diet and dental caries among later stone age inhabitants of the cape province, south africa

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 88:123-134 (1992)

Diet and Dental Caries Among Later Stone Age Inhabitants of the Cape Province, South Africa

J.C. SEALY, M.K. PATRICK, A.G. MORRIS, AND D. ALDER Departments of Archaeology (J.C.S., M.K.P., D.A.) and Anatomy and Cell Biology (A.G.M.), University of Cape Town, Private Bag, Rondebosch, 7700, South Africa

KEY WORDS S13C, Hunter-gatherers, Africa, Fluoride

ABSTRACT Stable carbon isotope measurements and incidences of dental caries are presented for three groups of prehistoric human skeletons from different regions of the Cape Province, South Africa. The isotopic analyses of bone collagen demonstrate the importance of marine foods in the diet and vary through time, across space, and according to sex. The incidence of dental caries ranges from 0% among heavily marine-dependent individuals from the south-western Cape coast, to 17.7% among skeletons from an archaeological site on the south coast. The extremely high incidence of caries in a hunter- gatherer population may be related to lack of fluoride in the water. 0 1992 Wiley-Liss, Inc.

The health and nutritional status of hunter-gatherers may vary widely in populations living in different environments, exposed to different pathogens, and consum- ing different diets. This paper documents such variability among Later Stone Age inhabitants of the Cape Province, South Af- rica. Three Holocene groups are compared: archaeological skeletons found i) along the south-western Cape coast, between Cape Town and Elands Bay (see Fig. l), ii) at the site of Faraoskop (about 30 kilometres inland from Elands Bay), and iii) at the site of Oakhurst, about 450 kilometres to the south-east.

All these sites are coastal or near-coastal. We expect that their inhabitants consumed marine foods, such as shellfish, and the meat of whales, seals, fish, and seabirds, in addition to terrestrial meat and plants. Analyses of excavated food-waste from archaeological sites indicate that plant foods, particularly the starchy underground corms of members of the iris family, and the meat of small bovids, tortoises, hyrax, and similar animals were staples (H.J. Deacon, 1976; J. Deacon, 1984; Sealy, 1986; Parkington et al., 1988). Although archaeologists know the kinds of foods likely to have been consumed

by Holocene hunter-gatherers, there remain a number of questions about the way that these resources were integrated into diets. How important were particular food items or classes of foods, such as marine resources? Do different sites, with different kinds of food-waste, represent the varied subsistence round of mobile bands of hunter-foragers, or did separate groups of people tend to exploit particular resources, perhaps in separate territories? Were Later Stone Age diets nutritionally satisfactory? What can we deduce about the health status of these people?

Two methods which reflect the impact of diet on the biology of the population are em- ployed here as a first step towards answer- ing these questions. Measurements of the stable carbon isotope ratio (13C/12C) of bone collagen provide information about the relative importance of different classes of foods in the diet. The incidence of dental caries is determined at least partly by the nature of the diet. To deepen our understanding of prehistoric lifeways, we seek correlations between these observations on human skel-

Received April 23,1991; accepted December 18,1991.

0 1992 WILEY-LISS. INC

124 J.C. SEALY ET AL.

Fig. 1. Map showing localities mentioned in the text. Skeletons included in the “south-western Cape coast” category come from the coastline between the Cape Peninsula and Elands Bay. Horizontal hatching represents areas where more than 90% of the grass species are C,, small circles show mixed C&, grasses, in shaded areas more than 90% of grasses are C, (after Vogel, 1978).

etons and reconstructions of diet based on excavated food-waste.

MATERIALS AND METHODS The skeletal sample

Three sets of Holocene human skeletons are compared. The first group (74 south- western Cape coastal skeletons) have been assembled and dated for intensive archaeo- metric analysis (Sealy, 1989). Most were not recovered under controlled circumstances, but in the course of building operations or other developments, and have little associ- ated documentation. They are generally isolated burials in shell middens or sand dunes. Direct radiocarbon dating of bone collagen therefore provides an essential archaeologicalkhronological context for the observations reported here.

Inland of the shifting dunes and highly visible shell middens of the coast, fewer human skeletal remains have been recovered. Recently, a series of skeletons were found at the site of Faraoskop, about 30 kilometres inland of Elands Bay. Initially, material was collected by a local farmer, but subsequent controlled excavations were carried out by

Manhire and others (Manhire et al., in prep- aration). At least twelve individuals are represented (Alder, 1988; Table 11, although some are very fragmentary. Six have been radiocarbon dated, all the dates falling between 2,300 and 1,900 B.P. (at two standard deviations, corrected for 613C). It seems likely that the remaining undated skeletons also fall into this time range.

The site of Oakhurst in the southern Cape was excavated in the 1930s, and many skeletons recovered (Drennan, 1938a,b). Recent re-analysis suggests that at least 48 individuals are represented, 27 of them juveniles (Patrick, 1989; Table 1). In this respect the Oakhurst sample differs from that from the south-western Cape, where the skeletons se- lected for analysis include few juveniles. Fif- teen individuals have been radiocarbon dated by direct measurements of bone collagen. Fourteen dates fall between 10,000 and 4,000 B.P.; one skeleton is circa 2,000 years old (Table 1; Patrick, 1989).

