19/11/05

EMB Workshop for EMB Workshop for GM Food, Food Labeling & GM Food, Food Labeling &

Food AdditivesFood Additives

Lai K. Leung, PhDLai K. Leung, PhD

Food & Nutritional Sciences Programme Food & Nutritional Sciences Programme ( Biochemistry Department)( Biochemistry Department)

MSc Programme in Nutrition, Food MSc Programme in Nutrition, Food Science and TechnologyScience and Technology

Diploma/Certificate in Food & Nutritional Diploma/Certificate in Food & Nutritional SciencesSciences

The Chinese University of The Chinese University of Hong KongHong Kong

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GM Food

• DefinitionDefinition:

– A food product containing some quantity of any genetically modified organism (GMO) as an ingredient.

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GM Food• Common GM Food in the Common GM Food in the

marketmarket:– Rice– Soybean– Corn– Tomato

• PurposePurpose:– Securing food supply (fast-

growing; resistant to temp/virus/insecticide)

– Economic factor– Nutrient enrichment

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GM Food

• TechniqueTechnique:

VECTOR

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GM Food• HistoryHistory:

– 1st GMF in the US market – tomato produced by Calgene in 1994; flavor not desirable, pulled out in 1997.

– Monsanto & USDA in 1998 patent on a technique for genetic seed sterilization (self-destruction of offspring); withdrawal due to public opposition.

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GM Food

• Hong KongHong Kong:– No farmers using GM technique.– Research performed at the Univ. level.– No specific regulation for GM food sale.– Public consultation on GM food labeling in

2001. – An impact assessment conducted in 2002.– 2003, difficulties were identified in mandatory

GM food labeling.– The Govm’t’s initiative: only safe GM food are

sold.

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GM Food

• Testing systemTesting system:

Polymerase Chain Reaction

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GM Food

• IssuesIssues:– Benefits (↑productivity & quality; ↓cost)– Potential hazards (food allergy; jeopardized

flora & fauna biodiversity; delayed response for long term consumption)

– Consumers’ right?

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Food Labeling (FL)

• FL provides the info for calculating the nutritional values. It consists of percentages of the Daily Values.

• Assist individuals to pursue a healthy dietary pattern.

• Chronic disease prevention and gov’t budget implication.

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Food Labeling (FL)

• The Daily Values:– Developed by FDA on FL for simplifying the

calculation of intake.– The % based on a 2000-kcalorie and/or 2500-

kcalorie diet.– 2000 kcalorie diet: about right for moderately

active women, teenage girls, and inactive men.

– 2500 kcalorie diet: about right for men, teenage boys, and active women.

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Food Labeling (FL)

• Nutrient claims:– Claims must be coherent physiologically.– e.g. “cholesterol-free” claim has to satisfy <2

mg of chol and also ≤ 2 g of saturated fat per serving.

• Health Claims– Related to a disease or health condition (most

people/specific population are at risk).– Supported by scientific evidence.

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ABC News

• Recent food labeling issues in the US:

– ABC News Watchdog Group Calls Out Food Products Mislabeled 'Healthy'.htm

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Food Additives

• ‘Any substance that affects the characteristics of any food.’– Coloring agents– Sweeteners– MSG, etc.

• Food Toxicology

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Food Toxicity

• Definition:– “the capacity of a

substance to cause adverse health effects on a living organism.”

– Paracelsus commented in the 15th century, “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy.”

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Food Additives

• Purpose:– Product consistency, texture, etc. – Nutrition value – Storage– Taste, attractiveness.

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• For sweetness without the taking in that much calories as sugar.

US FDA approved sweeteners

1. Aspartame

2. Saccharin

3. Sugar alcohols

4. Acesulfame-K

5. sucralose

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Acesulfame-K

“... acetoacetamide, a breakdown product, has been shown to affect the thyroid in rats, rabbits, and dogs. Administration of 1% and 5% acetoacetamide in the diet for three months caused benign thyroid tumors in rats. The rapid appearance of tumors raises serious questions about the chemical carcinogenic potency."

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Saccharin

• It causes bladder cancer in rats, but the dosage is too high (equivalent to hundreds of cans of diet drinks per day).

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Cyclamate

• Not approved yet. It causes bladder cancer in rats.

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Issues to be addressed

Projects can be focused on:• Environmental impact. • How to implement?• What are the potential difficulties?• Identify the ‘losers’ of any of these

new policies.• Are we overly cautious?• What are the new opportunities?

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My recommendation

• Grade the project as essays with science elements.

• Not scientific papers.