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:
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 has over 15 years experience as a respected author, columnist and
consultant, to the supplement, fitness, bodybuilding, and weight loss industry
and has been extensively published.Will graduated from Harvard University with
a concentration in the natural sciences, and is a consultant to major supplement,
dairy, and pharmaceutical companies.
His often ground breaking articles can be found in publications such 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.
Will was a former high level trainer with a rep for getting Olympic athletes, bodybuilders and fitness stars into shape and has gained a reputation for being a no "BS" industry insider who's not afraid to reveal the lies and hype found in the fat loss , muscle building & supplement industry.
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. 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 and now runs seminars for tactical law enforcement (SWAT).
He is the author, of Bodybuilding Revealed which teaches you how to gain solid muscle mass drug free and Fat Loss Revealed. which reveals exactly how to get lean , ripped and healthy completely naturally. Both e-books come with access to his private forums and numerous tools to aid you in either endevour.
Find out more at Bodybuilding Revealed or Fat Loss Revealed.