A team of researchers from Harvard School of Public Health recently published the results of two cohort studies that had been conducted over the course of 26 years showing how the health benefits of whole grains1 - such as oats, maize, whole wheat, quinoa, and amaranth - may increase longevity. The findings may prove helpful for investigating methods of combating heart disease and other conditions associated with premature death, such as type 2 diabetes.2
Cohort studies are preferred to controlled trials for diet and lifestyle studies because they allow researchers to gauge long-term trends instead of regimented treatment plans.
This paper combined the results of two cohort studies: one on all female participants and a second one on all male participants. All of them were screened to rule out a history of heart disease or cancer. The study lasted 26 years, during which the investigators took extensive notes on the diets of each participant, as well as other characteristics, every two to four years. This allowed them to estimate the individual consumption of whole grain foods. They then analyzed the data they had collected to see how these habits were connected to which participants died during the timeframe of the study.
What Came Out of it?
The average age of the people taking part in the study was 50 years old, and during the subsequent 26 years in which they were followed by the researchers, about a quarter of them died. Of the female participants, those who consumed the greatest amount of whole grains averaged about 36 grams per day, while male participants at the high end of the scale documented roughly 53 grams per day.
Together, those in the study who consumed the greatest amount of whole grains in their diet were found to be less likely to die by approximately 9% and less likely to die as a result of heart disease by 15%, when compared to those who consumed less whole grains. The study also found that those with the highest intake of whole grains in their diet were more likely to be physically active and less likely to smoke or have high alcohol consumption, but also more likely to display a high cholesterol level at the beginning of the experiment.
What Does This Mean?
Despite the wide variety of factors that needed to be considered in this research, the investigators concluded that increased intake of whole grains correlate strongly with a decreased risk of death and specifically death from heart disease, even after taking other lifestyle factors into account. The results also support the idea that greater consumption of whole grains can decrease the possibility of suffering from chronic diseases. The study corroborates previous research, supporting the benefits of including of whole grains as a dietary staple.
- JAMA Internal Medicine, Association Between Dietary Whole Grain Intake and Risk of Mortality, 2015
- Foods. (2022). Health Effects of Whole Grains: A Bibliometric Analysis. Retrieved September 19, 2023, from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9777732/
- The Committee on Population of the National Research Council at the National Academies. Measuring the Risks and Causes of Premature Death: Summary of Workshops. Retrieved September 19, 2023, from: https://www.ncbi.nlm.nih.gov/books/NBK279971/