New study suggests that eating nuts prolongs your life – or does it?

A new study published in the New England Journal of Medicine examined consumption of nuts in relation to total mortality.  According to a press release in the Arizona Daily Star “Eating nuts is tied to lower risk of death” “The risk of dying of heart disease dropped 29 percent and the risk of dying of cancer fell 11 percent among those who had nuts seven or more times a week compared with people who never ate them.”

Many studies suggest that eating nuts have a beneficial effect on health.  The study in question was a statistical study of 170,000 health-care professionals that were followed for many years.

The results of the study are consistent with the conclusion that eating nuts every day prolongs life.  However, the results were also consistent with the conclusion that healthier people tend to eat more nuts than less healthy people, so the association is a coincidence.  Correlation does not prove causation.  Hence the study can’t really determine cause and effect.

You can read the complete article in the New England Journal of Medicine here and form your own conclusion.

Here are some details of the study:

“Dietary intake was measured with the use of validated food-frequency questionnaires administered every 2 to 4 years.”  This assumes the respondents correctly remembered, and honestly reported nut consumption.

The study excluded people with history of cancer, heart disease, or stroke.  It also excluded smokers, the extremely thin, the extremely fat, and diabetics.  Therefore, the study selected people who were genetically healthy or who had good health habits.

The study concludes: “In conclusion, our analysis of samples from these two prospective cohort studies showed significant inverse associations of nut consumption with total and cause-specific mortality. Nonetheless, epidemiologic observations establish associations, not causality, and not all findings from observational studies have been confirmed in controlled, randomized clinical trials.”

Although the study did not really prove that nuts prolong life, nuts do have many benefits, so go nuts.

See also:

Statistical Games #1

Statistical Games #2 Stroke for Stroke

Statistical Significance in Science – how to game the system