• Cholesterol levels:It can increase levels of “good” HDL cholesterol. However, it does not appear to reduce levels of “bad” LDL cholesterol
• Triglycerides:It can lower triglycerides by about 15–30%
• Blood pressure:Even in small doses, it helps reduce blood pressure in people with elevated levels
• Plaque:It may prevent the plaques that cause your arteries to harden, as well as make arterial plaques more stable and safer in those who already have them
• Fatal arrhythmias:In people who are at risk, it may reduce fatal arrhythmia events. Arrhythmias are abnormal heart rhythms that can cause heart attacks in certain cases

Your brain is made up of nearly 60% fat, and much of this fat is omega-3 fatty acids. Therefore, omega-3s are essential for normal brain function. In fact, some studies suggest that people with certain mental disorders have lower omega-3 blood levels.

Obesity is defined as having a body mass index (BMI) greater than 30. Globally, about 39% of adults are overweight, while 13% are obese. The numbers are even higher in high-income countries like the US. Obesity can significantly increase your risk of other diseases, including heart disease, type 2 diabetes, and cancer. Fish oil supplements may improve body composition and risk factors for heart disease in obese people. Fish oil supplements may help reduce waist circumference, as well as aid weight loss when combined with diet or exercise.

Like your brain, your eyes rely on omega-3 fats. Evidence shows that people who don’t get enough omega-3s have a greater risk of eye diseases. Furthermore, eye health begins to decline in old age, which can lead to age-related macular degeneration (AMD). Eating fish is linked to a reduced risk of AMD, but the results on fish oil supplements are less convincing.

Inflammation is your immune system’s way of fighting infection and treating injuries. However, chronic inflammation is associated with serious illnesses, such as obesity, diabetes, depression, and heart disease. Reducing inflammation can help treat symptoms of these diseases. Because fish oil has anti-inflammatory properties, it may help treat conditions involving chronic inflammation. Moreover, fish oil supplements can significantly reduce joint pain, stiffness, and medication needs in people with rheumatoid arthritis, which causes painful joints.

Your skin is the largest organ in your body, and it contains a lot of omega-3 fatty acids. Skin health can decline throughout your life, especially during old age or after too much sun exposure. That said, there are a number of skin disorders that may benefit from fish oil supplements, including psoriasis and dermatitis.

Omega-3s are essential for early growth and development. Fish oil supplements in pregnant and breastfeeding mothers may improve hand-eye coordination in infants. Taking fish oil supplements during pregnancy and breastfeeding may also improve infant visual development and help reduce the risk of allergies.

Your liver processes most of the fat in your body and can play a role in weight gain. Liver disease is increasingly common — particularly non-alcoholic fatty liver disease (NAFLD), in which fat accumulates in your liver. Fish oil supplements can improve liver function and inflammation, which may help reduce symptoms of NAFLD and the amount of fat in your liver.

People with major depression appear to have lower blood levels of omega-3s. Studies show that fish oil and omega-3 supplements may improve symptoms of depression. Moreover, some studies have shown that oils rich in EPA help reduce depressive symptoms more than DHA.

A number of behavioral disorders in children, such as attention deficit hyperactivity disorder(ADHD), involve hyperactivity and inattention. Given that omega-3s make up a significant proportion of the brain, getting enough of them may be important for preventing behavioral disorders in early life. Fish oil supplements may improve perceived hyperactivity, inattention, impulsiveness, and aggression in children. This may benefit early life learning.

 As you age, your brain function slows down, and your risk of Alzheimer’s disease increases. People who eat more fish tend to experience a slower decline in brain function in old age. However, studies on fish oil supplements in older adults haven’t provided clear evidence that they can slow the decline of brain function. Nevertheless, some very small studies have shown that fish oil may improve memory in healthy, older adults.

Asthma, which can cause swelling in the lungs and shortness of breath, is becoming much more common in infants. In one review in nearly 100,000 people, a mother’s fish or omega-3 intake was found to reduce the risk of asthma in children by 24–29%. Furthermore, fish oil supplements in pregnant mothers may reduce the risk of allergies in infants.

During old age, bones can begin to lose their essential minerals, making them more likely to break. This can lead to conditions like osteoporosis and osteoarthritis. Calcium and vitamin D are very important for bone health, but some studies suggest that omega-3 fatty acids can also be beneficial. People with higher omega-3 intakes and blood levels may have better bone mineral density (BMD).