Agriculture was not introduced into this region until after European settlement in the seventeenth century A.D.; all skeletons discussed here pre-date this event. Pastoral- ism first appeared about 2,000 years ago, so

DIET AND DENTAL CARIES IN STONE AGE SOUTH AFRICA 125

that skeletons less than 2,000 years old (in this sample, from the south-western Cape coast only) may be the remains of pastoralists or of residual hunter-gatherers. There are very few sites a t the Cape known to have been occupied by pastoralists. Only one ex- cavation has yielded a human skeleton in association with large numbers of domesticated animals, and a slaughtering pattern indicative of stock management. Other fauna from the same site, however, include numerous seal bones and remains of other wild animals also utilised by hunter-gatherers (Klein and Cruz-Uribe, 1989). The degree of economic and social differentiation between pastoralists and hunter-gatherers is contentious (Schrire, 1980; Elphick, 1985; Parkington et al., 1986; Smith, 1986). We have no way of ascertaining the importance of domesticated animal-derived foods in the diets of isolated skeletons from the last two millennia. Carbon and nitrogen isotope analyses (Sealy et al., 1987; Sealy, 1989) have not helped us to answer this question. Thus the most recent skeletons from the south-western Cape coast may reflect diets somewhat different from those of the other individuals in this study; hunted and gathered foods, though, continued to be important. The majority of the skeletons discussed here, however, date to the period before 2,000 years ago and therefore must be the remains of hunter-gatherers.

Dietary tracing using 13C/'*C ratios in bone collagen

The basis of this technique has been re- viewed elsewhere (van der Merwe, 1982; De- Niro, 1987). Briefly, plants utilising different photosynthetic pathways incorporate different proportions of I3C and "C from the atmosphere. These differences are inherited by animal and human consumers higher in the food web and are reflected in their bones. Measurement of 13C/12C of human bone can therefore reveal the proportions of food consumed in life derived from C3 or Calvin pathway plants (grasses adapted to temperate climates, most shrubs and trees) as opposed to C, plants (tropical grasses). In the sea, the situation is complex but marine organisms, on average, have I3C/l2C more similar to C, than to C3 systems.

In temperate environments, where there are no C, grasses, 13C/12C ratios in the bones of hunter-gatherers reflect the proportions of marine and terrestrial foods eaten in life (Tauber, 1981; Chisholm et al., 1982, 1983; Hobson and Collier, 1984; Sealy and van der Merwe, 1985, 1986; Hayden et al., 1987; Yesner, 1988).

Stable carbon isotopes and the Later Stone Age of the Cape Province,

South Africa Distinguishing marine from terrestrial re-

sources is of value in the Later Stone Age of the south-western Cape, where the role of marine foods in the diets of coastal and near- coastal dwellers has been a major topic of research (Parkington, 1972, 1976; Parking- ton et al., 1988; Smith, 1987; Robertshaw, 1977,1979). Stable carbon isotope measurements of modern representatives of important food species for indigenous Later Stone Age people confirm the distinct isotopic character of the terrestrial foodweb (which is largely based on C, plants) and the marine system. Hence in this area, as in other winter-rainfall regions, we can use 13C/12C measurements of human skeletons as an in- dex of marine food consumption.

The situation in the southern Cape, at the site of Oakhurst, is more complicated. This region receives year-round rainfall, and the terrestrial flora includes an appreciable C, component (Vogel et al., 1978). We expect, therefore, that the separation in 13C/12C between marine and terrestrial foods will be less clear-cut than in the western Cape.

Dental caries and tooth-wear Dental caries result from a complex inter-

action of dietary, hereditary, and environmental factors. There have been a number of studies in which the incidence of dental caries is reported for prehistoric populations, and correlations sought with dietary factors. Some foods, particularly starchy andlor sug- ary ones, are known to be cariogenic. It is widely reported that caries rates among hunter-gatherers are low, but that people with access to agricultural products, with their (usually) higher carbohydrate intake, are more susceptible to caries (Cohen and Armelagos, 1984; Drennan, 1929; Goldstein,

TAB

LE 1

. Sk

elet

ons

from

Oak

hurs

t and

Far

aosk

op

No.

of

cari

ous

teet

h O

akhu

rst s

kele

tons

61

3C (O

leo)

Sex

Age

at d

eath

R

adio

carb

on d

ate

per

tota

l tee

th

UC

T 19

9 U

CT

200

UC

T 20

1 U

CT

201

UC

T 20

2 U

CT

203

UC

T 20

3 U

CT

204

UC

T 20

4 U

CT

204

(3 in

divi

dual

s)

UC

T 20

5 U

CT

205(

2)

UC

T 20

6(1)

U

CT

206(

2)

UC

T 20

6(3)

U

CT

207(

G)

UC

T 20

7(H

) U

CT

207(

I)

UC

T 20

8' '

UC

T 20

8(G

r9)

UC

T 20

8(G

r10)

U

CT

209

UC

T 20

9 U

CT

210(

10ci

U

CT

211

~ ~

- ~~

UC

T 21

2 U

CT

212

UC

T 21

3 U

CT

213(

G)

UC

T 21

3(G

r16/

2)

IJC

T 21

4 -

__ -~

~

UC

T 21

5(G

r10)

U

CT

215(

D)

UC

T 21

5(I)

U

CT

215'

(P/Q

?)

UC

T 21

6(5)

U

CT

lZS(

Q/D

?)

-14.

2 -1

2.4

-14.

0

-13.

4 -1

6.6

-13.

6 -1

4.5 - -

-

-

-12.

6 -1

2.4

-12.

3

-11.

1 -1

3.8

-14.

1

-15.

4 -1

0.9

-12.

3

-12.

4 -1

3.9 -

-

-

-

-

-

-

-15.

9

-15.

7 -1

1.7

-13.

8 -1

6.4

-10.

