Food Sources of Trans-Fatty Acids | UPSC Mains MEDICAL-SCIENCE-PAPER-II 2017

Q: Are all fried foods high in trans fats?

Not necessarily. The trans fat content depends on the type of oil used and how frequently it is reused. Using fresh, unsaturated oils and avoiding repeated frying can minimize trans fat formation.

Which foods are major source of trans-fatty acids?

How to Approach

This question requires a direct answer focusing on food sources of trans fats. The approach should be to define trans fats, categorize them into natural and artificial sources, and then list major food items contributing to their intake. Mentioning the health implications briefly adds context. Structure the answer by first defining trans fats, then detailing natural sources, followed by artificial sources, and finally, emphasizing foods high in artificial trans fats.

Trans-fatty acids (TFAs) are a type of unsaturated fat that come with significant health concerns, notably increasing LDL (bad) cholesterol and decreasing HDL (good) cholesterol, thereby elevating the risk of cardiovascular diseases. They exist in both natural and artificial forms. While naturally occurring TFAs are found in small amounts in some animal products, the majority of TFAs consumed are artificially produced through an industrial process called partial hydrogenation. The World Health Organization (WHO) recommends limiting trans fat intake to less than 1% of total energy intake, aiming for global elimination by 2023. Identifying major food sources is crucial for public health interventions.

Types of Trans Fats

Trans fats are broadly categorized into two types:

Naturally occurring trans fats: Found in small amounts in meat and dairy products.
Artificially produced trans fats: Created industrially from liquid vegetable oils through partial hydrogenation.

Natural Sources of Trans Fats

While the amount is relatively small, some foods naturally contain trans fats:

Beef and Lamb: These meats, particularly fatty cuts, contain a small percentage of trans fats.
Dairy Products: Milk and cheese, especially from ruminant animals, contain naturally occurring trans fats like conjugated linoleic acid (CLA).

Major Food Sources of Artificial Trans Fats

The primary sources of trans fats in the modern diet are artificially produced and found in:

1. Partially Hydrogenated Oils (PHOs)

PHOs were widely used to increase shelf life and improve the texture of foods. However, their use is being phased out in many countries due to health concerns.

Vanaspati (Hydrogenated Vegetable Oil): A common cooking medium in India, traditionally high in trans fats. Regulations are now pushing for lower trans fat vanaspati.
Margarine: Some margarines, particularly older formulations, contained significant amounts of PHOs.
Shortening: Used in baking and frying, shortening often contained PHOs.

2. Processed and Fried Foods

Foods prepared using PHOs or repeatedly fried in oil are significant sources of trans fats.

Baked Goods: Cakes, cookies, pastries, and pies often contained PHOs to improve texture and shelf life.
Fried Foods: French fries, doughnuts, fried chicken, and other deep-fried items can absorb trans fats from the frying oil, especially if the oil is repeatedly used.
Snack Foods: Some commercially prepared snack foods, like microwave popcorn and crackers, may contain trans fats.
Fast Foods: Many fast-food items, including burgers, pizzas, and fried sides, historically contained trans fats.

3. Other Sources

Non-Dairy Creamers: Some non-dairy creamers used in coffee and tea contained PHOs.
Some Ice Creams: Certain ice cream formulations used PHOs to improve texture.

Trans Fat Regulations and Current Trends

Recognizing the health risks, many countries have implemented regulations to limit or eliminate trans fats in food. India’s Food Safety and Standards Authority of India (FSSAI) has set a limit of 3% trans fats in oils and fats, with a target of reducing it to 0% by 2022 (extended to 2025). This has led to a shift towards using healthier oils and reducing the use of PHOs.

Food Category	Trans Fat Content (Approximate - varies by brand/preparation)
Vanaspati	Historically 15-40%, now regulated to <3%
Commercial Baked Goods (Cake/Pastry)	0-5g per serving
Fried Chicken (1 piece)	0.5-3g
French Fries (Medium Portion)	1-4g

Additional Resources

Key Definitions

Hydrogenation

Hydrogenation is a chemical process in which hydrogen is added to unsaturated fats, converting them into saturated fats. Partial hydrogenation creates trans fats as a byproduct.

LDL Cholesterol

Low-density lipoprotein (LDL) cholesterol, often referred to as "bad" cholesterol, contributes to plaque buildup in arteries, increasing the risk of heart disease.

Key Statistics

According to the WHO, trans fat intake is estimated to cause over 500,000 deaths annually from coronary heart disease.

Source: World Health Organization (2019)

A study published in the journal Circulation (2015) estimated that eliminating industrially produced trans fats from the US food supply could prevent 19,000 deaths annually.

Source: Circulation (2015)

Examples

Denmark's Trans Fat Ban

Denmark was the first country to introduce legislation in 2003 to limit trans fats in foods. This led to a significant reduction in heart disease rates.

Frequently Asked Questions

▶Are all fried foods high in trans fats?