Food Farmacy Part II: The Case for Broccoli
(Brassica oleracea L. var. italica Plenk)
by Erica Renaud

During the past fifty years, there have been pivotal changes in the way our food crops are grown and distributed. The crop varieties we grow and eat, the cultural practices used to produce these crops—including the use of synthetic fertilizers, pesticides, and herbicides, as well as the development of primary crop production areas—and the creation of global food distribution networks, have all contributed to these changes in our food system. These modifications in agriculture have affected not only small farms and the communities in which they reside, but also the overall quality of the foods and the health of the natural environment in which they are grown. Take broccoli for instance, the vegetable George Bush Senior loves to hate, but that we love to eat and on which we love to make nutritional and medical claims. Our per capita broccoli consumption has increased in the U.S. from the 1960s, when we consumed around 0.4 lbs. per year, to over 6 lbs. today. This increase in consumption has been partially attributed to highly publicized medical research linking compounds in broccoli with strong anticancer activity in the body as well as to a myriad of other nutritional claims.

Broccoli's Varietal Development
Broccoli, the first of the cole crops to evolve from wild species of kale or cabbage, was originally cultivated by the Romans. In 1775, broccoli was described in A Treatise on Gardening by a Citizen of Virginia by John Randolph as having "heads like cauliflower" and "stems like asparagus." However, it was only introduced commercially into the U.S. in the 1800s and didn't become popular until the 1930s. The Romans, the initial breeders of broccoli, developed the first known cultivar, calabrese. While calabrese is still the most common cultivar known today, much breeding work has been ongoing since then to adapt it to a broad range of growing areas, improve quality, and increase disease resistance, which has completely changed the crop as it was known by the Romans. Now broccoli varieties have been developed that are appropriate for spring, summer, and winter production as defined by their cold and heat tolerance. In addition to the drastic change in the crop's appearance and adaptability to broad areas and seasons of production, the nutritional and medicinal components of broccoli have changed.

Broccoli's Nutritional Contribution
The edible part of broccoli is a tender stem and unopened flower buds that are rich in nutritional content. Its rich green color is indicative of its high carotene content, and broccoli is well known as a good source of vitamin A, vitamin C, calcium, iron, and potassium. With half a cup of cooked broccoli providing over 1000 IU of vitamin A, this vegetable should be making frequent appearances on your plate. Folic acids are also abundant, with one-half cup of cooked broccoli registering 39 mcg. Broccoli offers 71.8 mg of calcium for a whole cup of cooked broccoli, which is as much calcium as 4 oz. of milk. A cup of broccoli also gives you 10% of your daily iron requirement and the vitamin C content helps the body to absorb the iron. One cup of cooked broccoli has as much vitamin C as an orange! In addition to all the nutrients mentioned above, broccoli contains the vitamins B1, B2, B3, B6, magnesium, and zinc. The darker colors, such as blue green or purplish green, in broccoli florets contain more beta carotene and vitamin C than those with lighter greens.

Broccoli's Medicinal Value
If taste and nutrition are not sufficient reasons for you to grow and eat your own broccoli, you might consider recent developments in the medical field. Studies by the National Cancer Institute and Johns Hopkins Hospital have indicated that broccoli is effective in the prevention of some types of cancer due to its beta carotene, vitamin C, calcium, fiber, and phytochemical content. These studies have shown that broccoli contains high levels of glucoraphanin, which along with its breakdown product, sulforaphane, stimulate enzymes that cleanse our cells. As people get older, their cells tend to get clogged with debris from living and breathing. The research suggests that glucophanins are not active in the body, but their breakdown products help detoxify carcinogens and suppress the growth of existing cancerous tumors. Eating glucoraphanin-rich broccoli means cleaner cells and a lower long-term risk of cancer. Studies have also shown that people who eat broccoli regularly have a lower incidence of colon and rectal cancers. Additional studies by the USDA Philadelphia Regional Center discovered that vegetables (including broccoli) contain a certain pectin fiber called calcium pectate that binds to bile acids, working to hold more cholesterol in the liver and release less into the bloodstream, thus lowering cholesterol levels. Studies have also indicated that broccoli's wealth of the trace mineral chromium may be effective in preventing adult-onset diabetes in some people. Clearly, what we eat has an effect on the development of disease. Now are you convinced to eat your vegetables?

