Calcium Conundrum Health Article

She is 54 years old, she is one of the world's top experts on calcium, and she rarely takes a calcium supplement. "I don't have to," says Connie Weaver. "I drink plenty of milk."

While her three boys were growing up, the world-renowned researcher had one unwavering mealtime rule: milk for breakfast, lunch and dinner. Call her the dairy queen, but the old-fashioned dictum was a direct result of evolving research on a mineral that is clouded by confusion and misinformation.

Weaver has masterminded studies that helped to form the most compelling advice yet for calcium intake in the world and in this country, where osteoporosis afflicts 25 million people. Much of her research at Indiana's Purdue University has focused on children during their peak bone-growing years, between the ages of 12 and 15. The results, however, have implications for men and women of all ages. As the number of bone fractures escalates across the globe, Weaver has found herself invited to advise nations like Malaysia and Thailand, countries that only a few decades past dismissed osteoporosis as a Western disease.

"About 60 percent of bone strength is determined by genetics," Weaver says. "You can't do anything about choosing your parents, but you can make a huge amount of difference in the other 40 percent with diet and exercise. My kids were such daredevils, they were constantly crashing and burning. I think their good bones saved them lots of problems."

Q: Is there a role for calcium in the body beyond bone strength?

If you don't maintain calcium in your body, you'll die. Calcium is needed in every life process: it's needed for your nerves to act, your muscles to contract, your brain to function, for practically every activity in the body. Ninety-nine percent of the body's calcium is in the skeleton, and only 1 percent, concentrated in your blood, is used for all of those vital functions I just mentioned.

Although it's a small amount, the calcium in your blood must be maintained. So either you keep the blood replenished from your diet, or your body will take it from the big bank it has, the bones, because they are a lower priority.

Q: How many of us get enough calcium?

Over the age of about 11, people on average get only half of the calcium they need.

Q: How does that calcium deficit affect most people?

A deficiency in calcium doesn't play out with an immediate consequence: you don't get a canker sore, you don't have a collapse right away. It plays out in later years, and often in the form of weakened bones. Look at the statistics: hip fractures occur in one out of every four Caucasian women over 50 and in one out of ten African-American women (who are the most protected genetically for having strong bones). Twenty percent of hip fractures occur in men, so they're not immune. Twenty percent of people who have a hip fracture die because their lack of mobility harms their lungs and they get pneumonia.

Q: Is it true that children are now suffering more bone problems?

Bone fractures in children are tripling. There's a vulnerable period at the start of your adolescent growth when you spurt up before your bones can fill in. Fractures are rising during this lag time when kids have relatively low bone density. Years ago it was more common to have milk with every meal: there wasn't such a plethora of soda and other calcium-absent drink choices.

Bone strength is also improved with weight-bearing exercise like walking, aerobics, basketball. But today people are much more sedentary, addicted to television and computer games.

There's one more factor: with the increase in childhood obesity, children are falling with greater force because of their weight, so the impact is higher.

Q: Bone density is established during adolescence, but we can still influence bone strength later in life, right?

After adolescence you can't do very much more in building bone, just in preserving it. Hips finish growing first, about age 16.

By the time you're 17, you have 95 percent of your bone. Your spine is still pliable through college, up until the late twenties, 30. But at Purdue, we're finding that sedentary women students are losing spine bone already. Others who exercise, drink milk or get other forms of dietary calcium continue to gain spine throughout that period.

Q: What kind of exercise do you follow?

I practice Aquacize [water aerobics] twice a week, circuit training when I can, and my vacations are active with skiing, hiking, etc. But I also wear a pedometer much of the time, take the stairs and practice other ways to get my daily 10,000 steps.

Q: Can you get a daily dose of calcium from vegetables alone?

Although calcium is well-absorbed from vegetables like bok choy, broccoli, kale and so forth, the amount you would need to eat is immense: the calcium in 2 1/4 cups of broccoli or nearly 5 cups of red beans rivals that in 1 cup of milk.

Q: So how do you explain cultures that rarely eat dairy but have few problems with osteoporosis and hip fractures?

If you have an Asian beside a Caucasian and they have equal bone density, the Caucasian will be more vulnerable on average to getting a fracture because their hip-bone length is longer. Asians' geometry is such that if they fall, they're much less likely to crack that shorter bone. There is nothing about diet that can change that. It's an advantage that Asians have over Caucasians.

Now to say that Asians don't have a problem with osteoporosis isn't my observation. Even though they're protected by their bone geometry, they do have a problem, an increasing problem. In over a decade of reporting hip fractures in Hong Kong, researcher Edith Lau has seen the incidence triple. She attributes that to poor diet, low calcium and, ironically, to better overall nutrition that is causing the Asian population to get taller—consider the Chinese professional basketball players of today. Just like fat children, taller people fall harder on their bones and are more likely to break them with a harder impact.