Title: Topics in nutrition and food science.
1Topics in nutrition and food science.
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3Characteristics of Modern life
- Urbanisation
- Ready to eat food, fast food and processed food.
- High calories (fat and carbohydrate) low fibre.
- Low in vitamins and minerals.
- Packaging. Not natural preservation.
- Refrigeration and freezing.
- Less physical activity.
4- Office based jobs.
- Chronic diseases, obesity etc.
- Aging, people live longer.
5- Diet together with physical exercise plays a
major role when we try to prevent or postpone the
onset of chronic conditions such as the metabolic
syndrome. - The food industry has already reacted to this
challenge and a large number of products have
been either reformulated or re-positioned to meet
the current need for healthier foods.
6WHO
- Chronic diseases are diseases of long duration
and generally slow progression. Chronic diseases
are by far the leading cause of mortality in the
world, representing 63 of all deaths. 36 million
people died from chronic disease in 2008.
7Noncommunicable diseases
- Cardiovascular diseases account for most NCD
deaths, or 17 million people annually, followed
by cancer (7.6 million), respiratory disease (4.2
million), and diabetes (1.3 million). These four
groups of diseases account for around 80 of all
NCD deaths, and share four common risk factors - tobacco use
- physical inactivity
- the harmful use of alcohol and
- poor diets.
8Bad habits
9Stages of life and R F
- In the uterus
- intrauterine growth retardation (IUGR)
- premature delivery of a normal growth for
gestational age fetus - over nutrition in utero
- Intergenerational factors.
10- Infancy
- Retarded growth in infancy can be a reflected in
a failure to gain weight and a failure to gain
height. Both retarded growth and excessive weight
or height gain can be factors in later incidence
of chronic disease. Such as CVD - There is increasing evidence that among term and
pre-term infants, breastfeeding is associated
with significantly lower blood pressure levels in
childhood. - Consumption of formula instead of breast milk in
infancy has also been shown to increase diastolic
and mean arterial blood pressure in later life.
Obesity
(type 1 diabetes, coeliac disease, some childhood
cancers, inflammatory bowel disease) have also
been associated with infant feeding on
breast-milk substitutes and short-term
breastfeeding
11- Childhood
- low growth in childhood and an increased risk of
CHD has been described, irrespective of size at
birth. - Relative weight in adulthood and weight gain have
been found to be associated with increased risk
of cancer of the breast, colon, rectum, prostate
and other sites. - Higher blood pressure in childhood (in
combination with other risk factors) causes
target organ and anatomical changes that are
associated with cardiovascular risk, including
reduction in artery elasticity. - High blood pressure in children is strongly
associated with obesity,
12- Most chronic diseases are present at later period
of life - the result of interactions between
multiple disease processes as well as more
general losses in physiological functions (due to
risk factors) - lack of oxygen and adapted metabolism.
13Angiogenesis
- Angiogenesis is a process of new blood vessel
growth that occurs in the human body at specific
times in development and growth. - Although crucial for embryonic development and
wound healing, angiogenesis also contributes to
disease, such as in the growth of solid tumors,
chronic inflammation, atherosclerosis, ischemia,
and diabetic retinopathy.
14Inducers
- A number of inducers of angiogenesis have been
identified, there is an emerging concept that
reactive oxygen species (ROS such as )
superoxide anion O2- hydroxyl radical (OH-),
lipid radical (LOO-), peroxy radicals (XOO-)
and singlet oxygen (O-).
Free radicals
ROS are products of mitochondrial respiration
(energy production).
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17Dietary sources of ROS
- High fat diet and deep fries
- High sucrose (or refined carbohydrates )diet
- Protein sugar in high temperature (glycation)
- Low fruit and veg. diet
- Low vitamin and mineral diet (antioxidant).
Life style stress, pollution, smoking and low
activity.
18Golden rule
- More free radicals chronic diseases faster
aging. - Less free radicals healthier body.
19How to slow down generation of Free radicals?
20Comparison
B
A
Distance 10,000 km Fuel consumption 50,000
liter
Distance 200, 000 km Fuel consumption 1000,000
liter
Waste? Maintenance? Type of fuel?
