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There's more good news about nuts.
Eating a small portion of nuts several times a week
actually benefit to one's health.
Due to their high fat content, nuts traditionally have
been viewed as an indulgent food. They're commonly used
in confections, ice cream snacks and baked goods, but
also have found place in entrees, salads and side dishes.
With more research coming out supporting nut health
benefits, formulators may consider using them in functional
foods.
Studies support the idea that nuts should become a
regular part of a healthy diet. They offer protein,
fiber, vitamin E, folate, and many vitamins and minerals.
They also derive a high percentage of their calories
from fat, but it is polyunsaturated and monounsaturated
fat.
The International Tree Nut Council sponsored a recent
conference called "Making the Claim for Nuts"
at the Georgetown University Center for Food and Nutrition
Policy. Summaries of some of the presentations highlight
the latest research on nut nutrition.
Cardiovascular Health
Both epidemiological and clinical studies indicate that
eating nuts benefit cardiovascular health. Gary Fraser,
professor of epidemiology, Lorma Linda University, has
conducted several detailed studies of more than 34,000
Seventh Day Adventists living in California. The results
of a six-year study showed that people who ate five
or more servings of nuts per week experienced 50% fewer
heart attacks than non-nut eaters did. Subjects consumed
the nuts of their choice, which included tree nuts or
peanuts. Thirty percent reported eating peanuts. Twelve-year
findings with this population yielded similar results.
Dr. Joan Sabate, M.D., Ph.D., professor of nutrition
and chairman, Dept. of Nutrition, School of Public Health,
Loma Linda University, found that people who ate moderate
amounts of walnuts had lower blood cholesterol levels.
In his first clinical study, he randomly placed 18 healthy
young men on two mixed natural diets. The diets were
identical, except that in one, 20% of the calories from
fat were derived from walnuts. Those on the walnut diet
had reductions of 12.4% in total cholesterol, 16.3%
in low density lipoprotein (LDL) cholesterol and 4.9%
in high density lipoprotein (HDD cholesterol. They also
exhibited a lowering in the ratio of LDL to HDL.
In another of Sabate's studies, 49 men and women with
a mean age of 56 years who had polygenic hypercholesterolemia
participated in a randomized, crossover feeding trial.
The control diet was a Mediterranean diet. The experimental
diet was similar in energy and fat content, but walnuts
replaced approximately 35% of the energy from fat. The
walnut diet produced mean reductions of 4.1% in total
cholesterol level, 5.9% in LDL cholesterol and 6.2%
in lipoprotein (a).
"We served the whole nut because we were interested
in the effect of whole foods served as commonly consumed,"
explains Sabate. "The main reason for the cholesterol
reduction was the nature of the fat. Walnuts are high
in polyunsaturated fat that contains alpha linolenic
acid, which is a precursor of the omega 3 fatty acids
found in fish oil. The decrease in cholesterol was even
greater than predicted because of other components that
may contribute, like fiber and protein."
In a study involving peanuts and peanut products Penny
Kris-Etherton, professor of nutrition, Pennsylvania
State University, showed that eating a diet that includes
polyunsaturated and monounsaturated fat can be heart
-healthy. Her group performed a randomized double-blind
crossover study to look at the cardiovascular disease
risk of five different diets. These included the Average
American Diet, the American Heart Association Step II
low fat diet and 'three diets high in monounsaturated
fatty acids (MUFA) The high MUFA diets contained 34-36%
fat and relied on olive oil, peanut oil or peanuts and
peanut butter.
Results showed that the three high MUFA diets lowered
total cholesterol 10% and LDL cholesterol 14% without
lowering HDL cholesterol. The Step II low fat diet lowered
total cholesterol and LDL cholesterol by comparable
amounts, but it also reduced HDL cholesterol. The Step
II diet raised triacylglycerol concentrations-a risk
factor for cardiovascular disease-while the high MUFA
diet lowered it.
Wanda Morgan, Ph.D., associate professor of human nutrition
and food science at New Mexico State University, asked
test subjects on self-selected diets to supplement their
diets with 68g of pecans every day. The control group
refrained from eating nuts. The pecan eaters lowered
their LDL cholesterol by 6% at the end of eight weeks.
This was in spite of the fact that the pecan eaters
ate more fat each day that the control subjects.
Cancer Prevention
Almonds showed promise in preventing colon cancer in
a study conducted by Paul Davis, associate research
nutritionist, Department of Nutrition, College of Agriculture
and Environmental Science, University of Califomia-Davis.
He fed high-fat diets to rats that were primed to develop
colon cancer. One of the diets contained 20 almonds
and the other cellulose as a control. The rats developed
Aberrant Crypt Foci, (ACFs), which are early markers
for colon tumor development. The animals fed almonds
had far fewer ACFs than did those fed the control diet.
"Almonds appear to inhibit the formation of ACFs,
precancerous lesions, which are red flags for colon
cancer," reports Davis. "The study was done
to question the assumption that people should avoid
nuts. Nuts, in fact, contain a variety of potentially
healthy components such as monounsaturated and polyunsaturated
fats, minerals and proteins that are especially high
in arginine, an amino acid that the immune system uses
as a messenger. We don't know which compound, or more
likely, combination of compounds, in the whole nut is
causing the reduced colon cancer risk we saw, but the
results certainly suggest that nuts may have a role
in cancer prevention."
Weight Control
Snacking on nuts does not lead to weight gain. In fact,
it may help people stick to their weight loss programs
for a longer time, according to a study conducted at
Brigham and Women's Hospital in Boston under the direction
of Kathy McManus, director of nutrition. She placed
subjects in a weight loss program on two plans, one
a low fat diet and the other a moderate fat diet In
the moderate fat diet, the subjects could snack on the
nuts of their choice. The subjects on both plans lost
about 10 pounds. However, those on the low fat diet
began to gain a small amount of weight back after one
year. In contrast, the group on the moderate fat diet
did not gain back any weight. More subjects on the moderate
fat diet remained with the program for the full 18 months.
* Fran Labell, Senior Editor Prepared Foods, March 2001 |
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