Regular readers of my work have come to expect articles
about the power of whey proteins to potentaily fight cancer
and improve immunity among its many benefits. The ability
of whey to fight cancer, improve glutathione levels and
immunity, is well documented.
Additional research suggests possible medical uses for
whey that are quite unexpected and different from whey’s
traditional role as an immune booster and anti cancer functional
food. For example, whey may be able to reduce stress and
lower cortisol and increase brain serotonin levels, improve
liver function in those suffering from certain forms of
hepatitis, reduce blood pressure, as well as other amazing
recent discoveries, such as whey’s possible effects
on weight loss, which is the focus of this article.
What is whey?
When we talk about whey we are actually referring to a
complex milk-based ingredient made up of protein, lactose,
fat and minerals. Protein is the best-known component of
whey and is made up of many smaller protein subfractions
such as: Beta-lactoglobulin, alpha-lactalbumin, immunoglobulins
(IgGs), glycomacropeptides, bovine serum albumin (BSA) and
minor peptides such as lactoperoxidases, lysozyme and lactoferrin.
Each of the subfractions found in whey has its own unique
biological properties. Modern filtering technology has improved
dramatically in the past decade, allowing companies to separate
some of the highly bioactive peptides - such as lactoferrin
and lactoperoxidase - from whey.
Some of these subfractions are only found in very minute
amounts in cow’s milk, normally at less than one percent
(e.g., lactoferrin, lactoperoxidase, etc.)
The medicinal properties of whey have been known for centuries.
For example, an expression from Florence, Italy. Circa 1650,
was "Chi vuol viver sano e lesto beve scotta e cena
presto" which translates into English as "If you
want to live a healthy and active life, drink whey and dine
early."
Another expression from Italy regarding the benefits of
whey (circa 1777) was "Allevato con la scotta il dottore
e in bancarotta." Which translates into English "If
everyone were raised on whey, doctors would be bankrupt."
Is whey a weight loss functional food?
A few years ago, I might have said no. Now I am not so
sure. Although there was a smattering of studies suggesting
whey had certain properties that might assist with weight
loss, a number of recent studies appear to further support
the use of whey as a possible weight loss supplement. Most
interesting - at least to nerds like me - the effect appears
to be not by a single mechanism, but several. This article
will briefly explore a few possible pathways by which whey
may assist the dieter.
"I’m hungry!"
Human hunger and appetite are regulated by a phenomenally
complicated set of overlapping feedback networks, involving
a long list of hormones, psychological factors as well as
physiological factors, all of which are still being elucidated.
It’s a very intensive area of research right now,
with various pharmaceutical companies looking for that "magic
bullet" weight loss breakthrough they can bring to
market.
One hormone getting attention by researchers looking for
possible solutions to obesity is cholecystokinin (CCK).
Several decades ago, researchers found CCK largely responsible
for the feeling of fullness or satiety experienced after
a meal and partially controls appetite, at least in the
short term.
Cholecystokinin (CCK) is a small peptide with multiple
functions in both the central nervous system and the periphery
(via CCK-B and CCK-A receptors respectively). Along with
other hormones, such as pancreatic glucagon, bombesin, glucagon-like
peptide-1, amide (GLP-1), oxyntomodulin, peptide YY (PYY)
and pancreatic polypeptide (PP)., CCK is released by ingested
food from the gastrointestinal tract and mediates satiety
after meals.
Such a list would not be complete without at least making
mention of what many researchers consider the "master
hormones" in this milieu, which is insulin and leptin.
If that’s not confusing enough, release of these hormones
depends on the concentration and composition of the nutrients
ingested.
That is, the type of nutrients (i.e., fat, protein, and
carbohydrates) eaten, the amount of each eaten, and composition
of the meal, all effect which hormones are released and
in what amounts... Needless to say, it’s a topic that
gets real complicated real fast and the exact roles of all
the variables is far from fully understood at this time,
though huge strides have been made recently.
Whey’s effects on food intake.
This (finally!) brings us to whey protein. Whey may have
some unique effects on food intake via its effects on CCK
and other pathways. Many studies have shown that protein
is the most satiating macro-nutrient. However, it also appears
all proteins may not be created equal in this respect.