21The challenges for nutrition in the twenty-first
century
- 1. Application of new scientific knowledge in
nutrition. - 2. Improved scientific knowledge on dietdisease
relationships. - 3. Exponential increase of health-care costs.
- 4. Increase in life expectancy.
- 5. Consumer awareness of nutrition and health
relationships. - 6. Progress in food technology.
22Functional foods
History
Japan 1940-1950 economical food with minimal
nutrients. 1950-1970 safe and hygienic food with
better taste. 1970- 1980 convenient food. Easy
or precooked food. 1980- Food for specific
health use (foshu). 1990 - Functional food.
(project)
23- The project also proposed for the first time the
new concept of functional food and defined food
functions as primary (nutritional), secondary
(sensory) and tertiary (physiological). Food with
physiological functions was of particular
interest, because such food would be useful for
improving the health of the general public
24Definition
- no simple, universally accepted definition of
functional food exists. Examples - food and drink products derived from naturally
occurring substances consumed as part of the
daily diet and possessing particular
physiological benefits when ingested. - food derived from naturally occurring substances
that can and should be consumed as part of the
daily diet and that serve to regulate or
otherwise affect a particular body process when
ingested. - food similar in appearance to conventional food,
which is consumed as part of a usual diet and has
demonstrated physiological benefit and/or reduces
the risk of chronic disease beyond basic
nutritional functions.
25The main aspects of this working definition are
- the food nature of functional food that is not a
pill, a capsule or any form of dietary
supplement - the demonstration of the effects to the
satisfaction of the scientific community - the beneficial effects on body functions, beyond
adequate nutritional effects, that are relevant
to improved state of health and well-being and/or
reduction of risk (not prevention) of disease - the consumption as part of a normal food pattern.
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28F F Science
- By reference to the new concepts in nutrition
outlined above, it is the role of functional food
science to stimulate research and development of
functional foods
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30Claim promise of improvement
- Disease reduction claims meaning
- consumers have difficulties to differentiate
between the terms disease risk reduction and
prevention of diseases.
31How to write a claim
32EFFECT OF FOOD PROCESSING ON FUNCTIONALITY OF
FOODS
In foods containing vastly different
phytochemicals, the physiological activity due to
food processing may be a result of more than one
mechanism. Consequently, there may be a
decrease, increase, or a slight change in the
content and functionality of phytochemicals.
No/slight effect carotenoids comprising of
b-carotene and lycopene are generally stable to
heat treatments encountered in blanching,
cooking, and pasteurization/sterilization.
Interactions between polyphenols and ascorbic
acid may slow the degradation of the latter
during storage.
33Decrease in content and activity of
phytochemicals a classic example is that of the
technological indicator, ascorbic acid, which
is by far the most sensitive nutrient, and can be
damaged during most treatments. Chemical and/or
enzymatic oxidations are reported to decrease the
antioxidant efficacy of polyphenolics, while
leaching into the cooking water is mainly
responsible for loss of folates.
34Heat processing of Brassica vegetables of the
Cruciferae family greatly reduces their
functionality . Manufacture of black tea causes
a higher degree of enzymatic aerobic oxidation of
flavonoids, resulting in lower antioxidant
activity. Some processing operations such as
peeling and juice clarification can remove the
polyphenolics .
35Increase in content and activity of
phytochemicals partially oxidized
polyphenolics that result during food processing,
have been recently shown to exhibit higher
antioxidant activity than the corresponding
non-oxidized forms, due to increased ability to
donate a hydrogen atom
A moderate increase in carotenoid bioavailability
and enhanced phytochemical nutrient function in
cereal processing
36Examples of functional ingredients
Vitamin antioxidant mineral premixes tomato
powder, garlic powder, onion powder, spice mixes
amino acids, chitosan Omega-3-fatty acids (fish
and flax seed) whey protein powder Guarana
extract, G. biloba extract, ginseng extract,
rosemary probiotics natural antioxidants (from
tea) shield liquid antioxidants vegetable
peptones
37essential fatty acids concentrates performance
proteins natural fruit based flowering
compounds natural colours total extracts of
medicinal plants antioxidants soy ingredient,
soy proteins, soy protein hydrolysate soya
protein isolate concentrate super critical
extracts of spices and herbs glutamine
peptides lactoferrin, milk calcium lycopene,
garcinia, raw herbs whey protein concentrate
wheat fiber, b-carotene A. vera gel powder.
