The good news: eating nuts and peanuts can prolong life expectancy. The bad news: peanut butter is not included. A study conducted as part of the Netherlands Cohort Study - which has been following the lifespan of Dutch men and women since 1986 - has identified nuts consumption as one of the markers for delayed mortality. Unfortunately, eating peanut butter was not as positive for long-term health.
Starting in 1986, researchers of the Netherlands Cohort Study have observed over 120,000 Dutch men and women between the ages of 55 and 59, and analyzed the correlation between their total lifespan with a large number of lifestyle habits that could potentially affect it - including tree nuts, meat, and fresh vegetables consumption, as well as physical activity and occupational history. As this is a very long-term enterprise, only now are different results coming in, highlighting the variety of potential lifestyle choices and their effects on long-term health.
The consumption of nuts, such as walnuts and Brazil nuts, as well as peanuts - which are actually legumes but nutritionally considered as nuts - was included as one of the variables of the study that aimed to establish a relationship between nuts and lifespan. Both portion size and intake frequency were considered. A remarkably lower mortality rate was discovered in those consumers who ate 15 grams of nuts or peanuts on average per day, but a higher intake did not mean further mortality risk reduction. It is believed the fatty acids, fiber, and antioxidants found in nuts and peanuts contributed to this effect.
On the other hand, since most peanut butter brands contain other less-favorable added ingredients - mainly salt, oil, trans fats, and occasionally sugar - there were adverse health effects attached to them that inhibited the positive effects of eating raw peanuts.
Over the years, this study has shown that those who consume at least 15 grams of peanuts or tree nuts per day are less at risk for mortality due to cancer, diabetes, and neurodegenerative diseases. Due to other compounds found in most peanut butter brands, the same positive results cannot be achieved by consuming the paste instead of raw peanuts.
What Does This Mean?
It would be a good idea to carry around a bag of your favorite nuts, which, besides the above mentioned, can include pecans, sacha inchi nuts, and almonds to make sure at least 15 grams are consumed daily in order to reduce the risk of death due to diabetes and cardiovascular disease, among other chronic and degenerative health conditions.
- International Journal of Epidemiology, Relationship of tree nut, peanut and peanut butter intake with total and cause-specific mortality: a cohort study and meta-analysis, 2015