Saturday, July 31, 2010

The Calcium Conundrum: New Research on Calcium and Heart Health

Calcium, in partnership with vitamin D, is critical to our bone health, a message that doctors, pharmaceutical companies, and marketers of calcium supplements have broadcast loud and clear. What is less well understood is the effect of calcium on heart health. It does appear that people who get enough food-based calcium in their diets have slightly lower blood pressure, better cholesterol numbers, and are a little less likely to become diabetic. But most of us have never thought to question whether there is a difference between calcium from our diet and calcium that we get from a pill or from fortified foods.

Research has shown that our bones tend to use calcium from food sources more effectively than supplemental calcium, and that, despite the hype, supplemental calcium may reduce the risk of bone fracture by a very modest 10%. Nevertheless, since most people don't choose to include enough calcium-rich foods in their diets, supplements have become standard care. Now an analysis of 15 major trials of calcium supplements, published this month in the British Medical Journal, raises serious concerns about this common practice.

After combing through data involving approximately 12,000 individuals, the researchers from New Zealand, Scotland, and Dartmouth Medical School in the US, reported that those taking at least 500 mg of supplemental calcium daily appeared to have a 30% higher risk for heart attacks, and a slightly higher risk for stroke, when compared to those who took no calcium supplements. Notably, the analysis did not include people who took Vitamin D along with the calcium; it is not known whether this would make a difference.

Dietary calcium is a completely different matter. In fact, other studies have suggested a lower risk for heart problems in women who choose foods that are high in calcium. So what foods are best? A list of foods naturally high in calcium can be found on the USDA website (scroll down the page until you find the section on calcium). Happily, most are also extremely heart healthy: sardines, salmon, soybeans (including tofu products), collard greens (and many other green leafy vegetables), and even molasses. Of course, dairy products also provide plenty of calcium. The moral of the story? As with so many other high dose supplements, we continue to learn that it's really not nice to try to fool Mother Nature!

Sunday, July 18, 2010

Salt: Shake it Down

Salt may not be the sexiest topic (unless maybe you're talking about the new Angelina Jolie flick), but since more than 90% of us consume too much of the stuff, it's time we acknowledged the issue and its effect on our health and well-being.

Excess salt, or sodium, is well-known to contribute to high blood pressure, an often silent killer that afflicts up to 60 million Americans, and is a major factor in heart attacks and strokes. The US Centers for Disease Control and Prevention estimate that by cutting salt consumption substantially, up to 120,000 heart attacks and 66,000 strokes could be prevented each year. Each year! That amounts to an enormous amount of misery, disability, and death that could be avoided with really simple changes in the way we eat.

Most of my patients will tell me that they rarely use the salt shaker-- and I believe them. The problem is that the vast majority of the salt we take in comes from processed foods and restaurant foods, while only about  10% comes from table salt. I will never forget a cooking demonstration I attended where I watched a local celebrity chef toss a fistful of salt on a hunk of meat before throwing it on the grill. What he said really struck me: "If I didn't use this much salt, you wouldn't want to pay for this steak." Why? Because we have allowed ourselves to become accustomed to the taste of salty foods, and now consider that taste to be normal.

While we get a lot of sodium from cooked meat, lunch meat and other animal products, surprisingly, we get even more from grain products, including breads and pasta dishes. People under age 40, without hypertension, should have no more than 2300 mg, or about one teaspoon daily. Those with high blood pressure and those over 40 will do better with less than 1500 mg daily. But most of us are getting more than twice the recommended amount of sodium.

If you eat out, a restaurant meal will typically provide 2300-4600 mg, or up to three times your daily limit. This is why the US Institute of Medicine recently asked the FDA to set new standards for the amount of salt that manufacturers and restaurants can add to their products. Of course, these businesses add salt because that is what we consumers have demanded, so the hope is that requiring progressive changes across the board will keep the playing field level.

Meanwhile, read labels when you buy frozen or canned food, and look for options with lower sodium. Even though an item is labeled "healthy," it may contain far more salt than it should. When you eat out, ask for sauces on the side, because that is often where the sodium lurks. Choose foods closer to nature, like fruits, vegetables, fresh fish and unprocessed whole grains. As a result, you may find that you are spending less on blood pressure pills. High blood pressure or not, you'll also retain less fluid, your shoes and rings will start to fit better, and your belt may even get a little looser.

Sunday, July 4, 2010

Why I Adore Watermelon

"If everyone in the nation ate watermelons, they'd get rid of all the doctors."
--Chester Reed, age 95, who credits watermelon for his longevity and good health

Watermelon is one of my all-time favorite foods, ranking right up there with chocolate and red wine. Maybe it's my African roots-- the fruit was first cultivated in Egypt, my dad's homeland-- or maybe that it is just so yummy, but somehow I can never get enough. I think I would love it even if it weren't such an incredibly heart healthy treat, but it turns out that watermelon is a super food in every sense of the word.

Not only is watermelon high in water (over 90% by volume) and low in calories (~50 calories per cup), but it is chock full of vitamin C, and a good source of vitamins A and B6 as well. Even more impressive, it is a fabulous source of lycopene, a very important antioxidant that has been linked to lower rates of heart disease and cancer. (Lycopene is also found in tomatoes and pink grapefruit.) And in 2007, researchers reported that watermelon supplies important amounts of citrulline, which the body uses to form arginine, an amino acid. This amino acid helps to relax the blood vessels, and may be important in keeping blood pressure nice and low. It might even have benefits for people with sickle cell anemia, erectile dysfunction and diabetes. Truly a fruity multitasker!

I love watermelon so much that I was excited to find out that it has its own website: http://www.watermelon.org/  You'll find some great recipes and a lot more interesting information.