July 5, 2019
Back in June, I adapted a recipe to make a nut-rich dough for fruit tarts in honor of National Walnut Day. We posted the recipe on our clinic website along with a short research review on walnuts and blueberries. Now that I’ve made half a dozen tries at using my recipe I’ve gone back onto the website to amend it; basically it was too complicated, too many steps, too many dirty pans to clean, and basically too much like what my dear wife calls “Cooks Illustrated” recipes. So, the recipe is different now, and no doubt will change over the summer as different fruits come into season. The updated recipe:
In looking at the recipe I also took a moment to do a literature search on walnuts and found a new clinical trial that was published since we sent out that Walnut Day Review, a study worth our looking at for a moment.
A group of researchers from Harvard’s T.H. Chan School of Public Health asked what happened if people increase their nut consumption to their risk of subsequent heart disease down the road? In other words, does it do any good to do this now or have we had to be eating nuts for our entire lives for it to make a difference in risk, or put another way, should we bother our patients to change their eating habits (something that doesn’t come easy)? Is it worth the effort?
Harvard’s researchers have the capacity to ask questions like this as they have data from several large patient cohorts at their disposal and are skilled at accessing it. In this study, they analyzed data pulled from 34,222 men enrolled in the Health Professionals Follow-up Study 77,957 women from the Nurses’ Health Study and 80,756 women from the Nurses’ Health Study II. Not quite 200,000 participants were followed for a mean of 17.2 years. This adds up 2,818,760 person-years of data; this was enough information to ask some very specific questions. Nut consumption had been assessed every four years. Using some sophisticated statistics, the researchers examined the difference shifting nut consumption had on risk of having a heart attack or having or dying of coronary artery disease, or stroke.
Their findings both confirmed earlier, weaker studies and assured us that making even slight changes in our diets, such as increasing nut consumption, pays off in the long run.
For each half a serving of walnuts per day that people added to their diets, the relative risk of cardiovascular disease over the following 4 years dropped by 14%. For other tree nuts and for peanuts, the relative risk dropped only 7%. Regular and consistent nut consumers had a significantly lower risk for cardiovascular disease, coronary heart disease and stroke.
While these numbers do not come as a great surprise, the strength of this study is striking. The fact that changing consumption patterns change outcome risk in a relatively short period of time is perhaps the most striking. That and the fact that walnuts appear to provide substantially more benefit than other types of nuts.
Oh, and before someone emails me as to what counts as a serving of nuts, the answer is one ounce of nuts or 28 grams. This study looked at the effect that half a serving a day has, so 14 grams of nuts. There are 12 -14 walnut halves in an ounce, so we are talking about half a dozen walnuts halves per day.
Once again, I feel an urge to take my hat off to the fine researchers at T.H. Chan.
For endless recipes using walnuts, check out the California Walnut website: https://walnuts.org/recipes/?
Liu X, Guasch-Ferré M, Drouin-Chartier JP, Tobias D, Bhupathiraju S, Rexrode K, Sun Q, Li Y. Increased Nut Consumption and Subsequent Cardiovascular Disease Risk Among U.S. Men and Women: Three Large Prospective Cohort Studies (OR17-08-19). Curr Dev Nutr. 2019 Jun 13;3(Suppl 1). pii: nzz039.OR17-08-19.
Full text of study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6577377/