4 -

-

mal

e m

ale

fem

ale

juve

nile

m

ale

fem

ale

juve

nile

fe

maI

e ju

veni

le

inde

term

inat

e ju

veni

le

mal

e m

ale

fem

ale

fem

ale

juve

nile

ju

veni

le

juve

nile

fe

mal

e ju

veni

le

juve

nile

m

ale

juve

nile

ju

veni

le

mal

e fe

mal

e ju

veni

le

juve

nile

ju

veni

le

juve

nile

m

ale

juve

nile

ju

veni

le

juve

nile

ju

veni

le

juve

nile

ju

veni

le

30-3

9 20

-29

30-3

9 0-

1 40

+ 30

-39

0-1

30-3

9 4-

5 in

dete

rmin

ate

5-9

20-2

9 30

-39

30-3

9 20

-29

1-4

5-9

1-4

25-4

5 1-

4 5-

9 20

-29

0-1

1-4

30-3

9 30

-39

1-4

1-4

0- 1

15

-19

20-2

9 5-

9 1-

4 1-

4 0-

1 0-

1

0- 1

Pta-

3718

Pt

a-43

54

Pta-

4426

Pta-

3724

Pt

a-44

31

Pta-

4449

-

AA

-211

9

-

-

-

Pta-

4347

Pt

a-43

67

-

-

-

AA

-211

5 -

-

-

-

Pta-

4348

AA

-211

7 Pt

a-37

19

-

-

-

-

-

-

Pta-

4467

-

-

-

-

AA

-211

6 -

6180

f 70

71

20 f 60

59

90 f 70

9100

f 90

41

00 i 60

48

70 f 21

0 45

30 5

70

-

-

-

-

4880

f 70

54

50 I 70

-

-

-

4830

i 25

0 -

-

-

-

4880

i 70

4995

f 21

5 53

30 f 60

-

-

-

-

-

-

4900

k 6

0 -

-

-

-

2065

f 1

05

-

UC

T 2

17(K

) U

CT

21

7i~

j U

CT

217

(M)

UC

T 2

17(N

) U

CT

218

U

CT

218

D (

2 in

divi

dual

s)

Tot

al

-

-14.

1 -1

5.4

-14.

4 -1

5.9

-13.

3 -1

2.0 -

juve

nile

ju

veni

le

juve

nile

ju

veni

le

juve

nile

ju

veni

le

mal

e in

dete

rmin

ate

5-9

1-4

0- 1

0-

1 0-

1 0-

1 20

-29

inde

term

inat

e

-

2/11

5/

12

4/21

Sku

ll U

CT

192

* 4/

16 L

oose

teet

h .1

4/19

2

Fara

osko

D s

kele

tons

~~

~

UC

T 3

85

-16.

9 fe

mal

e 25

-35

Pta-

5281

21

30 +

60

-

UC

T 3

88

-18.

8 ju

veni

le

6-7

-

-

-

UC

T 3

90

fem

ur: -

17.2

m

ale

30-4

0 -

UC

T 3

91/3

89

-17.

8 fe

mal

e 25

-35

Pta-

5284

U

CT

392

/387

-1

6.9/

-18.

2 m

ale

35-4

5 -

UX

T 39

3 -

juve

nile

2-

3 -

-

-

UC

T 3

94

-17.

5 m

ale

40+

Pta-

4964

21

50 +

70

017

UC

T 3

95

-

fem

ale

20-3

0 -

-

-

UC

T 3

96

-17.

7 in

dete

rmin

ate

30-3

5 Pt

a-49

65

2090

+ 60

-

UC

T 3

97

-16.

5 fe

mal

e 40

+ Pt

a-49

67

2130

rt 4

5 -

UC

T 3

98

-

inde

term

inat

e in

dete

rmin

ate

Tot

al

12/1

38

*Mul

tiple

lesi

ons

on o

ne to

oth

are

trea

ted

as o

ne o

ccur

renc

e.

UC

T 3

86

-16.

8 m

ale

40-4

5 Pt

a-52

83

2000

* 50

2/30

-

1/30

7/26

-

1/17

cran

ium

: -18

.0

2110

rt 7

0

1/28

Loo

se te

eth


1932; Morris, 1984; Pedersen, 1938; Powell, 1985; Schwartz, 1946; Turner, 1979; van Reenen, 1966; Walker and Hewlett, 1990).

Caries and tooth-wear data presented here are for individuals with fully adult dentitions only. Since juveniles are excluded, and some skeletons do not have dentitions preserved, fewer individuals are represented than in the case of the isotopic analyses.

Wear values are scored according to Mor- ris' (1984) adaptation of the system used by Brothwell (1981). Wear observations have been recorded on the left side of the mouth, and the right side used only when both max- illary and mandibular teeth on the left side are missing. The numerical values for max- illary and mandibular teeth are combined; if the two values are different the average is given. If unusual wear is obviously due to ante-mortem tooth loss and subsequent ab- normal occlusion, this part of the dentition is treated as absent. The five categories are: 0 (unworn), 1 (wear on enamel only), 2 (den- tin exposed, but some occlusal enamel remains), 3 (heavily worn, enamel rim only remains), 4 (entire tooth crown lost, pulp cavity exposed).

The presence of carious lesions has been recorded for both left and right sides, and upper and lower jaws. Multiple lesions on one tooth are treated as one occurrence.

RESULTS AND DISCUSSION Coastal dwellers in the

south-western Cape

Carbon isotopes

Stable carbon isotope measurements of 74 prehistoric human skeletons from the south- western Cape coast (between the Cape Pen- insula and Elands Bay; see Fig. 1) have recently been completed. All these skeletons were recovered from shell middens or other contexts in the immediate vicinity of the coastline. The aim of this study was to inves- tigate the role of marine foods, viz, To what extent did coastal people rely upon marine foods? Are there geographical differences in the use of seafoods along this 200 kilometre stretch of coastline? Is there change through time? Can one detect differences within populations, that is, between men and women, or adults and children?