Genetic Dilution Effect of Broccoli Cultivars
A study published in the Journal of the American College of Nutrition in 2004, entitled, "Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999," conducted by D.R. Davis, M.D. Epp, and H.D. Riordan, compared the nutritional analysis of vegetables in 1950 and in 1999. The study found noticeable decreases in six of the thirteen nutrients examined. These included protein, calcium, phosphorus, iron, riboflavin, and ascorbic acid. Percentage reductions ranged from 6% for protein to 38% for riboflavin. The study, conducted by the Biochemical Institute at the University of Texas, suggested that the easiest explanation for differences comes from changes in cultivated varieties between 1950 and 1999, in which there may have been trade-offs favoring higher yields while neglecting nutrient content. Specific to broccoli, Davis et al. found large genetic variations of five antioxidant nutrients in fifty broccoli varieties grown together under controlled conditions. They also found genetic variation in calcium and magnesium concentrations when these minerals were measured in twenty-seven commercial hybrids and nineteen inbred lines available for breeding programs. Calcium was also affected by the environment in which the broccoli varieties were grown, while magnesium was more affected by the varietal genetics itself.

Speculations as to why Davis et al. saw these drop-offs in major nutritional components in food crops include the fact that more foods eaten in 1950 were consumed near the geographical area in which they were grown. Crops were not transported thousands of miles and stored for several days. They were typically grown closer to where they were marketed, and eaten fresher. Crop varieties were bred in 1950 to be adapted to specific regions, while now they are selected for yield, disease resistance, adaptation to broad environments, and for increased "shipability" and shelf-life, not for nutritive content. As these varieties are selected for increased yield and larger fruit size and are often harvested early to reach distant markets, the plants are not storing their full potential nutritive content. Changes in climate and changes in soil quality may also contribute to the decrease in nutrient qualities found in today's vegetables. Notably, mineral decreases in food crops are often attributed to mineral deficiencies in soil brought about by increased use of synthetic fertilizers in lieu of traditional soil-building practices, as is often the case in conventional agricultural systems.

It is well accepted in agricultural research that selection for one resource-using function affects another. For example, there are often trade-offs between growth rate and pest resistance, between yield and resistance to herbivory, and between the number of seeds and their size. Cultivars selected for yield, rapid growth or other nonnutrient characteristics may suffer resource limitations in their abilities to extract soil minerals or transport them within the plant, or in their abilities to synthesize proteins, vitamins, and other nutrients. Such trade-offs are usually unpredictable in their outcome; what we have seen is that the choice for yield has negatively affected overall quality.

Grow and Eat Your Broccoli
As we have seen, broccoli is an example of a recent development in our cultural eating patterns that has contributed vastly to our nutritional uptake and can also help prevent disease. We have also seen that selecting the right cultivars, preferably older, open-pollinated varieties for our garden and our plate can put even more vitamins and minerals in our bodies than buying standard varieties off our supermarket shelves. To encourage you to grow your own broccoli from Seeds of Change's open-pollinated cultivars, easy steps to growing organic broccoli have been included below.

May your broccoli growing season be happy and healthy.
Erica Renaud
Research & Farm Manager

Organic Broccoli Growing 101 Broccoli is a cool season crop. It can be grown in spring or fall, but it is susceptible to cold injury. The optimum time for planting is when day temperatures are between 60–70°F and night temperatures are between 50–60°F. Temperatures below 32°F for periods of 36 hours kill broccoli, while extended periods in the 30s will stunt its growth. Broccoli Types: There are three main types of broccoli: sprouting, calabrese, and romanesco. Calabrese is most familiar because of its large heading portion and thick stalks. Calabrese is the most common type of broccoli grown and eaten—with tight, dome shaped, green-beaded heads. Sprouting broccoli has smaller flowering heads and many thinner stalks. The romanesco type reaches maturity in the fall and is distinguished by its yellowish-green multiple heads. Seeds of Change Broccoli Varieties: Seeds of Change offers five open-pollinated varieties of broccoli which are, or have been developed from, older cultivars bred for wide adaptability to diverse growing conditions. These include:

Variety	Description	History
Calabrese	58–90 days. Dark green 18–30 in. plant, close-beaded 3–8 in. bluish-green central head followed by abundant side shoots, bears until hard frost.	Brought to this country by Italian immigrants in the late 1880s.
De Cicco	48–85 days. Old, reliable European var., compact 2–3 ft. light-green plants, 3–4 in. bluish-green central head, then lots of medium-sized side shoots, non-uniform in maturity, more variable and more productive than hybrids, excellent quality.	Introduced in 1890
Early Green	70 days. Spring variety, large green heads with many side shoots, grows to 14 in. tall.	3–5 inches
Nutri-bud	55–70 days. An early maturing Seeds of Change Original variety. Vigorous plants grow to 24 in. tall. High in glutamine.	Developed by Alan Kapuler
Waltham	60–95 days. Compact stocky 20 in. plants, dark blue-green solid med-green heads, large crops of side shoots, not for spring, late summer and fall harvest, can survive dry spells, developed to withstand the increasing cold of fall maturity.	Introduced in 1951

