Bio Sem Final PP

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Transcript of Bio Sem Final PP

Omega-3 Fatty Acids and solutions to meet an increasing demandDANTE MORONI – SPRING 2015

The Big Picture• Health benefits now widely accepted

• Recommendations for consumption• 2 servings of fatty fish per week or at least 500mg/day EPA and

DHA• Most Americans get ~ 100mg/day• AHA: Coronary heart disease = 1g/day or more

• Main source is from fish and seafood

• Fisheries already at or above maximum output

•Alternative sources for omega-3 PUFAs are necessary

Associated health benefits / applications•Cardiovascular health and cardiovascular disease prevention

• Lowering of triglycerides (2-4 g/day)

• CHD mortality (lowers death risk)

• Anti-arythmatic

• Helpful with those who may have high blood pressure or cholesterol

• Reduced risk of clots (associated prostaglandins)

• Lowers risk of depression, and can alleviate some symptoms

• The list keeps on growing • Asthma, alzhimers, dementia, cancer, arthritis, stroke

Dietary Fat• Saturated fats – no CC double bonds• Ex: Meat and dairy products

•Monounsaturated fats – one CC double bond• Ex: Olive oil, Avacados

• Polyunsaturated fats - one CC double bond• Omega-6 or Omega-3 family (both essential)• USDA and AHA don’t distinguish

Figure 1. Nutrition information of an avocado. Note the different types of fat

Dietary Fat• Saturated fats – no CC double bonds• Ex: Meat and dairy products

•Monounsaturated fats – one CC double bond• Ex: Olive oil, Avacados

• Polyunsaturated fats - one CC double bond• Omega-6 or Omega-3 family (both essential)• USDA and AHA don’t distinguish

Figure 2. Basic saturated fat molecule consisting of 3 fatty acid tails plus 1 glycerol molecule

Chemistry of Omega-3s•ALA (short chain): Substrate for EPA and DHA synthesis

•EPA (long chain): Incorporated into cell membranes (phospholipids and red blood cells)• associated with cardiovascular health • Cellular communication

• DHA (long chain): Highly concentrated in brain, retinal, and nervous tissues. • Important for both postnatal and prenatal

•Omega-3s are prone to oxidation• Double bonds• Light, heat, and oxygen

•Several intermediates Figure 3. The three main omega-3 fatty acids (Source: Cargill website)

Biosynthesis of EPA and DHA• Eicosapentaenoic and Docosahexaenoic acids can be derived from α-linolenic acid via ∆ 6-desaturase enzyme

• Inefficient: ~8% to EPA, DHA 0.05% to 4%*

• Sources for EPA and DHA limited

• Competition with omega-6 fatty acids

• Higher conversion rate in women• 2.5X for EPA and 200X for DHA• Fetus requires ~400mg DHA/week (3rd)

trimester

Figure 4. Metabolic conversion pathway in humans (Source: Burdge and Calder, 2005)

Dietary sourcesPLANT* SOURCES = ALPHA LINOLENIC ACID (ALA)

• Concentrated in seed oils• Flax, Canola

• Varying levels in nuts• Walnuts

• Dark green leafy vegetables• Purslane, Kale, Spinach, etc.

ANIMAL* SOURCES = EICOSAPENTANOIC AND DOCAHEXANOIC ACIDS (EPA + DHA)• High levels in fatty fish• Salmon, Sardines, Herring, etc.

•Low levels in land animals• Potential for increased levels through

feed changes

Natural Fisheries and Aquaculture (fish farming)• > 70% exploited, overfished, or collapsed

• Aquaculture has provided another source for fish

• Fishmeal/oil sourced from open waters• 90% of fish oil stocks

•Need alternative fishmeal sources

Figure 5. Timeline showing change from underexploited fisheries to those more exploited fisheries in recent times (Source: Sea Around Us Project)

Algae oil as a supplement• Costly, option for vegans/vegetarians

• Infant formula• Purity

•Examples of uses• DHA oil supplement from Crypthecodinium• DHA for animal feed from Schizochytrium

Figure 7. One example of a biophotoreactor, used in mass production of algae. Many different configurations are used in the industry.

