For these reasons, plus the length of time we store foods, there is a staggering range of nutrient content in fruit and vegetables. An orange may provide from 180 mg of vitamin C to none at all, the average being around 60 mg. Yes, some supermarket oranges contain no vitamin C! A hundred grams of wheat germ (about three cups) provides from 3.2 to 21 IU of vitamin E. A large (3.5 oz. or 100 g) carrot can provide from 70 to 18,500 IU of vitamin A. While it’s great to eat lots of fruit and vegetables, the quality is just as important as the quantity. For this reason, it is best to buy local produce in season and consume it quickly. The worst thing you can do is buy fruit shipped in from the other side of the world and leave it hanging around for two weeks before you eat it. Organic food also tends to have much higher levels of both vitamins and minerals and other antioxidants.
VARIATIONS IN NUTRIENT CONTENT IN COMMON FOODS
Nutrient
Variation (per 3.5 oz. of food)
Vitamin A in carrots
70 to 18,500 IU
vitamin B5 in whole wheat flour
0.3 to 3.3 mg
Vitamin C in oranges
0 to 116 mg
Vitamin E in wheat germ
3.2 to 21 IU
Iron in spinach
0.1 to 158 mg
Manganese in lettuce
0.1 to 16.9 mg
Good food goes off
Food manufacturing, even more than farming practices, is the greatest cause of vitamin loss. Foods are refined so they last longer. Flour, rice, and sugar lose more than 77 percent of their zinc, chromium, and manganese in the refining process. Other essential nutrients, such as essential fats, will not be present in processed foods because these and other nutrients (except antioxidant vitamins A, C, and E, which preserve foods) can decrease shelf life. There is an old saying among nutritionists that “good food goes off”—the trick is to eat it first.
What about cooking?
More than half the nutrients in the food you eat are destroyed before they reach your plate, depending on the food you choose, how you store it, and how you cook it. Every process that food goes through, whether boiling, baking, frying, or freezing, takes its toll. Think about the life of a scarlet runner bean. It is picked, stored, cooked, frozen, stored in the supermarket until you buy it, partially defrosted on the way home, refrozen, boiled, and eaten. Just how much goodness is left?
The three main enemies of vitamins and minerals are heating, water, and oxidation. Vitamin C is very prone to oxidation, sacrificing itself to harmful oxides that make food go rancid. While it might protect your food, it will not protect you if there is none left by the time you eat it. The longer your food has been stored, and the more surface area is exposed to air and light, the less vitamin C there is likely to be. Orange juice, which is packed using a special process to minimize oxide exposure on packing, suffers a 33 percent loss of vitamin C in twenty-two weeks, which is a conceivable time lag between orange grove and breakfast glass. Once you open the carton, oxidation occurs rapidly, especially if you fail to put it back in the refrigerator, which also protects it from light. Analyses of rosehip tea bags have shown negligible traces of vitamin C or none at all, even before they are immersed in boiling water that is likely to kill off any remaining traces.
Nor is vitamin C the only vitamin susceptible to oxidation: the antioxidant vitamins A and E are also prone to damage. Being fat soluble, they tend to be protected by being in fattier foods. Beta-carotene, the vegetable form of vitamin A, is water soluble and highly prone to oxidation. While storing foods in cool, dark places tends to help, oxidation still occurs even in the refrigerator. Spinach stored in an open container will lose 10 percent of its vitamin C content every day.
On the whole, frozen foods keep their nutrient content much better. Chilled foods, kept for two weeks in the supermarket and one week in your refrigerator, will have lost their vitamin vitality, while there is little difference in nutrient loss between frozen peas and fresh peas, once boiled.
Any form of heating destroys nutrients. The degree of destruction depends on the cooking time and on whether the container disperses the heat evenly, but most of all on the temperature. On average, 20 to 70 percent of the nutrient content of leafy vegetables is lost in cooking.
