Influence balance1’
of dietary
fiber
on trace
2
Harold H. Sandstead,3 M.D., Juan M. Muhoz,4 Leslie M. Klevay,4 M.D., D.Sc., Sally J. Reck,6 Frederick R. Dintzis,8 Ph.D., George E. Inglett,8
Five
ABSTRACT protein,
40%
Twenty-six effects
fat,
and
grams on zinc,
period.
The
addition requirement Nutr.
and
white
so. Iron of
adult 44%
male white
wheat
bran was
31: 5180-5184,
prepared
from
high
American
bran
assessed
were
during
to decrease
the
added
to the
last
12 days
retention degree calculated
of zinc Copper
by
ofcalories)
by many daily
bread,
of each
in four balance
corn bran. by regression
16%
American
males. and
30-day
subjects was
but
improved
An apparent analysis.
the study not by
copper Am. J.
1978.
extraction
Journal
or corn
(as percent
consumed
bran and to a lesser for the volunteers was
wheat
and methods
The
containing
to that
treatments.
Five male volunteers who gave informed consent were housed in a controlled metabolic ward environment for 4 to 8 months. They were normal by clinical, nutritional, and psychological evaluations. Study periods were 28 to 30 days. After an initial 16- to 18-day equilibration,
Si 80
a diet
in all three
flour (1, 2). Because the cited studies tested people fed a Middle Eastern diet, the results may have limited application to Americans. On the other hand, low dietary intakes of zinc (3), copper (4), and iron (5) have been reported in some Americans, with and without associated clinical evidence of deficiency. For these reasons, and because it has been suggested that increased intakes of dietary fiber might have beneficial effects on the incidence of diverticulosis (6) and might also have a preventive effect on coronary vascular disease (7) and colon cancer (8), we have studied the effects of increased dietary fiber on balances of zinc, copper, and iron. Materials
fed
similar
were
appeared similar
The influence of dietary fiber on the availability of zinc, copper, and iron for intestinal absorption by humans is incompletely defined. Based on limited observations, it appears that people fed diets rich in vegetables and cereals but containing less than 30 g of animal protein per day may have impaired absorption of minerals when their intakes of dietary fiber are increased by consuming bread
bran
balance
retention
soft white wheat of 1.28 mg/day
were a diet
wheat
copper
M.D., Robert A. Jacob,5 Ph.D., M.A., George M. Logan, Jr.,7 M.A., Ph.D., and William C. Shuey,9 Ph.D.
volunteers
carbohydrate,
of soft
iron,
soft
significantly
Clin.
element
of Clinical
Nutrition
Downloaded from https://academic.oup.com/ajcn/article-abstract/31/10/S180/4656090 by guest on 15 March 2018
and duplicate diets were collected for 12 days for chemical assessment of the balance. Throughout the studies, caloric intake, energy expenditure and, hence, body weight were maintained as uniformly as possible. As an index of body composition, triceps, biceps, and subscapular and supraihiac skinfolds and upper arm circumference were measured weekly for estimation of fatness and muscle mass. The psychological status of the volunteers was assessed periodically, and a psychologist met with the volunteers both in a group and individually, as needed. At the end of each study period, the nutritional and clinical status of the volunteers was reassessed. The reliability of the fmdings was improved by replication of the studies in some individuals. The basal diet (Table 1) was prepared from conventional foods to satisfy the nutrient needs of the volunteers. The protein, fat, carbohydrate, and cholesterol contents of the basal diet were similar to the levels in diets of many middle-class American men. Fiber intake was increased by adding about 26 g of American Assoexcreta
of Agriculture Human Nutrition Laboratory (HNL), Grand Forks, North Dakota; Northern Regional Research Center (NRRC), Peona, Illinois; and Spring and Durum Wheat Quality 1
From
(USDA),
the
United
Agricultural
States
Department
Research
Service
(ARS):
(SDWQ),
Fargo, North Dakota. Address reprint requests to: Dr. Harold H. Sandstead, U.S. Department of Agriculture, Agricultural Research Service, Human Nutrition Laboratory, Grand Forks, North Dakota 58201. 3 Director, USDA, ARS, HNL. Medical Research Officer, USDA, ARS, HNL. 5Research Chemist, 2
USDA,
ARS,
ARS, HNL. kota School
OCTOBER
6Research
Biostatistian, of Medicine.
ARS, NRRC. SDWQ. 31:
HNL.
9Research
1978,
pp.
8
University Research
Chemist,
S180-Sl84.
Dietician,
USDA,
of North DaChemist, USDA,
USDA,
Printed
ARS,
in U.S.A.
