News - Mineral depletion in our soils – a growing problem
The role of minerals in the body is vast. They are vital for many body processes, such as the formation of bones, a healthy nervous system, growth and development. To quote Dr Linus Pauling, “you can trace every sickness, every disease and every ailment to a mineral deficiency”. It should concern us all, then, to hear that the mineral content of the food we eat today may contain only half the minerals it would have done in our grandparents’ time.
Since the 1930s, the British government has regularly produced Composition of Food Tables. These tables give extensive information on the nutrient content of foods commonly consumed in the UK. In a study published in the 1997 issue of British Food Journal, researcher Anne-Marie Mayer used these food tables to study the mineral content of fruits and vegetables grown in the 1930s compared to those grown in the 1980s. The study found that the levels of calcium, magnesium, copper and sodium were significantly reduced in vegetables and magnesium, iron, copper and potassium were significantly reduced in fruit. The only mineral that showed no significant difference over the 50-year period was phosphorus(1). In 2006, researcher David Thomas analysed the mineral content of meat and dairy food using the latest edition of the food tables published in 2002. Thomas found that the mineral content of popular meats and milk products had fallen significantly. In milk, the iron content had fallen by over 60% and the magnesium content by 21%. Meat products showed an average of loss of 10% for magnesium and a 60% decrease in copper, while dairy foods showed a typical 25% decrease in magnesium and a 90% decline in copper(2).
Some possible reasons for the decline in minerals in our food(3)
Plants develop nutrients on their own and also acquire them from soil content. Modern farming techniques are geared towards a high yield and researchers question the quality of the top soil, the amount of top soil loss and the possibility that top soil is overused. Farmers replace most of the nitrogen and potassium lost, but less attention is paid to the other nutrients, which could have long-term effects on the mineral content of plants.
As produce continues to ripen while it is being transported, crops may be harvested before they become fully ripe in order to prevent over-ripened produce. However, this may prevent plants from obtaining all the minerals they need from the soil as they grow.
Storage and transportation
Crops are being transported over increasing distances. Research suggests some fruits and vegetables may lose as much as 50% of their nutrients within three to five days of being harvested.
Pesticides, herbicides and chemical fertilisers
Increased use of these substances may affect the nutritional quality of crops.
The trend in today’s farming is to use modern, high-yield varieties of crops, which are grown for their carbohydrate and water content. Research has shown, however, that these modern varieties have a lower mineral content than older, lower-yielding varieties. In one study, over a two-year period, researchers grew 27 commercial broccoli hybrids in side-by-side plots, ensuring that all plants received the same levels of fertiliser, irrigation and pest control and that the overall growing conditions were consistent. After harvesting the broccoli and sampling the plants, the researchers found “significant inverse relationships” between yield and concentrations of calcium, magnesium and broccoli. In other words, as the broccoli heads grew bigger, the levels of calcium and magnesium in the heads decreased. Similar research has been conducted with wheat and corn and shown the same result; that higher-yielding plant varieties produced harvests with lower concentrations of minerals.
Changes in the methods of measuring the composition of food(6,7)
The food and farming industries challenge research that shows that levels of minerals have declined in our food, and argue that the testing methods have changed. The Food Standards Agency, which publishes The Composition of Food, agrees that using the government tables to make historical comparisons is problematic and any differences over time could be due to a wide variety of factors, including differences in analytical methodology. However, Dr Tim Lobstein, Director of the Food Commission, disagrees, stating that minerals are easy to detect and measure and it is impossible that methods changed to such an extent as to explain the huge differences in the figures.
Whether or not organic foods have a higher nutritional value is still controversial. Some studies suggest that, on average, organically grown fruits and vegetables may contain slightly higher levels of vitamin C, trace minerals, and antioxidant phytonutrients than conventionally grown produce. However, other studies have found no nutritional differences between organic and non-organic foods. Organic foods, however, do have other benefits, such as not containing pesticides or preservatives. Also, organically raised animals are not given antibiotics, growth hormones or fed animal by-products. Organic farming is also a more environmentally-friendly way of farming.
Selenium is a key antioxidant mineral, which helps the body maintain a healthy heart and arteries, immune system, brain, thyroid and reproductive functions. It is also needed for healthy hair and nails. The content of selenium in the diet is primarily dependent upon the concentration of selenium in the soil. Canada, Japan, Norway and the United States are the only four countries in the world where the dietary content of selenium is adequate(9).
A study published in the Journal of Food Sciences and Agriculture showed that levels of selenium in the blood of the British population has been dropping since the 1970s, when grain began to be sourced from EU countries with selenium-poor soil. The study also showed that levels of selenium in British wheat are up to 50 times lower than their American and Canadian counterparts.
Dr Seif Shaheen at King’s College London suspects that deficiency in the trace minerals iron and selenium could be responsible for a growing incidence of asthma among children the UK. In the UK, intake of selenium has been falling while asthma has been increasing. A selenium-enriched food-form supplement may therefore be a beneficial addition to the diet.
Other important minerals
Magnesium, the body’s fourth most abundant mineral, is needed for more than 300 biochemical reactions. It is essential for a healthy heart, immune system, muscle and nerve function, electrolyte balance and for strong bones and teeth. Magnesium also helps normal blood pressure, energy metabolism and protein synthesis.
Who may benefit from magnesium supplements?
Patients on certain medication, such as antibiotics, diuretics and drugs used to treat cancer, as these medications can affect mineral absorption, particularly magnesium.
