If you want to remain healthy as you age, you have to eat well. And recently a lot of evidence is showing that diets designed to improve heart health are also good for the brain.
In a recent study published in Neurology, researchers found that healthy seniors who regularly ate green leafy vegetables like spinach, kale and collard greens on a daily basis experienced a slower rate of cognitive decline when compared to those who ate little or no greens at all.1
Study author Martha Clare Morris a professor of nutrition at Rush Medical College in Chicago who also directs the Rush Institute for Healthy Aging says, "The association is quite strong.”
The study included 960 participants who were part of the Memory and Aging Project at Rush University.2
The average age of each participant was 81 and none of them had any signs of forgetfulness. In addition, as part of the project each participant underwent a series of yearly tests to evaluate their cognitive abilities and memory. Researchers also monitored their eating habits and activity levels.
In order to evaluate how leafy greens and age related cognitive changes were related, researchers split the participants up into five different groups based on the amount of greens eaten.
Participants who consumed the most greens were put into one group while the others were put into four additional groups based on how many greens they ate, the bottom group consisted of those who ate little to no greens.
After five years of data collection, Morris says, "the rate of decline for [those] in the top quintile was about half the decline rate of those in the lowest quintile.”
So, what’s the most efficient way to add greens to your diet?
Candace Bishop, one of the study participants says, "My goal every day is to have a big salad, I get those bags of dark, leafy salad mixes."
For reference a single serving of greens is defined as a half-cup of cooked greens, or a cup of raw greens.
While there are many factors in the aging process, this study does suggest that eating greens may be helpful but it certainly doesn’t prove it.
According to Morris, researchers can only establish association but not causation, between eating a heathy diet high in greens and a sharp mind.
However, even after adjusting the results to take in to account things such as lifestyle, education and overall health, she says. "we saw this association [between greens and a slower rate of cognitive decline] over and above accounting for all those factors."
Earlier studies came to similar conclusions. In one study published in 2006, women who consumed a lot of vegetables experienced less cognitive decline among older women.3
The connection was strongest with an increased consumption of leafy vegetables and cruciferous vegetables, like broccoli and cauliflower.
There’s also evidence that a Mediterranean-style diet, emphasizing the consumption of fish, nuts, vegetables and whole grains may also contribute to high levels of health late in life.4
It appears to be the fact that these vegetables contain a wide range of nutrients and bioactive compounds including vitamin E and K, lutein, beta carotene and folate.
"They have different roles and different biological mechanisms to protect the brain," says Morris.
However, there is a lot more research to be done in order to fully understand their role, but one thing appears to be certain, eating too few vegetables can be problematic.
For example, "if you have insufficient levels of folate in your diet you can have higher levels of homocysteine," Morris says.
This can lead to higher levels of inflammation and blood vessel damage, which increases the risk of stroke.
Studies show that high homocysteine levels are associated with cognitive impairment in older adults.5
In closing, Morris confirms, "So, when you eat leafy greens, you're eating a lot of different nutrients, and together they can have a powerful impact.”