FIBER ciation wheat
of Cereal Chemists bran or dry milled
Menus lignin
were contents
TABLE
1 characteristics
ON
INFLUENCE
(AACC) corn bran
standard to the
TRACE
soft white daily bread.
repeated of the
in 6-day cycles. Cellulose and bran (Table 2, dry weight basis) were determined by the Holst modification of the Van Soest acid detergent method (9). Starch content of the bran was estimated by taking a portion of 18- to 30-mesh sample, grinding it to pass a 16-mesh screen, and then incubating the material with amyloglucosidase (10). Starch was estimated by measuring glucose generated by the action of the enzyme by a glucostat procedure (1 1). Protein was measured by amino acid analysis of a separate portion of fmely ground bran (12). Phytic acid, as ferric phytate, was extracted and precipitated by the procedure of Wheeler and Ferrel (13). Phytate phosphorus was measured by wet ashing ferric phytate precipitate with concentrated nitric acid and determining phosphorus by a colonmetric method in which phosphomolybdic acid was reduced to a blue complex (14) and by gravimetric determination as ammonium phosphomolybdate (15). The particle size distribution of the bran was controlled by passage through a no. 18 mesh and collection on a no. 30 mesh U.S.A. Standard Sieve (1.00 and 0.59 mm openings, respectively). Excreta, diets, and blood were collected, using precautions to avoid trace mineral contamination. Six-day composites of diets and feces were prepared by homogenization in a 1 gallon stainless steel blender. Aliquots of
Constant, 6 day Conventional foodsa Rotating 6 day menus Low fiber (3.0 g/d crude fiber) Protein, 70% animal Fat, linoleate/saturated fat = 0.31 Total carbohydrate Sucrose Cholesterol a Eggs, margarine, potatoes,
16% of energy 40% of energy 44% of energy 9% of energy 750 mg/day bread, butter, peaches,
sucrose, white flour, noodles, tomatoes, round steak, chicken, rice, orange juice, grape juice, cherries, pineapplc, cheese, tea, coffee, powdered milk, bouillon, paprika, salt, pepper, jelly, pears, grapefruit juice.
affected
composition
of fiber
of
13
ported mixed mg
AACC bran
Corn
bran
Hemicellulose
32.0
70.0
Cellulose Lignin Ash Phytate phosphorus Starch Protein Oil Total fiber
9.1 3.0 5.7 0.5 31.0 15.0 4.0 44. 1
22.0 0.1 0.6
a
See References
dietary
intake.
a negative mg/day.
negative hospital of zinc
The
balance
of dietary
fiber
on trace
2
Harold H. Sandstead,3 M.D., Juan M. Muhoz,4 Leslie M. Klevay,4 M.D., D.Sc., Sally J. Reck,6 Frederick R. Dintzis,8 Ph.D., George E. Inglett,8
Five
ABSTRACT protein,
40%
Twenty-six effects
fat,
and
grams on zinc,
period.
The
addition requirement Nutr.
and
white
so. Iron of
adult 44%
male white
wheat
bran was
31: 5180-5184,
prepared
from
high
American
bran
assessed
were
during
to decrease
the
added
to the
last
12 days
retention degree calculated
of zinc Copper
by
ofcalories)
by many daily
bread,
of each
in four balance
corn bran. by regression
16%
American
males. and
30-day
subjects was
but
improved
An apparent analysis.
the study not by
copper Am. J.
1978.
extraction
Journal
or corn
(as percent
consumed
bran and to a lesser for the volunteers was
wheat
and methods
The
containing
to that
treatments.
Five male volunteers who gave informed consent were housed in a controlled metabolic ward environment for 4 to 8 months. They were normal by clinical, nutritional, and psychological evaluations. Study periods were 28 to 30 days. After an initial 16- to 18-day equilibration,
Si 80
a diet
in all three
flour (1, 2). Because the cited studies tested people fed a Middle Eastern diet, the results may have limited application to Americans. On the other hand, low dietary intakes of zinc (3), copper (4), and iron (5) have been reported in some Americans, with and without associated clinical evidence of deficiency. For these reasons, and because it has been suggested that increased intakes of dietary fiber might have beneficial effects on the incidence of diverticulosis (6) and might also have a preventive effect on coronary vascular disease (7) and colon cancer (8), we have studied the effects of increased dietary fiber on balances of zinc, copper, and iron. Materials
fed
similar
were
appeared similar
The influence of dietary fiber on the availability of zinc, copper, and iron for intestinal absorption by humans is incompletely defined. Based on limited observations, it appears that people fed diets rich in vegetables and cereals but containing less than 30 g of animal protein per day may have impaired absorption of minerals when their intakes of dietary fiber are increased by consuming bread
bran
balance
retention
soft white wheat of 1.28 mg/day
were a diet
wheat
copper
M.D., Robert A. Jacob,5 Ph.D., M.A., George M. Logan, Jr.,7 M.A., Ph.D., and William C. Shuey,9 Ph.D.
