Current
Nutrition & Food Science
ISSN: 1573-4013
Current Nutrition & Food
Science
Volume 4, Number 2, May 2008
Contents
Is Metabolic Syndrome X a Disorder of the Brain?
Pp. 73-108
Undurti N. Das
[Abstract]
Quantitative Analysis of Microbial Metabolism
in the Human Large Intestine Pp. 109-126
Alvaro Belenguer, Sylvia H. Duncan, Grietje Holtrop, Harry
J. Flint and Gerald E. Lobley
[Abstract]
Photoprotective Carotenoids Lutein and Zeaxanthin:
Their Role in AMD Pp. 127-134
A. Afzal and M. Afzal
[Abstract]
Taurine, Bone Growth and Bone Development
Pp. 135-144
Sung-Jin Kim, Hyeon Woo Lee and Ramesh C. Gupta
[Abstract]
Medical Management of Obesity Pp. 145-153
Mary H. Whited, Lori R. Roust, Sophie Bersoux, Anita P.
Mayer, Julia A. Files, Janis E. Blair and Marcia G. Ko
[Abstract]
Abstracts
[Back to top]
Is Metabolic Syndrome X a Disorder of the Brain?
Undurti N. Das
Abdominal obesity, atheroslcerosis, insulin resistance,
hyperlipidemias, hypertension, and type 2 diabetes mellitus
are important components of metabolic syndrome X. An increase
in pro-inflammatory cytokines, decrease in the concentrations
of endothelial nitric oxide (eNO) and adiponectin, and an
alteration in hypothalamic peptides that control satiety,
hunger, and food intake have been reported in metabolic syndrome
X. Although when and how metabolic syndrome X is initiated
is not clear, there is evidence to suggest that increased
consumption of high-energy diet, saturated and trans-fats
by pregnant women and lactating mothers could trigger changes
in the concentrations of long-chain polyunsaturated fatty
acids (LCPUFAs) in maternal and fetal plasma and tissues.
LCPUFAs have a modulatory influence on neuronal growth, maturation
and synapse formation; influence the actions of hypothalamic
peptides, neuropeptides, leptin, adiponectin, and various
cytokines, especially during the perinatal period. In addition,
LCPUFAs function as endogenous inhibitors of HMG-CoA reductase
and ACE (angiotensin converting enzyme), augment eNO synthesis,
modulate vascular tone, and potentiate insulin action both
in the peripheral tissues and brain. Hence, sub-optimal maternal
and fetal plasma and tissue concentrations of LCPUFAs increase
pro-inflammatory cytokine levels that could trigger the development
of metabolic syndrome X in those children who have a genetic
predisposition, and continue to take high-energy diet, and
saturated and trans-fats. This implies that perinatal interventions
in the form of adequate supplementation of LCPUFAs could be
of significant benefit in the prevention of metabolic syndrome
X. Preliminary evidence suggests that supplementation of LCPUFAs
can restore the levels of hypothalamic peptides to normal.
In addition, weight loss due to Roux-en-gastric bypass procedure
done in diet-induced obese animals decreased inflammation,
restored hypothalamic “body weight/ appetite/ satiety
set point” by restoring hypothalamic neuropeptides to
normal, suggesting a cross talk between gastrointestinal hormones
and hypothalamus. These evidences suggest that metabolic syndrome
X occurs in a genetically predisposed subject as a result
of interaction(s) between hypothalamic peptides, gastrointestinal
tract, cytokines, nutrition, and life style factors.
[Back to top]
Quantitative Analysis of Microbial Metabolism in the Human
Large Intestine
Alvaro Belenguer, Sylvia H. Duncan, Grietje Holtrop, Harry
J. Flint and Gerald E. Lobley
Microbial metabolism in the human colon impacts on health
and disease. Production of intermediate metabolites and end-products
depends largely on the supply of dietary carbohydrates, including
prebiotics (fructooligosaccharides) and functional foods (resistant
starch), that resist small intestinal digestion. Colonic bacteria
ferment these substrates to a wide range of products, predominantly
short-chain fatty acids, including metabolites that can be
either deleterious (e.g. D-lactate, sulphides) or beneficial
(e.g. butyrate) to gut health. Lactate accumulation in the
colon has been associated with gastrointestinal disturbance,
for example in severe ulcerative colitis, whereas in the healthy
state lactate is efficiently utilised by gut bacteria. Understanding
the interaction between microbial metabolism and diet-derived
nutrient supply is crucial for maintaining a healthy metabolic
balance in the colon. Prediction of such nutritional responses
can be achieved by integrating in mathematical models information
from stable isotope studies, that quantify metabolite flows,
and molecular techniques, that accurately determine changes
in microbial composition diversity. From such approaches,
better nutritional advice can be provided in order to improve
gut health. Furthermore, such understanding can be used to
manipulate and improve the action of prebiotics and probiotics.
