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Why are Monounsaturated Fats Key
to Skin Protection?
A recent study found that diets rich in oils containing
monounsaturated fats (MUFAs) such as oleic acid, which is found in very
high levels in canola oil, along with additional foods and nutrients,
may protect the skin against the damaging effects of the sun.
It is often overlooked that the skin is the largest
organ of the body. With its vast surface area, coupled with its rich
blood flow and increased light sensitivity, the skin is at a relatively
high risk of damage from reactive oxygen species (ROS), also known as
free radicals. This is bad news for sun lovers as ultraviolet light
is a rich source of ROS, which cosmetically have been shown to be damaging
to the underlying connective tissue. The result of excess generation
of ROS is premature aging. The particular type of damage caused by ultraviolet
light is commonly known as actinic damage. The promising news is that
a variety of different food components could modulate actinic damage.
Br Purba and co-workers published a paper recently
that profiled results from the International Union of Nutritional Sciences
(IUNS) "Food Habits in Later Life" study. Subjects included
177 Greek-born individuals living in Melbourne, 69 Greek subjects residing
in rural Greece, 48 Anglo- Celtic Australian elderly living in Melbourne,
and 159 Swedish subjects living in Sweden. Data on dietary intakes for
the past year were collected by food frequency questionnaires and a
non-invasive skin test was performed on the back of the hand to assess
actinic damage.
In this study, foods and nutrients positively associated
with a higher degree of actinic skin damage included full fat milk,
sweet milk desserts such as ice cream, sugar and sugar products, potatoes,
and red meat. Photoaging was reduced when overall diets contained more
vitamin C, calcium, phosphorus, magnesium, iron, zinc, retinal (Vitamin
A), and the MUFA, oleic acid. Foods that were found to be negatively
associated with photoaging included eggs, yogurt, legumes (especially
lima beans), vegetables (especially green leafy/spinach, eggplant, asparagus,
celery, onions/leaks, and garlic), nuts, olives, cherries, melon, dried
fruits/ prunes, multigrain bread, jam, tea and water.
Monounsaturated fats (MUFAs) as well as polyunsaturated
fatty acids (PUFAs), each constitute 25% of the fatty acid composition
of the upper layer of the skin know as the epidermis. The main difference,
however, is that unlike PUFAs MUFAs are more resistant to oxidation.
As such, increasing the MUFA content of the diet may increase the content
of MUFA in the epidermis, which may in turn result in a decrease in
oxidative damage. One of the richest sources of MUFAs is canola oil,
with about 61% of its fatty acid profile as oleic acid.
Br Purba, M., et. al. 2001. Skin Wrinkling: Can Food
Make a Difference? J. Am.Col. Nutr.Vol.20(1):71-80
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