Deep-frying produces temperatures in excess of 392°F, which oxidize fat and turn essential fatty acids into trans fats that are no good for anything. Animals fed such oils develop atherosclerosis. Refined oils, left for weeks on supermarket shelves exposed to light, are already damaged. These oils should not be used for frying as they increase the destruction of antioxidant nutrients like vitamins A, C, and E both in the food and later in the body See this page, this page, this page for the best way to fry food if you still want to use this cooking method.
Minerals and water-soluble vitamins leach into cooking water. The more water you use and the longer the cooking time, the more this is likely to occur. If the temperature is above 122°F, cell structures begin to break down, which enables nutrients within them to be leached out. High temperatures can also destroy some of the vitamins, though not the minerals. If you boil or steam food for a short while, the temperature at the core of the food will be much lower than at the outside. Foods can therefore be protected by being cooked whole or in large pieces. The loss of nutrients in boiled food tends to be around 20 to 50 percent. It is a good idea to use the mineral-rich water as stock for soups or sauces.
Microwaving water-based foods such as vegetables generates heat by vibrating the water particles in the food and vitamin and mineral losses are minimal. However, as far as essential fats are concerned, the heat generated by microwaving rapidly destroys them, so never microwave a dish with oils, nuts, or seeds in it. And if you do microwave your food, stand well back. You need to be about ten feet away to no longer be exposed to its electromagnetic radiation.
Some guidelines for getting the most vitamins out of your food
Eat foods as fresh and unprocessed as possible.
Keep fresh food cool and in the dark in the refrigerator in sealed containers.
Eat more raw food. Be adventurous: try raw beet and carrot tops in salad.
Prepare foods cold where possible (for example, carrot soup, see this page) and heat to serve.
Cook foods as whole as possible, slicing or blending before serving.
Steam or boil foods with as little water as possible, and keep the water for stock.
Fry as little food as possible and do not overcook, burn, or brown it.
Supplement your diet to ensure optimum levels of vitamins.
13
Elemental Health from Calcium to Zinc
More than a hundred years ago, the Russian chemist Mendeleyev noticed that all the basic constituents of matter, the elements, could be arranged in a pattern according to their chemical properties. From this he produced what is known as the periodic table. There were many gaps where elements should be, and sure enough, over the years these missing elements have been discovered. All matter, including your body, is made out of these elements.
At normal temperature, some of these are gases, like oxygen and hydrogen; some are liquids; and some, such as iron, zinc, and chromium, are solids. Ninety-six percent of the body is made up of carbon, hydrogen, oxygen, and nitrogen, which form carbohydrate, protein, and fat, as well as vitamins. The remaining 4 percent is made from minerals.
These minerals are mainly used to regulate and balance our body chemistry; the exceptions are calcium, phosphorus, and magnesium, which are the major constituents of bone. These three, plus sodium and potassium, which control the water balance in the body, are called macrominerals because we need relatively large amounts each day (300 to 3,000 mg). The remaining elements are called trace minerals because we need only traces each day (30 mcg to 30 mg). But all these minerals are required in tiny amounts compared with carbon, hydrogen, and oxygen. For instance, a 140-pound man needs 400 grams (14 oz.) of carbohydrate a day but only 40 micrograms of chromium, which is less
than a millionth of the amount. Yet chromium is no less important.
Mineral deficiency is widespread
Minerals are extracted from the soil in the first place by plants. Like vitamins, they may be obtained directly from those plants or indirectly via meat. And, again like vitamins, they are frequently deficient in our modern diets. There are three primary reasons for this.
Mineral levels in natural foods are declining
This is partly because soil gradually loses its mineral content through overfarming unless the farmer replaces the minerals by adding back mineral-rich manure. But many of the minerals that pass from plant to us are not needed to make the plant grow, so there is no incentive for the farmer to add them back. The minerals that are added back in fertilizer (nitrogen, phosphate, and potassium) make the plant grow faster and, in the case of phosphate, bind to trace minerals like zinc and make them harder for the plant to take up. Analyses of mineral levels in plants in 1939 compared with those in 1991 show, on average, a drop of 22 percent. (The accuracy of this data is, however, a little suspect as analytical methods have improved dramatically over this period.)
