Can fish oils and omega-3 oils benefit our health?
Fish oils come from fatty
or oily fish, such as trout, mackerel, tuna, herring, sardines, and salmon.
They contain omega-3 fatty acids, and many contain vitamins A and D.
Many people use fish oil
and omega-3 supplements because they believe that they have health benefits.
Guidelines from the
American College of Cardiology and American Heart Association (ACC/AHA)
recommend eating fish as part of a heart-healthy diet. Indeed, having a diet
rich in omega
3 fatty acids may help prevent heart disease, protect brain and eye
health, and contribute to fetal development.
However, studies into
supplement use have produced mixed results, and it is unclear whether or not
supplements are helpful.
In this article, learn
more about fish oils and omega
3, including some potential health benefits and some good food sources.
What are omega 3 fatty acids?
Omega 3 fatty acids are
fats commonly present in plants and marine life.
Two types are plentiful in
oily fish: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Alpha-linoleic acid (ALA), meanwhile, mainly occurs in plant-based foods, such
as flaxseed.
Omega-3 is present
throughout the body, especially in the brain, retina, and sperm cells. The body
cannot produce omega-3 on its own, however, so people need to obtain it from
dietary sources.
Potential health benefits
Scientists have linked
omega-3 to a number of health conditions. However, it is not always clear
whether or not taking additional omega-3 can offer benefits.
The following sections
outline some of these conditions and some other health benefits that omega-3
may provide.
COVID-19
In 2020, survey data
suggested that females who take probiotics,
vitamin D, fish oil supplements, or a combination of these may have a slightly
lower risk of developing COVID-19.
However, this
investigation has not yet undergone peer review, and the findings are far from
conclusive.
In fact, experts have
warned against using supplements in an attempt to prevent infection with the
virus.
Multiple sclerosis
Some people with multiple
sclerosis (MS) take omega-3 because it may have protective effects on the brain
and the nervous system.
However, at least one
study has concluded that omega-3 supplements do not reduce disease activity
with MS.
Prostate cancer
Some research has
suggested that eating a diet rich in omega-3 may help prevent prostate cancer.
However, a 2013 study suggested that a high fish oil intake may actually
increase the risk of high grade prostate cancer.
The precise link between
omega-3 and different types of cancer remains unclear, but a number of studies
have found no evidence to suggest that omega-3 either increases or reduces the
risk of various types of cancer.
Postpartum depression
People with low levels of
omega-3 during pregnancy and while breastfeeding may be more susceptible to
postpartum depression.
The authors of a 2018
review concluded that taking fish oil supplements around this time may help
reduce the risk of depression.
However, people should
avoid eating fish that may be high in mercury, such as shark and king mackerel,
during pregnancy. Some good alternative choices include canned light tuna,
salmon, pollock, and catfish.
Memory and other mental health benefits
In addition to postpartum
depression, some studies suggest that EPA and DHA could help treat various
neuropsychiatric conditions. These include:
· attention deficit hyperactivity disorder
· post-traumatic stress disorder
· Parkinson’s disease
· depression
· dementia
· schizophrenia
· cognitive decline, including memory loss
Some studies have
suggested that omega
3 fish oil supplementation may help prevent cognitive decline,
especially in older adults. However, their results are not conclusive,
according to one 2019 review.
More investigations are
necessary to confirm these benefits.
Heart and cardiovascular benefits
Omega 3 fatty acids in fish
oils may help prevent heart disease and stroke, according to the AHA.
Specifically, omega-3 may
help manage:
· triglyceride levels
· cholesterol
· high blood pressure
A 2013 study found that
people who took fish oil supplements for longer than 1 month had better
cardiovascular function during mentally stressful tests.
In 2012, researchers noted
that fish oil, due to its anti-inflammatory properties, appeared to help
stabilize atherosclerotic lesions.
The AHA recommends eating
fish, and especially oily fish, at least twice per week. They say that this may
reduce the risk of cardiovascular disease.
However, in 2012, a review
of 20 studies involving almost 70,000 people found “no compelling evidence”
linking fish oil supplements to a lower risk of heart attack, stroke, or early
death.
Vision loss and eye health
Some evidence suggests
that getting an adequate intake of omega 3 may help protect eye health.
In a 2012 study, mice that
received omega
3 supplements for 6 months appeared to have better retinal function and
a lower risk of age-related vision loss than mice that did not receive the
supplements.
Optometrists often
recommend taking omega-3 supplements to support eye health, even though
scientific evidence does not always support their use for this purpose. In some
cases, eating a healthful diet may be more beneficial than taking supplements,
according to some experts.
In 2019, for example,
scientists who looked at the data of 4,202 people in Holland found that those
who consumed fresh fruits and vegetables and 2 weekly servings of fish were
less likely to develop age-related macular degeneration compared with those who
did not.
Some people use omega-3 supplements for dry eyes. In 2018, however, a year-long study involving 349 people with moderate-to-severe dry eyes found no evidence to suggest that taking supplements was more helpful than taking a placebo for this purpose.
