about two thirds of the cohort had exhibited methamphetamine psychosis-a psychiatric complication of methamphetamine use.  Those with a history of this type of psychosis were no more likely to die than those without a history of the psychosis.

One problem with this type of study is difficulty assessing the specific effect of methamphetamine from other potential confounding factors.  For example, methamphetamine use is higher in smokers than smokers and so some increased mortality risk could be related to effects of smoking.  Methamphetamine dependence is more prevalent in a variety of mental disorders linked to increased suicide.

Nevertheless, this study shows the magnitude and type of mortality risk linked to methamphetamine dependence.  Public health interventions that reduce the prevalence of methamphetamine dependence would like reduce the excess mortality associated with this drug.

Wikipedia Commons chemical structure of methamphetamine image authored by Harbin.

Kuo CJ, Liao YT, Chen WJ, Tsai SY, Lin SK, & Chen CC (2010). Causes of death of patients with methamphetamine dependence: A record-linkage study. Drug and alcohol review PMID: 21355920