We often sing the praises of a Mediterranean diet, which has been associated with reduced risk for cardiovascular disease, certain types of cancer, Alzheimer’s disease and slower cognitive decline, and all-cause mortality. (See You Can Eat Your Way to a Longer Life.)
And a new study has shown another potential benefit: It may slow down the onset of disability in older women.
What is a Mediterranean Diet?
First things first, for those of you who may be unfamiliar with the Mediterranean diet, let’s cover the basics. A Mediterranean-style diet is basically the opposite of a traditional American-style diet (e.g., lots of red meat, blood-clotting fats/oils, blood pressure raising sugars/salts, few fruits and veggies). A Mediterranean-style diet, on the other hand, focuses on the following:
- Whole grain breads, pastas and cereals
- Olive oil
- Fresh vegetables and fruits
- Nuts and seeds
- Fish and seafood
- Red wine (See Red Wine to the Rescue? More Health Benefits Discovered.)
One More Reason to Go Mediterranean
The study at hand involved 1,410 subjects (527 men and 883 women), average age 76, who were community-dwellers from Bordeaux, France, and looked at the disability in activities of daily living over five years with at least one follow-up re-examination during this period.
Disability was assessed based on activities of daily living, including:
- Transferring from bed to chair
- Ability to use a telephone
- Managing medication
- Managing money
- Use of public or private transportation
At the baseline and in follow-up, a subject was considered disabled if he or she could not perform at least one of these activities without a given level of assistance. At baseline, only 206 of the 1,410 subjects were considered disabled, and a significant majority of those were women.
As for diet, each participant was visited at home by a specifically trained dietician to collect data. They were scored 0-9 based on their adherence to a Mediterranean diet (MeDi), according to the sex-specific medians of consumption of food groups. A score of 0–3 was considered low adherence, while 4–5 constituted medium adherence, and 6-9 was considered high adherence. The foods considered were vegetables, fruits, legumes, cereals (including bread, pasta and rice, without distinction between whole and refined grains), fish, meat and dairy products. Additionally, one point was given for mild-to-moderate alcohol consumption.
The diet scores ranged from 0 to 8 with a mean score of 4.4, and were slightly but not significantly higher in men. Greater MeDi adherence was characterized by higher intake of vegetables, fruits, legumes, cereals and fish, and lower intake of meat and dairy products. And high MeDi adherence was significantly more frequent in men.
Among the participants without disability at baseline, disability occurred for 284 subjects during the study period, and the incidence of disability was higher in women than in men. But how did it relate to the adherence to a Mediterranean diet?
Well, in 709 women at follow-up (some were excluded for missing data), each additional unit of MeDi score was associated with a 10% reduced risk of disability over time. And women in the highest MeDi category (score 6–8) had a 50% relative risk reduction of incident disability over time compared with those in the lowest MeDi category (score 0–3).
Unfortunately, the same could not be said for men. Among 470 men without missing data, researchers found no association between MeDi score and the risk of disability.
Why Women and Not Men?
First things first, what is the connection between higher MeDi scores and lower incidence of disability among women?
Researchers cite the apparent health benefits include a decrease in oxidative stress and inflammation, which helps cellular function, muscle damage and degenerative diseases, such as cognitive decline, cardiovascular diseases, atherosclerosis, cancer and frailty, which can all lead to disability.
The researchers conclude: “The Mediterranean-style diet pattern probably does not fully explain the better health of persons who adhere to it but it likely contributes directly. The possible beneficial effect of the MeDi identified in the current study on the onset of disability, at least in older women, could be added to its widely acknowledged health benefits.”
That’s great news for women, but why didn’t a Mediterranean diet seem to have the same effect for men? The authors give several factors that may help explain this discrepancy.
First of all, some chronic and acute conditions that would impact the disablement process may differ in men and women. For example, men are more likely than women to have cardiovascular disease, which could cause sudden death before they become disabled. But that doesn’t mean a Mediterranean diet doesn’t have an impact on men. As the authors note, this type of diet has been linked to lower risk of cardiovascular-related deaths.
A second reason for the gender differences could lie in how they collected and measured dietary intake data. The MeDi score was based on sex-specific consumption medians, which were similar among men and women with the exception of dairy and meat, and the study assessed number of servings but not portion size. This, the authors said, could have caused the results to underestimate the true association between MeDi adherence and the incidence of disability in men.
It could also have been due to a lack of statistical power since few men were disabled at the baseline. Because those with baseline disability were excluded, this led to a sub-sample of women with high baseline MeDi score and better health status for the continued analyses.
So even though this study in particular did not show a significant benefit for men when it came to lowering the incidence of disability, its life-improving and life-extending benefits for men have been documented in other studies. In short, it’s not a bad idea for women and men to incorporate as many elements of a Mediterranean-style diet as possible.
 Fe’art, C. et al. Adherence to a Mediterranean diet and onset of disability in older persons. European Journal of Epidemiology. 27 Aug 2011. [Epub ahead of print.]