4.1 fats in health and commerce ra macahig fm dayrit

4.1 Fats in Health and Commerce4.1 Fats in Health and Commerce

RA Macahig

FM Dayrit

4.1 Fats in Health and Commerce (Dayrit) 2

• Fats used to be a relatively uninteresting group of natural products. However, they have recently returned to prominence, particularly in two major areas of application:o As dietary fats: in nutrition and physiologyo As biofuels

• Fats occupy a metabolic position that covers both “primary” and “secondary” metabolism. In this discussion, we ignore this academic distinction.

• This discussion is divided into the following sections:1. Fats in the diet2. Fats and biological membranes3. Coconut and other oils4. Biofuel future?

Introduction


“To eat, or not to eat - fat is the question.”- from the Introduction

Many of the dietary regulations being promoted in the US (e.g., USDA and FDA), as well as the fad diets (e.g., Atkins diet) are erroneous. Despite its highly advanced food industry and high levels of healthcare, the US is suffering from an epidemic of a number of diseases and health conditions, such as coronary heart disease, stroke, diabetes, obesity, immune dysfunction, and mental illness.

1. Fats in the diet*

* (from: Mary Enig*, Know your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils, and Cholesterol, Bethesda Press, USA, 2000. Mary Enig is a biochemist and nutritionist. She holds a Ph.D. in Nutritional Sciences from the University of Maryland and is a Fellow of the American College of Nutrition. She has authored many journal articles on fats and oils, and nutrient/drug interactions.)


(http://www.faqs.org/nutrition/Met-Obe/Metabolism.html)

Interrelationships among Carbohydrates, Proteins and Fat in Human Metabolism

Protein FatCarbohydrate

Amino Acids Glycogen Triglycerides

Glucose

Pyruvate

Acetyl CoA

Krebs Cycle (TCA) and Electron

Transport System

Lactic acid

Fatty Acids

Glycerol

CO2, H2O, ATP

• Protein Fat• Carbo Protein• Carbo Fat• Fat Protein• Pr, Carbo, Fat Energy


• Are saturated fats a risk factor for CHD?

Role of Fats in the diet and its impact on health

Observed 15-year death rates per 100 men compared with death rates from coronary heart diseasepredicted from the multiple regression on the ratio of monounsaturated to saturated fatty acids in the diets ofthe cohorts: Seven Countries Study (Keys et al. 1986).

Key to symbols: A: US railroad men; C: Crevalcore (Italy); D:, Dalmatia (Yugoslavia); E:, East Finland; G: Corfu (Greece); H: Zutphen (Holland); K: Crete (Greece); M: Montegiorgio (Italy); R: Rome railroad men; S: Slavonia (Yugoslavia); T: Tanushimaru (Japan); W: West Finland; U: Ushibuka (Japan); V: Velika Krsna (Yugoslavia); Z: Zrenjanin (Yugoslavia)..

64.1 Fats in Health and Commerce (Dayrit)

“Vascular disease is uncommon in both populations and there is no

evidence of the high saturated fat intake having a harmful effect in

these populations.”

• Coronary heart disease (CHD): There is no relationship between the intake of saturated fat from coconut oil with CHD.


• Cancer: High levels of polyunsaturated fats are correlated with higher incidence of cancer. Epidemiological data suggest that coconut oil is the most cancer reducing oil.


• Immune dysfunction: Lipids play an important role in the regulation of immune function. Diets high in omega-6 fatty acids and partially hydrogenated fats have been reported to adversely alter immune function. Diets high in coconut oil or fish oil have been reported to improve immune response by decreasing pro-inflammatory cytokines.


• Alzheimers: Axona® is an MCT oil (C8 and C10) for the management of epilepsy and Alzheimer's disease. MCTs produce ketones which are an alternative energy source for glucose in the brain. Coconut oil is also being promoted for this ailment.


American dietary fat intake: 1930 vs 1985

Type of fat 1930 1985 % change*

Saturated 59 g (48%) 62 g (38%) -21%

Monounsaturated 50 g (40%) 68 g (41%) +2.5%

Polyunsaturated 15 g (12%) 34 g (21%) +75%

Total 124 g 164 g +32%


The biggest shifts in the American diet with regard to fats and oils since WW II have been:

• The dramatic increase in consumption of polyunsaturated fats. Much of this was pushed by the US soy bean industry lobby.

