Food

Seeds and Health

Seeds and Health Our seed foods provide us with many nutritional benefits. To begin with, they’re our most important staple sources of energy and protein, and carry the B vitamins that are required for the chemical work of generating energy and building tissue. In fact, they’re such a good source of these essential nutrients that cultures have occasionally relied on the grains too heavily, and suffered from dietary deficiencies as a result. The debilitating disease called beriberi plagued rice-eating Asia in the 19th century when milling machines made it easier to remove the inconvenient, unattractive outer bran layer from rice grains — and along with it their thiamin, which the rest of the largely vegetarian diet couldn’t make up (meats and fish are rich in thiamin). A different deficiency disease called pellagra struck the rural poor in Europe and the southern United States in the 18th and 19th centuries, when they adopted corn from Central and South America as a staple food, but without the processing method (cooking in alkaline water) that makes its stores of niacin available to the human body. Beriberi and pellagra led early in the 20th century to the discovery of the vitamins whose deficiencies cause them. Today, even though most people in Asia eat refined rice, and polenta and grits are still not cooked in alkaline water, more balanced diets have made these deficiency diseases far less common.

Valuable Phytochemicals From Seeds

Toward the end of the 20th century, we came to realize that seeds have more to offer us than the basic machinery of life. Epidemiological studies have found a general association between the consumption of whole grains, legumes, and nuts and a reduced risk of various cancers, heart disease, and diabetes. What do these foods provide that refined grains do not? Hundreds or even thousands of chemicals that are concentrated in the outer protective and active layers of the seeds, and that are not found in inner storage tissues, which are mainly depots of starch and protein. Among the chemicals that have been identified and seem likely to be helpful are a variety of vitamins, including antioxidant vitamin E and its chemical relatives the tocotrienols soluble fiber: soluble but undigestible carbohydrates that slow digestion, moderate blood insulin and blood sugar levels, and reduce cholesterol levels, and provide energy for beneficial intestinal bacteria, which alter their chemical environment, suppress the growth of harmful bacteria, and influence the health of intestinal cells insoluble fiber, which speeds passage of food through the digestive system and reduces our absorption of carcinogens and other undesirable molecules a variety of phenolic and other defensive compounds, some of which are effective antioxidants, some of which resemble human hormones and may restrain cell growth and thereby the development of cancer Medical scientists are still in the early stages of identifying and evaluating these substances, but in general it looks as though regular consumption of whole grains, legumes, and nuts can indeed make a real contribution to our long-term health.

Problems Caused by Seeds

 Seeds are not perfect foods. Legumes in particular contain defensive chemicals — lectins and protease inhibitors — that can cause malnourishment and other problems. Fortunately, simple cooking disarms these defenses. The fava bean contains amino-acid relatives that cause serious anemia in susceptible people, but both the bean and the susceptibility are relatively rare. Two other problems are more common.

Seeds are Common

 Food Allergens

True food allergies are overreactions of the body’s immune system, which mistakes a food component as a sign of invasion by a bacterium or virus and initiates a defense that damages the body. The damage may be mild and manifest itself as discomfort, itchiness, or a rash, or it may be a life-threatening asthma or change in blood pressure or heart rhythm. It’s estimated that about 2% of adults in the United States have one or more food allergies, and up to 8% of young children. Allergic reactions to food cause around 200 deaths per year in the United States. Peanuts, soybeans, and tree nuts are among the most common food allergens. The offending components are usually seed proteins, and cooking does not render them less allergenic. Tiny quantities of nut proteins are sufficient to cause reactions, including the levels sometimes found in mechanically extracted nut oils. Gluten Sensitivity A special form of food allergy is the disease called gluten-sensitive enteropathy, celiac disease, or sprue, in which the body forms defensive antibodies against a portion of the harmless gliadin proteins in wheat, barley, rye, and possibly oats. These defenses end up attacking the nutrientabsorbing cells in the intestine, and therefore cause serious malnourishment. Celiac disease can develop in early childhood or later, and is a lifelong condition. The standard remedy is strict avoidance of all gluten-containing foods. Several grains don’t contain gliadin proteins and therefore don’t aggravate celiac disease; they are corn, rice, amaranth, buckwheat, millet, quinoa, sorghum, and teff .