COLOR NUTRITION
This is an
interview by Christine Gable with Walter Last for an article in the May 07
issue of the N.Y. magazine Better Nutriton.
1. Blueberries and blackberries boast fiber and anticancer qualities,
thanks to the pigment anthocyanin. Why is anthocyanin beneficial? Are there any
other compounds that make dark colored fruits and veggies grand?
Anthocyanins
and related compounds belong to the group of flavonoids and are polyphenols
with three carbon rings that are responsible for the red, purple, and blue
colors of fruits, vegetables, and flowers. Various studies have
shown that mortality from cardiovascular disease is inversely
correlated with the intake of flavonoids in the diet, they also have
anti-microbial activities and help with cancers, strokes, vascular
problems and all kinds of inflammatory conditions. They are helpful with
diabetic retinopathy and macular degeneration, especially beneficial are the
purple pigments in Bilberries for improving night vision or visual
acuity and circulatory disorders.
The
main benefits of anthocyanins are probably due to their strong antioxidant and
free-radical quenching activity. Most foods contain a variety of anthocyanins
and related compounds. There exist thousands of variations of the basic
molecular configuration, and the specific health effect of most of these is
still unknown. One such ingredient that has in recent years risen to
prominence is resveratrol from the skin of grapes.
It
is attributed with inhibiting fungal infections, inflammations, cancers,
metastases, heart disease, Alzheimer's disease and other age-related brain
disorders, raising good HDL cholesterol, lowering PSA levels in males,
increasing immunity, controlling blood pressure, preventing blood clots
and strokes, and extending the lifespan by switching on a “longevity
gene.” While it is mainly ingested as an ingredient of red wine, supplements
are now available of whole grape skins which seem to be more beneficial than
more purified resveratrol. Also grape seed extract has similar impressive
health benefits.
2. Green veggies are well known as being an important part of a healthy
diet. What exactly is it about green vegetables that makes them so super?
The
obvious feature of green veggies is the green color due to chlorophyll.
Chlorophyll is a protein with the same structure as hemoglobin, and
therefore with a desirable amino acid composition. Veggies have a
very favorable protein to carbohydrate ratio. While low in fats they
are relatively high in alpha linolenic acid, a desirable omega-3-fatty
acid. In regard to vitamins they are especially high in vitamin K and
folate, or folic acid, which are generally deficient with most individuals.
They are low in pro-inflammatory phosphorus but high in
anti-inflammatory calcium and magnesium.
Spinach
is one of the best sources of magnesium, listed as 88 mg/100 g, which can be more
difficult to obtain from food than calcium. Green veggies are also high in
desirable fiber to feed the bowel bacteria and prevent constipation. The
overall composition is such that it is a highly desirable food for cancer and
all inflammatory conditions. However, this assumes that vegetables are steamed
or that the cooking water is ingested because it contains most of the
beneficial vitamins and minerals.
Even
more beneficial are green leaves, or wheat or barley grass as freshly pressed
or frozen juices or as commercial powders, usually organic and still high
in enzymes. For remaining young longer enzymes generally are even more
important than vitamins and minerals. This is also the advantage of raw green salads.
Generally the best base for an anti-inflammatory and anti-cancer diet is a
combination of chlorophyll-rich foods such as spirulina, chlorella, barley
or wheat grass powders, fresh raw, juiced and cooked green vegetables, and other
colored foods.
3. In your book you write about the benefits of purple foods. Can you
tell me more about the purple pigment betacyanin--why/how does it turn purple
foods into powerhouses?
There are four main
classes of plant pigment: chlorophylls, carotenoids, flavonoids and betalains.
Betacyanin is a betalain and the purple-crimson pigment in red beet
or beetroot and prickly pear. Like most of the bioflavonoids it is water soluble
while chlorophylls and carotenoids are insoluble in water.
Red beet is rich
in important minerals and micronutrients (especially folate/folic
acid) but its many health benefits are mainly due to its two ingredients
betacyanin and betaine. Traditionally it was regarded as being beneficial for the
blood, heart and digestive system and was used as a laxative, for bad breath,
coughs, headaches, and more recently also as an immune stimulant and
anti-cancer agent. In Roman times as well as in modern
Red beets have been used
for centuries in the treatment of cancers, and for this betacyanin is probably the
active ingredient, although the alkaloid allantoine in beets has also an
anti-tumour effect. In modern times it came to prominence with reports of
promising results by the Hungarian physician Alexander Ferenczi in the 1950s.
In the 1960s several
cancer researchers, especially the German P.G. Seeger, demonstrated that the
metabolism of cancer cells could be normalized with the pigments in beet juice.
However, cancer cells with high-grade malignancy as after chemotherapy or
radiotherapy could no longer be normalized, although beet juice was still
helpful.
Red beets were also an
important part of the recent South African fight against HIV and AIDS, although
this has now been de-railed by the proponents of drug treatments.
Betaine in red beet is a
mood modifier; it relaxes the mind and is useful for depression. Chemically betaine
is trimethylglycine (TMG) and related to choline. With this it is needed for
producing neurotransmitters, especially serotonin, and as a methyl donor it is
important for the liver and the fat metabolism. It also lowers levels of
homocysteine and with this reduces the risk of heart disease and strokes.
