Ecco un altro articoletto interessante in inglese.
Enjoy!
Ippo
RESEARCH UPDATE: Fat Burners and Free Radicals
-------------------------------------------------
"Special advice to anyone using fat burners..."
One of the ways in which popular fat burners (such as Xenadrine
and Hydroxycut) help you lose weight is to increase your
metabolic rate. However, what's not so well known is that this
increase in metabolic rate can also lead to a rise in the
production of substances known as free radicals.
Free radicals are molecules with an unpaired electron. Although
they've been implicated in many diseases, free radicals are a
normal part of your body chemistry, and can help to keep you
healthy. White blood cells, for example, use free radicals to
"attack" viruses and bacteria.
Optimal health, however, requires a balance between free radical
generation and antioxidant protection. One of the functions of an
antioxidant is to "quench" these free radicals before they create
too much damage. Slice an apple in half, and watch it turn brown.
That's an example of free radical damage. Dip the apple in lemon
juice, and the rate at which it turns brown is slowed. That's
because the vitamin C in the lemon juice slows the rate of
oxidative damage.
This is one of the reasons antioxidant vitamin supplements (such
as vitamin A, C and E) have become so popular. However, while you
can get some antioxidants from supplements, it's extremely
difficult to get all the nutrients you need from a pill. There
are eight different compounds that make up vitamin E, for
example, yet most vitamin supplements contain just one (usually
alpha-tocopherol). Of course, this doesn't mean that vitamin
pills are useless. Rather, they are a supplement to, not a
replacement for, a nutrient-dense diet.
Relying on supplements alone also ignores the fact that there are
many different nutrients in fruit and vegetables besides
vitamins. And, contrary to popular belief, some of these
nutrients become more available for absorption when the foods are
cooked (as opposed to eating them raw). Antioxidant activity in
cooked sweet yellow corn, for example, is 44% higher than the
same corn before cooking.
While it's true that vitamin C is partially destroyed by cooking,
the antioxidant activity of other nutrients in the food can be
increased by cooking. In fact, only a very small amount of an
apple's antioxidant activity comes from vitamin C. Instead, a
combination of phytochemicals supplies the antioxidants in
apples.
The term "phyto" comes from the Greek word meaning plant. You'll
see the terms "phytochemical" and "phytonutrient" used
interchangeably — they both mean essentially the same thing.
Of all the phytonutrients, we probably know the most about
carotenoids. They make tomatoes red, carrots orange and corn
yellow. The importance of carotenoids was first established back
in 1919. Harry Steenbock, a biochemist at the University of
Wisconsin fed rats one of two diets. One diet contained a lot of
"white" food, such as white corn, parsnips, or potatoes. The
second diet was rich in "yellow" foods like yellow corn and
carrots. The rats on the yellow diet thrived. Those on the white
diet died within three months.
The work of Dr. Rui Hai Liu, assistant professor of food science
at Cornell University, shows that heating certain foods increases
the availability of some phytonutrients. This is in contrast to
the conventional wisdom suggesting that cooking vegetables
reduces their nutritional value. In his earlier research, Liu
found that cooking tomatoes triggers a rise in total antioxidant
activity, mainly due to an increase in lycopene — a phytochemical
that makes tomatoes red.
Of course, these findings don't necessarily apply to all
nutrients in all foods. However, including more vegetables in
your diet — whether they're raw or cooked — is an important step
for anyone who wants to build a healthier body.
To view this update on-line, visit:
Enjoy!
Ippo
RESEARCH UPDATE: Fat Burners and Free Radicals
-------------------------------------------------
"Special advice to anyone using fat burners..."
One of the ways in which popular fat burners (such as Xenadrine
and Hydroxycut) help you lose weight is to increase your
metabolic rate. However, what's not so well known is that this
increase in metabolic rate can also lead to a rise in the
production of substances known as free radicals.
Free radicals are molecules with an unpaired electron. Although
they've been implicated in many diseases, free radicals are a
normal part of your body chemistry, and can help to keep you
healthy. White blood cells, for example, use free radicals to
"attack" viruses and bacteria.
Optimal health, however, requires a balance between free radical
generation and antioxidant protection. One of the functions of an
antioxidant is to "quench" these free radicals before they create
too much damage. Slice an apple in half, and watch it turn brown.
That's an example of free radical damage. Dip the apple in lemon
juice, and the rate at which it turns brown is slowed. That's
because the vitamin C in the lemon juice slows the rate of
oxidative damage.
This is one of the reasons antioxidant vitamin supplements (such
as vitamin A, C and E) have become so popular. However, while you
can get some antioxidants from supplements, it's extremely
difficult to get all the nutrients you need from a pill. There
are eight different compounds that make up vitamin E, for
example, yet most vitamin supplements contain just one (usually
alpha-tocopherol). Of course, this doesn't mean that vitamin
pills are useless. Rather, they are a supplement to, not a
replacement for, a nutrient-dense diet.
Relying on supplements alone also ignores the fact that there are
many different nutrients in fruit and vegetables besides
vitamins. And, contrary to popular belief, some of these
nutrients become more available for absorption when the foods are
cooked (as opposed to eating them raw). Antioxidant activity in
cooked sweet yellow corn, for example, is 44% higher than the
same corn before cooking.
While it's true that vitamin C is partially destroyed by cooking,
the antioxidant activity of other nutrients in the food can be
increased by cooking. In fact, only a very small amount of an
apple's antioxidant activity comes from vitamin C. Instead, a
combination of phytochemicals supplies the antioxidants in
apples.
The term "phyto" comes from the Greek word meaning plant. You'll
see the terms "phytochemical" and "phytonutrient" used
interchangeably — they both mean essentially the same thing.
Of all the phytonutrients, we probably know the most about
carotenoids. They make tomatoes red, carrots orange and corn
yellow. The importance of carotenoids was first established back
in 1919. Harry Steenbock, a biochemist at the University of
Wisconsin fed rats one of two diets. One diet contained a lot of
"white" food, such as white corn, parsnips, or potatoes. The
second diet was rich in "yellow" foods like yellow corn and
carrots. The rats on the yellow diet thrived. Those on the white
diet died within three months.
The work of Dr. Rui Hai Liu, assistant professor of food science
at Cornell University, shows that heating certain foods increases
the availability of some phytonutrients. This is in contrast to
the conventional wisdom suggesting that cooking vegetables
reduces their nutritional value. In his earlier research, Liu
found that cooking tomatoes triggers a rise in total antioxidant
activity, mainly due to an increase in lycopene — a phytochemical
that makes tomatoes red.
Of course, these findings don't necessarily apply to all
nutrients in all foods. However, including more vegetables in
your diet — whether they're raw or cooked — is an important step
for anyone who wants to build a healthier body.
To view this update on-line, visit:
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