Friday, April 22, 2011

Go to Health: More on Brassica Vegetables aka Cruciferous

This genus of plants contains more plants for human consumption than any other. You can think of them as roots: radishes, rutabaga, turnips, daikon, as stems: kohlrabi, as leaves: cabbage, kale, collards, bok choy, Brussels sprouts, arugula, cress, as flowers: cauliflower, broccoli, and as seeds: mustard seed and oil producing rapeseed (canola). Wasabi is also a brassica.

There are numerous beneficial compounds in these plants. Besides vitamins, carotenes and fiber, they contain nutrients with anti-cancer properties – the most promising one being sulforaphane.

Plants in the genus brassica produce sulforaphane (SGS) to defend against insect predators. Researchers at Johns Hopkins found that SGS is especially high in broccoli sprouts. SGS is an ‘indirect antioxidant’ that eliminates many types of free radicals before they can harm cells, and cycles over and over again, triggering a long lasting process. It stimulates other natural antioxidants, such as glutathione, the body’s most abundant antioxidant. Studies from the University of Michigan found that SGS, from broccoli, inhibits breast cancer stem cells in mice and cell cultures, and prevents new tumors from growing. Studies are also ongoing on protection against ovarian and prostate cancer. There is preliminary work on the ability of SGS to protect against skin cancer, ulcer-producing bacteria in the stomach (helicobacter pylori) and inflammation of blood vessels in the heart.
The researchers at Johns Hopkins have established a company that sells regular or decaf green or black tea with SGS – it is available from the Baltimore Coffee and Tea Company at 800-823-1408. You can also make home-grown broccoli sprouts – organic broccoli seed for sprouting is available by calling 800-695-2241. If you want some help in making broccoli sprouts at home, watch “how to grow broccoli sprouts with your homemade sprouter” on You Tube. The best way to prepare regular broccoli to maximize SGS is to steam it lightly for 3-4 minutes- until it is tough-tender.

There is a downside to brassica vegetables – eaten in high amounts they can interfere with the formation of thyroid hormone, and induce goiter formation. So – include them in your diet, especially if you are a cancer survivor, but eat a lot of other vegetables and fruits as well.

Dietary spices – These include onions, garlic, ginger, cloves, cinnamon, cardamom, mint, all Indian curry ingredients, all Italian herbs etc. These and other spices/herbs have been studied at MD Anderson Cancer Center at the University of Texas for their many roles in preventing cancer. There is interesting science here. Include them in your diet every day. I will be writing more details about these ‘nutraceuticals’.

Sadja Greenwood, MD, MPH see back issues on this blog

Friday, April 1, 2011

Bisphenol A (BPA): What you should know

BPA is one of the most commonly manufactured chemicals in the world. It is a component of polycarbonate plastic and is found in a wide range of common materials and food packaging. It has been known for many years that BPA has estrogenic properties; its effects on the reproductive systems of animals -fish, amphibians and mammals - have raised concern for humans. The chemical has been called an endocrine disrupter, which can mimic the body’s own hormones and lead to negative health effects. Animal studies (those unfortunate mice and rats) have suggested effects of BPA on the brain, breast, prostate, thyroid, obesity, sexual behavior et al. Some studies suggest an increased risk for breast and prostate cancer. Newborns and children may be specially affected by environmental BPA levels, due to their reduced capacity to eliminate the substance and their higher daily exposure, adjusted for weight. A study from Rockefeller University on primates in 2008 showed that even at relatively low exposure levels, BPA abolishes the ability of spinal synapses to respond to estrogen, which may play a critical role in cognition and mood. An English study published in the JAMA (University of Exeter - 2008) showed that higher levels of BPA in the urine of US adults correlated with cardiovascular disease, diabetes and abnormal liver enzyme levels. A study carried out by the Division of Research at Kaiser in Oakland showed that male workers in China with high occupational exposure to BPA had a significantly higher risk of lowered sexual desire, erectile dysfunction and difficulty ejaculating. This study is obviously important to men, and a motivator for youth to avoid exposure as much as possible. I have cited only a few examples of research on BPA that suggest negative health effects on humans and animals. While studies abound, our response in the US has been painfully slow.

Canada announced its intent to ban the import and sale of polycarbonate baby bottles containing BPA in 2008. Walmart announced soon thereafter that it would stop selling food containers, water and baby bottles, sippy cups and pacifiers containing BPA at its Canadian stores. In 2010, Canada declared BPA to be a toxic substance and is proceeding to decrease its use overall. European countries have been slower to act. But the European Union executive commission plans to stop the manufacturing of polycarbonate baby bottles containing BPA by June, 2011. Minnesota, Chicago, Connecticut, Massachusetts and Maine have taken steps to ban products containing BPA from baby food containers and other products. However, in 2009, California’s EPA unanimously voted against placing BPA on the state’s list of chemicals that are believed to cause reproductive harm.

What you can do
1) Shop wisely: BPA is found in the internal coating of food and beverage metal cans to protect the food from the metal. Choose fresh or frozen foods over canned whenever possible. Eden Organic has eliminated the use of BPA in their canned and packaged food, and Muir Glen organic tomato products will be BPA free this year. These products are available at natural food markets.
2) In your kitchen: If you feed your baby from a bottle, use glass, and avoid plastic pacifiers and cups. Don’t microwave food in plastic containers, and store leftovers in glass or ceramic containers. Carry extra water in a stainless steel or glass bottle. Nalgene is now selling plastic water bottles made of copolyester , with non-BPA materials. Hikers will want to have a light-weight water bottle, but more research may be needed on the long term safety of these new materials.
3) Go to the website of and sign their petition asking President Obama to eliminate the use of potentially cancer-causing chemicals in our environment, including BPA
4) Ask our assemblymember, Jared Huffman, to work on banning BPA containing products in California. Mention the 2009 California EPA vote when you call or write. Huffman is an environmentalist – 479-4920. Contact Governor Jerry Brown while you are at it: 916-445-2841. Go citizens!
Sadja Greenwood MD, MPH back issues on this blog