• Julia A. King, Ph.D.

The Strange Case of Excessive Bone Loss at the Patuxent Point Site

Updated: Apr 13

Julia A. King, Professor and Department Chair, St. Mary’s College of Maryland

During the analysis of the skeletal remains of 19 individuals recovered from the Patuxent Point Site, a c.1658-1695 plantation settlement in lower Calvert County, Smithsonian Curator of Biological Anthropology Doug Ubelaker observed that many of the skeletons exhibited some form of bone loss, or inadequate bone mineralization.

Fully one-half of the skeletons recovered from the Patuxent Point cemetery show evidence of bone loss. Six of the 19 individuals exhibit generalized or focal bone loss, two have bowing of the leg bones, and one suffered from spina bifida. The ages of the afflicted individuals range from 1 to 60 years. While bone loss is not unexpected in older populations, its presence in younger individuals is surprising. Three of the affected individuals were under the age of 5 years at the time of death. Five were in their late 20s and 30s, ages at which bone mass in modern populations is at its highest. Only one individual, a female, was in her late 50s or early 60s.

Twenty-first century doctors recommend exercise and diet to mitigate against bone loss. Most of the adult skeletons recovered from the site exhibit evidence of hard work which, while not exercise in the modern sense, nonetheless should have improved bone density. As for diet, historical documents and the analysis of animal bones from contemporary sites indicate that late 17thcentury diets were nutritionally sufficient. Why, then, were a majority of these individuals suffering from bone loss?

Thao T. Phung (St. Mary’s College of Maryland ’06) set out to answer this question by researching the causes of bone loss in modern populations. She found that the explanation likely lies in the excessive but culturally acceptable consumption of meat, alcohol, and tobacco by the Chesapeake colonists, including the Patuxent Point residents.

Historians estimate that, in the 17th century, an adult male would have consumed on average approximately 70 g of animal protein per day, well above today’s recommended 60 g limit. Increased intake of dietary protein is associated with increased urinary calcium loss. The high acid content of animal protein creates more acidic blood. In an attempt to buffer this acid, the body brings calcium stored in bone into the bloodstream and more calcium is excreted through urination. This loss of calcium is not compensated by a proportionate increase in intestinal calcium absorption since the high phosphorus content of animal meat competes with calcium for absorption in the digestive tract.

Alcohol consumption (although not drunkenness) was a common practice in 17th-century England and the colonies. Alcohol has a direct and toxic effect on osteoblasts, cells responsible for the formation of bone. Studies indicate that the consumption of more than just two to three ounces of alcohol per day compromises bone health and increases the risk of developing osteoporosis. The mechanical properties of bones, such as their elasticity, stiffness, load-carrying capacity, and toughness, are all negatively affected by the heavy consumption of alcohol, effects that cannot be reversed over time. Alcohol consumption also reduces the intestinal absorption of calcium by restricting the stomach’s production of hydrochloric acid.

Tobacco consumption was ubiquitous in the 17th-century Chesapeake, certainly more prevalent than in England or elsewhere in Europe. The presence of pipe facets on the teeth of 7 individuals – including a 13-year-old! – suggests that the Patuxent Point residents were ready consumers of tobacco. Nicotine, a drug believed to be toxic to osteocytes (which are derived from osteoblasts), restricts blood flow to all tissues, especially newly forming tissues involved in bone repair and healing. Smoking appears to affect the body’s ability to absorb calcium from the intestine, also impacting the amount of calcium available for bone repair. Smoking further causes the liver to metabolize estrogen faster, increasing the risk among women for developing osteoporosis.

The skeletal evidence from Patuxent Point along with anecdotal evidence from other contemporary Chesapeake sites suggests that a significant portion of the Chesapeake English population suffered nutritional deficiencies to some extent and that the effects of these deficiencies are found inscribed on the skeletal remains archaeologists recover some 300 years later. The skeletal evidence suggests that, while documents and animal bones indicate an “adequate” diet, many 17th-century English colonists in the Chesapeake region were unable to absorb all of the nutrients they ingested due to the excessive consumption of animal protein, alcohol, and tobacco.

For further reading:

Phung, Thao T., Julia A. King, and Douglas H. Ubelaker 2009 Alcohol, Tobacco, and Excessive Animal Protein: The Question of an Adequate Diet in the Seventeenth-Century Chesapeake. Historical Archaeology 43(2):61-82.

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