What is nutrient density
Nutrient dense foods are those that have a higher ratio of nutrients to calories. The more of those valuable nutrients our body can get from a lower calorific intake, the better off we are.
Every food has a nutritional profile. For example, compare what youâ€™d gain from eating 250g kale to what youâ€™d gain from 250g ice cream. More vitamins and minerals, less calories.
In terms of nutritional density, kale is one of the highest ranking foods on the Nutrient Density scale, and unparalleled among green leafy vegetables.
To find out the nutrient density of various foods check the ANDI (Aggregate Nutrient Density Index) scores on this website.
The declining nutrient density in our fresh food
One hypothesis surrounding the epidemic of obesity that is prevalent in the western world is that there are less nutrients and minerals per calorific value in the food we eat compared to just 50 years ago, so our bodies are craving more.
If we take a look at conventional agricultural practices, the focus is on yield. If a farmer is paid on kilos of produce he does whatever it takes to get those kilos. Somewhat infamously chicken producers were caught red handed injecting water into chicken tissues that would go on to be eaten as meat and we pay for chicken by the kilo. Water is cheap!
Dairy farmers are paid by the percentage butterfat in the milk. Grain growers by the amount of protein in the grain. Certified organic growers of all produce are paid for compliance with the set of rules that allow a grower to call that produce; certified organic.
The organic certification system ensures only approved inputs are used, that cultural practices are compliant and the resulting food is free of chemicals and artificial fertilizers. In general it ought to be better for you and the planet. It is certainly free of genetic modification, absent of any chemical residues but thatâ€™s where the certainty stops.
Assessing the nutrient qualities of food is a fickle topic to tackle and arrive at definitive answers.
What science does agree on is:
Nutrient density is important because the less we have to eat to gain the nutrition we need, the better off we are (nutritionally and financially).
- There is a link between the mineralisation of the soil, what the plant takes up and hence what is available for our bodies to absorb from that plant. If you are a French vigneron, youâ€™d express this as terroir. The qualities of the food (or wine) are a direct result of the soil and conditions in which it was grown.
- That the fresher the produce, the less likely you are to suffer from a loss of a foods nutritional quality.
- That excessive use of chemicals to grow a crop and then a failure to observe the prescribed withholding periods will result in consumers eating those toxic chemicals.
- That nutrient density of fresh produce has declined between the 1950â€™s and 2009.
Some of the leading scientific research in this area comes from US biochemist, Donald Davis. In his comparisons between 1950 and 2009 he found declines in five nutrients in various fruit and vegetables. He gives examples of iron which declined by 43 percent and calcium which declined by 19 percent.
Davis and others are blaming our agricultural practices that reward quantity not quality.
Paul Finnigan of the UK based Institute of Food Research summarises one of the problems as â€œfoods are being bred for yield, and not necessarily for nutritional composition."
It gets worse given the effects of rising CO2 levels. Fresh produce has been shown to have lower levels of zinc and iron as a result of increasing concentrations of this greenhouse gas.
A survey of 43 crops in the USA found the following decline in key nutrients:
|Vitamin C down 15%
||Iron down 15%
|Vitamin B2 down 38%
||Calcium down 16%
|Protein down 6%
||Phosphorus down 9%
According to Donald Davis, â€œthe most important thing you can do is eat more fruits, vegetables and whole grains and cut down on highly refined human made foods, vegetable oils and added sugars.
Organic produce takes you only part of the way in addressing these very real concerns about the declining nutrient density of our food. Although buying organic food almost guarantees it is chemical-free, it doesnâ€™t necessarily guarantee higher nutrient density.
The taste test
Itâ€™s not difficult to identify nutrient dense food - the easiest way of telling is in the taste. If it tastes delicious, almost definitively the taste is a result of high mineralisation. Just think of the difference between a home grown tomato and a supermarket tomato (or carrot, lettuce, nectarine or peach etc). Consider what was different about the way they were grown.
Growing your own
If you want nutrient dense food you have to put the minerals into the soil right from the start and then ensure high microbial activity so the plants can feed cafÃ© style and take up what they need when they need it.
How is this done? It starts with soil testing, then adding the required minerals and retesting. Increasing carbon in the soil by way of composts, humates and surface mulching helps. Good soil carbon levels will act as a buffer ensuring excess minerals are bound up and that there are â€œhomesâ€ for minerals that may be lacking. Applying â€˜plant foodsâ€™ with a broad spectrum of minerals makes the minerals immediately available to the plant which can then use them or store them as required.
Growing your own food allows you to control the inputs into your soil, build up the minerals and enjoy the resulting produce that is both densely nutritious as well as delicious.