Blueberries Enhance Brain Blood Flow

Numerous studies have shown the brain-boosting benefits of blueberries, especially with regard to cognition and improved memory.

Now, an important human study has confirmed the connection between blueberries and brain health.

This study showed that blueberries increase brain activity and improve working memory. It is the first to link these cognitive benefits to specific changes in brain function and improvements in brain blood flow.¹

Brain blood flow is a vital component of brain function, memory, and cognition.²

Diminished brain blood flow is a cause of ischemic stroke, mild cognitive impairment, and neurodegenerative disorders.^3-5

One of many ways that blueberries promote brain function is to improve cerebral circulation, which has strong implications in helping to combat neuro-degenerative disorders.

Blueberry Enhances Brain Activation

Research has shown that the flavonoids found in blueberries protect brain cells from oxidative stress and inflammation.⁶

British researchers conducted a study investigating the impact of using a blueberry concentrate or a placebo for 12 weeks in two groups of older adults (averaging 68 years old).

Their focus was on brain blood flow, localized brain activation, and cognition.¹

What makes this study unique is that the scientists evaluated subjects’ brain function with a battery of cognitive tests while the subjects were inside a powerful MRI scanner. This allowed the researchers to observe brain activity in real time, while the subjects performed the tests.¹

This is called a functional MRI (or “fMRI”), and it allows the researchers to detect the activity of areas of the brain that are in use for specific cognitive functions. They can then correlate that activity with the amount of blood flowing to those brain regions.⁷

Here are findings from this study revealing how blueberries benefit brain health:

1. Blueberries increased brain activity. Compared to the placebo group, subjects in the blueberry-supplemented group showed significant increases in brain activity while taking the cognitive tests.¹ The relevant brain areas were those called upon for performance of each of the tests.

2. Blueberries improved blood flow to the grey-matter brain regions. In the blueberry group, the brain blood flow was significantly improved in the grey matter of the parietal and occipital lobe. This is where sensory, touch, and visual information is processed.¹ Such changes were not significant in the placebo recipients.

3. Blueberries improved working memory. The blueberry-supplemented people demonstrated improved working memory compared with those receiving placebo.¹ Working memory has to do with holding temporary information, like remembering those five items you needed at the grocery store. It’s also important for decision-making.⁸

This seminal study revealed in real time the impact of blueberries on cognition in human subjects. It is also the first to link blueberries’ cognitive benefits to specific changes in brain function and blood flow.

One reason this is exciting is because diminished brain blood flow can sometimes be a cause of acute events like strokes. It also underlies more chronic, slowly progressive problems such as mild cognitive impairment, and it is associated with neurodegenerative disorders such as Alzheimer’s.^3-5

This impressive human study shows us that blueberry anthocyanins have the capacity to enhance brain blood flow, potentially preventing further mental decline.¹

Blueberries Enhance Cognition

Two previous human studies of blueberry supplementation and cognition provide some context.

In one case, researchers evaluated a small group of older adults with early changes in their memory, which is often one of the first warning signs of more severe trouble to follow.⁹

When the subjects consumed wild blueberry juice daily for 12 weeks, they experienced significant improvements in learning and memory functions (there were also statistical trends suggesting a reduction in depressive symptoms and glucose levels).

A later comparison of this data with a separate placebo group confirmed the learning improvements in the supplemented subjects.⁹

This study provided one of the earliest human indicators of the effect of blueberries on cognition when taken over a period of a few weeks.

Fast-Acting Brain Boost

A more recent study examined the acute impact of blueberry supplementation on cognitive function in children to determine how quickly any cognitive improvements made their appearance.¹⁰

Children ages 7-10 years old received either a placebo drink, or one containing low- or high-dose freeze-dried wild blueberry powder. They underwent a battery of cognitive tests before supplementation, and at 1.25, 3, and 6.25 hours after supplementation.

Compared with placebo, the blueberry group showed significant improvements in memory in as few as 1.25 hours, improvements in word recognition over the entire evaluation period, and improved accuracy on cognitively demanding tests by 3 hours.¹⁰

The higher dose consistently produced better results than the lower dose or placebo across all tests.

