Rejuvenating the Brains of the Elderly!? The Day Snacks Become "Brain Training": The Real Impact of 60g of Peanuts a Day on the Brain and Blood Pressure

"The Usual Snack" Boosted Brain Blood Flow?

"Peanuts May Increase Brain Blood Flow"

Such headlines are appearing in international media and are a hot topic on social media. Fox News covered the latest clinical trial by a team from the Netherlands' NUTRIM Institute (Maastricht University Medical Center). The results showed that when elderly individuals consumed peanuts daily, there was a slight improvement in blood circulation to the brain and memory.Fox News

Amidst flashy advertisements for "brain-boosting supplements" and "dementia-preventing foods," the star of this study is the "ordinary peanuts" that can be easily found in supermarkets. This has sparked both interest and skepticism, with questions like "Is it true?" and "How effective is it?"

Study Details: 31 Elderly Participants and 16 Weeks of "Peanut Life"

This study is a randomized crossover trial published in the scientific journal Clinical Nutrition. The research team compared two periods involving 31 healthy men and women aged 60 to 75.PubMed

• Peanut Period:

  • Participants consumed unsalted, skin-on roasted peanuts 60g per day (approximately "a heaping handful")

  • This was done every day for 16 weeks

• Control Period:

  • The same participants had a period of 16 weeks without consuming any peanuts

• An 8-week washout period was included in between, with the order randomly switched

Participants were asked to incorporate the specified amount of peanuts into their meals without significantly altering their usual lifestyle. They were required to eat them as they are, as crushing or heating could change their nutritional composition.New York Post

The impact on the brain was measured by MRI (arterial spin labeling) to assess overall brain blood flow. Cognitive function was evaluated using the standardized test battery CANTAB.PubMed

What Happened: 3.6% Increase in Brain Blood Flow and 5.8% Improvement in Memory

In summary,

"After consuming 60g of peanuts daily for 16 weeks, there was a slight but significant improvement in brain blood flow and some memory test scores in the elderly."

Specifically:PubMed

• Global Brain Blood Flow (Global CBF)

  • During the peanut consumption period, blood flow increased by approximately 3.6% compared to the non-consumption period

• Gray Matter Blood Flow

  • In the gray matter, which is involved in memory, emotions, and decision-making, there was an increase of approximately 4.5%

• Frontal and Temporal Lobes

  • Larger increases were observed in areas related to language and higher-order thinking, such as around 6% in the frontal lobe.

• Verbal Memory Tests

  • In tests where participants had to recall words after some time, the number of correct answers improved by an average of about 5.8%

  • Roughly speaking, this means they could recall 1 to 2 more words

• Other Cognitive Functions

  • No significant improvements were observed in other cognitive tests, such as executive functions (planning, switching, etc.) and reaction speed

A 3-4% increase in brain blood flow does not mean a dramatic improvement in intelligence. Nonetheless, the fact that brain blood flow, which gradually declines with age, showed a positive shift through dietary habits alone is a rather intriguing signal for researchers.

Blood Pressure Also Dropped Slightly, but No Weight Gain

Interestingly, there were changes in cardiovascular indicators as well.PubMed

• Systolic Blood Pressure: Decreased by an average of about 5mmHg

• Pulse Pressure: Decreased by about 4mmHg

On the other hand, 60g of peanuts per day is approximately 340kcal, which is not a light snack. However, the trial reported no significant weight changes among participants. This aligns with the general notion about nuts: "High in calories but also high in satiety, making it difficult to significantly increase total calorie intake."

That said, this is a small-scale, controlled trial. In real life, if peanuts are added to the usual sweet snacks and alcohol, the risk of weight gain naturally increases. In this sense, the mindset of "replacing snacks with peanuts" is important.

What in Peanuts Might Be Beneficial for "Brain Blood Vessels"?

The research team and related reports suggest several components in peanuts as potential candidates.PubMed

• L-Arginine: An amino acid that serves as a precursor for nitric oxide (NO), which dilates blood vessels

• Unsaturated Fatty Acids: Fats believed to have positive effects on cardiovascular health, similar to olive oil

• Polyphenols and Antioxidants: Abundant in skin-on peanuts, potentially protecting blood vessels from oxidative stress

• Dietary Fiber: May indirectly benefit blood vessels through gut health and blood sugar control

• Plant-based Protein: May contribute to overall metabolic improvement

The study specifically focused on **"unsalted, skin-on roasted"** peanuts, which is noteworthy. The skin contains a high amount of polyphenols and dietary fiber, which might differentiate them from "just peanuts."

However, these are merely potential mechanisms considered likely, and the study did not establish causality, such as "3.6% increase in blood flow thanks to arginine."

Reactions on Social Media: Excitement, Anxiety, and Criticism

When such news is reported, various voices emerge on social media. Below is an imagined summary of typical reactions, not actual posts.

• "From today, peanuts are my only snack choice. They're cheap, tasty, and good for the brain—perfect!" (60s, Male)

• "As a generation fearful of Alzheimer's, I'm willing to try anything, so this research is hopeful." (70s, Female)

• "Is it wise to make a big deal out of a study with only 31 participants? I'd like to see larger trials before making a judgment." (40s, Researcher)

• "For those with allergies, this news is like hell... I hope similar effects are studied with other nuts." (30s, Female)

• "The problem is the 'unsalted' part. That's the toughest for those who enjoy drinking." (50s, Male)

Many positive reactions focus on the "low barrier" aspect, such as "cheap and easy to continue" and "it's food, not medicine." Meanwhile, cautious voices point out the limitations of the study design, such as "sample size," "only healthy elderly participants," and "only peanuts were tested," expressing concerns about "headlines running ahead of the facts."PubMed

For those with peanut allergies, this news doesn't even offer the option to "try it." Comments like "I hope similar research is conducted with other nuts" are also seen, reminding us that health information can be both "hopeful" and "alienating" depending on the person.

Researchers Are Cautious: "It's Not a Magical Food"

Even in reports by Fox News, researchers emphasize that while improvements in brain blood flow were observed, it's still just a small step.Fox News

The main limitations are as follows:

1. Few participants (31 people)
   Even if statistically significant differences are found, the number of participants is not enough to cover individual differences. It's unknown whether the same trend will be observed in large-scale studies.

2. Only "healthy elderly" were targeted
   The study does not indicate whether the same effects would occur in people with high blood pressure, diabetes, dementia, or younger individuals.

3. Highly specific conditions

   • Unsalted

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