Introduction

Lung cancer, cardiovascular disease, emphysema. Ask most people why smoking is hazardous to their health, and chances are they will name one of these deadly diseases. One that they are less likely to mention is the negative effects of smoking on bone health. A Swiss study recently published in the European Journal of Clinical Nutrition adds to the evidence that women who smoke may jeopardize their bone strength, in part because they consume too little calcium and vitamin D.

A closer look at smokers' diets

The study included more than 2300 women ages 35 to 74. Each completed a record of their usual food intake and indicated whether or not they smoked. On analyzing the nutrient content of the women's diets, the researchers found that current smokers consumed significantly less calcium and vitamin D when compared with non-smokers. The non-smokers ate more cheese and yogurt than others in the study, and these dairy foods contributed substantially to their intake of calcium. The non-smokers also consumed more cold water fish such as salmon, a good source of vitamin D.

Scientists have known for some time that people who smoke eat differently than those who do not. They suspect that non-smokers are more attuned to lifestyle habits, like diet, that can affect their health, and may make more of an effort to eat well.

Even without factoring in diet, though, smoking is hard on bone health. Studies have shown a loss of bone density in post-menopausal women and older men who smoke. Smokers also tend to exercise less, consume more alcohol, and, as this study shows, consume fewer calcium and vitamin D-rich foods than their non-smoking counterparts. All these factors contribute to a loss of bone minerals that, over time, weakens bones and makes them more prone to fractures.

Health statistics show that the average women over age 45 does not meet her body's need for calcium. In fact, the average daily intake of even the non-smokers in this study fell short of the 1000-1200 mg. recommended in US dietary guidelines. Smokers, however, appear to be at an even greater disadvantage.

Don't let healthful eating go up in smoke

The authors of this study warn women who smoke that they may be shortchanging their body of much-needed calcium and vitamin D. The best advice--don't smoke. Second best advice-- substitute calcium and vitamin D-rich foods for less nutrient dense foods, and choose calcium and vitamin D-fortified foods when available. This at least gives bones a fighting chance against osteoporosis.

Good food sources of calcium:

• Dairy foods--milk, yogurt, cheese
• Salmon with bones
• Dark green leafy vegetables--spinach, kale, mustard greens
• Calcium fortified foods--orange juice, cereals
• Tofu processed with calcium

Good food sources of vitamin D:

• Fortified milk (in the US)
• Salmon, herring, sardines
• Eggs
• Margarine

Note: Vitamin D is produced in the skin on contact with sunlight; 20-30 minutes of exposure, two to three times a week is thought to be adequate for most older people living in colder climates. Vitamin D is toxic at high levels, so individuals should always check with their healthcare provider before taking vitamin D as a supplement.