• The dramatic increase in consumption of unnatural fats and oils, mainly partially hydrogenated fats and oils which produced trans-fats, and more recently, synthetic fats, such as Olestra™.


Fats and Obesity


Unnatural Fats in the Modern Diet


CO2H

9

CO2H

9

Oleic acid, C18:1 cis-9

Elaicic acid, C18:1 trans-9

• Trans- fatty acids are present processed food products (snack chips, crackers, cookies, donuts, cakes, artificial coffee creamers) that use partially hydrogenated oils.

• Shortenings and margarines with partially hydrogenated oils have 25-50% trans-fatty acids.

• Trans- fatty acids are not metabolized in the same way as natural cis- fatty acids.

• Trans- fatty acids alter the characteristics of membranes where they are incorporated.

• Developmental effects in infants.

• Change in reproductive functions.



• trans-Fatty acids in the diet, created from partially hydrogenating vegetable oils, have been implicated as causing or exacerbating most of our modern diseases, including heart disease, cancer, diabetes, obesity, immune dysfunction and bone loss. (Mary Enig, Trans Fatty Acids in the Food Supply: A Comprehensive Report Covering 60 Years of Research, 2nd Edition, Bethesda Press, 1995 )

• “Consumption of a solid fat rich in lauric acid gives a more favorable serum lipoprotein pattern than consumption of partially hydrogenated soybean oil rich in trans-fatty acids. Thus, solid fats rich in lauric acids, such as tropical fats, appear to be preferable to trans-fats in food manufacturing, where hard fats are indispensable.” (de Roos et al., J. Nutr. 131 (2): 242, 2001)


Unnatural Oils in the American Diet


O

O

OOO

O

O

O

O O

OO

O

O

OO

• Olestra is an artificial sucrose polyester fat developed by P&G to meet the “low-fat low-calorie” craze in the US.

• Olestra is not metabolized by the body (so it is a “zero-calorie fat”) and is excreted unchanged (acts like an inert solvent).

• Potential for nutritional deficiency or imbalance, among others. Adjunct technology to high food consumption.


Short-chain fatty acids and intestinal health (from: Wikipedia)


• Short chain fatty acids (SCFA) are a sub-group of fatty acids with less than eight carbons. This group includes: Acetic acid, Propionic acid, Lactic acid, Butyric acid, Isobutyric acid, Valeric acid, Isovaleric acid, Caproic acid, and Succinic acid.

• SCFAs are used by the intestinal mucosa or absorbed through the colonic wall into the portal circulation (supplying the liver) that transports them into the general circulatory system. The major SCFA in humans are butyrate, propionate and acetate. Butyrate is the major energy source for epithelial cells lining the colon (colonocytes); propionate is taken up by the liver; and acetate enters the peripheral circulation to be metabolized by peripheral tissues.

CH3CO2H CH3CH2CO2H CH3CH2CH2CO2H CHCO2H

OH

CH3

CH3CHCO2H

CH3

CH3CH2CH2CH2CO2H CH3

CHCH2CO2HCH3

CH3CH2CH2CH2CH2CO2H HO2CCH2CH2CO2H .



• Collectively, SCFA have extensive physiological actions promoting health effects, among which major functions are:

• stabilize blood glucose levels by acting on pancreatic insulin release and liver control of glycogen breakdown

• stimulate gene expression of glucose transporters in the intestinal mucosa, regulating glucose absorption

• provide nourishment of colonocytes, particularly by butyrate

• suppress cholesterol synthesis by the liver and reduce blood levels of LDL cholesterol and triglycerides responsible for atherosclerosis

• lower colonic pH (i.e., raises the acidity level in the colon) which protects the lining from formation of colonic polyps and increases absorption of dietary minerals

• stimulate production of T helper cells, antibodies, leukocytes, cytokines and lymph mechanisms having crucial roles in immune protection

• improve barrier properties of the colonic mucosal layer, inhibiting inflammatory and adhesion irritants, contributing to immune functions

Refs:Bach and Babayan, Am J Clin. Nutr.,1982, 36, 950.CS Dayrit, “Health Aspects of Coconut Oil,” Proceedings of the World Conference on Lauric Oils, TH Applewhite (ed), 1994.

Medium-chain fatty acids: C8, C10, C12

Are all saturated fats unhealthy? (FMDayrit) 18

“Abstract. Medium chain fatty acids (MCFA) are readily oxidized in the liver….MCTs increase energy expenditure, may result in faster satiety and facilitate weight control when included in the diet as a replacement for fats containing LCT.”