Example of transgenic oleaginous plant: Camelina sativa e.g. false flax (Betancor et al. 2015)• Wild type oil 45% ALA

• 5 microalgal desaturase and elongase genes• 20% EPA in seed oil

• Experiment conducted to see difference in fish growth

• No difference between fish oil and transgenic Camelina oil diet

• Still didn’t have significant DHA in fish fleshFigure 6. Camelina sativa e.g. false flax, an oleaginous (oily) seed plant.

Reliability of fish oil supplements (Albert et al. 2015)• Researchers analyzed 32 fish oil brands• On average: supplements contained

68% of level on label• 2/3 contained < 67% of level

• 50% exceeded international oxidation recommendations

• Not correlated with “best by” date

• Agreed with similar studies Figure 8. Actual omega-3 content (EPA and DHA) in fish oil supplements. Dotted line indicates amount listed on label. (Source: Albert et al. 2015.)

ALA still important!• Still get ALA into your diet despite low conversion rate• Can obtain from a variety of

sources• Flax seeds, walnuts, canola oil,

soybean oil*, dark leafy greens

• Omega-3 enriched eggsFigure 9. Intake of ALA is correlated linearly with incorporation in body tissues. (Source: Burdge and Calder, 2005.)

Conclusion• Omega-3s have several health benefits

• Recommendations are becoming more frequent

• Population is still growing

• Fisheries are strained

• Eating lower on the food chain and from a variety of sources

• Other alternatives include algae oil and ALA

• Aquaculture + transgenic oilseeds

Sources Albert BB, Derraik JGB, Cameron-Smith D, Hofman PL, Tumanov S, Villas-Boas SG, Garg ML, Cutfield WS. 2015. Fish oil supplements in New Zealand are

highly oxidized and do not meet label content of n-3 PUFA. Scientific Reports 5 (7928). DOI:10.1038/srep07928

Allport S. The queen of fats, why omega-3s were removed from the western diet and what we can do to replace them. University of CA press, Berkeley and Los Angeles, CA. 2006. Pgs: 4, 6, 11, 42, 115, 128.

Apt KE, Behrens PW. 1999. Commercial developments in microalgal biotechnology. J Phycol. 35: 215-226.

Betancor MB, Sprague M, Usher S, Sayanova O, Campbell PJ, Napier JA, Tocher DR. 2014. A nutritionally-enhanced oil from transgenic Camelina sativa effectively replaces fish oil as a source of eicosapentaenoic acid for fish. Scientific Reports. 5 (8104). DOI:10.1038/srep08104

Burdge GC, Calder PC. 2005. Conversion of α-linolenic acid to longer-chain polyunsaturated fatty acids in human adults. J Reprod Nutr Dev. 45: 581-597.

Harriss WS, Pottala JV, Sands SA, Jones PG. 2007. Comparison of the effects of fish and fish-oil capsules on the n-3 fatty acid content of blood cells and plasma phospholipids. Am J Clin Nutr. 86: 1621-1625.

Kris-Etherton PM, Hill AM. 2008. N-3 fatty acids: food or supplements?. J Am Dietetic Assoc. 108: (7) 1125-1130.

Nichols PD, Petrie J, Singh S. 2010. Long-chain omega-3 oils – an update on sustainable sources. J Nutrients. 2: 572-585.

Simopoulos AP. 2002. The importance of the ratio of omega-6/omega-3 essential fatty acids. J Biomed Pharmacother. 56 (2002) 365-379.

Stoll AL, Severus E, Freeman MP, Rueter S, Zboyan HA, Diamond E, Cress KK, Marangell LB. 1999. Omega 3 fatty acids in bipolar disorder a preliminary double-blind placebo-controlled trial. J Gen Psych. 56: 407-412

Su KP, Huang SY, Chiu CC, Shen WW. 2003. Omega-3 fatty acids in major depressive disorder a preliminary double-blind placebo-controlled trial. J European Neuropsych. 13: 267-271

Picture Sources 1 - http://www.californiaavocado.com/nutrition-and-health-2/

2 - http://sphweb.bumc.bu.edu/otlt/MPH-Modules/PH/PH709_BasicCellBiology/PH709_BasicCellBiology24.html

3 - http://www.cargillfoods.com/na/en/products/oils-shortenings/ingrevita/EPA-DHA/index.jsp

5 - http://www.kampachifarm.com/the-blue-horizon-imperative/

6 - http://www.agroatlas.ru/en/content/related/Camelina_sativa/

7 - http://en.wikipedia.org/wiki/Photobioreactor