In a paper that was published in the Journal of the American Geriatrics Society, the researchers describe how they came to this conclusion after analyzing data from published studies that had followed older adults and compared their diets with incidence of frailty.
"We found," says Dr. Kate Walters, joint study leader and director of the Centre for Ageing and Population Studies at University College London, "the evidence was very consistent that older people who follow a Mediterranean diet had a lower risk of becoming frail."
The Mediterranean diet was initially defined in the 1960s, when researchers studied the eating habits of people in Greece and Southern Italy and then began comparing the heart risks of Mediterranean populations with those of the United States and Northern Europe.
Since the 1960s, while researchers have used various definitions of the Mediterranean diet, they generally emphasize the same key components.
These key components include: a high intake of plant-based foods, such as vegetables (including leafy vegetables), fruits, nuts, pulses, whole cereals, and olive oil; a moderate intake of fish, dairy, meat, and red wine; and a low intake of sweets and eggs.
'A state of increased vulnerability'
There is, as yet, no "gold standard" for defining frailty, but researchers and clinicians tend to regard it as a condition that meets three out of the following five criteria:
- low physical activity
- weak grip strength
- low energy
- slow walking speed
- non-deliberate weight loss
Frailty is common among older adults and is associated with a lower quality of life and a higher risk of disability, falls, dementia, hospitalization, and premature death.
As the population ages, we can expect numbers of people with frailty to increase.
For their analysis, the team included data from four studies that had examined the link between following a Mediterranean diet and incidence of frailty in 5,789 people from China, France, Italy, and Spain, who were followed for an average of 3.9 years.
Frailty risk lower with Mediterranean diet
All four studies had categorized adherence to Mediterranean diet in the same way: they had put their participants into three groups, depending on how closely they followed the diet.
The results showed that incidence of frailty was significantly lower for those participants who most closely followed the Mediterranean diet.
"People who followed a Mediterranean diet the most," explains Dr. Walters, "were overall less than half as likely to become frail over a nearly 4-year period compared with those who followed it the least."
The researchers say that the findings support the idea that a Mediterranean diet could help older people to remain healthy as they age — for example, by boosting activity, weight, energy levels, and muscle strength.
However, they also point out that a limitation of their study is that it was not clear whether or not other factors may have helped to protect the participants from becoming frail.
Dr. Walters says that these factors might include, "for example, their age, gender, social class, smoking, alcohol, how much they exercised, and how many health conditions they had."
"We now need large studies that look at whether increasing how much you follow a Mediterranean diet will reduce your risk of becoming frail."
Dr. Kate Walters