Milk as a source of bioactives in health foods The example...
Transcript of Milk as a source of bioactives in health foods The example...
Milk as a source of bioactives in health foods
The example of functional juices
STELA-FIL 2013 "Innovating for the future
of the dairy sector" May 13-16, 2013 Montreal, Canada
Élise Méric, Charles Lavigne, Simone Lemieux, Sylvie Turgeon and Laurent Bazinet Institut sur la nutrition et les aliments fonctionnels (INAF) Centre de recherche en sciences et technologie du lait (STELA) Laval University Quebec, Canada, G1V 0A6 E-mail: [email protected]
Introduction •Type 2 diabetes
•Socioeconomic context and solutions Review of the Literature
•Glycemia •Protein sources
Problem and Objectives
Methodology, Results and Conclusion
• In vitro study • Nutritional study
Type 2 diabetes
Genetic disease
Physiological anomalies: tissue insulin resistance, insufficient production of insulin by the pancreas, and excessive production of glucose by the liver
Genetic predisposition, excess weight and lack of physical activity contribute to
its appearance
Serious long term complications: cardiovascular disease, cerebral embolism, blindness, amputations, kidney failure, death
Socioeconomic Context
It is currently a major problem
in most developed countries
A sharp increase in obesity can be observed in increasingly young populations
There are 365 million diabetics in the world, and this number is expected to double by 2025. Diabetes is a new epidemic.
It represents a huge economic and social burden:
2 billion dollars every year (Quebec)
Existing treatments (which can influence glycemic and/or insulin
response):
Nutritional-hygienic = diet and physical activity
Pharmacological = use of medication (oral anti-diabetic drugs)
Food ingredients: polysaccharides (Casiraghi et al., 2006), plant extracts (Williams et al., 2007) proteins, promising but still experimental! =>
Creation of functional foods
Solutions?
Glycemia
Definition
Level of sugar in the blood
Depends on the nutritional state (fasting blood glucose, postprandial glucose), age, and physiological condition (especially pregnancy)
Ranges from 0.7 g/l to 1.1 g/l (normal level 0.85g/l)
If too high = hyperglycemia (a sign of diabetes)
If too low = hypoglycemia
Glycemia
Regulation
Pancreas: hormonal regulation cells α (elevate blood glucose = glucagon)
cells β (lower blood glucose = insulin)
Insulin: enhances glucose uptake by muscles and peripheral tissues, and reduces liver glucose production (inhibited glycogenolysis)
Regulation of the pancreas: incretin hormones (GLP-1 and GIP) in enterocytes
Blood glucose +++
Enterocytes (L and K cells)
Small intestine
Insulin production
Pancreas
Regulation ---
Regulation +++
Incretin production GIP / GLP1
Storage
Glycemia: global regulation system
Liver and peripheral tissues (muscles)
Protein sources
Observed Effects
Effect on satiety (Luhovyy et al., 2007)
Insulinotropic effect (Frid et al., 2005 / Claessens et al., 2007)
Reduced glycemic response (Von Post-skagegard et al., 2006)
Increased plasmatic concentration of incretin => reduced glycemic response (Hall et al., 2003)
A global mechanism has yet to be identified.
Protein sources
Impact of form, composition, quantity and co-ingestion
The hydrolyzed form produces better results than the whole protein (Calbet et al., 2002 and 2004)
Amino acids with proven effects: leucine, phenylalanine, tyrosine…
(Van Loon et al., 2000) Co-ingestion: association of proteins + carbohydrates (Manders et al., 2006 and
2006) and/or amino acids (Nuttall et al., 2006) => Potentiation of effects
Effective at a theoretical minimum of 12g/drink = 4% of proteins (V/P)
PROBLEM AND HYPOTHESIS
When choosing a protein ingredient, what are the most important
parameters to consider in order to most effectively influence the glycemic metabolism in vivo, and is it possible to predict effects in vitro?
The effects of protein ingredients in a digestate or a fruit-based drink on the glycemic mechanism (in vitro and/or in vivo) depend on dosage, form
and source.
1. To study in vitro the effects and impact of the amino acids content, dosage, and type, and of the source of protein ingredients on the
secretion of GLP-1
2. To clinically validate (in vivo with humans) the effects of various protein ingredients added to a fruit-based beverage on the glycemic and
insulin responses and on the secretion of GLP-1, and to analyze the impact of the dosage, the type and the source of these ingredients on
these responses.