People who suffer from certain health conditions, such as cardiovascular disease, PMS, diabetes, osteoporosis and high blood pressure.
Patients with health conditions leading to malabsorption, such as coeliac disease, ulcerative colitis and Crohn’s disease, as they may have reduced mineral absorption and also increased loss of minerals in the urine.
Elderly people, as they tend to be on a higher level of medication and may have poorer digestive function.
Alcoholics, as low blood levels of magnesium occur in 30% to 60% of alcoholics, and in nearly 90% of patients experiencing alcohol withdrawal.
Individuals with chronically low blood levels of potassium and calcium, as they may have an underlying problem with magnesium deficiency.
This is the most abundant mineral in the body and is required for vascular contraction and vasodilatation, muscle function, nerve transmission, intracellular signalling and hormonal secretion.
Who may benefit from calcium supplements?
Postmenopausal women, because they experience greater bone loss and do not absorb calcium as well
People who are lactose intolerant
Vegetarians and vegans
Patients with certain health conditions, such as cardiovascular disease and high blood pressure
Zinc is involved in cellular metabolism, the catalytic activity of approximately 100 enzymes, immune function, wound healing and protein synthesis. A daily intake of zinc is required because the body has no specialised zinc storage system.
Who may benefit from zinc supplements?
Vegetarians and vegans, because they do not eat meat, which is a good source of zinc. Also, the beans and grains they typically eat have compounds that keep zinc from being fully absorbed by the body.
Pregnant and lactating women
Patients who suffer from a poor immune system, diarrhoea, or skin problems
Which Higher Nature products may be suitable?
There are a number of Higher Nature True Food® products which may be appropriate. These are nutrients in their food-based form, which the body is designed to digest and is readily absorbed for optimum bioavailability. The yeast cell walls are gently pre-digested and broken down with enzymes from pineapple and papaya fruit to release the nutrients within each cell. This aids digestion and breaks up the cell wall into smaller fragments. This is important for yeast-sensitive people. The allergen that causes yeast sensitivity is a protein on the cell wall. When the cell wall is broken down, its ability to evoke an allergic response is largely lost but for certain groups of people, including those with yeast overgrowth and compromised immune systems, the possibility that there may be antigenic residues from yeast cell walls may still be a potential problem.
True Food® Calcium and Magnesium is easily digested and absorbed for optimum bioavailability. These minerals are in a form similar to food, which the body is designed to digest.
True Food® Magnesium specifically helps replace the Magnesium lost through modern farming methods.
True Food® Zinc – Zinc is provided with Copper in a balanced ratio in a True Food® formula for optimum bioavailability.
Sea Calcium provides a naturally calcium-rich seaweed, harvested from pristine seas off the West Coast of Ireland, with over 30% natural Calcium, Magnesium and a spectrum of trace minerals.
Sublingual Zinc contains Zinc granules, with Vitamin C and tooth-friendly Xylitol, which taste like sherbet and are absorbed directly from the mouth.
Super OsteoFood provides a full spectrum of nutrients for bone strength, which includes not only Calcium and Magnesium, but many other nutrients that may support bone strength, e.g. Manganese, Zinc, Copper, Vitamin B6, Vitamin C and Vitamin D, plus True Food® SuperPotency Soyagen.
Zinc contains Zinc in the citrate form for high bioavailability, plus Copper in the correct ratio.
Eight ways to boost mineral intake
Eat plenty of fruit and vegetables; they are still an important source of nutrients in our diet.
Choose the smallest fruits and vegetables on offer.
Choose traditional, lower-yielding varieties, avoiding any variety that emphasises high yield.
Choose locally grown produce.
Refrigerating fruits and vegetables will help to slow down nutrient losses.
Steaming, rather than boiling, minimises loss of water-soluble vitamins.
Use an ionic mineral and trace mineral supplement, which is easily absorbed in the body.
A separate supplement of magnesium, calcium or zinc may be helpful for certain health conditions.
1. Mayer AM. Historical changes in the mineral content of fruits and vegetables. British Food Journal. 1997; 99(6):207-211.
2. www.foodmagazine.org.uk/articles/meat_and_dairy/ [Online] [Accessed 4/1/11].
3. United States Department of Agriculture: Food and Nutrition Information Center: http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=3&tax_subject=279&topic_id=1468&level3_id=6746&level4_id=0&level5_id=0&placement_default=0. [Online].
4. Fan MS, Zhao FJ, Fairweather-Tait SJ, Poulton PR, Dunham SJ, McGrath SP. Evidence of decreasing mineral density in wheat grain over the last 160 years. Journal of Trace Elements in Medicine and Biology. 2008; 22(4):315-324.
5. http://www.ezgarden.com/Articles/Benefits-of-Vegetable-Gardening/Improve-Food-Quality-with-Vegetable-Garden.aspx [Online] [Accessed 4/1/11].
6. http://www.guardian.co.uk/uk/2006/feb/02/foodanddrink. [Online] [Accessed 11/1/11].
7. http://www.dailymail.co.uk/news/article-559965/GM-foods-answer-worlds-food-shortage-crisis-report-says.html. [Online] [Accessed 11/1/11].
8. http://helpguide.org/life/organic_foods_pesticides_gmo.htm. [Online] [Accessed 11/1/11].
9. Combs GF Jr. Selenium in global food systems. Br J Nutr 2001; 85:517-47.