2. Fats and biological membranes

In the past, lipids were simply considered as membrane components and biological energy source. Today we know that the role of lipids is much more complex. The biological membrane is made up of various fatty acids which are ester-linked to a phosphatidyl group, such as:

Phosphatidylcholine (PC):

Phosphatidylethanolamine (PE):Phosphatidylserine (PS):

Phosphatidic acid (PA):

Phosphatidylinositol (PI):



Biological membranes

• Their composition and structure are not thought to have subtle biophysical properties which result in heterogeneous membrane domains. Membranes are also regarded as a reservoir for precursors of molecular messengers. This could represent a clue for understanding the molecular diversity observed in membrane phospholipids.

•Biological membranes perform a complex multitude of tasks. This complexity is reflected in the complexity of its composition. For example, the human red cell which contains only a plasma membrane contains about 300 molecular species of glycerophospholipids formed by different long chain (C14–C22) fatty acids.



Lipids as functional biomolecules

Consider the role of phosphatidic acid (PA) in the cell. Its role can be classified into three categories:

• PA is the precursor for the biosynthesis of all other acylglycerol lipids in the cell.

• The physical properties of PA influence membrane curvature.

• PA is a signaling lipid, recruiting cytosolic proteins to appropriate membranes.

PA concentrations are maintained at very low levels in the cell by lipid phosphate phosphohydrolases (LPPs), which rapidly convert PA into DAG. PA is, therefore, essential for lipid synthesis and cell survival, yet, under normal conditions, is maintained at very low levels in the cell.


3. Coconut oil and other oils

The Coconut Palm (Cocos nucifera), is a member of the family Arecaeae (palm family) and is the only species in the genus Cocos. It is a large palm, growing to 30 m tall.The origin of the coconut is still undetermined. Various experts believe that it may be native to Southeast Asia or South America. Fossils dating more than 15 m years have been found in New Zealand and India. Regardless of its origin, the coconut has spread across the tropics, generally growing at 20 N/S latitude. (from: Wikipedia)

Zone 1: High coconut productivityZone 2: MediumZone 3: Low or none


Some History, Facts and Myths

• Pre-history. Coconut oil has been traditionally used as food, medicine and cosmetic throughout Asia and the Pacific for at least 4,000 years.

• Spanish era. The government decrees the planting of coconut trees throughout the Philippine islands.

• 1850. The English develop a copra milling process. Crude coconut oil and copra are exported to the US for use as edible oil.

• 1902. German chemist W. Normann patents (heterogeneous) hydrogenation of vegetable oils. In 1911, Procter & Gamble launched the first hydrogenated shortening, Crisco. (http://en.wikipedia.org)



• 1920-1940s. American Soybean Association (ASA) is formed. During WW II, soya oil production is increased to replace tropical oils which were blocked by the war. (www.soygrowers.com)

• 1934. Henry Ford develops enamel coating for cars from soya oil by free-radical polymerization process. (www.thesoydailyclub.com)

• 1949. The export of US soya expands using US foreign assistance programs. (www.soygrowers.com)

• 1987. ASA pressures US FDA to enact a “truth-in-labeling” campaign against “highly saturated tropical fats in foods … (to) increase market share for soybean oil”. (www.soygrowers.com)



• 2006. In the 1990s, the Harvard School of Public Health helped sound the alarm about trans fat and coronary heart disease risk and advocated that it be explicitly listed on food labels. In an updated analysis of the trans fat-heart disease link, HSPH researchers found that removing trans- fats could prevent tens of thousands of heart attacks and cardiac deaths each year in the US. (See: New England J. Med., April 13, 2006; ref: http://www.hsph.harvard.edu/reviews/transfats.html)

• 2006. US FDA amended its regulations to require that trans-fatty acids be declared in the nutrition label. Further, the agency withdrew the proposed footnote stating: “Intake of trans-fat should be as low as possible.” This rule took effect January 1, 2006. (http://www.cfsan.fda.gov/)


Fats in World Commerce

(www.cyberlipid.org/glycer/glyc0005.htm)


4. Biofuel Future?• Biofuels are broadly defined as fuels derived from biological

sources. These can be solid, liquid, or gas. Liquid biofuels include bioethanol and biodiesel. Because of its use for transportation, the biggest attention is focused on liquid biofuels.

