Negative Nutrition factors that may influence Bone Health

Alcohol

Moderate alcohol intake is not thought to be harmful to bone. In contrast, higher levels of alcohol intake – more than 2 standard units of alcohol daily – were found to produce a significant increase in the risk of hip and other osteoporotic fractures. Excessive alcohol intake is known to have direct detrimental effects on bone-forming cells and on the hormones which regulate calcium metabolism. In addition, chronic, heavy alcohol consumption is associated with reduced food intake (including low calcium, vitamin D and protein intakes) and overall poor nutritional status, which will, in turn, have adverse effects on skeletal health. Excess alcohol use also increases the risk of falling, thereby increasing the opportunity for fracture.

Weight loss diets and eating disorders

Being underweight is a strong risk factor for osteoporosis. Very low body weight is associated with lower peak bone mass development in the young and increased bone loss and risk of fragility fractures in older persons. The effect of low body weight on fracture risk is largely due to its effects on BMD. Weight loss diets could also jeopardise bone health, especially if undertaken repeatedly, given that nutrients such as calcium, vitamin D and protein are necessary to maintain bone and muscle strength. In elderly men and women, weight loss promoted BMD loss, whereas weight maintenance and also commonly practiced forms of physical activity protected again BMD loss. In overweight adults who are restricting energy (calorie) intake in order to lose weight, prudent measures to prevent bone loss include ensuring sufficient intake of calcium and vitamin D, taking weight bearing physical activity, and avoiding ‘fad’ diets in which whole foods groups are eliminated.

The eating disorder anorexia nervosa is a chronic psychiatric illness with an onset usually during adolescence – the time of life when maximal bone mass accrual occurs, thereby putting these patients at very high risk for compromising their peak bone mass. The extreme body thinness in female anorexia patients leads to estrogen deficiency and amenorrhea (cessation of menstruation). Estrogen deficiency in younger women contributes to bone loss in much the same way that estrogen deficiency after menopause does. Anorexia patients with an average illness duration of about 6 years are found to have an annual fracture rate 7 times greater than that of healthy women of the same age.

Even recovery from anorexia nervosa does not always confer full establishment of normal bone density, and fracture risk is therefore increased throughout life. Particular attention needs to be paid to the skeletal health of anorexic patients, in order to prevent and/or treat osteoporosis; they need to be identified early and given appropriate support. Maintaining a healthy body weight will help to preserve bone density. Young girls and women and of late, even teenage boys, are particularly at risk of becoming underweight, due to excessive concerns with staying slim.

Lactose Intolerance

When people are unable to digest all the lactose they have eaten, they are said to have lactose maldigestion. It results from a deficiency in the enzyme lactase, produced in the small intestine, which is responsible for breaking down lactose (the principal sugar found in milk) into simpler sugars, which are then absorbed by the body. The term lactose intolerance refers to the abdominal symptoms (e.g. cramps, bloating) resulting from the inability to digest lactose Lactose intolerance is a potential risk factor for bone loss and osteoporosis, due to the avoidance of dairy products and hence possibly lower calcium intakes.

People with lactose intolerance need to pay careful attention to diet, to ensure a sufficient calcium intake. Being lactose intolerant does not necessarily preclude all dairy products from the diet; some people with this disorder can still drink small quantities of milk without suffering any symptoms. In some countries lactose-reduced kinds of milk are available. Yoghurt with live cultures can often be tolerated because the bacteria in the cultures produce the enzyme lactase, and some hard cheeses contain only negligible amounts of lactose. Another alternative is to take lactase tablets or drops along with dairy foods.

Other foods and drinks can provide good sources of calcium, such as green leafy vegetables, nuts, canned fish with soft, edible bones such as salmon and sardines, calcium-fortified beverages and calcium-rich mineral waters. People who are lactose intolerant should consult with their doctor to discuss the best way of ensuring adequate calcium intake, either through diet or if necessary, through the use of supplements.

Carbonated beverages

Concerns have been raised that consumption of carbonated soft drinks, notably cola drinks, may adversely affect bone health. Although a few observational studies have shown an association between high carbonated beverage consumption and either decreased BMD or increased fracture rates in teenagers, there is no convincing evidence that these drinks adversely affect bone health.If there is any negative effect of carbonated beverages, it is more likely to be due to the fact that these drinks displace milk in the diet, and hence impact on calcium intake. Finally, it should be noted that the carbonation is not the culprit. Many commercial mineral waters are carbonated, and some are rich in calcium and other minerals.

Are salt and coffee bad for me?

A high sodium (salt) intake promotes urinary calcium excretion and is therefore considered to be a risk factor for osteoporosis. The Dietary Approaches to Stopping Hypertension (DASH) study showed that lowering salt intake was beneficial for bone metabolism.

Coffee is often implicated in the development of osteoporosis, but there is no convincing evidence that this is the case. Caffeine does, however, produce a small increase in urinary calcium excretion and a very small decrease in calcium absorption, but the body appears to balance this out by reducing calcium excretion later in the day. However, if calcium intake was already low (< 800mg per day), more than three cups of brewed coffee a day was associated with more bone loss.

In addition to a balanced diet, other lifestyle measures like regular exercise and not smoking can help maintain your bone density.