This study demonstrates the fast-acting nature of blueberry constituents on brain tissue—and shows just how quickly this leads to improvements in everyday, practical brain performance.

Numerous laboratory and animal studies have given us insight into the broad-spectrum, multitargeted mechanisms by which blueberries enhance brain performance.

Multitargeted Brain-Boosting Mechanisms

The decline in cognitive function that occurs with aging is the result of the complex interactions of myriad cellular and molecular events. To improve cognition, any intervention must be capable of addressing multiple degenerative factors.

Studies are showing that blueberries and their anthocyanin constituents act at precisely the multiple targets necessary to prevent age-related cognitive decline, and, potentially, to reverse at least some of its features.

A growing body of animal research documents that blueberry supplementation can not only prevent cognitive decline and memory deficits, but can also enhance cognitive function.^11-16

We noted earlier that blueberry anthocyanins enhance brain blood flow,¹ which is critical, since diminished brain blood flow is a root cause of mild cognitive impairment and neurodegenerative disorders.^3-5

Another powerful and far-reaching cause of deteriorating cognition and memory in aging adults is excitotoxicity.¹⁷ This term describes the damage done to brain cells by persistent excitatory stimuli, which are those that trigger ever-increasing activity of brain cells. This activity generates massive oxidative stress, and over time it results in chronic, low-grade inflammation, which imposes even more oxidative stress in a vicious, age-promoting cycle.¹⁸

Lab studies show that blueberry polyphenols can fight the brain cell-destroying effects of excitotoxicity, the oxidative stress it induces, and the resulting inflammatory damage.^6,11,17

Supplementation studies in rats reveal that whole blueberries also fight oxidative stress directly, providing an important layer of additional protection.¹⁹

Blueberry supplementation in aged animals also promotes levels of a growth factor called BDNF, which enhances brain cell growth and repair, with clear-cut improvements in certain types of memory formation.¹²

And now, blueberries have been shown in rats to protect against the toxicity caused by beta-amyloid proteins, which are implicated in Alzheimer’s disease.²⁰ Beta-amyloid imposes massive oxidative stress and triggers inflammation in brain tissue—effects that blueberries combat with precision, in part by promoting natural defense systems in brain tissue, and in part by downregulating inflammatory responses.^20,21

Research also shows that blueberry supplements can fight the accumulation of equally toxic tau proteins associated with both Alzheimer’s and Parkinson’s disease.²²

It’s important to note that in many of these animal studies, blueberries’ effects are most prominent in protecting or enhancing spatial and working memory.^6,12,14-16

Spatial memory is what we use to locate things and people in three-dimensional space. Defects in spatial memory are associated with distressing behaviors, such as getting lost or wandering off.

Working memory is the brain’s central processing function, where memories and current sensory inputs are integrated to produce an appropriate response, such as joy on encountering a loved one, or suspicion on hearing a deal that’s too good to be true from a telemarketer.

The animal and lab studies presented here show the promising impact that blueberries may have in improving the quality of life of older adults with memory dysfunction, and ease the load on their caregivers as well. We look forward to seeing further human research confirming these findings.

Summary

Aging Americans are at risk for cognitive decline, neurodegenerative disorders, and strokes.

Underlying the epidemic of dwindling cognitive function is a small group of age-accelerating factors: declining brain blood flow, excitotoxicity from overactive brain cells, chemical stress, inflammation, and accumulation of toxic proteins in brain tissue.

A human study has now shown that supplementation with blueberries can improve brain blood flow, brain activity in memory- and cognition-intensive regions, and, most importantly, can enhance cognitive function.

Lab and animal studies demonstrate that blueberries and their active polyphenol constituents such as anthocyanins have multiple additional targets for their beneficial activity. These include potent chemical stress-protection, anti-inflammatory properties, prevention of toxic protein accumulations, and fighting the long-term effects of excitotoxicity.

Scientific studies continue to show that supplementing with blueberries can help protect against the detrimental effects of age-accelerating factors, which may help preserve cognition and memory well into advanced age.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.

References

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