LATEST RESEARCHES ON NATURAL FOOD & NUTRITION
Blueberries May Help Protect Heart!
Wild blueberries were shown to strengthen blood vessels against
oxidative stress that may lead to heart disease in rats, report scientists
in the Journal of Nutritional Biochemistry (2006, vol.17, no.2:
109-116).
For a 13-week period researchers fed a control group of rats a standard diet, while feeding an intervention group’s diet was supplemented with powdered wild blueberry.
They found that the diet enhanced with blueberry significantly altered the composition and structure of rat aorta in terms of glycosaminoglycans (GAGs).
These are carbohydrate molecules directly involved in a variety of
functions in the body. Specifically, there was an increase in a GAG
called galactosaminoglycan (GalGAG). By maintaining higher levels
of GalGAGs, blood vessel walls are more resistant to oxidative
stress that can lead to cardiovascular disease. .
Olive Oil In Mediterranean Diet & Vitamin E Protects Older Blood Vessels!
Consuming a Mediterranean-style diet, which is rich in olive oil,
fresh vegetables and vitamin E, could help reduce the risk of peripheral
vascular disease (PVD) in the elderly, according to a new study.
PVD can be caused by hardening of the arteries, inflammation, and
thrombosis. The study, published in the journal Atherosclerosis
(2006, vol.186: 200-206), assessed nutrient and dietary intake of
1251 people with an average age of 68.
The researcher found, among other things, that a daily intake of 34 grams or more of vegetable lipids, mostly from olive oil, cut the risk by more than 60 percent. Vitamin E intake of 7.7 milligrams per day or more also
reduced the risk of PVD, again by more than 60 percent.
Green and Black Tea Prove Beneficial to Brain Functioning
Research in the European Journal of Neuroscience (2006, vol.23,
no.1: 55-64) indicates that both green and black tea may help protect
the brain against age-related neurodegenerative conditions such as Alzheimer’s disease. Cell cultures from rats were treated with amyloid proteins, which are associated with the onset of Alzheimer’s disease.
Extracts from both green and black tea, with concentration
levels of between five and 25 micrograms per milliliter, were found
to exhibit protective activity against the effects of amyloid proteins.
Another Reason to Eat Salads: Vegetables, Spices, and Herbs contain powerful Antioxidant Properties!
This literature summary is part of the HerbClip, an educational mailing service of the American Botanical Council
Fruits and vegetables contain polyphenols, compounds that
reduce oxidative stress and prevent chronic diseases. The
antioxidant properties of polyphenols are responsible for
their anticancer, antiviral, and anti-inflammatory properties and
can prevent capillary fragility and platelet aggregation.
The authors report the phenolic, flavonoid, and flavanol content as
well as the antioxidant capacity of a number of fresh vegetables,
herbs, and spices consumed in central Italy. The authors also
studied these same parameters in cooked vegetables, salads, and
common Italian salad dressings.
The authors obtained and tested 27 different types of vegetables,
15 different types of herbs, six spices, and 10 dressings.
Phenolic compounds were assayed and total phenolic content
was expressed as caffeic acid equivalents in milligrams per gram
of fresh vegetables. Flavonoids and flavanols were also measured.
Antioxidant capacity was measured using the oxygen radical
absorbance capacity (ORAC) method. Using a multiple
linear regression model, the authors provided significant evidence
that ORAC values are strictly dependent on the total
phenols (P = 0.048) and flavanols (P = 0.001), and that the contribution to ORAC of the flavonoids is not significant (P = 0.156).
Among the vegetables showing the highest phenolic content were the artichoke, beetroot, cabbage, broccoli, red chicory, red chili, and yellow pepper. The authors report that different cultivars cause vegetables of the same family to possess significant different phenolic, flavanol, and ORAC values.
The authors measured the loss of phenolics and antioxidant capacity in vegetables that need to be cooked. Steamed vegetables
retained about 80 percent of the phenolic and ORAC values
of raw vegetables; boiled vegetables retained only 30 percent
of antioxidants. The preferred cooking process for vegetables
should be steaming at the mildest temperature and for the least
possible time to protect phenolics and vitamins.
Among the aromatic herbs receiving high ORAC values
were garden sage, marjoram, rosemary, and garden thyme.
Their values are many times greater than those of the vegetables
studied.
The authors showed that introducing aromatic herbs into
salads markedly increases the phenolic and ORAC values of the
whole salad. Lemon balm and marjoram at a concentration of
1.5 percent w/w increased by 150 percent and 200 percent,
respectively, the antioxidant capacity of a salad portion.
Amon the selected spices, cumin revealed the highest ORAC value,
although its phenolic and flavonoid content were not the highest.
Fresh ginger also made a significant contribution to the
antioxidant capacity.
Noting the importance of the use of salad seasonings, the
authors state that extra-virgin olive oils, carefully produced
using freshly gathered olives at the right degree of maturation,
should be the principal condiment for their content of phenolic
compounds, which, because of their marked antioxidant capacity,
protect the cardiovascular system.
The authors stress the importance of educating consumers
on the benefits of varying vegetable consumption, choosing
those that have the highest antioxidant capacity to promote a
healthy diet, and the need to introduce aromatic herbs as a seasoning
supplement in the diet of every age group.
Results of this analysis provide “a simple and compelling
tool for nutrition professionals to guide family vegetable consumption”
and “can be used in public health campaigns to stimulate
the consumption of vegetables able to provide significant
health protection in order to prevent chronic diseases.
Fish Oil Helps Asthma Sufferers
Omega-3 fatty acids may protect asthma sufferers from exercise induced
bronchoconstriction (EIB), a narrowing of the airways that
can be triggered by vigorous exercise, reports a recent study in the
journal Chest (2006, vol.129, no.1: 39-49).
Researchers supplemented the diets of 16 volunteers with asthma and documented EIB for three weeks with either a fish oil capsule containing omega-3
fatty acids (3.2 grams of eicosapentaenoic acid (EPA) and 2.0 grams
of docosahexaenoic acid (DHA)) or placebo.
A two-week washout period followed then another three weeks of the
supplemented diet. The fish oil diet improved pulmonary function to below the diagnostic EIB threshold. The improvement was accompanied by a
reduction in bronchodilator use of more than 31 percent.
Citrus Flavonoid Repairs DNA
Naringenin, a flavonoid found in grapefruit and oranges, helped
repair damaged DNA in cancer cells, according to a lab study, the
results of which were published in the Journal of Nutritional Biology
(2006, vol.17: 89-95). Specifically, researchers examined the effect of naringenin on DNA repair in human prostate cancer cell cultures.
After 24 hours of exposure to 80 micromoles per liter of naringenin,
the flavonoid stimulated DNA repair. The proposed function
of naringenin is that it stimulates the so-called Base Excision Repair
(BER) cellular mechanism that repairs DNA during the replication
stage.
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