Pharma companies are spending billions in search of a medical Holy Grail.
Drugs able to defeat or delay dementia — even normal age-related brain decline — would reap enormous profits.
But, given the failure of this gambit to date, many scientists stress the potential for diet and lifestyle to help preserve people’s memory and thinking power.
And recent news supports the promise of the antioxidants and fats in certain foods as allies in the fight against brain fog and outright dementia.
Let’s look at some exciting new evidence on three promising brain-protectors: caffeine, tea, and omega-3s.
Caffeine: Benefits far beyond morning fog-lifting
Signs that caffeine promise potential brain protection continue to grow.
Seven years ago, researchers conducted a review of the evidence then available, which came from epidemiological and animal studies. (No clinical trials existed then or now.)
The authors found evidence that caffeine brings key brain-health benefits:
*It remains unclear whether amyloid-beta brain plaque is a cause of Alzheimer’s or a side effect. Either way, it damages brain cells and promotes deepening dementia.
Italian researchers came to a similar conclusion two years ago, after reviewing the available evidence: “…a protective effect of coffee, tea, and caffeine use against late-life cognitive impairment/decline … with a stronger effect among women than men.” (Panza F et al. 2015)
Epidemiological studies cannot prove that a food or nutrient causes, prevents, or treats a disease.
But when evidence from many such diet-health population studies seems consistent, it should be taken seriously.
And when you combine the signs provided by epidemiological studies with supportive evidence from clinical and animal studies, those indications gain credibility.
Swiss group's clinical studies pinpointed some brain effects
Four years ago, Swiss researchers published a rare clinical investigation of caffeine’s effects on aging brains (Haller S et al. 2013).
The Swiss team recruited 24 people — seven men and 17 women — and measured caffeine’s effects on “working” memory while their brains were being scanned via functional magnetic resonance imaging (fMRI).
(Working memory is critical to reasoning and decision-making. Short-term memory retains information briefly, but can’t do much with it.)
Their findings showed that caffeine enhanced the participants’ working memory while the fMRI scans showed greater connectivity among brain regions.
One year later, the Swiss team published a similar study conducted among elderly people with mild cognitive impairment or MCI — the medical term describing significant “brain fog” (Haller S et al. 2014).
And the results of that follow-up study suggest that caffeine helps the brains compensate for age-related memory and thinking deficiencies.
Wisconsin study linked caffeine to brain protection
More encouraging signs appeared last year from researchers at the University of Wisconsin–Milwaukee (UMW).
Their study involved 6,467 women, who were asked to report their typical daily intakes of caffeinated beverages.
Over a 10-year period, women who averaged an estimated 261mg of caffeine per day were less likely to develop dementia or any cognitive impairment, compared to the women who averaged 64mg of daily caffeine.
The study’s lead author, Ira Driscoll, expressed hope: “Anything that potentially lowers the odds of Alzheimer’s disease could have an enormous impact on what is rapidly becoming a global healthcare and economic crisis.”
Coffee was the main source of caffeine among all the study participants. A typical cup of black coffee contains 85mg of caffeine, so the women in the high-caffeine group were drinking about three cups a day.
(The amount of caffeine in coffee depends on brewing method, brew strength, and the coffee. Cheap Robusta beans contain more caffeine than gourmet Arabica beans, while espresso contains considerably less than drip filter, French press, or percolator coffee.)
Indiana mouse study details one protective pathway
Why would caffeine protect the brain against degeneration?
The answer is probably multi-faceted, but earlier this year, Indiana University researchers reported their discovery of one possible factor (Ali YO et al. 2017).
They were looking for food factors that raise levels of an enzyme called NMNAT2, which the body uses to protect brain cells. (People with Alzheimer’s, Huntington’s, and Parkinson’s diseases typically have lower NMNAT2 levels.)
Among the many food compounds they tested in mice bred to produce lower levels of NMNAT2, caffeine stood out as a clear winner.
To test caffeine, the Indiana team divided mice lacking normal amounts of NMNAT2 into three groups.