• Biofuels is one strategy being considered to reduce greenhouse gas emissions and increase energy security for countries without fossil fuels.

• Many issues and concerns have been raised regarding biofuels, such as: cost and energy of inputs: labor, fertilizer, water; food vs. energy; and impact on biodiversity due to land conversion.

• The main concern for us in this chapter is the use of vegetable oil and biodiesel (transesterified vegetable oil, e.g., CME).


4. Biofuel future?

Biodiesel refers to a diesel-equivalent processed fuel consisting of short chain alkyl (methyl or ethyl) esters, made by transesterification of vegetable oils or animal fats, which can be used (alone, or blended with conventional diesel fuel) in unmodified diesel-engine vehicles.

Oil yields of common crops for biodiesel use.

Crop kg oil/ha liters oil/ha

corn (maize) 145 172

soybean 375 446

euphorbia 440 524

sunflowers 800 952

rapeseed (Canola) 1,000 1,190

jatropha 1,590 1,892

coconut 2,260 2,689

oil palm 5,000 5,950

Algae (actual yield) 6,894 7,660

Algae (theoretical yield) 39,916 47,500

(from Wikipedia)


4. Biofuel future?

Palm The African Oil Palm was introduced to Sumatra and Malaya in the early 1900s; many of the largest palm oil plantations are now in this area, with Malaysia growing over 20,000 km2 and the largest producer with 51% of world production.

For every 100 kilograms of fruit, 22 kg of palm oil and 1.6 kg of palm kernel oil can be extracted. This high productivity – as high as 7,250 L/ha/yr – has has made it the prime source of vegetable oil in many tropical countries and candidate for biofuels.

http://en.wikipedia.org/wiki/Image:Elaeis_guineensis0.jpg


4. Biofuel Future?

• Jatropha (family Euphorbiaceae) is a genus of approximately 175 succulents, shrubs and trees (some are deciduous, like Jatropha curcas L.). Plants from the genus natively occur in Africa, North America, and the Caribbean. It was spread as a valuable hedge plant to Africa and Asia by Portuguese traders.

• Because jatropha grows well in degraded soil and drought conditions, it is suitable for soil and watershed restoration. Its deep root system makes it attractive for sloping agriculture and protection against erosion. (www.jatrophaworld.org)

Jatropha


4. Biofuel Future?

• J. curcas trees, also called physic nut, produce 1600 liters of oil per hectare. The seed yields 31 to 37 % of oil which is trans-esterified with MeOH to yield the fatty acid methyl esters.

A Mercedes-Benz C-Class tested jatropha biofuel covering around 5,900 kms crossing India. (www.daimlerchrysler.com)

Estimated yield of Fatty Acid oils Biodiesel yield=oil yield x 0.95 (approx.)

Crop kg oil/ha litres oil/haCorn 145 172Jatropha 1,590 1,892Coconut 2,260 2,689Palm oil 5,000 5,950

Fatty acid composition: Myristic acid: 0-0.5%Palmitic acid: 12-17%Stearic acid: 5-6%Oleic acid: 37-63%Linoleic acid: 19-40%

• Jatropha has medicinal properties. Jatropha oil can be used for candles and soap and the residual cake can be used for compost or fertilizer. However, its most attractive property is as a source of biofuel.

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4. Biofuel Future?

Partial Lifecycle Analysis of Biofuels

Agricultural production

CO2

H2OFertilizer (N,P,K)

SunlightLand

Labor

O2Biomass

Water pollution

Other products

Biofuel production

ChemicalsEnergy

Labor

Biomass

Waste products

Other products

Commercial fuel

LaborTransport

Energy

Particulates

NOx CO2

Blending

Note: The various inputs and outputs can be beneficial or harmful.


4. Biofuel Future?

Algae Biofuels Biofuels from photosynthetic algae:

•Algae can be grown using land and water unsuitable for plant or food production, unlike some other first- and second-generation biofuel feedstocks.

•Select species of algae produce bio-oils through the natural process of photosynthesis — requiring only sunlight, water, carbon dioxide and N-source.

•Growing algae consume carbon dioxide; this provides greenhouse gas mitigation benefits.

•Bio-oil produced by photosynthetic algae and the resultant biofuel will have molecular structures that are similar to the petroleum and refined products we use today.

4.1 fats in health and commerce ra macahig fm dayrit

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