Sunday, March 28, 2010

Good News about Soy and Breast Cancer

For years, doctors and scientists have fretted over whether to recommend soy foods to women at risk for breast cancer. On the one hand, we know these foods help to protect against heart disease. They do so mainly by providing a high quality source of protein without all the saturated fat and other toxins found in meat products. Soy foods may also improve LDL and HDL cholesterol numbers, especially in women. Yet there has been concern that because soy has "phytoestrogenic" properties, it might stimulate the growth of estrogen sensitive cancer cells. (By phytoestrogen, we mean a plant-based substance that has the ability to bind to estrogen receptors on our cells, thus potentially modifying the way the cell behaves).

In the past year, a number of very reassuring studies have been published that give us much more clarity about soy and breast health. The most notable comes from my alma mater, Vanderbilt University, and from the Shanghai Institute of Preventive Medicine. Researchers followed over 5000 Chinese breast cancer surivivors, ages 20-25, for nearly 4 years. They found that those women who included moderate amounts (more than 5.3 grams of soy protein) in their daily diets were about 30% less likely to have recurrence of breast cancer than those who avoided soy. In general, the more soy a woman ate, the healthier she was likely to be, regardless of whether her cancer was estrogen-sensitive or not. The researchers  were quick to make the point that they studied soy food intake, and not supplements, which have not been shown to have the same health benfits.

Researchers from Shanghai also followed younger, healthy women for more than 7 years, and found that those who chose more soy foods had about half the risk of developing breast cancer than those who preferred a meat-based diet. The same group found that a higher carbohydrate diet, especially starchy carbs, appeared to raise breast cancer risk in women uner 50.  In a similar vein, a study from Colorado State University in cooperation with USC, the University of Minnesota, and the National University of Singapore reported that a diet based on vegetables, fruit, and soy was associated with a 30% lower risk of breast cancer in post-menopausal women, when compared with a meat and starch diet.


In a separate study, researchers from USC reported that Asian American women who ate the most typical meat-and-potato Western diets had over twice the breast cancer risk as women who chose more soy foods and vegetables.

While we've known for years that soy is heart-friendly, these studies provide some much needed clarity on the subject of soy and breast health. As always, before you make a major change in your diet, it makes sense to talk with your doctor first.

Thursday, March 18, 2010

The Lastest Buzz on Coffee

If you're sensitive to caffeine, a cup of joe may make your heart jump and jive, but for many people, it's a wake-up essential. In my practice as a cardiologist, I find that people are often a little embarrassed to tell me about their coffee habits, worried that I will try to snatch away this little bit of morning comfort. Now coffee drinkers can take heart. There is some really good news on the horizon about the effects of coffee on our health and well-being.

First off, recent research from both the United States and Finland suggests that coffee drinkers might live a little longer. The therory is that the antioxidants in coffee might help protect the heart arteries against cholesterol build-up. Coffee also may help protect the brain, with several studies suggesting a lower risk for strokes and Parkinson's disease in coffee lovers. There is even evidence that coffee may help protect against diabetes.

Even more surprising is a recent report that coffee quaffers might be less prone to irregular heart rhythms. This sure seems counterintuitive to me, but a report from the Kaiser Permanente Division of Research found that people who drank at least 4 cups of coffee every day were significantly less likely to be hospitalized for heart rhythm problems. Even more surprising was the finding that those who chose decaf did not appear to have this protection.

Now a word from Dr. Sarah: If coffee makes your heart race- don't drink it! Some people are very sensitive to caffeine, and just need to avoid it. Another important caveat is that coffee prepared without a filter (eg boiled coffee or French press coffee) can raise levels of cholesterol, so it's best to limit your coffee to the filtered stuff. And as always, check with your doctor before you make any drastic changes.