-I2 i -I4 i

1 -16 I

A . *

. A A

A

_ _ 6000

DATE (RADIOCARBON YEARS B.P.)

Fig. 2. 6'"C values for male (squares), female (trian- gles) and neutraUjuvenile (stars) skeletons from the south-western Cape coast, plotted as a function of radiocarbon date. 6'"C values are calculated as follows:

'3C/'2C,,,,, 1 y y

p c r %standard

Results are reported relative to the internationally accepted standard, PDB. This i s a marine limestone, arbi- trarily assigned a 6% value of O"/oo (parts per milk, or parts per thousand). values reported here are bone collagen measurements. The laboratory procedures used isolate collagen "pseudomorphs" of whole bone: All samples have C/N ratios within the range of variation of modern collagen (Hassan and Hare, 1978; DeNiro, 1985). Isotopic values are therefore unlikely to have been altered by post-mortem degradation.

The answers to these questions are discussed in some detail elsewhere (Sealy, 1989). Briefly, it seems that there was con- siderable variability in the extent to which people relied upon marine foods: some individuals ate large amounts, others relatively little. There is no correlation between geographical location and the amount of seafood consumed.

There is, however, marked chronological patterning in the carbon isotope ratios (and hence the marine food intake) of these people (see Fig. 2). All but one of the 74 south- western Cape coastal skeletons discussed here have been directly dated by radiocarbon measurements of bone collagen. Only twelve skeletons pre-date 3,000 B.P., too few for us to be able to draw any firm conclu- sions about lifestyles at that time. Values of S13C (see caption to Fig. 2) for these individuals span almost the entire range from fig- ures indicative of a large marine food intake (number approaching -ll0/oo) to those rep-


resenting little reliance on seafood (numbers approaching - l8"/oo).

Between 3,000-2,000 BP, the picture is very different. Stable carbon isotope readings generally are enriched (x = -12.82 ? 1 . 2 8 ° i ~ ~ n = 27), reflecting high marine food consumption. This is in accor- dance with the archaeological evidence from the west coast site of Elands Bay, where food waste from the third millennium B.P. con- sists almost entirely of marine shells which have accumulated in open middens, often near shellfish-rich rocky areas of the shore- line (Parkington et al., 1988). It seems from the isotopic data, however, that heavy reliance on marine foods at this time is charac- teristic not only of Elands Bay, but of much of the south-western Cape coast.

Skeletons post-dating 2000 BP have more depleted 13C/12C ratios, (x = -14.80 * l.6lo/oo n = 271, reflecting diets which in- corporated a larger proportion of terrestrial foods. The distributions of SI3C readings in the 3,000-2,000 and post-2,000 B.P. periods are significantly different (Mann-Whitney approximate Z-value = 4.2, P < 0.001. Only skeletons with dates falling into these time brackets a t two standard deviations have been included). This picture corresponds with that gained from the excavated sites, where post-2,000 B.P. food-waste includes large numbers of the bones of small terrestrial animals and markedly increased quantities of plant food remains. Such a pattern has been tentatively interpreted as an en- forced shift towards the use of less desirable, and probably more labour-intensive foods as population density increased and large parts of the landscape of the south-western Cape were occupied by pastoralists and so unavailable to hunter-gatherers (Parking- ton et al., 1986,1988). Skeletons post-dating 2,000 B.P. probably include pastoralists, a s well as hunter-gatherers.

Thus there is clear evidence of chronological patterning in the carbon isotope ratios (and hence the marine food intake) of prehistoric human skeletons from the south- western Cape coast. In the main, these patterns are consistent with those reported for food-waste excavated from archaeological sites.

The chronological patterning may, however, be different for male and female skele-

tons. Over the entire time range in Figure 2, there is no linear trend in the association of 613C and radiocarbon date for female skeletons (r2 = 0.00001, d.f. = 26) while there is for male skeletons (r2 = 0.34, d.f. = 31, P < 0.01). Women's diets underwent less change during the period under consider- ation than did those of men.

Male skeletons, on the whole, have more positive S13C values (i.e., they are enriched in the heavy isotope) compared with female skeletons (Mann-Whitney approximate Z-value = 2.43, P < 0.01). Men appear to have consumed more marine foods, and women more terrestrial foods. It seems likely that these latter were mostly plant foods, perhaps consumed in the course of gathering expeditions.

Dental caries and tooth-wear

A total of 948 teeth were examined, of which 25 (2.6%) were carious (Table 2). This is similar to the averge value (1.6%) for 12 hunter-gatherer populations for which Turner (1979) compiled data. (The range was 0-5.3%.) Comparisons of the number and proportion of carious teeth in male and female skeletons is of some interest, given the more depleted S13C values, possibly rep- resenting a higher intake of carbohydrate- rich terrestrial plant foods among women. Of the teeth from female skeletons, 11 out of 438 (2.5%) are carious, compared with 13 out of 504 (2.6%) for males. More than half the carious teeth of the males are from one individual (SAM-AP 5091) with advanced dental disease. If this skeleton is excluded, the incidence of carious teeth among male skeletons drops to 6 out of 474 (1.3%). Unfor- tunately, the numbers of carious teeth are so small that comparison of caries incidences in males and females gives a value of the approximate chi-squared statistic (D2 = 1.9, d.f. = 1) that is not statistically significant.

