Vegan diets are lacking in calcium, study says
An examination of the amount of calcium in strict vegetarian diets that exclude dairy products has found that these diets -- known as vegan diets -- lack the calcium needed to prevent osteoporosis later in life.Vegan diets are not likely to provide enough calcium, the dietary review concluded, even if people avoid salt, protein, caffeine and other substances that increase calcium loss.
Connie Weaver, head of Purdue University's department of foods and nutrition, says she doubts that many people could follow such a strictly limited diet. "A lot of vegetarians include milk in their diets, so getting enough calcium isn't a problem," she says. "But if they give up dairy products, and don't eat calcium-fortified foods, I don't know how they're going to do it."
The research was published in the September issue of The American Journal of Clinical Nutrition and was funded by the National Institutes of Health.
Weaver said many nondairy foods contain calcium, and many vegan diets substitute vegetables for dairy products. But the amount of calcium in vegetables is very low compared to dairy products, and many of the vegetables also contain substances that block the body's ability to absorb the calcium.
"Broccoli is very well absorbed by the body and contains a good amount of calcium for a vegetable. But how much broccoli would you have to eat? We did the math for you," Weaver says.
The study found that 4 1/2 servings of broccoli offer the same amount of calcium as one cup of milk. A person forsaking dairy products would need to eat as many as 20 servings of broccoli each day to get enough of the nutrient.
Want to have a baby? Don't wait too long
Women who put off having a baby might be hurting their chances to conceive.
A woman is born with all the eggs she will ever have and as she gets older, the health and fertility of the eggs begin to decrease.
Eggs from women at age 30 have about a 19 percent chance of being chromosomally abnormal, whereas at age 40, it's 39 percent. At that age, fertility begins to plummet, miscarriage rates soar and the rate of birth defects increases dramatically, as well. While many women over 40 do successfully get pregnant and have healthy children, the chances of problems are related to the egg's age and not that of the woman.
Did you know exercise cuts risk of cancer?
A survey commissioned by the American Institute for Cancer Research has revealed that a high percentage of Americans don't know that regular exercise can reduce the risk of cancer. In contrast, most do know that eating vegetables and fruits can contribute to the body's defense against the disease.
The link between exercise and cancer prevention was confirmed in 1997 by a panel of 16 renowned scientists assembled by the group in conjunction with its international affiliate the World Cancer Research Fund. The panel examined 4,500 scientific studies on the association between diet and activity level on one hand and cancer risk on the other and published its conclusions in the 670-page report, "Food, Nutrition and the Prevention of Cancer: A Global Perspective."
The panel concluded that a predominantly plant-based diet would reduce cancer incidence by 20 percent. Additional steps like exercising regularly and controlling weight brought the figure up to 40 percent.