Writing in the Journal of Nutrition, the findings add to a large library of evidence that outline the many benefits of including walnuts as part of a healthy diet.
Walnuts are rich in alpha-linolenic acid (ALA), a plant-based omega-3 fatty acid, which makes up one of the nut’s profile of healthy polyunsaturated fats.
The study focused on data collected from 54,762 women in the Nurses' Health Study, which tracked women for over 30 years.
A healthy diet includes nuts
The team, from the Brigham and Women's Hospital in collaboration with Harvard Medical School, found that participants who increased intake of walnuts, along with oranges, orange juice, apples and pears, and romaine or leaf lettuce, were less likely to have incidents of physical impairment that could restrict independence.
However, associations with each component and with specific foods were generally weaker than the overall score, suggesting overall diet pattern was more important than individual parts.
Numerous studies have linked regular consumption of nuts with a reduced risk of cardiovascular disease. Their anti-inflammatory and anti-oxidant properties have been shown efficacy in diabetic patients.
"There's a lot of research that looks at specific health conditions in ageing, such as diabetes and heart disease, but less attention to research on quality of life and ability to maintain independence with ageing," said Dr Francine Grodstein of Brigham and Women's Hospital and Harvard Medical School.
"The simple message from this study is that eating an overall healthy diet, including certain foods, such as walnuts and other whole foods, may help women with the ability to do key everyday tasks as they age, like carrying groceries or dressing themselves."
The team pointed to the limitations of the study commenting that the sample only included women, so may not be generalisable to men. Additionally, participants were not assigned to eat walnuts or other foods, and were just asked about their dietary choices.
Source: Journal of Nutrition
Published online ahead of print, doi: 10.3945/jn.115.227900
“Greater Adherence to the Alternative Healthy Eating Index Is Associated with Lower Incidence of Physical Function Impairment in the Nurses’ Health Study.”
Authors: Kaitlin Hagan et al.