The teeth of individuals who ate large amounts of marine foods (S13C values equal to or more positive than -13'/00) are somewhat more heavily worn than those of people with S13C values of - IV/oo or less (Table 3). A study of dental attrition among the prehistoric inhabitants of the Santa Barbara Channel of California also found that greater reliance upon seafood was associ- ated with increased toothwear, and attrib-


TABLE 2. Numbers of carious teeth per total teeth'

Cape West Coast Cape West Coast Cape West Coast total -13 5 6I3C 5 - 1 0 -18 5 6I3C 5 -15 Faraoskop Oakhurst

No. of individuals 49 Incisors 0/184 Canines 0/118 ~ ~~~~~ ~ ~

Premolars Non-id. I/C/PM

2/235 017

First molars 6/148 Second molars 8/141 Third molars 5/110 Non-id. molars 4/5 Total 25/948 Percentage 2.6

18 0/60 0/35 0/75 0/3 0/55 0/50 0/30 011 0/309

0

13 0153 0/31 1/59 0/1 2/34 4/36 4/35

11/249 4.4

-

5 0/35 0/19 2/34

7/16 1/19 2/15

12/138 8.7

-

-

13 0/36 1/27 9/52

8/25 9/28 6/23 1/1

34/192 17.7

-

'Multiple lesions on one tooth are treated as one occurrence.

TABLE 3. Average toothwear scores

I1 12 C PI P2 M1 M2 M3

Cape West Coast (total) 2.8 2.6 2.5 2.3 2.2 2.3 2.0 1.7 Cape West Coast (-13 5 6% 5 -10) 2.9 2.7 2.6 2.1 2.1 2.2 1.9 1.8 Cape West Coast (-18 5 6I3C 5 -15) 2.6 2.4 2.3 2.1 1.7 2.1 1.7 1.4

Oakhurst 2.8 2.8 2.7 2.6 2.4 2.2 2.1 1.4 Faraoskop 3.4 3.1 2.8 2.5 2.2 2.5 2.0 1.2

uted this to sand and grit in foods from the littoral zone (Walker, 1978). The slightly greater degree of wear in the heavily marine-dependent group at the Cape is, however, probably not sufficient to account for the marked absence of caries in these individuals. Not one tooth (out of 309) from individuals with SI3C 2 - 13%0 is carious. Skel- etons with -18 s 613C G -15 yielded 11 carious teeth out of a total of 249. These frequencies are significantly different (D2 = 13.9, d.f. = 1, P < 0.005).

Comparisons of caries incidences based on total numbers of teeth examined may be misleading. Some individuals have several carious teeth. The presence of an initial carious lesion increases the chances of additional lesions developing, and thus violates the assumption that the observations are in- dependent. It may be more appropriate to compare the numbers of dentitions with caries, even though most have suffered postmortem losses. None of the eighteen individuals with S13C 2 -13"/00 have caries, compared with five out of thirteen skeletons with -18 4 S13C G -15. These frequencies are significantly different (D2 = 8.2, d.f. = 1, P < 0.01).

At least two factors may contribute to the lower incidence of caries among individuals

who ate diets rich in marine foods: lower carbohydrate intake andlor the possible cariostatic effects of seafood. The influence of carbohydrates on caries has been mentioned above. One possible explanation for the lack of carious lesions in individuals who ate a great deal of seafood (Walker and Erland- son, 1986; this study) may simply be that they ate relatively little carbohydrate food. It has also been suggested that marine foods, particularly fish, contain high levels of fluoride and inhibit the development of caries (Sognnaes, 1941; Pu and Lilienthal, 1961; Hadjimarkos, 1964). This effect has been challenged, however, by analysis of non-carious teeth from a strongly fish-dependent population, which contained less fluoride than expected (Holloway et al., 1965). The relationship between marine food intake and dental caries probably re- quires further investigation.

Non-coastal dwellers in the south-western Cape

Carbon isotopes

Stable carbon isotope measurements are available for nine of the Faraoskop skeletons. They range from -16.8 to -18.8"/00. These values are similar to those obtained


previously for skeletons from the Olifants River Valley, approximately 30 kilometers further inland than Faraoskop (Fig. 1). Val- ues of 613C for all sixteen non-coastal skeletons range from -16.0 to -19.0°/oo. This sample is too small to provide the chronological or social information obtained from the much larger number of coastal skeletons; it is of interest mainly for the light it throws upon the more terrestrially-based subsistence patterns of inland people (Sealy, 1986; Sealy and van der Merwe, 1985; 1986; but see also Parkington, 1986,1987,1991).

These S13C values overlap with those of the coastal skeletons, but all lie towards the more negative end of the range, indicating largely terrestrial diets. It has been argued that inland individuals followed a different subsistence round from that of coastal people (Sealy, 1986; Sealy and van der Merwe, 1985,1986,1987).

Such comparisons have previously fo- cussed on coastal skeletons from Elands Bay and individuals from the Olifants River Val- ley. As noted above, the site of Faraoskop is almost half-way between these two areas, only about 30 kilometres from Elands Bay. The presence of significant quantities of marine shell in the Faraoskop deposits is evidence of contact with the coast. Skeletons from Faraoskop, however, like those from the Olifants River Valley, have S13C values which reflect only a small marine food intake. We do not yet have skeletons from Elands Bay which date to exactly the same period as those from Faraoskop. This period is a particularly interesting one in the coastal sequence, marking as it does the end of the “megamidden” period, during which evidence of human occupation at Elands Bay is found almost entirely in huge open- air shell middens located near shellfish-rich rocky outcrops (Parkington et al., 1988). Contemporary coastal skeletons from further south are often enriched in 13C compared with the Faraoskop skeletons, indicating large intakes of marine foods (Sealy, 1989; Sealy and van der Merwe, 1988). Why did the people whose skeletons are buried at Faraoskop not eat more marine foods, if they were only 30 kilometres from the coast? One possibility is that there was an intervening social boundary, so that restricted access to

another group’s territory may have limited the availability of seafoods.