Some
people pass red urine (beeturia) and red stool, even after eating only a modest
amount of beetroot. This may be overcome with magnesium supplements; also iron
deficiency is often present with beeturia.
4. Do all foods that are red, blue or purple contain bioflavonoids?
What should people know about bioflavonoids?
Basically
all foods that produce a red, blue or purple juice when pressed with
skin contain bioflavonoids or betalains. If just the skin is colored,
such as with apples, eggplant and some sweet potatoes there may be
colorless polymers present inside that can still have a high antioxidant value.
However, by far the highest flavonoid content is usually in the skin. Yellow
and orange foods are commonly colored by carotenes with a different
chemical structure.
Flavonoids
is the name for thousands of polyphenolic plant chemicals with
a three-ringed structure. Those that are biologically most active are
also called bioflavonoids. Nutritionally important sub-groups of
flavonoids are the anthocyanins, the citrus bioflavonoids and the tea polyphenols.
Citrus
bioflavonoids have quercetin as the basic chemical structure; common
members include rutin, quercitrin, hesperidin, and naringin. These remain
generally in the pulp after pressing out the juice. To extract the
bioflavonoids blend the pulp or inner skin with some water and strain.
When
many individual anthocyanin molecules are linked together they are also
called proanthocyanidins and oligo-proanthocyanins or OPC's. One such
compound is commercially extracted from pine bark as pygnogenol while
grape seed extract has similar qualities.
The
flavonoids in tea are based on catechin, the main active ingredient
is epicatechin. It improves blood flow and thus seems good for the heart
but also helpful with cancer.
However,
adding cows' milk to tea eliminates its beneficial effect on the
heart as caseins in milk render the catechins inactive. While the
catechins in tea are beneficial, the tea itself is now so very high in fluoride
that regular consumption may be a health danger, especially in fluoridated
areas. It may be better to use cocoa instead with its much higher antioxidant
power, provided you can do so without adding cows' milk, goats' milk should be
acceptable.
Another
group of flavonoids that I would give a miss are the soy isoflavones (e.g.
Genistein and Daidzein). There is a high probability that they are produced
from GM soy. Also because of the high concentrations of anti-nutrients in soy
foods these are only healthy if they are traditionally fermented (this may not
apply to lecithin because it does not contain soy proteins). There are also
concerns about the effects of soy phytoestrogens on our natural hormone
balance.
Bioflavonoids
are powerful antioxidants, and their acknowledged health benefits include
anti-microbial, anti-inflammatory, anti-cancer, antihistamine and
anti-allergy effects. They work synergistically with vitamin C, decrease
capillary permeability and fragility, and protect collagen, blood
vessels and the heart.
In
conclusion I recommend reducing "empty" calories from sugar and white
flour to the barest minimum and use instead a wide range of colored fruit,
vegetables and spices.
5. Is it correct that spinach, lettuce, broccoli and peas contain
lutein and zeaxanthin? Are they carotenoids that help protect the eyes from
macular degeneration?
There
are two groups of carotenoids, carotenes, such as beta carotene, and
xanthophylls with lutein and zeaxanthin. Both groups form yellow and orange plant
pigments.
The
chemical structures of both are nearly identical but they seem to perform
different functions in the macula of the eye, as the concentration of
zeaxanthin is highest in the center, and lutein in the periphery of the
macula. They are also found in the lens and so may protect against
cataracts as well as age-related macular degeneration (AMD) and some forms of
cancer. Their main function seems to be as antioxidants, protecting the eye
from ultraviolet light and free radicals. They may improve vision in retinitis
pigmentosa, are helpful in glaucoma and stimulate immune functions.
Both
tend to occur in the same foods and are often reported together. Lutein is
usually present in much higher amounts than zeaxanthin. Kale contains the
highest amount of lutein in a vegetable with 21.9 mg/100 g but contains only 0.173
mg/100 g of zeaxanthin. Corn with .78 mg/100 g of lutein has the highest amount
of zeaxanthin at 0.528 mg/100 g. Spinach has a combined value of about 12
mg/100 g. Next come turnip leaves and collards, and other foods have much less.
The amount of lutein in chicken egg yolk is approximately 290 micrograms per
yolk, and of zeaxanthin 210 micrograms per yolk, or combined 3 mg per 100 g.
Sometimes also higher or lower values can be found in food tables.
A
recommended food supplement with high values of lutein and zeaxanthin is spirulina.
Two teaspoons or 10 g provide 6 to 8 mg with about 3 mg of zeaxanthin. Lutein
is commercially extracted from marigold petals as a food coloring, especially
to add to chicken feed for coloring the yolk. The lutein content of these
petals is about 1%.
Lutin
and zeaxanthin, like all carotenoids, are fat soluble. Therefore to absorb them
they need to be ingested with fat or oil, preferably in addition to some
lecithin for better absorption. Unfortunately, there is now widespread mineral
and fat malabsorption due to the twins of gluten sensitivity and antibiotic use
causing dysbiosis, and this makes it very difficult for affected individuals to
absorb these nutrients even from a good diet and even less from tablets. The
solution is generally intestinal sanitation with garlic and probiotics to
improve absorption.