One group received a placebo (saline solution), while mice in the other two groups received different amounts of caffeine.
And the results showed that the mice given caffeine — at either dose — produced the same levels of the brain-cell-protecting enzyme as normal mice.
A daily cuppa — of tea, that is — may help
Tea and coffee both contain caffeine — plus full complements of potent antioxidants.
As we’ve just seen, caffeine, regardless of source, appears to help protect brain function over time.
Now, a population study from Singapore reinforces the idea that tea offers distinct brain-protection benefits.
Researchers from the medical school at the tiny city-state’s National University of Singapore (NUS) recruited 957 ethnically Chinese people aged 55 years or older.
The Singapore scientists asked the participants about their tea consumption. Then, every two years, from 2003 or 2005 to 2010, the seniors’ cognitive function was measured using standardized tests.
The researchers also collected information about the volunteers’ lifestyles, health status, and activities, in order to take these potential “confounding” factors into account.
And the Singapore team’s analysis suggested that regular consumption of tea reduces the risk of cognitive decline in the elderly by 50 percent.
Better yet, participants who carried the APOE e4 gene — which puts people at much higher risk for Alzheimer’s disease — were up to 86 percent less likely to show signs of brain decline during the study.
Importantly, the apparent protection provided by tea applied to all types: green, black, and oolong.
Green tea gets all the good press, but that’s misleading, as we reported in Black or Green, Tea Protects Brain Cells Against Alzheimer’s and Black Tea May Confer Memory-Saving, Anti-Stress Benefits.
Oxidation changes the antioxidant profile of tea, but apparently does not affect its ability to help protect brains cells. Black tea is heavily oxidized, oolong tea is partially oxidized, green tea is slightly oxidized, and white tea (which is relatively rare) is virtually non-oxidized.
According to the study’s lead author, NUS professor Feng Lei, “Our findings have important implications for dementia prevention. Despite high quality drug trials, effective pharmacological therapy for neurocognitive disorders such as dementia remains elusive and current prevention strategies are far from satisfactory.”
As he said, “… this long-term benefit of tea is due to the bioactive [polyphenol] compounds, such as catechins, theaflavins, thearubigins and L-theanine [which] exhibit anti-inflammatory and antioxidant potential ...”.
Although the ways in which these polyphenol-type antioxidants protect the brain aren’t fully understood, there’s little doubt that they’re responsible for the benefit.
We know this in part because cocoa — which abounds in the uncommon antioxidants (catechins) that distinguish green tea — also appears to protect the brain against age-related decline.
Omega-3s lifted brain fog in older people
It’s quite clear that seafood-source omega-3s are good for brain health.
One omega-3 in particular — called DHA — is absolutely critical to brain structure and function.
Unsurprisingly, there’s ample evidence that diets rich in fish or supplemental omega-3 fish oils help deflect or delay brain decline — and may even boost brain performance in younger people: see the Omega-3s & Brain Health section of our news archive.
Evidence in favor of omega-3s as brain protectors grew with publication earlier this year of a Chinese clinical trial, led by that nation’s own Center for Disease Control and Prevention.
The Chinese team recruited 86 people who’d been diagnosed with mild cognitive impairment (“brain fog”) for a six-month clinical trial (Bo Y et al. 2017).
They then randomly assigned the participants to one of two groups:
Unlike many prior trials, which tested relatively low doses of omega-3s, the authors of this one wisely gave the participants robust amounts.
(The U.S. hasn’t set a recommended daily allowance for omega-3s, but health authorities worldwide agree that people should consume at least 250mg to 500mg of DHA + EPA daily.)
After six months, the omega-3 group performed significantly better on standard brain tests designed to measure cognitive functions (thinking) and “working” (short-term) memory, as well as perceptual speed and space imagery efficiency.
In contrast, the placebo group displayed no improvements in brain performance.
Men and women responded a bit differently to the omega-3 regimen, but both genders enjoyed similar gains in thinking capacity, and both outperformed the placebo group in all four tests of brain performance.