For example, two studies using human volunteers compared
whey vs. casein (another milk based protein) on appetite,
CCK, and other hormones (Hall WL, Millward DJ, Long SJ,
Morgan LM.Casein and whey exert different effects on plasma
amino acid profiles, gastrointestinal hormone secretion
and appetite. Br J Nutr. 2003 Feb;89(2):239-48).
The first study found that energy intake from a buffet
meal ad libitum was significantly less 90 minutes after
a liquid meal containing whey, compared with an equivalent
amount of casein given 90 minutes before the volunteers
were allowed to eat all they wanted (ad libitum) at the
buffet. In the second study, the same whey preload led to
a plasma CCK increase of 60 % ( in addition to large increases
in glucagon-like peptide [GLP]-1 and glucose-dependent insulinotropic
polypeptide) following the whey preload compared with the
casein.
Translated, taking whey before people were allowed to eat
all they wanted (ad libitum) at a buffet showed a decrease
in the amount of calories they ate as well as substantial
increases in CCK compared to casein. Subjectively, it was
found there was greater satiety followed the whey meal also.
The researchers concluded "These results implicate
post-absorptive increases in plasma amino acids together
with both CCK and GLP-1 as potential mediators of the increased
satiety response to whey and emphasize the importance of
considering the impact of protein type on the appetite response
to a mixed meal." Several animal studies also find
whey appears to have a pronounced effect on CCK and or satiety
over other protein sources.
It should be noted however that not all studies have found
the effect of whey vs. other protein sources on food intake
(Bowen J, Noakes M, Clifton P, Jenkins A, Batterham M.Acute
effect of dietary proteins on appetite, energy intake and
glycemic response in overweight men. Asia Pac J Clin Nutr.
2004;13(Suppl):S64.).
It should also be noted that although studies find protein
to be the most satiating of the macro-nutrients, certain
protein sources (e.g. egg whites) may actually increase
appetite (Anderson GH, Tecimer SN, Shah D, Zafar TA. Protein
source, quantity, and time of consumption determine the
effect of proteins on short-term food intake in young men.
J Nutr. 2004 Nov;134(11):3011-5.), so protein sources appear
worth considering when looking to maximize weight loss and
suppress appetite.
How whey achieves this effect is not fully understood,
but research suggests it’s due to whey’s high
glycomacropeptide and alpha-lactalbumin content, as well
as its high solubility compared to other proteins, and perhaps
it’s high percentage of branch chain amino acids (BCAA’s).
Whey’s effects on bodyfat, insulin
sensitivity, and fat burning... .
So we have some studies suggesting whey may have some unique
effects on hormones involved in satiety and or may reduce
energy (calorie) intake of subsequent meals, but do we have
studies showing direct effects of whey vs. other proteins
on weight loss? In animals at least, whey has looked like
a promising supplement for weight loss.
Although higher protein diets have been found to improve
insulin sensitivity, and may be superior for weight loss
(with some debate!) then higher carbohydrate lower protein
diets, it’s unclear if all proteins have the same
effects.
One study compared whey to beef (Damien P. Belobrajdic,,
Graeme H. McIntosh, and Julie A. Owens. A High-Whey-Protein
Diet Reduces Body Weight Gain and Alters Insulin Sensitivity
Relative to Red Meat in Wistar Rats. J. Nutr. 134:1454-1458,
June 2004) and found whey reduced body weight and tissue
lipid levels and increased insulin sensitivity compared
to red meat.
Rats were fed a high-fat diet for nine weeks, then switched
to a diet containing either whey or beef for an additional
six weeks. As has generally been found in other studies,
the move to a high dietary protein reduced energy intake
(due to the known satiating effects of protein compared
to carbs or fat), as well as reductions in visceral and
subcutaneous bodyfat.
However, the rats getting the whey, there was a 40% reduction
in plasma insulin concentrations and increased insulin sensitivity
compared to the red meat. Not surprisingly, the researchers
concluded "These findings support the conclusions that
a high-protein diet reduces energy intake and adiposity
and that whey protein is more effective than red meat in
reducing body weight gain and increasing insulin sensitivity."
Other studies suggest taking whey before a workout is superior
for preserving/gaining lean body mass (LBM) and maintaining
fat burning (beta oxidation) during exercise over other
foods taken prior to a workout. The study called "A
preexercise lactalbumin-enriched whey protein meal preserves
lipid oxidation and decreases adiposity in rats" (Am
J Physiol Endocrinol Metab 283: E565-E572, 2002.) came to
some very interesting conclusions.
