The US Recommended
Dietary Intake (DRI) for fruits and vegetables is 8 to 10 servings per
day. I know this sounds like a high
hurdle but I cannot emphasize enough the health benefits to be gained by
following this suggestion. You would be
hard-pressed to find a comparable health benefit from any single supplement. Fruits and vegetables are loaded with
plant-derived phytochemicals that give them flavor, a rainbow of colors and most
importantly, resistance to disease. Not
only are the plants protected but so are you.
These phytochemicals, also called phytonutrients, share their immune-boosting
and anti-inflammatory properties with every bite. This is achieved through a number of
bioactivities that include anti-oxidation, which protects DNA and other cell
components from oxidative damage. Other
phytochemicals affect gene expression leading to the synthesis of
health-promoting proteins while others function analogously to hormones.
As a Professor of Nutrition
Sciences, two text books that I reply heavily on for current nutritional
information are Nutrition Concepts and
Controversies by Sizer and Whitney and Prescription
for Nutritional Healing by Phyllis A. Balch. Both books provide an in depth and well-balanced
review of the roles played by Phytochemicals.
Among the most recognizable antioxidants are the carotenoids and
flavonoids. Carotenoids, which include
beta-carotene, lycopene and lutein, can be found in deeply pigmented fruits and
vegetables such as apricots, broccoli, carrots, sweet potatoes and tomatoes.
Flavonoids are widespread in berries, vegetables, soybeans, whole wheat and
other whole grains, wine and tea. Wine
and tea are also excellent sources of the antioxidants resveratrol and tannins. Curcumin is an antioxidant and
anti-inflammatory agent found in turmeric that may reduce blood clot formation
and inhibit enzymes that activate carcinogens.
Phytonutrients found in whole grains
include alkylresorcinol, lignans and phytic acid, all of which reduce the risk
of some cancers. Lignans, found in flaxseed,
contain phytoestrogen that blocks estrogen activity so reduces the risk of
cancer of the breast, ovaries, colon and prostate. Phytoestrogens, such as genistein, are found
in soybeans and soy foods. In cell-based
studies genistein was shown to accelerate the growth of breast cancer cells at
low doses and inhibit growth at high doses.
(Further details surrounding this controversy can be found at http://egglrock.blogspot.com/2014/10/are-you-afraid-of-soy.html). Indoles and isothyiocyanates, found in cruciferous
vegetables such as broccoli, brussel sprouts, cabbage, cauliflower,
horseradish, mustard greens and kale, may trigger the production of enzymes
that block DNA damage from carcinogens.
Other phytochemicals that have the capacity to neutralize carcinogens
include monoterpenes found in citrus fruit peels and oils, and phenolic acids
found in coffee beans, fruit, oats, potatoes and soy beans. Saponins found in
alfalfa sprouts, green vegetables, potatoes and tomatoes are thought to prevent
cancer by interfering with DNA replication.
As an added bonus, saponins also stimulate the immune response. Capsaicin found in hot peppers is a
phytonutrient that modulates blood clotting and pain perception. Chives, garlic, leeks and onion contain a
phytonutrient called allicin that functions as an antimicrobial agent and may
also lower blood cholesterol.
As a pharmacologist I have spent
decades searching for a magic (i.e. billion dollar) pill that would mimic these effects. After spinning my wheels for so many years I
have come to the conclusion that the health benefit of whole foods containing many thousands of these nutrients, simply cannot be duplicated with a single chemical
compound formulated into a once-daily dose pill. For those individuals who are reluctant to
embrace fruits, vegetables and whole grains a product called Juice Plus+ may
help to bridge this gap. The Juice Plus+
company makes capsules and chewables from 30 whole fruits and vegetables. Although the company certainly has its fair
share of detractors the wealth of published data in peer-reviewed journal
articles has conclusively demonstrated the product’s ability to positively
affect biomarkers of human health. Juice
Plus+ is endorsed by a formidable number of physicians who clearly believe it
is the next best thing to whole foods.
While the product cannot be used as a meal replacement it is a simple
way to consume the best that phytonutrients have to offer.
