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