In general, our diets need improving. Our diets are depleted of vitamins, minerals, essential fatty acids, as well as other nutrients due to our lifestyles as well as the quality of our food supply. A combination of a healthy diet and complementary supplements is a major step towards achieving optimal health.
Our modern lifestyles devote little time to making quality food choices. A study of 2000 adults found that the most significant factors in choosing a lunch was convenience and taste, rather than health (1). This leads to a typical North American diet that will include:
Too much (2,3):
Saturated and trans fats
Not enough (2,3):
Vitamins A, C, D, E, K
Essential fatty acids
Even if we follow the recommended guidelines for servings of fruits, vegetables, protein, and essential fats, we still may not be reaching adequate intake of nutrients due to changes in the way our food is produced, stored, and selected. A comparison study that looked at the average nutrient content of 43 different fruits and vegetables between 1950 and 1999 found (4):
6% decrease in protein
9% decrease in phosphorus
15% decrease in iron
16% decrease in calcium
20% decrease in ascorbic acid (vitamin C)
38% decrease in riboflavin (vitamin B2)
These changes in the nutrient content of foods can be attributed to multiple factors including:
1. Storage Time and Maturity at Harvest
Harvesting plants before they are properly mature and/or delaying time between when the plant was harvested and consumed significantly reduces the levels of essential nutrients including fiber, vitamin A, vitamin C, and phenolic compounds (5). Fruits and vegetables grown in North America may spend up to 5 days in transit after harvest before arriving at the supermarket. Food grown in the southern hemisphere for our winter and spring consumption range from 4-5 days (if transported by air freight) all the way to several weeks (if transported by refrigerated ship). After these fruits and vegetables arrive at the grocery store, they may spend 1-3 days on display before being purchased by the consumer who may store them for up to a week before consuming them. In addition to this, nutrients can be harmed during the storage or transportation by factors including temperature, relative humidity, light exposure, and oxygen/CO2 levels (6).
2. Genetic Selection
Modern fruits and vegetables have been genetically selected (and in some cases modified) for shelf life, high yield, pesticide resistance, or other growth characteristics (to increase profitability) rather than their ability to extract or synthesize nutrients from the environment (to increase health). Compared with wild plants, most modern varieties have been selected so they are higher in sugar and lower in protein, fiber, vitamins, minerals, and essential fatty acids (7).
3. Fertilization Quality and Environmental Conditions
Fertilization of the soil with isolated forms of key nutrients such as nitrogen, phosphorus and potassium (NPK), as opposed to more comprehensive fertilizers, can alter the composition of plants and lead to nutrient imbalances. An example of this is that plants raised on high potassium soil have higher levels of potassium, but reduced levels of calcium and magnesium (8,9).
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. Differences in rainfall depending on the region can create wide variations in vegetable/fruit mineral composition, particularly for calcium, magnesium and potassium (9,10).
4. Farming Practices
Free-range animals produce meat with significantly higher levels of omega-3 fatty acids and conjugated linoleic acid (11). Dairy products made from grass-fed animals are also higher in vitamin A, E and beta-carotene (12). Feed-lot fed animals produce meat containing lower levels of these critical nutrients. Antibiotics fed to these animals can also result in altered bacterial profiles, potentially altering the consumer’s gut microflora which can lead to gastrointestinal disorders as well as other health issues (13).
Use of herbicides has skyrocketed in the last few years. Some studies quote 100 fold increased frequency and volume of glyphosate, also known as Roundup (14). One example related to a particularly large increase of herbicide usage is that after Monsanto introduced “Roundup Ready” genetically modified seeds including soy, corn, canola, alfalfa, cotton, and sorghum (14). Roundup is a broad-spectrum herbicide that has been linked to an increased risk for various cancers including non-Hodgkin lymphoma (15). In 2015 the World Health Organization’s International Agency for Research on Cancer classified glyphosate as “probably carcinogenic in humans” (Category 2A; the same category as Human Papilloma Virus- HPV) (16,17,18). So, industrial farmers use these seeds which are resistant to this herbicide, allowing them to use massive amounts of this herbicide, effectively clearing the fields of the competition of weed or other unwanted plants. Great for the farmers, yields increase so they make more money, but very bad for the health of the consumers of these foods.
5. Industrial waste and contamination
On top of the toxic chemicals that are being added on purpose to our foods, chemical residues and industrial waste, including heavy metals, pollute the land, water and food supply (19). A study conducted in 2004 analyzed 2,644 individuals and found “most people in the U.S. carry a significant body burden of pesticides and pesticide metabolites,” with the average person testing positive for 13 out of the 23 analyzed. Estrogen stimulating compounds, such as DDT and its metabolites, polychlorinated biphenyls (PCBs) and p-nonyl-phenol and bisphenol-A, are of particular concern. Processing and neutralizing these toxins require your body to work particularly hard and require increased levels of amino acids, vitamins and minerals to process (20). High levels of atmospheric pollutants can limit the plants’ ability to produce energy, extract nutrients from the soil (particularly calcium, magnesium, and zinc), and can overwhelm their detoxification capabilities (10).
So, what should we be doing about all this?
1. Choose nutrient dense foods
Brightly coloured fruits and vegetables, seeds, and nuts typically have high nutrient levels. Choosing organically grown fruits and vegetables as well as lean, free-range protein sources is important for obtaining the most nutrients possible from our foods and decreasing any contamination that may be present.
2. Preserve nutrients during cooking
The way food is cooked will change its nutrient content. Avoid overcooking to preserve the more delicate nutrients contained in your food. Your food should remain crisp and colourful whether baked, grilled, or steamed (21).
3. Buy fresh and local foods
Any reduction in the time from harvest to consumption will increase the available nutrients in our food. Fresh and local produce is much more likely to have been picked at an appropriate time of ripeness rather than being picked well before this point.
4. Take a high-quality nutritional supplement
Unfortunately, the top priority for most companies producing nutritional supplements is profitability. Most will jump at anything that can be done to decrease the cost, even if this means creating an inferior product. Therefore it is quite important to choose a high-quality (preferably hypoallergenic) nutritional supplement brand that is free of coatings, binders, artificial colors, added preservatives, hydrogenated oils, or other unwanted fillers. These undesirable ingredients can diminish the bioavailability or health-promoting potential of the nutrients (22). Unlike foods, supplements also have the benefit of providing consistent levels of vitamins and minerals if taken as directed.
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