What is DHA? The 11 greatest benefits

Veröffentlicht am: November 04, 2024
Irina  Fink
Irina Fink

Naturopath

Considering how important the healthy fatty acid docosahexaenoic acid (DHA) is, it's no wonder that more and more people are taking DHA supplements to boost the health of their nervous system, heart and brain.

Fortunately, food supplements and foods containing docosahexaenoic acid are increasingly available. This is mainly due to the growing number of studies showing the importance of DHA for adults and children. This means that nowadays it is relatively easy to obtain DHA regularly from food. The best food sources of omega-3 fatty acids include wild-caught fish such as salmon, sardines and herring.

If you have ever bought fish oil or algae supplements, you will know that you can choose from a wide range of products. In addition to eating fatty fish, DHA supplements are recommended for most people - whether you're pregnant, giving your child docosahexaenoic acid or an adult wanting to maintain healthy cognitive function as you age. In this article, we look at the benefits of DHA, the best food sources and what type of supplement you should look for.

Contents

What is DHA? 

Docosahexaenoic acid (DHA) is a polyunsaturated omega-3 fatty acid that is found throughout the body and is important for normal brain function, including growth and development of the child's brain. It is one of the major structural fats and accounts for 97 percent of omega-3 fatty acids in the brain and 93 percent of omega-3 fatty acids in the retina. It is also an essential component of the heart.

How exactly does DHA affect our health and what are the benefits of increasing our DHA intake?

11 Benefits of DHA

1. DHA supports the nervous system

Adequate intake of DHA is important for adults when it comes to brain health and function . DHA is also needed for the growth and proper development of the brain in infants and for the maintenance of normal cognitive function into old age. 

We humans primarily cover our DHA requirements through our diet because our body can only produce a limited amount of the fatty acid itself. Our brain actually prefers DHA to other fatty acids, so it absorbs more of it than other fats. It is dependent on a constant supply as it uses DHA quickly and constantly.

Docosahexaenoic acid is the most important structural fatty acid foundin the gray matter of the humanbrain and retina . Granule neurons in the hippocampus (the part of the brain where memory is mainly located) proliferate throughout life. The formation of these new cells in the hippocampus provides an explanation as to why we need DHA to maintain learning and brain function into old age.

2 DHA supports development in the womb and infancy

Why is DHA good for babies? Babies are supplied with DHA in utero and through breast milk. The function and integrity of neurons and neural pathways can be permanently impaired by deficiencies in omega-3 essential fatty acids during development in the womb and in infancy. The level of DHA in the cerebral cortex increases with age, especially the longer a child is breastfed. Studies suggest that a long-term benefit that infants with higher levels of DHA experience is that behavioral functions develop faster. A lack of DHA can lead to learning disorders, as docosahexaenoic acid is involved in cell signaling.  

If a mother is healthy and gets enough docosahexaenoic acid from her diet or by taking appropriate supplements, a breastfed baby should be able to get enough DHA from breast milk. Some infant formulas contain DHA, others do not. You should therefore read the product information carefully if you want to feed your baby with infant formula.

DHA for pregnant women and infants

Over the past 50 years, many formula-fed infants have developed a deficiency in DHA and other omega-3 fatty acids. Some see this as one reason why we have seen an increase in learning disabilities since that time, including ADHD. However, more research is needed to test this hypothesis. However, recent studies have shown that there is a lower level of omega-3 fatty acids in the blood of ADHD patients compared to patients without ADHD. It does indeed appear that omega-3 supplements can help to prevent ADHD.

DHA is not only important for cognitive development in infants, but also plays a role in the optimal development of vision.

3. DHA supports vision and eye health

DHA plays an important role in the development of visual function in infants. Studies of both premature and normal infants indicate that adequate intake of docosahexaenoic acid, either from breast milk or DHA-enriched infant formula, is associated with better visual function and faster visual development. This shows how important docosahexaenoic acid is for the eyes.

The retina contains a high concentration of DHA, which improves visual function, the fluidity of the photoreceptor membranes and the integrity of the retina. Many studies show that DHA protects the retina. Scientists now recommend that older people should increase their DHA intake (from food and/or fish oils) to protect their vision. A poorer ratio between omega-6 and omega-3 is often found in this group of people. 

