|
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 (readers interested in brushing up on the
effects of whey on cancer, immunity, etc, can read previous articles by
me at the LEF’s web site: www.lef.org and www.BrinkZone.com).
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.
* Ebook can be found
at:
www.musclebuildingnutrition.com
Additional references of interest:
Curzon G.Serotonin and appetite.Ann N Y Acad Sci. 1990;600:521-30;
discussion 530-1.
Pierson ME, Comstock JM, Simmons RD, Kaiser F, Julien R, Zongrone J,
Rosamond JD. Synthesis and biological evaluation of potent, selective,
hexapeptide CCK-A agonist anorectic agents. J Med Chem 1997 Dec
19;40(26):4302-7
Blundell JE, King NA. Overconsumption as a cause of weight gain:
behavioural-physiological interactions in the control of food intake
(appetite). Ciba Found Symp 1996;201:138-54; discussion 154-8, 188-93
Zittel TT, von Elm B, Teichmann RK, Rabould HE, Becker HD.
Cholecystokinin is partly responsible for reduced food intake and body
weight loss after total gastrectomy in rats. Am J Surg 1995
Feb;169(2):265-70
Smith GP, Gibbs J. Are gut peptides a new class of anorectic agents? Am
J Clin Nutr 1992 Jan;55(1 Suppl):283S-285S
Strader AD, Woods SC. Gastrointestinal hormones and food intake.
Gastroenterology. 2005 Jan;128(1):175-91.
About the Author - William D. Brink
Will Brink is a columnist, contributing consultant, and writer for
various health/fitness, medical, and bodybuilding publications. His
articles relating to nutrition, supplements, weight loss, exercise and
medicine can be found in such publications as Lets Live, Muscle Media
2000, MuscleMag International, The Life Extension Magazine, Muscle n
Fitness, Inside Karate, Exercise For Men Only, Body International,
Power, Oxygen, Penthouse, Women's World and The Townsend Letter For
Doctors.
He is the author of
Priming The Anabolic Environment and Weight Loss Nutrients Revealed. He
is the Consulting Sports Nutrition Editor and a monthly columnist for
Physical magazine and an Editor at Large for Power magazine. Will
graduated from Harvard University with a concentration in the natural
sciences, and is a consultant to major supplement, dairy, and
pharmaceutical companies.
He has been co author of several studies relating to sports nutrition
and health found in peer reviewed academic journals, as well as having
commentary published in JAMA. He runs the highly popular web site
BrinkZone.com which is strategically positioned to fulfill the needs and
interests of people with diverse backgrounds and knowledge.
The BrinkZone site has a
following with many sports nutrition enthusiasts, athletes, fitness
professionals, scientists, medical doctors, nutritionists, and
interested lay people. William has been invited to lecture on the
benefits of weight training and nutrition at conventions and symposiums
around the U.S. and Canada, and has appeared on numerous radio and
television programs.
William has also worked with athletes ranging from professional
bodybuilders, golfers, fitness contestants, to police and military
personnel.
See Will's ebooks online
here:
Muscle
Building Nutrition
A complete guide bodybuilding supplements and eating to gain lean muscle
Diet
Supplements Revealed
A review of diet supplements and guide to eating for maximum fat loss
He can be contacted at: PO Box 812430
Wellesley MA. 02482.
BrinkZone.com
Email: will@brinkzone.com
Natural
Bodybuilding at its Finest - Lift for Life.com |
