Fats: The Good, the Bad,
by Thomas Sherman
October 15, 2004
We need fat to absorb vitamins, to
keep our brains sharp, to survive. But not all fats are our
friends. Find out which ones are the heroes and the villains
in your diet.
In a lot of cases health fads don't live up to their
hype. But the case for consuming more good fats-the omega-3
fatty acids found primarily in fish, flax and hemp oils-is
strong and growing stronger. As a nation we eat too little
of these good fats, and our health would improve greatly if
we relied a little less on the bad saturated fat in burgers,
skipped the ugly trans fats in fries and indulged in more
salmon and other seafoods.
Fish and the Heart
Need proof? A wealth of research supports fish oil's
desirable effects, especially on heart health. While many
people believe that heart disease is primarily a problem for
men, women who have passed through menopause are just as
susceptible to heart problems.
" [Our] findings suggest that all women, and most likely
men, would benefit from regular fish intake," says Alice H.
Lichtenstein, DSc, director of the Cardiovascular Nutrition
Laboratory at Tufts University in Boston. "A tuna fish
sandwich counts, as does almost any other type of fish that
is baked, broiled, grilled, or poached." But she points out
that fried fish, which is often cooked in hydrogenated oils,
is not helpful.
In research on more than 200 women, performed at the Jean
Mayer US Department of Agriculture Human Nutrition Research
Center on Aging at Tufts, scientists found that the arterial
blockages among women who dined on fish were less (and
impeded blood flow less) than in women who hardly ever ate
seafood. Fish was especially helpful for women who had
diabetes, a disease that makes you more prone to heart and
circulation problems (American Journal of Clinical Nutrition
These effects are important: Heart disease is the number one
cause of death for women, and older women who suffer from
diabetes are particularly susceptible. The number of people
with diabetes has been increasing of late, mainly due to the
fact that Americans are overweight. Right now about 18
million people have diabetes and another 20 million are
expected to suffer this condition in the next four decades.
" This study shows that following the current guidelines of
eating at least two servings of any type of fish per week
slows down the progression of heart disease in women with
coronary artery disease (CAD), especially those who were
also diabetic," says Dr. Lichtenstein, coauthor of the
study. "We further found that eating one or more servings
per week of fish that is rich in omega-3 fatty acids, such
as tuna or other dark-fleshed fish, is equally effective."
Dangerous disruptions in heartbeat, known as arrhythmias,
may also be affected by fish oil. "[E]xperiments show that
fatty acids from omega-3 fish oils are stored in the cell
membranes of heart cells and can prevent sudden cardiac
death or fatal arrhythmias," notes Alexander Leaf, MD,
medical researcher and professor at Harvard University.
Fat for Your Brain
The right kind of fat is also crucial for the function of
your nerves and brain tissue, which is 60% to 70% fat.
Incorporating omega-3 fatty acids into those cells can help
keep your brain firing on all synapses. It may lower your
risk of Alzheimer's disease, an irreversible form of mental
deterioration that kills 100,000 Americans a year. About a
thousand people a day in the US are found to have
Alzheimer's, and experts believe that over the next 40 years
14 million of us will be doomed to being enveloped by the
mental fog this condition produces.
Research indicates that our brains probably need omega-3
fats for protection against the kind of damage that causes
our mental capacities to slip. Once Alzheimer's starts,
deterioration accelerates because brain cells start losing
In experiments performed at the David Geffen School of
Medicine at UCLA (Neuron 9/2/04), scientists looked at how a
lack of docosahexaenoic acid (DHA, one of the omega-3 fats
found in fish), affected the cellular processes that lead to
Alzheimer's. They found that the part of brain cells that
receive signals from other brain cells, the receptors, are
vulnerable to damage from chemical reactions that take place
inside the cells. However, DHA offers antioxidant protection
against this destruction.
When brain cells were denied DHA, the cells' receptors
suffered extra harm. But when fish oil was present, brain
cells were protected. In addition, animals that received
extra omega-3s were better able to learn and find their way
Greg Cole, PhD, senior researcher on this study and a
professor of neurology at Geffen, says, "We saw that a diet
rich in DHA, or docosahexaenoic acid, dramatically reduces
the impact of the Alzheimer's gene [which made the animals
more susceptible to Alzheimer's]. Consuming more DHA is
something the average person can easily control. Anyone can
buy DHA in its purified form, fish-oil capsules, high-fat
fish or DHA-supplemented eggs." Fishes rich in omega-3s
include salmon, halibut, mackerel, sardines and herring.
Protecting Kids from Asthma
A surprising benefit of omega-3s has been found in pregnant
women and their newborns: Pregnant women with asthma who eat
fish rich in omega-3s during their pregnancy lower their
children's risk of asthma.
Not just any fish will do. The study (American Thoracic
Society International Conference 5/25/04) discovered that
mothers who ate fish sticks during pregnancy doubled the
asthma risk in their kids. " Fish sticks are deep-fried, and
they contain omega-6 fatty acids, which encourage
inflammation of the airways," says study co-author Frank
Gilliland, MD, PhD, professor at the Keck School of Medicine
at the University of Southern California. "Oily fish [like
salmon and trout] contain omega-3 fatty acids, which appear
to be anti-inflammatory, and lead to the reduced potential
for developing asthma and allergies."
The USC investigation showed that when women with asthma ate
oil-bearing fish during pregnancy, the risk of asthma for
their children dropped more than 70%. The more fish that mom
consumed, the less likely her baby was to develop asthma.
Unfortunately, the study did not find the same benefit in
women without asthma.
" A family history of asthma is a very strong risk factor
for a child developing asthma," Dr. Gilliland says. "It
appears that oily fish interacts with the genes involved in
the predisposition to develop asthma, and somehow reduces
Although most of us try to avoid accumulating unsightly fat
around our hips, the right kind of fat plays an integral
part in the functioning of our bodies and may even keep us
alive. Fats don't get much better than that.