Depression is one of the most common mental disorders in the world.

Symptoms include sadness, lethargy and a general loss of interest in life (1, 2).

Anxiety, also a common disorder, is characterized by constant worry and nervousness.

Interestingly, studies indicate that people who consume omega-3s regularly are less likely to be depressed.

What’s more, when people with depression or anxiety start taking omega-3 supplements, their symptoms improve.

There are three types of omega-3 fatty acids: ALA, EPA and DHA. Of the three, EPA appears to be the best at fighting depression.

One study even found EPA as effective against depression as a common antidepressant drug.

DHA, a type of omega-3, is a major structural component of the retina of your eye.

When you don’t get enough DHA, vision problems may arise.

Interestingly, getting enough omega-3 is linked to a reduced risk of macular degeneration, one of the world’s leading causes of permanent eye damage and blindness.

3. Omega-3s Can Promote Brain Health During Pregnancy and Early Life

Omega-3s are crucial for brain growth and development in infants.

DHA accounts for 40% of the polyunsaturated fatty acids in your brain and 60% in the retina of your eye.

Therefore, it’s no surprise that infants fed a DHA-fortified formula have better eyesight than infants fed a formula without it.

Getting enough omega-3s during pregnancy is associated with numerous benefits for your child, including:

• Higher intelligence
• Better communication and social skills
• Fewer behavioral problems
• Decreased risk of developmental delay
• Decreased risk of ADHD, autism and cerebral palsy

Heart attacks and strokes are the world’s leading causes of death.

Decades ago, researchers observed that fish-eating communities had very low rates of these diseases. This was later linked to omega-3 consumption.

Since then, omega-3 fatty acids have been tied to numerous benefits for heart health .

These benefits address:

• Triglycerides:
  Omega-3s can cause a major reduction in triglycerides, usually in the range of 15–30%
• Blood pressure:
  Omega-3s can reduce blood pressure levels in people with high blood pressure.
• “Good” HDL cholesterol:
  Omega-3s can raise “good” HDL cholesterol levels.
• Blood clots: Omega-3s can keep blood
  platelets from clumping together. This helps prevent the formation of harmful
  blood clots
• Plaque: By keeping your arteries
  smooth and free from damage, omega-3s help prevent the plaque that can restrict
  and harden your arteries
• Inflammation:
  Omega-3s reduce the production of some substances released during your body’s
  inflammatory response

For some people, omega-3s can also lower “bad” LDL cholesterol. However, evidence is mixed — some studies find increases in LDL.

Despite these beneficial effects on heart disease risk factors, there is no convincing evidence that omega-3 supplements can prevent heart attacks or strokes. Many studies find no benefit.

Attention deficit hyperactivity disorder (ADHD) is a behavioral disorder characterized by inattention, hyperactivity and impulsivity.

Several studies note that children with ADHD have lower blood levels of omega-3 fatty acids than their healthy peers.

What’s more, numerous studies observe that omega-3 supplements can reduce the symptoms of ADHD.

Omega-3s help improve in attention and task completion. They also decrease hyperactivity, impulsiveness, restlessness and aggression.

Recently, researchers observed that fish oil supplements were one of the most promising treatments for ADHD

Metabolic syndrome is a collection of conditions.

It includes central obesity — also known as belly fat — as well as high blood pressure, insulin resistance, high triglycerides and low “good” HDL cholesterol levels.

It is a major public health concern because it increases your risk of many other illnesses, including heart disease and diabetes.

Omega-3 fatty acids can improve insulin resistance, inflammation and heart disease risk factors in people with metabolic syndrome.

Inflammation is a natural response to infections and damage in your body. Therefore, it is vital for your health.

However, inflammation sometimes persists for a long time, even without an infection or injury. This is called chronic — or long-term — inflammation.

Long-term inflammation can contribute to almost every chronic Western illness, including heart disease and cancer.

Notably, omega-3 fatty acids can reduce the production of molecules and substances linked to inflammation, such as inflammatory eicosanoids and cytokines.

Studies have consistently observed a connection between higher omega-3 intake and reduced inflammation.

