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JAMES HEBERT, ScD
Hebert
JR, Gupta PC, Bhonsle RB, Mehta H, Zheng W, Sanderson M,
Teas J. Dietary exposures and oral precancerous lesions in
Srikakulam District, Andhra Pradesh, India. Public Health
Nutr. 2002 Apr;5(2):303-12.
OBJECTIVE: To test the effect of dietary nutrients on oral
precancerous lesions in a reverse-smoking (i.e. smoking with
the glowing end inside the mouth) population in South India.
DESIGN: Case-control. Cases with precancerous lesions were
matched to an equal number of lesion-free controls matched
on age (+/- 5 years), sex and village. All subjects used
tobacco in some form. Dietary data were obtained using an
interviewer-administered food-frequency questionnaire,
designed for use in this population. All interviews were
conducted blinded to the disease status of the subject. Data
were analysed using logistic regression. SETTING: Nineteen
rural villages in Srikakulam District, Andhra Pradesh.
SUBJECTS: From a survey of 6007 tobacco users, 485 (79%
women) were found to have precancerous, mostly palatal,
lesions (cases), and 487 lesion-free subjects were selected
as controls. RESULTS: All eligible subjects consented to
participate and nearly all (> 99%) had complete data for
analyses. Reverse smoking was the most common form of
tobacco use among cases (81.9%) and controls (73.5%), and
reverse smokers were 5.19 times more likely than chewers to
have these lesions (95% confidence interval = 1.35, 19.9).
After controlling for relevant covariates, including the
type of tobacco use, protective linear effects were observed
for zinc (70% reduction across the interquartile range, P <
0.002), calcium (34% reduction, P < 0.002), fibre (30%
reduction, P < 0.009), riboflavin (22% reduction, P < 0.03)
and iron (17% reduction, P < 0.05). CONCLUSIONS: Several
dietary nutrients appear to protect against oral
precancerous lesions that are strongly associated with
reverse smoking. The results of this study indicate scope
for targeting dietary factors in preventing oral cancer,
which should be coupled with aggressive anti-tobacco use
efforts.
Saxe GA, Hebert JR, Carmody JF, Kabat-Zinn J, Rosenzweig
PH, Jarzobski D, Reed GW, Blute RD. Can diet in conjunction
with stress reduction affect the rate of increase in
prostate specific antigen after biochemical recurrence of
prostate cancer? J Urol. 2001 Dec;166(6):2202-7.
PURPOSE: Epidemiological and laboratory evidence indicates
that a Western diet is associated with an increased
incidence of prostate cancer. Specific components of the
diet, such as high saturated fat, low fiber and high meat
content, may have greatest clinical significance in the
later stages of tumor promotion and progression. However,
departure from the conventional diet is difficult to
initiate and maintain. Therefore, we combined the well-known
Mindfulness-Based Stress Reduction (MBSR) program with a low
saturated fat, high-fiber, plant-based diet to determine the
effect on the rate of change in prostate specific antigen (PSA)
in patients with biochemical recurrence after prostatectomy.
MATERIALS AND METHODS: We enrolled 10 men and their partners
in a 4-month group-based diet and MBSR intervention. A
pre-study post-study design in which each subject served as
his own control was used to compare the rate of increase in
and doubling time of PSA before and after intervention.
RESULTS: The rate of PSA increase decreased in 8 of 10 men,
while 3 had a decrease in absolute PSA. Results of the
signed rank test indicated a significant decrease in the
rate of increase in the intervention period (p = 0.01).
Estimated median doubling time increased from 6.5 months
(95% confidence interval 3.7 to 10.1) before to 17.7 months
(95% confidence interval 7.8 to infinity) after the
intervention. CONCLUSIONS: Our small study provides evidence
that a plant-based diet delivered in the context of MBSR
decreases the rate of PSA increase and may slow the rate of
tumor progression in cases of biochemically recurrent
prostate cancer. Larger-scale randomized studies are
warranted to explore further the preventive and therapeutic
potential of diet and lifestyle modification in men with
prostate cancer.
Hebert JR, Peterson KE, Hurley TG, Stoddard AM, Cohen N,
Field AE, Sorensen G. The effect of social desirability
trait on self-reported dietary measures among multi-ethnic
female health center employees. Ann Epidemiol. 2001
Aug;11(6):417-27.
PURPOSE: To evaluate the effect of social desirability
trait, the tendency to respond in a manner consistent with
societal expectations, on self-reported fruit, vegetable,
and macronutrient intake. METHODS: A 61-item food frequency
questionnaire (FFQ), 7-item fruit and vegetable screener,
and a single question on combined fruit and vegetable intake
were completed by 132 female employees at five health
centers in eastern Massachusetts. Intake of fruit and
vegetables derived from all three methods and macronutrients
from the FFQ were fit as dependent variables in multiple
linear regression models (overall and by race/ethnicity and
education); independent variables included 3-day mean
intakes derived from 24-hour recalls (24HR) and score on the
33-point Marlowe-Crowne Social Desirability scale (the
regression coefficient for which reflects its effect on
estimates of dietary intake based on the comparison method
relative to 24HR). RESULTS: Results are based on the 93
women with complete data and FFQ-derived caloric intake
between 450 and 4500 kcal/day. In women with college
education, FFQ-derived estimates of total caloric were
associated with under-reporting by social desirability trait
(e.g., the regression coefficient for total caloric intake
was -23.6 kcal/day/point in that group versus 36.1
kcal/day/point in women with education less than college)
(difference = 59.7 kcal/day/point, 95% confidence interval
(CI) = 13.2, 106.2). Except for the single question on which
women with college education tended to under-report
(difference =.103 servings/day/point, 95% CI = 0.003,
0.203), there was no association of social desirability
trait with self-reported fruit and vegetable intake.
