A Harvard-led study has shown a correlation between walnut consumption and a longer life expectancy. According to the study, higher walnut consumption — whether in terms of the amount or frequency — is closely associated with a lower risk of death and increased life expectancy among adults.
The study was supported by the California Walnut Commission (CWC) and was published in the journal Nutrients. They found that five or more servings of walnuts per week were associated with a 14 percent lower risk of death and a 25 percent lower risk of dying from cardiovascular disease, specifically. This, in turn, provides adults with an extra 1.3 years of life expectancy compared to non-walnut eaters. One serving of walnuts equates to one ounce of walnuts.
“What we’ve learned from this study is that even a few handfuls of walnuts per week may help promote longevity, especially among those whose diet quality isn’t great, to begin with. It’s a practical tip that can be feasible for a number of people who are looking to improve their health, which is top of mind for many people,” said Yanping Li, a senior research scientist at the department of nutrition at Harvard’s T.H. Chan School of Public Health, and lead investigator of this research, in a press release.
For this study, the researchers examined data on 67,000 women from the Nurses’ Health Study with an average age of 63.6 years. They also reviewed data on 26,000 men with an average age of 63.3 in 1986 from the Health Professionals Follow-up Study. This was the first cycle of collected data of walnut consumptions in both cohorts.
When the participants joined the study, they were healthy with no diseases and followed for 20 years, from 1998 to 2018. Their diets were assessed every four years, where participants were required to report their overall dietary intake, which included how often they consumed walnuts and other tree nuts. In addition, they were also required to input data about their lifestyle, such as their exercise and smoking status. Inputting this data allowed researchers to study the information and find associations between walnut consumption and their health indicators at different levels.
The results showed that individuals who consumed more walnuts were also more physically active, have healthier diets overall, lower alcohol consumption, and take vitamins daily. Of course, these factors were also aspects of their life that influenced the life expectancy, but researchers adjusted for this and took it into account in their analysis.
Walnuts contain a number of essential nutrients, including protein, fiber, and magnesium and have a decent amount of omega 3 fatty acids. In California alone, the walnut industry consists of more than 4,500 growers and 85 handlers represented by the California Walnut Boards and the CWC.
In July 2021, it was reported that the walnut market is expected to see significant growth and increasing demand from end-users in the industry. In 2020 the walnut market accounted for $5.3 billion in sales and is expected to reach a value of $6.5 billion by 2026 with a CAGR of 3.3 percent.