In autoimmune diseases, your immune system mistakes healthy cells for foreign cells and starts attacking them.

Type 1 diabetes is one prime example, in which your immune system attacks the insulin-producing cells in your pancreas.

Omega-3s can combat some of these diseases and may be especially important during early life.

Studies show that getting enough omega-3s during your first year of life is linked to a reduced risk of many autoimmune diseases, including type 1 diabetes, autoimmune diabetes and multiple sclerosis.

Omega-3s also help treat lupus, rheumatoid arthritis, ulcerative colitis, Crohn’s disease and psoriasis.

Low omega-3 levels have been reported in people with psychiatric disorders.

Studies suggest that omega-3 supplements can reduce the frequency of mood swings and relapses in people with both schizophrenia and bipolar disorder.

Supplementing with omega-3 fatty acids may also decrease violent behavior.

A decline in brain function is one of the unavoidable consequences of aging.

Several studies link higher omega-3 intake to decreased age-related mental decline and a reduced risk of Alzheimer’s disease.

One review of controlled studies suggests that omega-3 supplements may be beneficial at disease onset, when the symptoms of AD are very mild.

Keep in mind that more research is needed on omega-3s and brain health.

Cancer is one of the leading causes of death in the Western world, and omega-3 fatty acids have long been claimed to reduce the risk of certain cancers.

Interestingly, studies show that people who consume the most omega-3s have up to a 55% lower risk of colon cancer.

Additionally, omega-3 consumption is linked to a reduced risk of prostate cancer in men and breast cancer in women. However, not all studies give the same results.

Asthma is a chronic lung disease with symptoms like coughing, shortness of breath and wheezing.

Severe asthma attacks can be very dangerous. They are caused by inflammation and swelling in the airways of your lungs.

What’s more, asthma rates in the UK have been rising over the past few decades.

Several studies associate omega-3 consumption with a lower risk of asthma in children and young adults.

Non-alcoholic fatty liver disease (NAFLD) is more common than you think.

It has increased with the obesity epidemic to become the most common cause of chronic liver disease in the Western world.

However, supplementing with omega-3 fatty acids effectively reduces liver fat and inflammation in people with NAFLD.

Osteoporosis and arthritis are two common disorders that affect your skeletal system.

Studies indicate that omega-3s can improve bone strength by boosting the amount of calcium in your bones, which should lead to a reduced risk of osteoporosis.

Omega-3s may also treat arthritis. Patients taking omega-3 supplements have reported reduced joint pain and increased grip strength.

Menstrual pain occurs in your lower abdomen and pelvis and often radiates to your lower back and thighs.

It can significantly affect your quality of life.

However, studies repeatedly prove that women who consume the most omega-3s have milder menstrual pain.

One study even determined that an omega-3 supplement was more effective than ibuprofen in treating severe pain during menstruation (93Trusted Source).

Good sleep is one of the foundations of optimal health.

Studies tie sleep deprivation to many diseases, including obesity, diabetes and depression.

Low levels of omega-3 fatty acids are associated with sleep problems in children and obstructive sleep apnea in adults.

Low levels of DHA are also linked to lower levels of the hormone melatonin, which helps you fall asleep.

Studies in both children and adults reveal that supplementing with omega-3 increases the length and quality of sleep.

DHA is a structural component of your skin. It is responsible for the health of cell membranes, which make up a large part of your skin.

A healthy cell membrane results in soft, moist, supple and wrinkle-free skin.

EPA also benefits your skin in several ways, including:

• Managing oil production
  and hydration of your skin.
• Preventing
  hyperkeratinization of hair follicles, which appears as the little red bumps
  often seen on upper arms.
• Reducing premature aging
  of your skin.
• Reducing the risk of
  acne.

Omega-3s can also protect your skin from sun damage. EPA helps block the release of substances that eat away at the collagen in your skin after sun exposure.

Omega-3 fatty acids are vital for optimal health.

Getting them from whole foods — such as fatty fish two times per week — is the best way to ensure robust omega-3 intake.

However, if you don’t eat a lot of fatty fish, then you may want to consider taking an omega-3 supplement. For people deficient in omega-3, this is a cheap and highly effective way to improve health.