Nutrient Related Facts About Today's Food Supply
Consuming a balanced diet that meets the recommended servings of fruits, vegetables, whole grains, essential fatty acids and lean sources of protein still may not ensure ample nutrient intake due to changes in our food supply.
Changes in the average nutrient content of 43 fruits and vegetables between 1950 and 1999 resulted in the following:
• 6% decrease in protein
• 16% decrease in calcium
• 9% decrease in phosphorus
• 15% decrease in iron
• 38% decrease in riboflavin
• 20% decrease in ascorbic acid
Food quality changes like these are the result of multiple factors:
Storage time and maturity at harvest
Nutrients can be harmed during storage or transportation. Storing tomatoes for 5 days decrease ascorbic acid by almost 13%. Harvesting plants prior to proper maturity diminishes nutrient content potential, particularly for fiber, vitamin A, vitamin C and polyphenols.
Modern fruits and vegetables are genetically selected, and in some cases modified, for shelf life, high yield or other growth characteristics rather than their ability to extract or synthesize nutrients from the environment.
An increased level of CO2 in the atmosphere, due to pollution, decreases the nitrogen, potassium, magnesium and protein content of plants.
Fertilization of the soil with isolated key nutrients such as nitrogen, phosphorus and potassium, as opposed to more comprehensive fertilizers, can alter the composition of plants and lead to nutrient losses. For example, plants raised on high-potassium soil have higher levels of potassium, but reduced levels of calcium and magnesium.
Differences in climate and soil type can cause large variations in nutrient content. Calcium-rich soil will produce plants higher in protein, while potassium-rich soils produce plants higher in carbohydrates. Regional rainfall can create wide variations in vegetable mineral composition, particularly for calcium, magnesium and potassium.
Free-range animals produce meat with significantly higher levels of omega-3 fatty acids and conjugated linoleic acid. Dairy products made from grass-fed animals are also higher in vitamin A, E and beta-carotene. Unfortunately, most farm animals are restricted to feedlots and given regular hormone or antibiotic treatments, resulting in meat containing lower levels of these critical nutrients.
Industrial waste and contamination
Chemical residues and industrial waste, including heavy metals, pollute the land, water and food supply. Most of us carry a significant body burden of pesticides and pesticide metabolites.
Unlike foods, supplements also have the benefit of providing consistent levels of vitamins and minerals. Beyond the food supply, there are myriad reasons for taking supplements which we have discussed incessantly: stress, nutrient-depleting meds, genetic variables, environment, chronic or acute disease, etc.