Planting Using transplants gives greater control over the quality of the crop. If transplanting, plant 15 inches between rows with 15 inches between plants or follow directions on the seed packet. Allow five weeks in the greenhouse from seeding to transplanting. Be sure to harden off the seedlings before transplanting. If direct seeding, seed rows 15 inches apart and thin to desired spacing once the seedlings develop true leaves. Soil Fertility Fertile soils that are well drained and have high organic matter are ideal. Optimum soil pH is between 5.7–6.5. Liming to raise soil pH in acid soils may be necessary as broccoli is susceptible to disease when pH is not within range. Signs of boron deficiency are apparent when a black, hollow stem develops. A ton of broccoli will remove 10 lbs. of nitrogen, 3 lbs. of phosphorus, and 8 lbs. of potassium from the soil. Insects Problems Generally, good vigorous seedlings planted in healthy soil will resist most pests, but broccoli can be attacked by several insects such as aphids (Brevicorne brassicae), cabbage maggots (Hylemyia brassicae), cabbageworms (Pieris rapae), cabbage loopers (Trichoplusia ni) and diamondback moth larvae (Plutella xylostella). Thoroughly mulching your plots and using a floating row cover over the plants are simple ways to help control these pests. Companion plants such as Ammi visnaga, coriander, clovers, alyssum, and dill are effective in attracting beneficials, which also help to control unwelcome insect species. Last-resort organic controls for non-manageable insect problems include Dipel for cabbageworm and Pyganic for harlequin bug. While both of these organic insecticides are OMRI (Organic Materials Review Institute) approved, remember that they will eliminate more insects than just your target pest and, thus, potentially create further imbalance in your garden ecosystem—so use them as a last resort only. Disease Problems Disease can become a problem with broccoli, so good crop rotation and intercropping are fundamental to continued success. Some of the diseases that can affect broccoli include: Black Rot Xanthamonas campestris (seedborne bacterium). Recognizable by the presence of large, yellow to yellow-orange, V-shaped areas extending inward from the margin of the leaf. Black Leg Phoma lingam (fungus). Oval, depressed light-brown canker near the base of the stem. The canker enlarges until the stem is girdled. Wirestem Rhizoctonia (fungus). Reddish brown discoloration. Plant may bend or twist without breaking. Alternaria Leafspot (Alternaria brassicae). Initially, a small, dark spot on the leaf surface. Spot enlarges, concentric circles. Can defoliate plant if uncontrolled. Downy Mildew (Pernospora parasitica). Caused by transplant bed or blown spores. Young plants show white mildew mostly on the underside of the leaf. Later a slight yellowing shows on the upper surface. Harvest & Preparation Harvest the main head at its peak size, just before the flowers open. Harvest side shoots at 2–3 inches or before flowers open. For the best flavor and nutritional benefit, prepare broccoli soon after harvest. Vegetables that are stored for a week, even if refrigerated, will lose considerable nutritional value along with flavor. For salads and stir-fries, cut the broccoli into bite-size pieces. Do not discard the leaves or peel the stems as you will be discarding much of the valuable nutrients and fiber. Cut the stems into julienne strips to take advantage of their valuable vitamins, minerals, and phytochemicals. Enjoy!

References:
Davis, D.R., Epp, M.D., and H.D. Riordan. 2004. Changes in USDA food composition data for 43 garden crops, 1950 to 1999. Journal of the American College of Nutrition, 23, no. 6: 1–14.

Mithen, R. 2005. Glutathione S-tranferase M1 polymorphism and metabolism of suforaphane from standard and high-glucosinolate broccoli. American Journal of Clinical Nutrition 82:1283.

United States Department of Agriculture. Profiling Food Consumption in America in Agricultural Fact Book 2001-2002, chapter 2. http://www.usda.gov/factbook/chapter2.htm

Cancer, genes and Broccoli—study of genetic differences in cancer protection. 2005. PSA Rising—Prostate Cancer Survivor Support and News (December 7). http://psa-rising.com/eatingwell/broccoli_super05.htm

Photo captions: (1) Early Green broccoli (2) Nutri-Bud broccoli (3) Waltham broccoli (4) De Cicco broccoli (5) Calabrese broccoli