One thing we have known a long time is the composition
of the pre-exercise meal will affect substrate utilization
during exercise and thus might affect long-term changes
in body weight and composition. That is, depending on what
you eat before you workout can dictate what you use for
energy (i.e. carbs, fats, and or proteins) which alters
what you burn (oxidize) for energy.
The researchers took groups of rats and made the poor buggers
exercise two hours daily for over five weeks (talk about
over training!), either in the fasted state or one hour
after they ingested a meal enriched with a simple sugar
(glucose), whole milk protein or whey protein.
The results were quite telling. Compared with fasting (no
food), the glucose meal increased glucose oxidation and
decreased lipid oxidation during and after exercise. Translated,
they burned sugar over body fat for their energy source.
In contrast, the whole milk protein and whey meals preserved
lipid oxidation and increased protein oxidation. Translated,
fat burning was maintained and they also used protein as
a fuel source.
Not surprisingly, the whey meal increased protein oxidation
more than the whole milk protein meal, most likely due to
the fact that whey is considered a "fast" protein
that is absorbed rapidly due to it’s high solubility.
As one would expect, by the end of the five weeks, body
weight was greater in the glucose, whole milk protein and
whey fed rats than in the fasted ones. No shock there. Here
is where it gets interesting: In the group getting the glucose
or the whole milk protein, the increase in weight was from
bodyfat, but in the whey fed group, the increase in weight
was from an increase in muscle mass and a decrease in bodyfat!
Only the rats getting the whey before their workout increased
muscle mass and decreased their bodyfat. The researchers
theorized this was due to whey’s ability to rapidly
deliver amino acids during exercise. Is this the next big
find in sports nutrition or those simply looking to preserve
muscle mass loss due to aging?
Hard to say at this time being it was done in rats, but
if it turns out to be true in humans (and there is no reason
people can’t try it now) it would indeed be a breakthrough
in the quest to add muscle and lose fat.
Effects on serotonin, blood sugar regulation, and
more!
Although the above would probably be the major mechanisms
by which whey could help the dieter, there are several secondary
effects of whey that may assist in weight loss. For example,
whey’s effects on serotonin levels. Serotonin is probably
the most studied neurotransmitter since it has been found
to be involved in a wide range of psychological and biological
functions. Serotonin ( also called 5-hydroxytryptamine or
5-HT) is involved with mood, anxiety, and appetite.
Elevated levels of serotonin can cause relaxation and reduced
anxiety. Low serotonin levels are associated with low mood,
increased anxiety (hence the current popularity of the SSRI
drugs such as Prozac and others), and poor appetite control.
This is an extremely abbreviated description of all the
functions serotonin performs in the human body - many of
which have yet to be fully elucidated - but a full explanation
is beyond the scope of this article.
Needless to say, Increased brain serotonin levels are associated
with an improved ability of people to cope with stress,
whereas a decline in serotonin activity is associated with
depression and anxiety. Elevated levels of serotonin in
the body often result in the relief of depression, as well
as substantial reduction in pain sensitivity, anxiety and
stress. It has also been theorized that a diet-induced increase
in tryptophan will increase brain serotonin levels, while
a diet designed for weight loss (e.g., a diet that reduces
calories) may lead to a reduction of brain serotonin levels
due to reduced substrate for production and a reduction
in carbohydrates.
Many people on a reduced calorie intake in an attempt to
lose weight find they are often ill tempered and more anxious.
Reductions in serotonin may be partially to blame here.
One recent study (The bovine protein alpha-lactalbumin increases
the plasma ratio of tryptophan to the other large neutral
amino acids, and in vulnerable subjects raises brain serotonin
activity, reduces cortisol concentration, and improves mood
under stress. Am J Clin Nutr 2000 Jun;71(6):1536-1544) examined
whether alpha-lactalbumin - a major sub fraction found in
whey which has an especially high tryptophan content - would
increase plasma Tryptophan levels as well reduce depression
and cortisol concentrations in subjects under acute stress
considered to be vulnerable to stress.
