Nutrient Density

What’s the Problem?

• Our agricultural practices improve traits (size, growth rate, pest resistance) of produce rather than nutrition.
• Between 1950 and 1999, 43 different fruits and vegetables had reliable declines in the amount of protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and vitamin C over the past half-century.
• From 1975 to 1997, average calcium levels in 12 fresh vegetables dropped 27 percent; iron levels 37 percent; vitamin A levels 21 percent, and vitamin C levels 30 percent.
• From 1930 to 1980, in 20 vegetables the average calcium content had declined 19 percent; iron 22 percent; and potassium 14 percent.
• One would have to eat eight oranges today to derive the same amount of Vitamin A as our grandparents would have gotten from one!

How Can Building Healthy Soil Help?

• Carbon farmed soil are less likely to lose nutrients through leaching.
• Carbon farming systems from conservation agriculture to perennial crops also reduce or eliminate tillage of the soil. The elimination or reduction of tillage reduces erosion and increases the complexity and diversity of life in the soil, notably of the highly beneficial arbuscular mycorrhizal (AM) fungi. These mycorrhizae help plants use nutrients more efficiently by capturing and transferring nutrients from plant to plant.

Sources

• Davis et al. –Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999
• A Kushi Institute analysis of nutrient data from 1975 to 1997
• Scientific American – Dirt Poor: Have Fruits and Vegetables Become Less Nutritious?
• A similar study of British nutrient data from 1930 to 1980, published in the British Food Journal
• Anne-Marie Mayer Independent Researcher, Devon, UK – Historical changes in the mineral content of fruits and vegetables
• Donald R. Davis in HortScience – Declining Fruit and Vegetable Nutrient Composition: What Is the Evidence?
• Harvey et al. – Climate-smart landscapes
• Microbial Life/Increased Diversity.