ABC’s for Brain and Eye Health

Written by Dr. Marc S Micozzi, M.D., Ph.D. a worldwide leader in nutritional and
complementary/alternative medicine.

Three simple—and delicious—ways to keep your vision
AND your mind sharp, no matter what your age

Natural substances don’t just have one, single mechanism of action.
Rather, they have many different active constituents that act in
synergy to help them survive and thrive.

That’s why, unlike drugs—which use artificial compounds concocted
in a pharmaceutical lab, and are designed to treat a single disease or
symptom—foods and nutrients help keep you healthy from head to toe.

So it’s no surprise that there’s new research showing how a variety
of nutrients and foods can support both healthy brain function and

In fact, these studies suggest that the same nutrients that reach the
brain also reach the eye. This makes sense, considering these organs
are derived from the same kind of embryological tissue during fetal

Consequently, science is now showing that when we talk about
preserving good cognitive function in the brain, the findings are
typically relevant to preserving good eyesight, too.

And there are a variety of foods and nutrients that have been
demonstrated to support both brain and eye health. I call them
my ABCs for brain and eye health because they’re that fundamental to
healthy function—especially as we age. (Not to be confused, of course,
with my ABCs of joint health, which I’ve shared with you many times

So, without further ado, let’s take a look at some simple—and
delicious—ways to keep your vision and your mind sharp, no
matter what your age…

A is for avocados

Avocados contain monounsaturated fat, which supports heart health.
Plus, they’re packed with fiber, which feeds the probiotics in the
gastrointestinal (GI) tract and promotes a healthy GI microbiome.

Avocados are also good sources of vitamins B, C, E, and K. They even
have more potassium than bananas! All of this makes avocados one
of the original “health foods.” (Remember those Angie Dickinson
commercials in the 1970s?) And now, new research shows that these
creamy fruits are particularly good for your brain and eyes.

That’s because avocados are loaded with lutein—one of my favorite

In fact, one new study showed that lutein in avocados can improve
brain function, and specifically, attention span.
(That should be good news for all of those avocados
toast fans—before they shift their attention to the next trendy food!)

The study looked at adults who were overweight or obese, which
is estimated to affect 70 percent of the U.S. population. For 12 weeks,
researchers prepared daily meals for the 84 study participants. Diets
were identical in nutrients and calories, but half of the participants
consumed an avocado each day, and half did not.

The researchers measured lutein levels in all participants’ blood and
eye fluids. (It’s rare to measure nutrients within the eye itself, as
often done in forensic sciences, but those levels are most relevant
to determining eye function.) Participants also completed three
tests to evaluate attention span and other cognitive functions.

Ultimately, the researchers found that the avocado group had better
performance on their cognitive assessments.

They also had markedly higher levels of lutein in their blood and eyes.
Other studies have found similar results. One 2017 study of nearly
50 men and women with an average age of 63 found that eating one
avocado a day for six months increased lutein levels in the eye by
25 percent. And that also translated into improvements in memory and
attention span.

Recommended amount: Two to three avocados per week. And there
are much healthier ways to eat them than as a spread on toast. Try
an avocado chopped up in a salad, diced into an omelet, or as a tasty
topping for grilled chicken.

B is for blueberries

A growing amount of research shows you really can “get your
thrill on blueberry hill” (as originally sung by Fats Domino)—
at least when it comes to brain and eye health.

As you know, blueberries have become the focus of a number
of health investigations in recent years. Studies using both the fruit
and blueberry dietary supplements have shown benefits for cancer,
cardiovascular disease, cognitive function, and metabolic syndrome.

Initially, it was theorized that the antioxidant properties of
blueberry flavonoids were primarily responsible for these benefits.
Blueberries are particularly high in anthocyanins—a flavonoid that
gives them their deep blue color. (Interestingly, research shows
that wild blueberries have three times more flavonoids than their
cultivated cousins.)

But recent studies suggest other ways blueberries work to
support brain and eye health. For instance, some lab studies show
that blueberries reduce chronic inflammation in brain neural tissues.
And chronic inflammation has been linked with cognitive decline and
dementia, along with other chronic diseases.

Plus, one study on mice found that blueberry, strawberry, and spinach
consumption for just eight weeks led to an actual reversal of aging
changes in brain cells.

In addition, studies consistently show that dietary intake of
blueberries is associated with better cognitive function and memory.

One of the most compelling was the huge Nurse’s Health Study,
which analyzed the diets of just over 16,000 women, ages 70 and
older, during a 20-year period. Researchers found that increased
consumption of blueberries was related to a 2.5-year delay in
cognitive decline.