Objectives
Objective 1
To study in vitro the effects and impact of the amino acids content, the
dosage, the type and the source of protein ingredients on the secretion
of GLP-1
3 ingredients and 4 amino acids + controls
Enzymatic digestions with PEPSINE AND PANCREATINE (Ma & Xiong 2009)
Enterocytes (Nci-H716) : incretin production (GLP-1)
1 concentration of protein ingredient or amino acids (2%)
1 contact time (2 h) 2 digestions (repetitions)
5 tests per digestion on different cells
Methodology
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pM /
μg
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Standardized secretion of GLP-1 on Nci-H716 cells
Significant increase of GLP-1 secretion in relation to "normal" secretion, regardless of protein ingredient (double the control)
Generated secretions were similar regardless of the source or type of protein ingredient
used
There is a difference in GLP-1 secretion at the basal level and after contract with a protein ingredient
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IPS IPL HPL
Soya: glycine x2
Whey: leucine x2
Unlike alanine and aspartate, leucine and glycine can increase the basal secretion of GLP-1.
Amino acids composition is an important factor to take into account because it
influences the intensity of GLP-1 secretion.
Effect of amino acids composition
Objective 2
To clinically validate (in vivo with humans) the effects of various
protein ingredients added to a fruit-based beverage on the glycemic and
insulin responses and on the secretion of GLP-1, and to analyze the
impact of the dosage, the type and the source of these ingredients on
these responses.
4 fortified beverages + 1 unfortified control beverage ⇒ 5 beverages to test
Selection of 25 volunteers: Men ranging in age from 18 to 55 AND in good health
Determination of the basal constants: sampling blood at -15 minutes and time 0 Ingestion of 300 ml of beverage at time 0 after blood sampling
AND Determination of the effects caused by the beverages: blood sampling at times 30, 60, 90, 120, 150 and
180 minutes
Methodology
Analysis of quantities of insulin, C-peptide, glucose and GLP-1 in each of the 8 blood samples
Beverages tested in vivo:
Two sources = whey and soya
Two types for whey = IPL and HPL
Choice of two concentrations to verify the quantitative effect of the ingredient which can most easily be used industrially = IPL
At the outset, 4 protein ingredients:
6% IPS / 6% HPL / 6% IPL / 2.6% IPL
Methodology
0 1 2 3 IPL
0 1 2 3 IPS
a
bc
ab
c
bc
HPL 6% IPL 6% IPS 6% IPL 2.6% Matrix
time
pM
Nutritional study: insulin secretion in vivo
The effect of the beverage containing 2.6% IPL was not significantly
different than the effect of the matrix alone
=> there is therefore a quantitative effect related to the glycemic and insulin responses
A significant effect occurs only above a minimum
threshold
Ingredients containing 6% IPL perform significantly better than ingredients containing 6% HPL or IPS.
⇒ There is therefore a qualitative effect:
the source and type of ingredient used are also parameters which influence physiological
responses in vivo
a
ab
b
ab
a
IPL 6% HPL 6% IPS 6% IPL 2.6% Matrix
time
pM a
a
b
b
b
Nutritional study: GLP-1 secretion in vivo
At 6%, ingredients produce a significantly different secretion in vivo
than that produced by the matrix alone.
At 2.6%, the ingredient is not significantly different than the matrix.
⇒ There is therefore a quantitative effect:
The GLP-1 response in vivo is affected by the dosage ingested
In vivo and in vitro responses for the protein ingredients which were tested were similar.
Nutritional study: GLP-1 secretion in vivo
The amount of protein ingredient ingested has an important impact on in vivo physiological effects. There is a threshold of response to protein ingredients.
THE IN VIVO GLYCEMIC METABOLISM IS INFLUENCED BY THE DOSE INGESTED,
AS WELL AS THE SOURCE AND TYPE OF PROTEIN INGREDIENT USED.
There is an vivo/in vitro correlation between the GLP-1 responses of all the protein ingredients.
IN VITRO TESTS CAN IDENTIFY
WHEY OR SOYA BASED INGREDIENTS WHICH WILL HAVE AN IMPACT ON THE GLP-1 RESPONSE IN VIVO.
LASSONDE and NSERC
Joseph Makhlouf
Diane Gagnon, Pascal Dubé and Monica Araya-Farias
Bruno Marcotte, Yannève Rolland, Simon Peletier
Acknowledgements
Web Site: http://www.laurentbazinet.fsaa.ulaval.ca
Experimental design of the study of GLP-1 secretion of Nci-H716 cells 1. Experiment (Chen&Reimer 2009 ; Anini&Brubaker 2003 ; Reimer 2001)
Basal control: KRB + 0.2% BSA Positive control: KRB + 0.2% BSA + DMSO Negative controls: KRB + 0.2% BSA + 2% leucine+ Wortmannin KRB + 0.2% BSA + Wortmannin 3 ingredients and 4 amino acids to test at 2% (Wt/Vol): KRB + 0.2% BSA + 2% leucine KRB + 0.2% BSA + 2% glycine KRB + 0.2% BSA + 2% aspartate KRB + 0.2% BSA + 2% alanine KRB + 0.2% BSA + 2% ING (IPL / HPL / IPS)
C+ C- C-
IPL
AA1
IPS
AA2 AA4 AA3
HPL
C