The researchers examined twenty-nine "highly stress-vulnerable
subjects" and 29 "relatively stress-invulnerable"
subjects using a double blind, placebo-controlled study
design. The study participants were exposed to experimental
stress after eating a diet enriched with either alpha-lactalbumin
(found in whey) or sodium-caseinate, another milk based
protein. They researchers looked at:
- Diet-induced changes in the plasma Tryptophan and its
ratio to other large neutral amino acids.
- Prolactin levels.
- Changes in mood and pulse rate.
- Cortisol levels (which were assessed before and after
the stressor).
Amazingly, the ratio of plasma Tryptophan to the other
amino acids tested was 48% higher after the alpha-lactalbumin
diet than after the casein diet! This was accompanied by
a decrease in cortisol levels and higher prolactin concentration.
Perhaps most important and relevant to the average person
reading this article, they found "reduced depressive
feelings" when test subjects were put under stress.
They concluded that the "Consumption of a dietary
protein enriched in tryptophan increased the plasma Trp-LNAA
ratio and, in stress-vulnerable subjects, improved coping
ability, probably through alterations in brain serotonin."
This effect was not seen in the sodium-caseinate group.
If other studies can confirm these findings, whey may turn
out to be yet another safe and effective supplement in the
battle against depression and stress, as well as reduced
serotonin levels due to dieting.
Although there is a long list of hormones involved in appetite
regulation, some of which have been mentioned above, serotonin
appears to be a key player in the game. In general, experiments
find increased serotonin availability or activity = reduced
food consumption and decreased serotonin = increase food
consumption. If whey can selectively increase serotonin
levels above that of other proteins, it could be very helpful
to the dieter.
Other possible advantages whey may confer to the dieter
is improved blood sugar regulation (Frid AH, Nilsson M,
Holst JJ, Bjorck IM. Effect of whey on blood glucose and
insulin responses to composite breakfast and lunch meals
in type 2 diabetic subjects. Am J Clin Nutr. 2005 Jul;82(1):69-75.)
which is yet another key area in controlling appetite and
metabolism.
Finally, calcium from dairy products has been found to
be associated with a reduction in bodyweight and fat mass.
Calcium is thought to influence energy metabolism as intracellular
calcium regulates fat cell (adipocyte) lipid metabolism
as well as triglyceride storage. It’s been demonstrated
in several studies the superiority of dairy versus non-dairy
sources of calcium for improving body composition, and the
whey fraction of dairy maybe the key.
The mechanism responsible for increased fat loss found
with dairy-based calcium versus nondairy calcium has not
is not fully understood but researchers looking at the issue
theorized "... dairy sources of calcium markedly attenuate
weight and fat gain and accelerate fat loss to a greater
degree than do supplemental sources of calcium. This augmented
effect of dairy products relative to supplemental calcium
is likely due to additional bioactive compounds, including
the angiotensin-converting enzyme inhibitors and the rich
concentration of branched-chain amino acids in whey, which
act synergistically with calcium to attenuate adiposity."
It appears components in whey - some of which have been
mentioned above - are thought to act synergistically with
calcium to improve body composition (Zemel MB. Role of calcium
and dairy products in energy partitioning and weight management.
Am J Clin Nutr. 2004 May;79(5):907S-912S.).
Conclusion
Taken in isolation, none of these studies are so compelling
that people should run out and use whey as some form of
weight loss nirvana. However, taken as a total picture,
the bulk of the research seems to conclude that whey may
in fact have some unique effects for weight loss and should
be of great use to the dieter. More studies are clearly
needed however.
So what is the practical application of all this information
and how does the dieter put it to good use? Being the appetite
suppressing effects of whey appear to last approximately
2-3 hours, it would seem best to stagger the intake throughout
the day. For example, breakfast might be 1-2 scoops of whey
and a bowl of oatmeal, and perhaps a few scoops of whey
taken between lunch and dinner.
If whey does what the data suggests it does in the above,
that should be the most effective method for maximizing
the effects of whey on food (calorie) intake on subsequent
meals as well as the other metabolic effects covered. If
working out, the schedule may be different however and people
should follow the pre and post nutrition recommendations
made in my ebook "Muscle Building Nutrition" or
advice easily found on the ‘net via the many sports
nutrition and bodybuilding related web sites.
>> Click here for Will Brink's Bodybuilding Revealed
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