38Risk factor or state Design a Functional Food
CVD
osteoporosis
diabetes
Irritable bowl syndrome (IBD)
Pregnant woman
39OXIDATIVE STRESS AND ROS
- Oxidative stress rusting of tissues.
- Oxidative stress is imposed on the body s cells
when the level of ROS outweighs the reducing
capacity of antioxidant and antioxidative stress
mechanisms
ROS
40Sources of ROS
- Endogenous sources of ROS
- tissue injury
- via auto - oxidation reactions in the presence of
transition metal ions. Fe 2 or Cu - during cytochrome P450 cycling.
- at inflammatory sites by activated and
phagocytes.
41- Exogenous sources of ROS
- Exposure to ultraviolet (UV) radiation.
- Overexercise.
- Extrinsic xenobiotics found in tobacco smoke.
- Heavy metals.
- Organic pesticides.
- Lipid hydroperoxides in particular are
potentially toxic products of peroxidized
polyunsaturated fatty acids (PUFAs) derived from
dietary fats. - Compounds present in foods such as transition
metal ions, heme from meats, isoprostanes,
additives, lipids,
42DEFENSE SYSTEMS
Endogenous antioxidants and antioxidative defenses
- Glutathione ( GSH )
- tripeptide of ? glutamylcysteinylglycine.
- directly scavenge free radicals or act as a
substrate. - GSH present in foods and secreted in the bile can
contribute to GSH concentrations in the
intestinal lumen.
43- Antioxidative stress enzymes
- glutathione peroxidase (GPx).
- glutathione S -transferase ( GST ).
- Catalase
- Additional antioxidants
- uric acid.
- bilirubin - bound albumin, and albumin itself.
- Histidine - containing peptides such as
carnosine. - Melatonin.
- Amino acids, peptides, and even proteins.
- Se, Zn, Cu, Mn and riboflavin can all have
co-factor functions for one of the above enzymes.
44Phytochemicals with antioxidant activities
- Polyphenols
- 5000 polyphenols and over 2000 flavonoids having
been identified. - Phenolic acids, Flavonoids, Lignans
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48- Amides
- strong antioxidants capsaicinoids in chili
peppers. - Carotenoids
- Lycopene, ß carotene, xanthophylls such as
zeaxanthin.
49Mechanism of action
- direct radical scavenging
- (2) downregulation of radical production
- (3) elimination of radical precursors
- (4) metal chelation
- (5) Inhibition of xanthine oxidase
- (6) elevation of endogenous antioxidants.
Curcumin and flavonoids have been shown to
upregulate intracellular GSH synthesis and
increase antioxidant enzyme activities
50METABOLISM AND BIOAVAILABILITY OF FLAVONOIDS
- The extent of absorption of dietary polyphenols
in the small intestine is relatively small. - Bacterial enzymes may catalyze several reactions.
- Anthocyanins were found in the cerebellum,
cortex, hippocampus. important for learning and
memory.
51Antioxidant and C D
- CVD
- Antioxidant prevent LL oxidation.
- Cancer
- Block activation to carcinogens.
- DNA repair.
- Inhibit the formation and growth of tumors.
52Dietary Fiber
- Dietary fiber (DF) has been consumed for
centuries and most food labels in the supermarket
now list dietary fiber. - Even though fiber is not considered a nutrient,
health professionals and nutritionists agree that
fiber is required in sufficient amounts for the
proper functioning of the gastrointestinal tract.
53Definition
- DF is the edible parts of plants or analogous
carbohydrates that are resistant to digestion and
absorption in the human small intestine with
complete or partial fermentation in the large
intestine.
54Why ?
- DF consumption has established the basis for
associating high-fiber diets in epidemiological
studies with reduced risk of most of the major
dietary problems in the U.S.A. namely, obesity,
coronary disease, diabetes, gastrointestinal
disorders, including constipation, inflammatory
bowel diseases.
