Milk represents a good balance between nutrients and CO2 emissions

17 September 2010

Milk scores significantly better than soft drinks, alcoholic beverages and soy drinks when it comes to the relationship between the nutrients it provides and the greenhouse gasses discharged to produce it. This was revealed by an analysis carried out by scientists from the United States and Sweden which involved a type of Life Cycle Analysis (LCA) of drinks. The team of scientists developed a Nutrient Density to Climate Impact (NDCI) index to show the relationship between the number of essential nutrients in a product and the corresponding CO2 emissions.

The production of food makes a substantial contribution to the emission of greenhouse gasses. The production of vegetable-based foods seems attractive as it apparently requires less energy than animal-based foods such as meat and dairy.

However, the researchers from Uppsala (Sweden) and Seattle (US) stress that this has not yet been fully substantiated as too little research has been carried out into different consumption patterns for the purpose of reducing greenhouse gas emission. For instance, no account has been taken of the nutrient density of food products.

New index
To compare different products, the scientists developed a Nutrient Density to Climate Impact (NDCI) index. They compared the levels of vitamins, calcium, fat and proteins of the drinks with the corresponding volume of greenhouse gases emitted. A total of 21 nutrients were compared. The lower the score on the index, the poorer the ratio of nutrients / environment. An NDCI index score has been established for bottled carbonated water, soy milk, milk, soft drinks, orange juice, beer and red wine.

Results
Carbonated water, soft drinks and beer all score zero owing to their low nutritional value. Red wine has a marginally better score of under 0.1. Orange juice and soy milk score somewhat higher with at 0.25 and 0.28, respectively. The NDCI index for milk is notably better: 0.54.

In the Food & Nutrition Research Journal, the scientists conclude that “in future discussions on how we can prevent climate changes by adapting our eating patterns, it should be borne in mind that it is not merely an issue of greenhouse gas emissions but also of the nutritional density of food products.”