UK study shows improved heart rate variability in response to mental stress for participants eating almonds in place of typical snacks
As part of a recent clinical trial, researchers at King’s College London measured Heart rate variability (HRV) in participants undergoing a mental stress challenge and saw improved measures of HRV in participants who had been replacing typical snacks with almonds over a six-week period. The study was funded by the Almond Board of California.
Higher HRV represents greater adaptability of the heart in response to environmental and psychological challenges, while low HRV is linked to cardiovascular disease and sudden cardiac death.
This new research finding was part of the Almonds Trial Targeting Dietary Intervention with Snacks (ATTIS) study, a 6-week randomized control, parallel-arm trial, where participants with above average cardiovascular disease risk consumed a daily snack of almonds or a calorie-matched control snack providing 20% of each participants’ estimated daily energy needs.
In this study, researchers measured participants’ real-time heart rate (HR) and heart rate variability (HRV) at rest (lying down for 5-minute periods) and during a Stroop test (in which participants were asked to read colored words i.e. say “red” in a green font) to simulate short period of mental stress.
During acute mental stress, participants in the almond group showed better heart rate regulation compared to the control group, indicated by statistically significant differences in high frequency power, which specifically evaluates beat-to-beat intervals (a measure of HRV).
“This study shows that the simple dietary strategy of swapping almonds for typical snacks may bolster resilience to the adverse cardiovascular effects of mental stress by improving regulation of heart rate. We found that the stress-induced reduction in heart rate variability was lessened in the almond group compared to control following the dietary intervention, which indicates a cardiovascular health benefit. It is useful to think of having a higher HRV as the heart being able to switch gears faster in response to demands on the body, which means more cardiac resilience and flexibility during periods of stress. In the long term, this is beneficial for cardiovascular health,” said Dr. Wendy Hall, PhD, co-principal investigator (together with Dr. Sarah Berry, PhD) and Reader in Nutritional Sciences at King’s College London.
The research suggests that eating almonds in place of typical snacks may diminish the drop in HRV that occurs during mental stress, thereby improving cardiac function. This dietary strategy has the potential to increase cardiovascular resilience to mental stress, along with other heart health benefits of consuming almonds such as lowering LDL-cholesterol and improving the function of blood vessels.
Speaking about the study, Regional Head-Dietetics, Max Healthcare – Delhi, Ritika Samaddar commented, ““The results of this study are favourable, especially for a country like India where mental stress and cardiovascular diseases (CVD) are big areas of concern. The results of this new study showcase how regular almond consumption helped improve heart rate variability in response to mental stress for participants eating almonds in place of typical snacks. Therefore, I strongly recommend replacing calorie high junk food with almonds, which are a healthier and wholesome snacking option. In the long run, this simple change will also aid in a person’s overall heart health.”
This new study was part of the ATTIS trial. A recently published paper from ATTIS also examined the role of almond eating on LDL-cholesterol levels and endothelium-dependent vasodialation (measured through flow meditated dilation, or FMD), which is a predictor of cardiovascular disease risk.
Commenting on the results of the study, Sheela Krishnaswamy, Nutrition and Wellness Consultant commented, “The results of this study are very promising, and relevant especially now when several Indians are experiencing high levels of stress due to the current pandemic. This research suggests that revising one’s dietary strategy to include almonds can increase cardiovascular resilience to mental stress in addition to reducing LDL-cholesterol and improving endothelial function of the blood vessels (as shown in other studies) – thereby improving cardiac risk factors. Simply by replacing unwholesome snacks with almonds, people who are suffering from CVD or are at risk, can make a healthy difference to their lives.”