Substances that Can Interfere with Thyroid Function

Certain very nutritious foods from the cabbage family contain substances known as thiocyanates that interfere with thyroid metabolism if iodine is in short supply in your diet. Thiocyanates are naturally present in broccoli, brussels sprouts, cabbages, cauliflower, collard greens, kale, kohlrabi, and flaxseeds; these nutritious foods normally cause no problems if adequate iodine is available from other sources. Fermentation, a food-preservation technique used, for example, in making sauerkraut, eliminates thiocyanates. The water pollutants perchlorate (a by-product of solid fuels) and nitrogen (from fertilizers) also can amplify thyroid problems in people who are iodine deficient or whose intakes are low. For these reasons, you are well advised to get iodine in recommended amounts.^{75, 86}

Thyroid and Iodine Tests

Lab tests that assess thyroid status and function typically have “T” in their name, such as “T4” and “TSH.” Do-it-yourself skins tests using iodine solutions have not proved to be a valid way to assess iodine deficiency; the rate at which the iodine stain fades from your skin is related to other factors, such as atmospheric pressure and temperature.

Excess Iodine

For iodine, as for many nutrients, an upper level (UL) of intake that is “likely to pose no risk of adverse effects” has been set. For adults this is 1,100 micrograms of iodine. High intakes of sea vegetables or other iodine sources can damage the thyroid gland and cause hyper- or hypothyroidism or thyroid cancer. In the north islands of Japan, where people consume a great deal of sea vegetables, excess iodine intake has resulted in a type of goiter. Scientists estimate that regular and high intakes of kelp—Laminaria species, which is adept at picking up iodine and heavy metals from the area where it grows—could cause thyroid problems. Furthermore, a kelp intake of 41 milligrams per day from herbal supplements has been known to deliver toxic levels of arsenic, despite a supplement label stating that it contributes to “vital living and well-being.”^{69, 85, 86, 93–95, 97–99, 115}

The right dose differentiates a poison and a remedy.

IRON

Raw Research

In the Giessen study, iron intakes met the DRIs on average (see table 9.2, page 185), although many individual diets were short of iron. Lab tests showed that the participants’ serum iron and ferritin levels were low, and for those who had been on raw diets the longest, 43 percent of the men and 15 percent of the women were anemic. Among all women of childbearing age, 70 percent had menstrual irregularities and 23 percent had stopped menstruating.^{40, 71, 102} On the high-raw Hallelujah Acres diet, women over fifty and men of all ages typically met the DRI for iron, while women of childbearing age, whose DRI is usually higher due to menstrual losses of iron, fell short.^{72, 103} Finns on a living-food diet had significantly higher intakes of iron (18–25 milligrams). They maintained their hemoglobin levels on diets that included nuts and seeds; sprouted buckwheat, lentils, mung beans, rye, and wheat; fermented cucumber, oats, and red cabbage; fresh and dried fruit; plenty of vegetables; and small amounts of sea vegetables.^{74, 76, 78} The various diets previously mentioned provided two to six times the DRIs for vitamin C. This feature, along with many food preparation practices that reduced phytate, gave excellent support for iron absorption when a reasonable amount of iron was present in the foods.

Although the iron DRI for vegetarians has been set at 1.8 times the DRI for nonvegetarians, this is based on research that may be inappropriate for raw diets because the experimental diet that was the basis for this recommendation contains many foods not used in raw diets and was far lower in fresh fruits, vegetables, and vitamin C.^{69, 104}

Functions of Iron

Iron, the mineral at the heart of the hemoglobin molecule in blood, plays a central role in transporting oxygen throughout the body, releasing this life-giving substance where it is needed, and carrying away the metabolic waste product carbon dioxide. As part of many enzyme systems, iron also plays key roles in the production of cellular energy, in immune system functioning, and in certain mental processes. Our body does its best to recycle this precious mineral; our intake must replenish losses through perspiration, urine, and cells that are sloughed off from skin and from the intestinal lining. Women of childbearing age lose iron during menstruation, increasing their requirements over those of men. Iron deficiency is the most common nutritional deficiency in North America, occurring most commonly in women and children.^{69, 85}

Vegetarians are not more likely than nonvegetarians to have iron-deficiency anemia. Vegetarians often have relatively low amounts of stored iron (as shown by low serum ferritin levels in lab tests), yet this is not accompanied by fatigue or other symptoms. In fact, this could even be an advantage, linked to improved insulin resistance and decreased risk of heart disease, since there is less free iron to act as a pro-oxidant. If one’s iron supply is replenished by good dietary choices, low iron stores do not seem to be a problem. To some extent, the body can adjust its absorption efficiency, depending on our need for iron.^{85, 105, 106}

When an actual iron deficiency exists, lab tests will show decreases in serum iron and the degree that transferrin (the iron-transport protein) is saturated with iron. Symptoms commonly include fatigue and increased sensitivity to cold. With further depletion, iron-deficiency anemia develops, a condition in which blood hemoglobin falls below the normal range. Since the body’s oxygen-delivery system is diminished, people with this condition are likely to feel exhausted, irritable, and lethargic, and may also experience headaches. Due to the dilution of the red hemoglobin molecule in the tiny blood vessels just below the surface of the skin, the skin may appear pale.