CONCLUSIONS: The effect of social desirability trait on FFQ
reports of macronutrient intake appeared to differ by
education, but not by ethnicity or race. The results of this
study may have important implications for epidemiologic
studies of diet and health in women.
Matthews CE, Freedson PS, Hebert JR, Stanek EJ 3rd,
Merriam PA, Rosal MC, Ebbeling CB, Ockene IS. Seasonal
variation in household, occupational, and leisure time
physical activity: longitudinal analyses from the seasonal
variation of blood cholesterol study. Am J Epidemiol. 2001
Jan 15;153(2):172-83.
The authors examined seasonal variation in physical activity
in longitudinal analyses of 580 healthy adults from
Worcester, Massachusetts (the Seasonal Variation of Blood
Cholesterol Study, 1994-1998). Three 24-hour physical
activity recalls administered five times during 12 months of
follow-up were used to estimate household, occupational,
leisure time, and total physical activity levels in
metabolic equivalent (MET)-hours/day. Trigonometric models
were used to estimate the peak-to-trough amplitude and phase
of the peaks in activity during the year. Total activity
increased by 1.4 MET-hours/day (121 kcal/day) in men and 1.0
MET-hours/day (70 kcal/day) in women during the summer in
comparison with winter. Moderate intensity nonoccupational
activity increased by 2.0-2.4 MET-hours/day in the summer.
During the summer, objectively measured mean physical
activity increased by 51 minutes/day (95% confidence
interval: 20, 82) in men and by 16 minutes/day (95%
confidence interval: -12, 45) in women. The authors observed
complex patterns of seasonal change that varied in amplitude
and phase by type and intensity of activity and by subject
characteristics (i.e., age, obesity, and exercise). These
findings have important implications for clinical research
studies examining the health effects of physical activity
and for health promotion efforts designed to increase
population levels of physical activity.
Fowke JH, Longcope C, Hebert JR. Brassica vegetable
consumption shifts estrogen metabolism in healthy
postmenopausal women. Cancer Epidemiol Biomarkers Prev. 2000
Aug;9(8):773-9.
Previous studies suggest that the estrogen metabolite
16alpha-hydroxyestrone acts as a breast tumor promoter. The
alternative product of estrogen metabolism,
2-hydroxyestrone, does not exhibit estrogenic properties in
breast tissue, and lower values of the ratio
2-hydroxyestrone:16alpha-hydroxyestrone (2:16) in urine may
be an endocrine biomarker for greater breast cancer risk.
Vegetables of the Brassica genus, such as broccoli, contain
a phytochemical, which may shift estrogen metabolism and
increase the 2:16 ratio. Adding 500 g/day of broccoli to a
standard diet shifts 2:16 values upward in humans; however,
it is unknown as to whether healthy women are able to
consume a sufficient quantity of Brassica to affect breast
cancer risk through this mechanism. In this study, 34
healthy postmenopausal women participated in an intensive
intervention designed to facilitate the addition of Brassica
to the daily diet. The diet was measured by repeated 24-h
recall, and estrogen metabolites were measured by enzyme
immunoassay in 24-h urine samples. In a crude analysis,
there was a nonsignificant increase in the urinary 2:16
ratio associated with greater Brassica consumption. With
adjustment for other dietary parameters, Brassica vegetable
consumption was associated with a statistically significant
increase in 2:16 values, such that for each 10-g/day
increase in Brassica consumption, there was an increase in
the 2:16 ratio of 0.08 (95% confidence interval, 0.02-0.15).
To the extent that the 2:16 ratio, as measured in urine, is
associated with breast cancer risk, future research should
consider Brassica vegetable consumption as a potentially
effective and acceptable dietary strategy to prevent breast
cancer.
Hebert JR, Gupta PC, Mehta H, Ebbeling CB, Bhonsle RR,
Varghese F. Sources of variability in dietary intake in two
distinct regions of rural India: implications for nutrition
study design and interpretation. Eur J Clin Nutr. 2000
Jun;54(6):479-86.
OBJECTIVE: Limited inter-person variability in nutrient
intake hampers epidemiologic studies of diet-disease
relationships. Despite conjecture about non-traditional
study bases providing large inter-person differences,
virtually nothing is known about variations in nutrient
intake outside of Europe and North America. The current
study was conducted in India to determine sources of
variability in the intakes of nutrients thought to be of
public health importance. DESIGN: Adult subjects in Gujarat
(North India; n=60) and in Kerala (South India, n=60) were
administered 24 h diet recall interviews six and eight
times, respectively, over a 1 y period. To assess subject
(inter-person) and residual (intra-person) contributions to
variance, regression models were fit to the data. From this,
the variance ratio (VR, total within or intra-person: total
between or inter-person) was computed. SETTING: Rural
communities in North and South India. RESULTS: In both
regions, inter-person variability was larger than that
observed in the West. This was most pronounced in Gujarat,
for which the VR was <1.0 for seven of the 12
energy-adjusted nutrient intakes in both men and women. In
analyses of the combined data, region accounted for >20% of
variance for fat, iron, copper, zinc, beta-carotene and
riboflavin in both men and women. With the region term
removed from this model, virtually all of the variability
ascribed to region contributed to inter-person variability.
CONCLUSIONS: The relatively large inter-person variability
observed here could contribute to improved 'resolution' of
diet-outcome relationships in epidemiologic studies. While
this applies to data from each region, it was especially
evident in analyses of the combined data.
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