Chronic diseases
55Classification Of Dietary Fiber
- dietary fiber has been to differentiate dietary
components on their solubility in a buffer at a
defined pH, and/or their fermentability in an in
vitro system using an aqueous enzyme solution
representative of human alimentary enzymes.
56Solubility
- Soluble fiber dissolves in water
- This includes gums, mucilages, pectin and some
hemicelluloses. - found in all types of peas and beans like
lentils, split peas, pinto beans, black beans,
kidney beans, garbanzo beans, and lima beans, as
well as oats, barley, and some fruits and
vegetables like apples, oranges, and carrots.
57Benefits
- For people with diabetes, eating foods that
contain soluble fiber can help control or lower
the level of sugar in their blood and decrease
insulin needs - It may also help lower blood cholesterol levels,
especially LDL-cholesterol or the bad
cholesterol.
58- Insoluble fiber does not dissolve in water.
- Whole grains, wheat and corn fiber, and many
vegetables like cauliflower, green beans, and
whole potatoes are good sources of insoluble
fiber. - aids digestion by trapping water in the colon.
- helps prevent two kinds of intestinal diseases,
diverticulosis and hemorrhoids.
59Fermentability
- Fibers that are well fermented include pectin,
guar gum, acacia (gum arabic), inulin,
polydextrose, and oligosaccharides. - Generally, well fermented fibers are soluble in
water, while partially or poorly fermented fibers
are insoluble.
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62Physiological Effects of D fiber
- major physiological effects of dietary fiber
originate from the interactions with colonic
content throughout its fermentation. - It influences several metabolic processes,
including the absorption of nutrients,
carbohydrate and fat metabolism, and cholesterol
metabolism.
63- influences the colonic structure and barrier
function, and as the large intestine encompasses
a significant body of the human immune system. - Some form gels (pectins), while others have a
high water holding capacity (WHC). - its ability to adsorb or bind bile acids and its
fermentability by microorganisms in the gut.
64Colonic Fermentation And Its Consequences
- The large intestine is the most heavily colonized
region of the digestive tract, with up to 1011
-1012 anaerobic bacteria /gram. - end products produced from the fermentation,
including gases (methane, hydrogen, carbon
dioxide), short chain fatty acids (SCFA). - Increases in microbial mass from fiber
fermentation contribute directly to stool bulk
65- Gas production from colonic fermentation can also
have some influence on stool bulk. - Poorly fermented cellulose produces very little
acid during its fermentation, most of which is
only acetic acid by contrast, in the case of
more fermentable fibers, large quantities of SCFA
are formed. - The metabolic end products of fermentation
including the gases, SCFA, and increased
microbiota, play a pivotal role in the
physiological effects of fiber and implications
for local effects in the colon and systemic
effects
66PHYSIOLOGICAL FUNCTIONS OF DIETARY FIBER
- Dietary Fiber And Cancer
- Colon cancer is one of the leading causes of
cancer morbidity and mortality among both men and
women in the Western countries, including the
U.S.A. - Dietary Fiber And Carbohydrate Metabolism
- An association between insufficient dietary fiber
intake and increased risk of diabetes has been
postulated since 1970s.
67- Dietary Fiber, Lipid Metabolism, And
Cardiovascular Disease - bind bile acids increasing their excretion and
decrease cholesterol in the liver. - SCFA are absorbed from the colon to the liver.
- Dietary Fiber, Mineral Bioavailability And Bone
Health. - certain highly fermentable fibers have resulted
in improved metabolic absorption of certain
minerals, such as calcium, magnesium, and iron,
68- Dietary Fiber, Role In Gut Barrier Function And
Gastrointestinal Disorders. - SCFA stimulating repair in a damaged colon.
- barrier to prevent foreign materials from dietary
or microbial origin from crossing into the
internal body cavity. Prevent Intestinal
permeability or leaky gut syndrome.
69Probiotics
- Intestinal tract is home to one hundred trillion
(1014) microorganisms. - called the intestinal microflora.
- over 400 different species of microbes.
- The 400 species of microbes living in your body
are fighting for space. They want to live, thrive
and reproduce in your intestinal tract, an
environment that offers the ideal temperature,
humidity and food sources.