[Back to top]
Photoprotective Carotenoids Lutein and Zeaxanthin: Their Role
in AMD
A. Afzal and M. Afzal
Carotenoids are commonly present exclusively in flora
and microbes where they perform critical functions in photosynthesis
and photoprotection. These lipophilic molecules are not synthesized
by vertebrates and invertebrates. Carotenoids are recognized
as high-value antioxidant food supplements and their antioxidant
activity may be higher than β-carotene
and α-tocopherol
leading to a prevention of lipid peroxidation. In addition,
other beneficial effects of carotenoids are well established.
These include reduction in gastric inflammation, bacterial
load reduction in H-pylori infected humans and mice,
age related macular degeneration, prevention of carcinogenesis,
atherosclerosis, cardiovascular ailments etc. Epidemiology
and clinical studies have shown that each carotenoid has its
own individual characteristics. For example β-cryptoxanthin
has been shown to be potent in lung cancer and lycopene is
inversely associated with prostate cancer and astaxanthin
inhibits LDL oxidation. Over 700 natural carotenoids with
diverse molecular structures have been identified with potential
medical benefits. However, only a handful of carotenoids,
such as α-carotene,
β-carotene,
astaxanthin, β-cryptoxanthin,
lycopene, canthaxanthin, lutein and zeaxanthin have been explored
for their health benefits. Leutin and zeaxanthin are commonly
found in human fluids including macula. This review summarizes
role of these two carotenoids in age related macular degeneration.
[Back to top]
Taurine, Bone Growth and Bone Development
Sung-Jin Kim, Hyeon Woo Lee and Ramesh C. Gupta
Taurine (2-Amino ethane sulfonic acid) is a naturally
occurring sulphur amino acid, found in several mammalian and
non mammalian tissues. Taurine is believed to be involved
in several life processes. Its deficiency is a cause of concern
in developing abnormalities in many organs like eye, heart,
kidney, brain etc during developmental stages and even later
on. Taurine contents are believed to be high in bone tissue
mostly due to accumulation by transport, as taurine synthesis
in bone is yet to be recorded. A strong stimulating role of
taurine in bone matrix formation and collagen synthesis has
been observed in osteoblast like UMR-106 cells; together with
this, inhibition of bone resorption and osteoclast formation
by taurine has also been identified, making taurine an agent
for preventing inflammatory bone resorption in periodontal
diseases. Thus, taurine acts as a double beneficial agent;
stimulating bone formation and inhibiting bone loss. Along
with these actions in bone, it also has beneficial action
in radio protection, wound healing, bone gain through exercise
and many others. Taurine has the potential to replace bisphosphonates;
suitable taurine analogues may further accelerate this. An
extensive analytical study of taurine contents in both the
stages of bone formation and bone loss may make taurine as
a single marker of bone metabolism. However taurine-bone interaction
needs more deep study towards regulation of taurine, interaction
with ions, and many other pharmacological and physiological
actions. An in depth clinical study of its actions in bone
may make taurine an ideal agent for desired effect; yet, all
these recorded taurine - bone interactions, are milestones
for future research.
[Back to top]
Medical Management of Obesity
Mary H. Whited, Lori R. Roust, Sophie Bersoux, Anita P.
Mayer, Julia A. Files, Janis E. Blair and Marcia G. Ko
This review of current medical knowledge about the etiology,
evaluation, medical, and pharmacologic treatment of obesity
suggests patient care strategies emphasizing office evaluation
and treatment. Office assessment of obesity, which is the
consequence of multiple genetic, neurohormonal, environmental,
and behavioral factors, should include a careful chronological
history with calculation of body mass index and a focused
examination. Treatment consideration should be given to recommendations
about calorie intake, but debate continues over the ideal
macronutrient composition. Other treatment recommendations
for successful weight loss and maintenance include a high
level of physical activity, behavior modification programs
that improve adherence to diet and exercise, and pharmacologic
therapy. Obesity is an increasingly prevalent medical problem
in the United States that is best treated using a multidisciplinary
approach. Medical providers require the most up-to-date information
in order to provide their patients with a multifaceted approach
to successful weight loss and lifelong weight maintenance.
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