Data on caries and tooth-wear are available only for five adult skeletons from Faraoskop (Tables 1 and 2). Of 138 teeth examined, 12 (8.7%) were carious. The average tooth-wear scores for the anterior teeth are slightly higher than in the case of the coastal skeletons; for the posterior teeth the values are similar. Based on total number of teeth examined, the incidence of dental caries is not significantly different from that seen in coastal skeletons with comparable S13C values (-18 s S13C 4 -15) (D2 = 2.9, d.f. = 1). If numbers of dentitions with caries are compared, the conclusion remains the same (D2 = 2.5, d.f. = 1). Thus, on the currently available sample, the Faraoskop results are consistent with the picture for those coastal individuals who ate more mixed diets, probably including a greater proportion of terrestrial carbohydrate foods. If a larger sample were available, statistically significant differences might emerge. Four out of five of the Faraoskop dentitions show caries, and the one that does not is that of an elderly individual with only seven anterior teeth remaining. The sample is, however, very small and subject to bias: it is possible that all the individuals were related to one another, and their susceptibility to caries influenced by genetic factors.

Oakhurst (Southern Cape)

Carbon isotopes Thirty S13C values have been obtained for

skeletons from Oakhurst. They range from -10.4 to - l6.6%0. These numbers are diffi- cult to interpret, since enriched 13C/12C measurements in areas such as the southern Cape may indicate marine foods in the diet, or alternatively C,-based terrestrial food (e.g. the meat of grazing animals). Ma- rine shells and fish-bones have been identi- fied from the Oakhurst deposits (but not quantified), so we know marine foods were consumed (Patrick, 1989). The complex ecology of the southern Cape, however, pre- cludes confident interpretation of 613C values without extensive monitoring of the

132 J.C. SEALY ET AL

surrounding areas. There does not appear to be any marked shift in SI3C with time (Patrick, 1989).


One hundred and ninety-two adult teeth were available for examination. Tables 1, 2, and 3 show the incidence of caries, and average toothwear scores. The toothwear values are not markedly different from those for the south-western Cape skeletons discussed above. 34/192 teeth (17.7%) showed caries. This is an extraordinarily high incidence of caries; higher than any of the published values we have seen reported for hunting-and- gathering societies (e.g. Cohen and Armela- gos, 1984; Drennan, 1929; Goldstein, 1932, Morris, 1984; Pedersen, 1938; Powell, 1985; Schwartz, 1946; Turner, 1979; van Reenen, 1966; Walker and Erlandson, 1986; Walker and Hewlett, 1990), or for the European Me- solithic (Meiklejohn et al., 1984, 1988).

Skeletons with S13C more positive than - 13*/00 may have carious teeth, in contrast to the situation in the south-western Cape. Although we cannot be sure that enriched carbon isotope ratios at Oakhurst necessar- ily reflect marine foods in the diet, the marine shells and fish bone found at the site strongly suggest that such items were eaten. Any cariostatic properties of these foods were inadequate to prevent or arrest dental decay in the inhabitants of Oakhurst.

The explanation for the high prevalence of caries is almost certainly related to the extremely low fluoride content of the groundwater in the southern Cape. Fluoride con- centrations are below 1 ppm in the area surrounding Oakhurst, and contemporary populations with limited access to dental care suffer rampant caries (Ockerse, 1949). Fluoride in the groundwater of the south- western Cape, on the other hand, varies from less than 1 to more than 6 ppm. The northern Cape and the Kalahari have relatively high levels of fluoride in the groundwater, no doubt a contributing factor in the low incidence of caries (0.7%) reported for the Kalahari San (van Reenen, 1966). Mor- ris’ (1984) analysis of late prehistoric skeletons from the northern Cape shows similar low caries rates for high fluoride zones, and

much greater incidences (up to 5%) in areas where the fluoride level is currently less than 2 ppm,

C 0 N C L U S I0 N S The relative importance of marine and

terrestrial foods (as revealed by SI3C measurements) in the diets of coastal and near- coastal hunter-gatherers from three areas of the Cape Province, South Africa is discussed. The degree of tooth-wear and incidence of dental caries has been recorded for these same skeletons, and correlations sought between diet and pathology. The incidence of dental caries is different in each of the three areas: It is lowest (2.6%) among coastal skeletons in the south-western Cape, intermediate (8.7%) in individuals from the non-coastal site of Faraoskop, also in the south-western Cape, and highest (17.7%) among skeletons from Oakhurst in the southern Cape. In the sample of coastal skeletons from the south-western Cape, individuals who ate large amounts of seafood have a lower incidence of caries than do people who ate more mixed marine and terrestrial diets. In the southern Cape, the high incidence of caries probably results from low levels of fluoride in the groundwater. This paper highlights the substantial variability in diet and caries rates among hunter-gatherers in a fairly limited area.

ACKNOWLEDGMENTS Drs. Graham and Margaret Avery and

Mr. Mike Wilson of the South African Mu- seum arranged access to the physical anthropological collections in their care. Mr. John Lanham provided invaluable laboratory and computer assistance. We thank Dr. John Vogel and staff of the Department of Earth and Marine Science and Technology at the Council for Scientific and Industrial Research in Pretoria for numerous radiocarbon dates, without which this work would be meaningless. Additional dates were provided by Dr. Timothy Linick of the Depart- ment of Physics, University of Arizona, Dr. Robert Hedges and staff of the carbon-14 accelerator laboratory at the Research Labo- ratory for Archaeology and the History of Art at Oxford University; and Mr. H.