70- Depending on the type of bacteria, there is a
different effect on the body bacteria can have
healthy, e.g., - immune-boosting benefits or cause harm to the
body. - A careful balance is necessary for health.
71- Bad microbes live in your intestines and normally
do not cause any disease-like symptoms. - Bad microbes flourish in an alkaline environment.
- Opportunistic and neutral the majority.
- Good microbes found in the body, called
probiotics. - Probiotics have a positive impact on the bodys
health. They prefer a more acidic intestinal
environment. Many of the probiotics are called
lactic acid bacteria.
72They define the term probiotic as live
microorganisms which when administered in
adequate amounts confer a health benefit on the
host.
How do they work? What are these health
benefits? How can we get them? What species can
provide them? Whats the relationship with
Chronic diseases? How can we maintain them?
73Some history
- Pasture 1880,
- Eli Metchnikoff 1908,
- Tisser 1900,
- W W I Nissil
- Southeast Asia, Boulardi. Cholera.
- 1950, group of scientists, found out that mice
that were given oral antibiotics, which kill all
bacteria, including probiotics, were more
susceptible to infection.
74- Yakult Company of Japan in the 1930s. Yakult
Company introduced a fermented milk product that
contained a probiotic culture. - The term probiotic was not actually coined until
the 1960s. - In 1978, Dr. Tomotari Mitsuoka, illustrated how
the composition of intestinal flora changes
during a lifetime. - Probiotics decrease with aging.
- WHY?
75How Do Probiotics Work?
- The intestinal microflora has the metabolic
activity potential equal to that of the liver,
the most active organ in the body! - The exact mechanisms of action by which
probiotics elicit their beneficial effects are
not fully understood.
76Suggested mechanisms
- Probiotics Compete for Receptor Sites
77- Change secretion to mask receptors
mucus
78- Probiotics Affect the Immune System
- Gastrointestinal tract is equipped with effective
immune system, the most number of lymphoid is
around the gut. - Immune system is the key element of what to enter
your body or not to. - By producing antibodies these are messengers for
all tissues connected with immune system. - Probiotics supplementation is useful in a wide
variety of immune-based ailments including
allergies, asthma, eczema and irritable bowel
disease.
79- probiotics help balance good and bad messengers
of the immune system by keeping the system in
check. - The result is healthy immune reactions and a
healthier you. A careful balance of inflammation
is required in the intestinal tract. - Too much of an immune reaction can result in
inflammation and damage to the intestines
reducing their ability to digest and absorb
nutrients I B D.
80- Too little immune reaction allows pathogens to
grow in the intestines, causing infectious
diarrhea, which can develop into a chronic
illness such as allergies. - All in all, it appears that probiotics
- reduce allergic reactions
- improve overall immunity
- promote proper immune reactions against pathogens.
81- Probiotics Consume Available Nutrients
- There are lots of nutrients available in the
digestive tract that support the needs of lactic
acid bacteria to grow. By consuming a large
portion of the available nutrients suitable for
microbes, lactic acid bacteria restrains the
growth of bad microbes. - Probiotics Create an Acidic Environment
- Many bad microbes do not like a low pH.
82- Probiotics Produce Beneficial Enzymes
- The enzyme activity of probiotics has been found
to help fight infectious disease, lactose
intolerance, immune system deficiencies, and
urogenital and vaginal diseases. - Probiotics Produce Antimicrobial Effects
- Many of the probiotic strains of bacteria are
able to produce substances that kill bacteria,
called bacteriocins
83- Probiotics Support Gut Barrier
- Lactobacilli and Bifidobacteria produce fats that
encourage the growth of cells that line the
intestinal tract. These fats are called short
chain fatty acids. These fats also have
nutritional effects on the intestinal cells,
keeping them well nourished and healthy. - Gut integrity.
84- Probiotics Encourage Healthy Microflora
- In clinical trials, the use of combinations of
probiotic species has been found to offer greater
health benefits than any one of the probiotic
species alone. - Example
- Lactobacillus reuteri produces protein to enhance
the growth of other lactobacilli.