Dietary Sources of Iron

To boost iron intakes, raw foodists have access to a wealth of food sources (see table 9.4, page 198). Furthermore, by consuming items that provide at least 25 milligrams of vitamin C (see table 8.2, page 154) at the same meal or snack that we have our iron sources, we can double the amount of iron we absorb. With 50 milligrams or more of vitamin C, we can increase iron absorption by a factor of three to six. The practices of soaking, sprouting, and fermenting foods increase the ease with which the body absorbs the iron present by breaking down phytate. Sprouting generates the production of vitamin C, further increasing iron absorption. Note that when seeds and nuts are soaked, some minerals are leached into the soaking water and then discarded.^{38, 85, 95, 105}

MAGNESIUM

Raw Research

Magnesium is at the center of the chlorophyll molecule, so it is not surprising that average intakes on German, American, and Finnish raw diets have been well above the DRIs. In contrast, average dietary intakes of North American women on nonvegetarian diets fall below the DRIs. The DRI for magnesium increases from 400 to 420 milligrams for men age thirty-one and older and from 310 to 320 milligrams for women age thirty-one and older.⁶⁸

Functions of Magnesium

The functions of this mineral are more diverse than those of any other. Magnesium is a structural component for strong teeth and bones. It helps convert the calories from food into useable energy. It is necessary for the transmission of nerve impulses, and it helps to maintain the rhythm of the heart. A magnesium-rich diet (which is typically a diet that is rich in vegetables and fruits) is associated with lower blood pressure and reduced risk of type 2 diabetes, heart disease, and stroke.^{46, 107}

Dietary Sources of Magnesium

Greens, colored by chlorophyll, are good sources of magnesium (see table 9.4, page 198). So are other vegetables, nuts, seeds, fruits, legumes, and cacao (and chocolate). Wheatgrass juice, being rich in chlorophyll, is very high in magnesium. Intakes on raw diets tend to be good unless caloric intakes are restricted.^{72, 85}

MANGANESE

Raw Research

Intakes of manganese by Americans on the Hallelujah Acres diet were found to be about triple the DRI.⁷²

Functions of Manganese

Manganese is required for proper bone formation and wound healing and is part of an important antioxidant in cells. It activates enzymes that produce energy from protein, fat, and carbohydrate.

Dietary Sources of Manganese

Manganese is present in a wide variety of raw foods and deficiency is unlikely.⁸⁵

PHOSPHORUS

Raw Research

Average intakes on the high-raw Hallelujah Acres diet exceeded the DRI by about about 57 percent for men and about 22 percent for women.⁷²

Functions of Phosphorus

Phosphorus is the second most abundant mineral in the body after calcium. In its inorganic form, 85 percent of the body’s phosphorus, along with calcium, gives strength and rigidity to bones and teeth, whereas protein gives bone some flexibility. Phosphorus is present in blood and in the fluid between cells, where it helps to maintain the body’s pH. Our ability to store and release energy requires phosphorus in the compound adenosine triphosphate (ATP). Phosphorus is a component of the genetic material in every cell of humans, animals, and plants. In soft tissues, it is combined with fat in organic complexes called phospholipids.^{68, 107}

Dietary Sources of Phosphorus

Phosphorus is widely distributed among plant foods, as shown in table 9.4, page 198. Most of the phosphorus in plant foods is stored in compounds called phytates, where phosphorus-containing phytic acid is bound together with calcium, magnesium, iron, and zinc. Phytates are not easily broken down in the human digestive tract. However, the practices of soaking and fermenting nuts, seeds, legumes, and grains change phytates so that the phosphorus (as inorganic phosphate) and other minerals become more available for absorption. Although phytic acid (or phytate) used to be blacklisted as an antinutrient that blocks mineral absorption, it is now also receiving favorable press as an antioxidant that can help protect us against cancer.^{67, 72, 85}

POTASSIUM

Raw Research

When it comes to potassium intakes, raw diets excel, whereas the standard Western diet fails. Potassium intakes on the Hallelujah Acres diet and Finnish living-food diet exceeded the DRIs (see table 9.2, page 185).^{72, 76, 77}

Functions of Potassium

Potassium has a role in attracting and holding water inside cells that parallels the role of sodium outside cells. It acts with sodium to create an electrochemical charge across cell membranes that supports the transmission of nerve impulses and the contraction of muscles, including the heart. Potassium acts to blunt a rise in blood pressure when we consume too much sodium. It tips our acid-base balance in an alkaline direction and decreases the recurrence of kidney stones. People whose diets are high in potassium, and who take their habit of eating plenty of fruits and veggies into old age, reduce their risk of bone fractures.^{17, 85}

Dietary Sources of Potassium

Potassium is abundant in a wide assortment of fruits and vegetables, so getting enough of this mineral on a raw diet is easily accomplished. Though bananas have somehow become famous as a potassium-rich food, cantaloupes, brussels sprouts, grapefruits, green beans, strawberries, and tomatoes have more potassium per calorie than bananas.

SELENIUM

Raw Research

In the Hallelujah Acres study, diets of 42 percent of the participants met the selenium DRI, while 58 percent of the participants’ intakes were below the DRIs.⁷² Selenium intakes of the Finns were lower still (see table 9.2, page 185). However, lab tests showed the Finns to have higher levels of antioxidant enzymes that depend on selenium, which the scientists took as an indicator of good absorption of this mineral from the sprouted and fermented foods in the living-food diet.⁷⁴