Krueger and staff of the Geochron Laborato- ries, Cambridge, Massachusetts. Dr. Tim Dunne of the Department of Mathematical Statistics of the University of Cape Town and Dr. Mary-Lou Thompson, formerly of the same department, advised on statistics. An earlier version of this paper was read at the 6th International Conference on Hunt- ing and Gathering Societies in Fairbanks, Alaska during May 1990. Comments from delegates a t that meeting have improved our arguments, as have suggestions from Professor Andrew Sillen and three anony- mous reviewers. Financial support from the Foundation for Research Development of the C.S.I.R. and the University of Cape Town is gratefully acknowledged.

LITERATURE CITED Alder D (1988) The Faraoskop human skeletal remains.

Unpublished honours project, Department of Anat- omy and Cell Biology, University of Cape Town.

Brothwell DR (1981) Digging Up Bones. London: British Museum (Natural History).

Chisholm BS, Nelson DE, and Schwarcz HP (1962) Sta- ble carbon isotope ratios as a measure of marine ver- sus terrestrial protein in ancient diets. Science 216t1131-1132.

Chisholm BS, Nelson DE, and Schwarcz HP (1983) Ma- rine and terrestrial protein in prehistoric diets on the British Columbia coast. Curr. Anthropol. 24:396-398.

Cohen MN, and Armelagos GJ (eds) (1984) Palaeopa- thology at the origins of agriculture. New York: Aca- demic Press.

Deacon H J (1976) Where Hunters Gathered: A Study of Holocene Stone Age People in the Eastern Cape. Claremont: South African Archaeological Society.

Deacon J (1984) Later Stone Age people and their de- scendants in southern Africa. In RG Klein (ed.): Southern African Prehistory and Palaeoenviron- ments. Rotterdam: A.A. Balkema, pp. 221-328.

DeNiro MJ (1985) Postmortem preservation and alter- ation of in vivo bone collagen isotope ratios in relation to palaeodietary reconstruction. Nature 31 7:806-809.

DeNiro MJ (1987) Stable isotopy and archaeology. Am. Sci. 75; 182-1 91.

Drennan MR (1929) The dentition of a Bushman tribe. Ann. S. Afr. Mus. 24:61-87.

Drennan MR (1938a) Archaeology of the Oakhurst Shel- ter, George. Part 111: The cave-dwellers. Trans. Roy. SOC. S. Afr. 25:259-280.

Drennan MR (1938b) Archaeology of the Oakhurst Shel- ter, George. Part N: The children of the cave-dwellers. Trans. Roy. SOC. S. Afr. 25:281-293.

Elphick R (1985) Khoikhoi and the founding of white South Africa. Johannesburg: Ravan Press.

Goldstein MS (1932) Caries and attrition in the molar teeth of the Eskimo mandible. Am. J . Phys. Anthro- pol. 16r421-430.

Hadjimarkos DM (1964) Fluoride in fish flour-effect on teeth. J. Pediatr. 65:782-784.

Hassan AA, and Hare PE (1976) Amino acid analysis in radiocarbon dating of bone collagen. In GF Carter (ed.): Archaeological Chemistry 11. Advances in Chemistry, Series no. 171. Washington, D.C.: Ameri- can Chemical Society, pp. 109-116.

Hayden B, Chisholm B, and Schwarcz HP (1987) Fish- ing and foraging: Marine resources in the Upper Palaeolithic of France. In 0 Soffer (ed.): The Pleis- tocene Old World: Regional Perspectives. New York: Plenum Press, pp. 279-291.

Hobson KA, and Collier S (1964) Marine and terrestrial protein in Australian aboriginal diets. Curr. Anthro- pol. 25t238-240.

Holloway PJ, Speirs RL, and Slack GL (1965) Fluoride content of extracted teeth from some islanders of Tristan da Cunha. Br. Dent. J. 118t283-285.

Klein RG, and Cruz-Uribe K (1989) Faunal evidence of prehistoric herder-forager activities at Kasteelberg, western Cape Province, South Africa, S. Afr. Ar- chaeol. Bull. 44t82-97.

Meiklejohn C, Schentag C, Venema A, and Key P (1984) Socioeconomic change and patterns of pathology and variation in the Mesolithic and Neolithic of western Europe. In MN Cohen and GJ Armelagos (eds.): Palaeopathology at the Origins of Agriculture. New York: Academic Press, pp. 75-100.

Meiklejohn C, Baldwin JH, and Schentag CT (1988) Caries as a probable dietary marker in the western European Mesolithic. In BV Kennedy and GM Le- Moine (eds. ): Diet and Subsistence: Current Archaeo- logical Perspectives. Proceedings of the 19th Annual Conference of the Archaeological Association of the University of Calgary, Canada, pp. 273-279.

Morris AG (1984) An osteological analysis of the proto- historic populations of the northern Cape and western Orange Free State, South Africa. Unpublished Ph.D. dissertation, University of the Witwatersrand.

Ockerse T (1949) Dental caries: Clinical and experimen- tal investigations. Pretoria: Department of Health.

Parkington J E (1972) Seasonal mobility in the Late Stone Age. Afr. Stud. 31:223-243.

Parkington J E (1976) Follow the San: An analysis of seasonality in the prehistory of the south-western Cape, South Africa. Unpublished Ph.D. dissertation, Cambridge University.

Parkington J E (1986) On “Isotope assessment and seasonal mobility in the south-western Cape of South Africa.” Curr. Anthropol. 27t145-146.

Parkington J E (1987) On “Isotope assessment and seasonal mobility in the south-western Cape of South Africa.” Curr. Anthropol. 28t91-93.