Essential minerals are refined out of food
Refining food to make white rice, white flour, and white sugar removes up to 90 percent of the trace minerals. Foods like refined cereals must meet a legal minimum nutrient requirement and therefore have some calcium, iron, and B vitamins added back. To help sell them the package says “enriched” or “with added vitamins and minerals.” The irony is that the number of required vitamins and minerals keeps increasing. The United States now enriches flour with folic acid and Britain is thinking of following suit. This would not be necessary if the food we ate was not refined in the first place.
Our mineral needs are increasing
Dr. Stephen Davies from London’s Biolab Medical Unit has analyzed sixty-five thousand samples of blood, hair, and sweat over the past fifteen years. Without exception, the results, when looked at alongside the ages of the patients, show that levels of lead, cadmium, aluminum, and mercury are increasing, while those of magnesium, zinc, chromium, manganese, and selenium are decreasing. The first group is toxic minerals, antinutrients that compete with essential minerals. As we age, these toxic elements accumulate. Today we need more “good” minerals than ever to protect us from the unavoidable toxic minerals that reach us via polluted food, air, and water.
MINERAL LOSS CAUSED BY FOOD PROCESSING
For these reasons, and because many of us choose to eat foods such as refined bread, pasta, and cereal and avoid the mineral-rich foods such as seeds and nuts, modern humans are mineral deficient. The average dietary intake of zinc (7.8 mg according to one survey) is a lot less than the recommended daily allowance (RDA) of 15 mg. The recommended intake for a breastfeeding woman is 25 mg, more than three times the average intake, leaving breast-fed infants hopelessly deficient in a mineral that is essential for all growth processes including intellectual development.
The average intake of iron is well below RDAs. The average intake is 10 mg compared with the RDA of 18 mg. While no RDAs exist for manganese, chromium, and selenium, dietary intakes are certainly below estimates of what we need for optimal health.
In animals such a state of mineral malnutrition is a known cause of a wide range of illnesses. For this reason livestock feed is enriched with minerals. Not so with humans. Is it any wonder we are not healthy?
Percentage of minerals lost in refining flour.
The macrominerals
The minerals that are present in the body in relatively large amounts include calcium, magnesium, phosphorus, potassium, and sodium.
Calcium—the bone builder
Nearly 3 pounds of your body weight is calcium, and 99 percent of this is in your bones and teeth. Calcium is needed to provide the rigid structure of the skeleton. It is particularly important in childhood when bones are growing and also in the elderly because the ability to absorb calcium becomes impaired with age. The remaining 10 or so grams of calcium are found in the nerves, muscles, and blood. Working together with magnesium, calcium is needed to enable nerves and muscles to “fire.” It also assists the blood in clotting and helps maintain the right acid-alkaline balance.
The average Western diet provides marginally more than the RDA for calcium. Most of it comes from milk and cheese, which are poor sources. However, vegetables, legumes, nuts, whole grains, and water provide significant quantities of both calcium and magnesium, and it is likely that our ancestors relied on these for their calcium.
Calcium—how much is absorbed?
The ability to use calcium depends not only on its intake but also on its absorption. The amount absorbed depends on the food, but is normally around 20 to 30 percent. The calcium balance of the body is improved by adequate vitamin D intake and by weight-bearing exercise. It is made worse by vitamin D deficiency, exposure to lead, consumption of alcohol, coffee, and tea, or a lack of hydrochloric acid produced in the stomach. The presence of naturally occurring chemicals called phytates, which are found in grains, and excessive phosphorus or fat in the diet also interferes with absorption. Excessive protein consumption also causes loss of calcium from the bones.
Symptoms of deficiency include muscle cramps, tremors, or spasms, insomnia, nervousness, joint pain, osteoarthritis, tooth decay, and high blood pressure. Severe deficiency causes osteoporosis. However, this is more likely to be connected with protein and excess hormone imbalances (see chapters 8 and 20).
