Here’s another good reason to center your meals around fruits and veggies rather than meat: A new study has found that older people were 38 percent less likely to develop Alzheimer’s disease if they ate more green leafy vegetables, cruciferous vegetables (such as broccoli and cauliflower), fruits (including tomatoes), nuts, fish, poultry and salad dressings and less high-fat dairy products, red meats, organ meats and butter.
Yes, that diet does sound a lot like the Mediterranean one, which has also been linked to a reduced risk of Alzheimer’s (and by the same Columbia University researchers who conducted this study). But the specific food choices in this study were a bit broader (yet similar in nutrients) than those typically consumed in Mediterranean countries.
Specifically, the study [PDF] (which was posted online Monday in the Archives of Neurology and will appear in that journal’s June print issue) followed 2,148 older New York City residents, aged 65 and older, for four years. The dietary reports of the residents were closely analyzed for consumption of seven nutrients: vitamin E, vitamin B12, folate, saturated fatty acids, monounsaturated fatty acids, and omega-3 and omega 6 polyunsaturated fatty acids.
Here are the findings:
- Some 16 percent (117 of 749 individuals) of the study’s subjects whose diets ranked in the highest third in terms of saturated fats and vitamin B12 (nutrients found in high-fat dairy products and red and organ meats) developed Alzheimer’s disease during the study.
- By contrast, only 7 percent (50 of 682 individuals) of those whose diets were rich invitamin E, folate and mono- and polyunsaturated fat (nutrients found in nuts, fish, and fruits and vegetables, including vegetable oils) developed Alzheimer’s.
- Of those whose diets fell somewhere in the middle, 12 percent (86 of 717) developed the disease.
The usual caveats
This was only an observational study, so it can’t show cause-and-effect — in other words, it doesn’t prove that a specific dietary pattern protected any of the subjects from Alzheimer’s. Other, confounding factors may have been at play. People who eat a Mediterranean-style diet may exercise more, for example, or even have greater access to health care — factors that may have lowered their risk of Alzheimer’s.
Still, other research suggests that polyunsaturated fatty acids, vitamin E and folate may have neurobiological protective effects on the brain.
The researchers note in their study that their results “reinforce the importance of studying [dietary patterns] rather than individual foods or nutrients.” It’s the combination of the foods, they suggest, not a specific nutrient that seems to offer the “optimal biological synergy” for reducing the risk of disease.
Also, there may be factors in the foods — particularly in their combinations — that help the brain stay healthier. So don’t think you can short-cut the process by simply adding the nutrients in the form of supplements.
Of course, it’s also important to keep in mind that even if these results prove to be true, no diet can completely eliminate the risk of Alzheimer’s disease. Many factors, including genetics, are involved in this debilitating neurodegenerative disease.