volunteers
carbohydrate,
of soft
iron,
soft
significantly
Clin.
element
of Clinical
Nutrition
Downloaded from https://academic.oup.com/ajcn/article-abstract/31/10/S180/4656090 by guest on 15 March 2018
and duplicate diets were collected for 12 days for chemical assessment of the balance. Throughout the studies, caloric intake, energy expenditure and, hence, body weight were maintained as uniformly as possible. As an index of body composition, triceps, biceps, and subscapular and supraihiac skinfolds and upper arm circumference were measured weekly for estimation of fatness and muscle mass. The psychological status of the volunteers was assessed periodically, and a psychologist met with the volunteers both in a group and individually, as needed. At the end of each study period, the nutritional and clinical status of the volunteers was reassessed. The reliability of the fmdings was improved by replication of the studies in some individuals. The basal diet (Table 1) was prepared from conventional foods to satisfy the nutrient needs of the volunteers. The protein, fat, carbohydrate, and cholesterol contents of the basal diet were similar to the levels in diets of many middle-class American men. Fiber intake was increased by adding about 26 g of American Assoexcreta
of Agriculture Human Nutrition Laboratory (HNL), Grand Forks, North Dakota; Northern Regional Research Center (NRRC), Peona, Illinois; and Spring and Durum Wheat Quality 1
From
(USDA),
the
United
Agricultural
States
Department
Research
Service
(ARS):
(SDWQ),
Fargo, North Dakota. Address reprint requests to: Dr. Harold H. Sandstead, U.S. Department of Agriculture, Agricultural Research Service, Human Nutrition Laboratory, Grand Forks, North Dakota 58201. 3 Director, USDA, ARS, HNL. Medical Research Officer, USDA, ARS, HNL. 5Research Chemist, 2
USDA,
ARS,
ARS, HNL. kota School
OCTOBER
6Research
Biostatistian, of Medicine.
ARS, NRRC. SDWQ. 31:
HNL.
9Research
1978,
pp.
8
University Research
Chemist,
S180-Sl84.
Dietician,
USDA,
of North DaChemist, USDA,
USDA,
Printed
ARS,
in U.S.A.
FIBER ciation wheat
of Cereal Chemists bran or dry milled
Menus lignin
were contents
TABLE
1 characteristics
ON
INFLUENCE
(AACC) corn bran
standard to the
TRACE
soft white daily bread.
repeated of the
in 6-day cycles. Cellulose and bran (Table 2, dry weight basis) were determined by the Holst modification of the Van Soest acid detergent method (9). Starch content of the bran was estimated by taking a portion of 18- to 30-mesh sample, grinding it to pass a 16-mesh screen, and then incubating the material with amyloglucosidase (10). Starch was estimated by measuring glucose generated by the action of the enzyme by a glucostat procedure (1 1). Protein was measured by amino acid analysis of a separate portion of fmely ground bran (12). Phytic acid, as ferric phytate, was extracted and precipitated by the procedure of Wheeler and Ferrel (13). Phytate phosphorus was measured by wet ashing ferric phytate precipitate with concentrated nitric acid and determining phosphorus by a colonmetric method in which phosphomolybdic acid was reduced to a blue complex (14) and by gravimetric determination as ammonium phosphomolybdate (15). The particle size distribution of the bran was controlled by passage through a no. 18 mesh and collection on a no. 30 mesh U.S.A. Standard Sieve (1.00 and 0.59 mm openings, respectively). Excreta, diets, and blood were collected, using precautions to avoid trace mineral contamination. Six-day composites of diets and feces were prepared by homogenization in a 1 gallon stainless steel blender. Aliquots of
Constant, 6 day Conventional foodsa Rotating 6 day menus Low fiber (3.0 g/d crude fiber) Protein, 70% animal Fat, linoleate/saturated fat = 0.31 Total carbohydrate Sucrose Cholesterol a Eggs, margarine, potatoes,
16% of energy 40% of energy 44% of energy 9% of energy 750 mg/day bread, butter, peaches,
sucrose, white flour, noodles, tomatoes, round steak, chicken, rice, orange juice, grape juice, cherries, pineapplc, cheese, tea, coffee, powdered milk, bouillon, paprika, salt, pepper, jelly, pears, grapefruit juice.
affected
composition
of fiber
of
13
ported mixed mg
AACC bran
Corn
bran
Hemicellulose
32.0
70.0
Cellulose Lignin Ash Phytate phosphorus Starch Protein Oil Total fiber
9.1 3.0 5.7 0.5 31.0 15.0 4.0 44. 1
22.0 0.1 0.6
a
See References
dietary
intake.
a negative mg/day.
negative hospital of zinc
The
balance