Parkington J E (1991) Approaches to dietary reconstruction in the western Cape. J. Archaeol. Sci. 18:331- 342.

Parkington JE, Yates R, Manhire A, and Halkett D (1986) The social impact of pastoralism in the south- western Cape. J. Anthropol. Archaeol. 5:313-329.

J.C. SEALY ET AL 134

Parkington J , Poggenpoel C, Buchanan B, Robey T, Manhire T, and Sealy J (1988) Holocene coastal settlement patterns in the western Cape. In G Bailey and J Parkington (eds.): The Archaeology of Prehistoric Coastlines. Cambridge: Cambridge University Press,

Patrick MK (1989) An archaeological, anthropological study of the human skeletal remains from the Oak- hurst rockshelter, George, Cape Province, South Af- rica. Unpublished M.A. thesis, Department of Archae- ology, University of Cape Town.

Pedersen PO (1938) Investigations into dental condi- tions of about 3,000 ancient and modern Greenland- ers. Dent. Record 58:191-198.

Powell ML (1985) The analysis of dental wear and caries for dietary reconstruction. In RI Gilbert and J H Mielke (eds.): The Analysis of Prehistoric Diets. Or- lando: Academic Press, pp. 307-338.

Pu MY, and Lilienthal B (1961) Dental caries and mot- tled enamel among Formosan children. Arch. Oral Biol. 5125-136.

Robertshaw PT (1977) Excavations at Paternoster, south-western Cape. S. Afr. Archaeol. Bull. 32:74-76.

Robertshaw PT (1979) Excavations at Duiker Eiland, Vredenburg District, Cape Province. Ann. Cape Prov. Mus. (Human Sciences) 1.1-26.

Schrire C (1980)An enquiry into the evolutionary status and apparent identity of San hunter-gatherers. Hum.

Schwartz J (1946) The teeth of the Masai. J . Dent. Res.

Sealy J (1986) Stable carbon isotopes and prehistoric diets in the south-western Cape Province, South Af- rica. Oxford: British Archaeological Reports Interna- tional Series 293, Cambridge Monographs in African Archaeology 15.

Sealy JC (1989) Reconstruction of Later Stone Age diets in the south-western Cape, South Africa: Evaluation and application of five isotopic and trace element techniques. Unpublished Ph.D. dissertation, Univer- sity of Cape Town.

Sealy JC, and van der Merwe, N J (1985) Isotope assessment of Holocene human diets in the south-western Cape, South Africa. Nature 315:138-140.

Sealy JC, and van der Merwe NJ (1986) Isotope assessment and the seasonal mobility hypothesis in the south-western Cape, South Africa. Curr. Anthropol.

Sealy JC, and van der Merwe N J (1987) Carbon isotopes, Later Stone Age diets and seasonal mobility in the south-western Cape. In J Parkington and M Hall (eds.): Papers in the Prehistory of the Western Cape,

pp. 2241 .

E d . 8:9-32.

25:17-20.

27:135-150.

South Africa. Oxford: British Archaeological Reports International Series 332, pp. 262-268.

Sealy JC, van der Merwe NJ, Lee Thorp JA, and Lan- ham J L (1987) Nitrogen isotopic ecology in southern Africa: Implications for environmental and dietary tracing. Geochim. Cosmochim. Acta 51.2707-2717.

Sealy JC, and van der Merwe NJ (1988) Social, spatial, and chronological patterning in marine food use as determined by 6I3C measurements of Holocene human skeletons from the south-western Cape, South Africa. World Archaeol. 20.87-102.

Smith AB (1986) Competition, conflict, and clientship: Khoi and San relationships in the western Cape. S. Afr. Archaeol. SOC. Goodwin Ser. 5:36-41.

Smith AB (1987) The Economy of Prehistoric Herding a t the Cape. Final report to the Human Sciences Re- search Council of South Africa.

Sognnaes RF (1941) A condition suggestive of threshold dental fluorosis observed in Tristan da Cunha. J. Dent. Res. 20:303-313.

Tauber H (1981) I3C evidence for dietary habits of prehistoric man in Denmark. Nature 292.332-333.

Turner CG (1979) Dental anthropological indications of agriculture among the Jomon people of central Japan. X. Peopling of the Pacific. Am. J. Phys. Anthropol.

van der Merwe NJ (1982) Carbon isotopes, photosynthe- sis, and archaeology. Am. Sci. 70:596-606.

van Reenen JF (1966) Dental features of a low-caries primitive population. J. Dent. Res. 45.703-713.

Vogel J C (1978) Isotopic assessment of the dietary habits of ungulates. S. Afr. J. Sci. 74.298-301.

Vogel JC, Fuls A, and Ellis RP (1978) The geographical distribution of Kranz grasses in South Africa. S. Afr. J. Sci. 74:209-215.

Walker PL (1978) A quantitative analysis of dental attrition rates in the Santa Barbara channel area. Am. J. Phys. Anthropol. 48,101-106.

Walker PL, and Erlandson JM (1986) Dental evidence for prehistoric dietary change on the northern channel islands, California. Amer. Antiq. 51:375-383.

Walker PL, and Hewlett BS (1990) Dental health diet and social status among central African foragers and farmers. Amer. Anthropol. 92.383-398.

Yesner D (1988) Subsistence and diet in north-temperate coastal hunter-gatherers: Evidence from the Moshier Island burial site, south-western Maine. In BV Kennedy and GM LeMoine (eds.): Diet and Subsis- tence: Current Archaeological Perspectives. Proceed- ings of the 19th Annual Conference of the Archaeolog- ical Association of the University of Calgary, Canada,

51.619-636.

pp. 207-226.

diet and dental caries among later stone age inhabitants of the cape province, south africa

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