Magnesium—calcium’s comrade in arms
Magnesium works with calcium in maintaining both bone density and nerve and muscle impulses. The average diet is relatively high in calcium but deficient in magnesium, because milk, our major source of calcium, is not a very good source of magnesium. Both minerals are present in green, leafy vegetables, nuts, and seeds. Magnesium is a vital component of chlorophyll, which gives plants their green color and is therefore present in all green vegetables. However, only a small proportion of the magnesium within plants is in the form of chlorophyll.
Magnesium is essential for many enzymes in the body, working together with vitamins B1 and B6. It is also involved in protein synthesis and is therefore essential for production of some hormones. It may be its role in hormone production or prostaglandin production that is responsible for its beneficial effects on premenstrual problems.
A lack of magnesium is strongly associated with cardiovascular disease: people who die from this cause have abnormally low levels of the mineral in their hearts. Lack of magnesium causes muscles to go into spasm, and there is considerable evidence that some heart attacks are caused not by obstruction of the coronary arteries but by cramping of them, resulting in the heart being deprived of oxygen.
Sodium—for nerve transmission and water balance
Sodium is eaten mainly in the form of sodium chloride, more familiarly known as salt; there is 92 grams of sodium in the human body. More than half is in the fluids surrounding cells, where it plays a vital role both in nerve transmission and in the maintenance of water concentration in blood and body fluids.
Sodium deficiency is exceedingly rare, because too much is added to foods and also because its excretion is carefully controlled by the kidneys. It is present in small amounts in most natural foods and is mainly supplied in processed foods. There is no need to add it to food and good reasons not to. Excess sodium is associated with raised blood pressure, although it appears that some people are not salt-sensitive in this way. As sodium levels in the body rise, fluids are made less concentrated by retaining more water. This gives rise to edema or fluid retention.
Not all salts are bad news. One I sometimes use is Solo salt. This is a type of sea salt that has 46 percent less sodium, and more potassium and magnesium, than other types of salt. A study in the British Medical Journal gave this salt to people with high blood pressure and blood sugar came down.28 This is because potassium and magnesium are good news as far as the arteries and your blood pressure are concerned.
Potassium—sodium’s partner
This mineral works in conjunction with sodium in maintaining water balance and proper nerve and muscle impulses. Most of the potassium in the body is inside the cells. The more sodium (salt) is eaten, the more potassium is required, and since the average daily intake of potassium is only 4 grams, relative deficiency is widespread. The same level of intake of these two minerals is more consistent with good health. Fruit, vegetables, and whole grains are rich in potassium.
Severe potassium deficiency may result in vomiting, abdominal bloating, muscular weakness, and loss of appetite. Potassium deficiency is most likely to occur in people taking diuretic drugs or laxatives or using corticosteroid drugs over a long period.
The trace minerals
Iron—the oxygen carrier
Iron is a vital component of hemoglobin, which transports oxygen and carbon dioxide to and from cells. Sixty percent of the iron within us is in the form of red pigment or heme. This is the form present in meat and is much more readily absorbed than the nonheme iron present in nonmeat food sources. Nonheme iron occurs in the oxidized or ferric state in food and not until it is reduced to the ferrous state (for example by vitamin C) during digestion can it be absorbed.
The symptoms of iron deficiency include pale skin, sore tongue, fatigue or listlessness, loss of appetite, and nausea. Anemia is clinically diagnosed by checking hemoglobin levels in the blood. However, symptoms of anemia can be caused by a lack of vitamin B12 or folic acid. Iron-deficiency anemia is most likely to occur in women, especially during pregnancy. Since iron is an antagonist to zinc, increasing the requirement for zinc, supplements containing more than 30 mg of iron—almost twice the RDA—should not be taken without ensuring that enough zinc is also being consumed. Although iron supplements are often given in doses above 50 mg, there is little evidence that this is more effective than lower doses in raising hemoglobin levels.
The New Optimum Nutrition Bible Page 12