Another recent analysis reviewed 11 different studies on blueberries
and cognition. Four studies looked at adults ages 60 and older. Four
studies were on children ages 7 to 10. And three studies looked
at adults with mild cognitive impairment (MCI), specifically.

In children, blueberry consumption was associated with increased
memory and executive function, like decision-making. In older
adults, both with and without MCI, there were improvements in
executive function and memory, as well as psychomotor function—
which is strongly associated with increased lifespan and longevity.

These results are also particularly important for people without MCI.
That’s because most botanical supplements are used to help
memory in older adults who already suffer from memory problems—but
they don’t boost cognitive function in people without memory problems.

Meanwhile, blueberries are beneficial to eye health, too.
One new research review noted that our retinas have the highest
cellular respiratory rate of any of our tissues, making our eyes
particularly prone to damage from oxidative stress.

And guess what? Blueberries’ anthocyanins may relieve that
oxidative stress!

The review cited one study of more than 35,000 women, ages 45 and
older, which found a significant association between blueberry
intake and lower risk of age-related macular degeneration.

Sadly, there currently aren’t many other human studies on blueberries
and vision—although animal and lab studies do look promising. (As
always, I’ll be sure to report on all of the latest research here in my
newsletter, as well as in my Daily Dispatch.)

Recommended amount: Half a cup of fresh blueberries per day, or
400 mg of blueberry powder per day (which can be added to water,
tea, or smoothies).

C is for carotenoids

Earlier, I discussed the carotenoid lutein, which is found in avocados
and other foods. Carotenoids are the pigments that make certain
fruits and vegetables red, orange, or yellow. (Indeed, the word actually
comes from carrots, which are bright orange.)

But carotenoids do more than just make fruits and vegetables colorful.
They also help plants absorb light to use in photosynthesis. And they
act as powerful antioxidants in the human body.

There are even a variety of studies linking carotenoids to cancer
prevention. And they also have strong anti-inflammatory properties,
which help protect against a whole host of chronic diseases.

In fact, there are more than 600 types of carotenoids. The single
most well-known is beta-carotene— even though my research years
ago, with scientists at the Human Nutrition Research Lab at the
USDA Agricultural Research Center, revealed that healthy foods
had far more abundant sources of other carotenoids, besides just beta-carotene.

(But that doesn’t mean you should overlook the health benefits of beta-carotene—

or alpha-carotene—in the proper dosages and natural forms, or preferably from foods.
Both are tried-and-true carotenoids for supporting healthy eyesight.)

Still, in recent years, there has been more research into some “new”
carotenoids—like the lutein and avocado studies I mentioned earlier.

And along with lutein, astaxanthin and zeaxanthin also show intriguing
evidence for brain and eye health. Thus far, most of the research
focuses on combinations of these carotenoids rather than the
individual compounds themselves.
Let’s take a look…

Astaxanthin. This potent carotenoid is found in sea plants,
and is what gives crab, lobster, shrimp, and salmon (which eat
these plants) their pinkish colors.

One new analysis of seven studies showed the benefits of both

astaxanthin and lutein for cognitive function in healthy adults without
memory impairment (like the blueberry study I mentioned earlier).
Five of the studies focused on lutein supplementation, and two analyzed
astaxanthin supplementation.

Middle-aged and young adults who took 10 mg of lutein a day for 12
months had consistently improved memory, attention span, and focus.
Astaxanthin also showed similar benefits in one of the studies.

And there’s even more evidence on astaxanthin’s effects on eye
health. In fact, one new research review found that the carotenoid
is effective for treating retinal diseases, cataracts, ocular surface
disorders like dry eye syndrome, eye strain, and eye inflammation.

Zeaxanthin. This carotenoid gives corn, saffron, and other botanicals
their distinctive yellow colors.

Several studies link zeaxanthin to lower risk of macular degeneration.
And now, researchers are focusing on the link between zeaxanthin,
lutein, and brain health.

One recent study involving 62 adults, with a median age of 74,
found that taking 10 mg of lutein plus 2 mg of zeaxanthin for one
year significantly increased the levels of both carotenoids in the

study participants’ eye fluid.
Those who took the carotenoid combination also had significant
improvements in attention span, executive function, and memory.

Recommended amount:
If you take supplements, I suggest
10 mg a day of lutein, 2 mg daily of zeaxanthin, and 4-6 grams a day
of astaxanthin. (Or you can look for liquid formulas that combine
astaxanthin with vitamin D for a one-two health punch.)