4 DHA relieves symptoms associated with rheumatoid arthritis

Scientists have found that low DHA levels are associated with the development of rheumatoid arthritis. This is an autoimmune disease that affects the joints and leads to the destruction of bone and cartilage. DHA inhibits inflammation in the body and thus helps to alleviate the damage, swelling and pain in the joints that occur as a result of the disease.

Studies have found that the Japanese population, which consumes a greater amount of DHA-rich foods compared to many other countries, has a lower incidence of rheumatoid arthritis. A controlled case study found that subjects who consumed two or more fish meals per week had a 43 percent lower risk of developing rheumatoid arthritis than those who consumed less than one serving of fish per week.

5 DHA improves memory performance

The results of a study with mice were published in the journal "Applied Physiology, Nutrition, and Metabolism". They show that memory cells in the hippocampus can communicate better with each other and send messages faster when DHA levels in this region of the brain are increased. For this reason, DHA-rich foods are considered food for the brain.

Researchers believe that DHA supplements may facilitate synaptic plasticity (the ability of synapses in the brain to strengthen or weaken over time, affecting learning and memory performance). This could explain why a DHA-rich diet boosts memory performance. When a healthy diet is supplemented with DHA supplements or fish consumption is increased, additional stores of the omega-3 fatty acid are created in the brain. These stores can contribute to changes in cognitive function as a result of falling DHA levels in old age.

6 DHA reduces the risk of heart disease

Docosahexaenoic acid has been associated with a reduced risk of cardiovascular disease. DHA has anti-inflammatory properties. A higher intake can reduce blood triglyceride levels, the risk of clotting, blood pressure and cholesterol levels. 

Fish oil containing DHA has been shown to help lower blood triglyceride levels, reduce the incidence of thrombosis and prevent cardiac arrhythmias. DHA may also protect against endothelial dysfunction, which is a catalyst for cardiovascular disease. The American Heart Association recommends consuming fish, especially fatty fish, at least twice a week to support overall heart health.

7 DHA soothes acne

According to the American Academy of Dermatology, acne is considered the most common skin condition in the United States, affecting more than 50 million Americans each year. Acne breakouts can be painful and uncomfortable. They can also be difficult to control. DHA supplements and foods can help.

Surprisingly, acne rarely occurs in countries where people consume more omega-3 fatty acids in relation to omega-6 fatty acids. In a case study conducted in Korea, people with acne ate more fast food and less fish oil than the control group. In Italy, scientists found that eating fish can protect against moderate to severe acne.

8. dHA has an anti-cancer effect

Docosahexaenoic acid, alone or in combination with chemotherapy, can have an anti-cancer effect by causing apoptosis (cell death) in human cancer cells. A study from Italy concluded that taking two grams of fish oil per day for the first nine weeks of chemotherapy led to a delay in tumor progression in colorectal cancer patients. Further research is needed to determine the anti-cancer effect of DHA in more detail. However, the results so far are very promising.

9 DHA relieves asthma symptoms

Asthma is a chronic lung disease characterized by inflammation, hypersensitivity of the airways and blockages . Allergic asthma is triggered by allergens such as dust or pollen. Non-allergic asthma can be caused by exercise or occupational factors. Some studies have found that children who eat fresh oily fish more than once a week have a lower risk of developing asthma.

A study observed 4,162 American children over a period of 20 years. The scientists documented the intake of omega-3 fatty acids and the children who developed asthma over time. The results showed that children with the highest intake of omega-3 fatty acids were 54 percent less susceptible to asthma. The scientists also observed that DHA is the most important omega-3 fatty acid in the fight against asthma. Docosahexaenoic acid is known to regulate inflammatory processes and reduce the level of inflammation. It is therefore not surprising that a higher intake of DHA has the potential to prevent inflammation of the airways and reduce the risk of asthma.

10 DHA strengthens the immune system

In a study published in the Journal of Leukocyte Biology, researchers observed that omega-3 fatty acids can boost B cells (a type of white blood cell) and possibly increase intestinal immunity. Prior to this study, fish oil was thought to have a different effect on the immune system. This study calls into question the assumption that fish oil only has an immunosuppressive effect, according to the authors.

They conducted their study on mice, half of which received a DHA-rich fish oil supplement for five weeks. As a result, the mice in the treatment group showed increased antibody production and cell activation.

DHA also has protective effects against many chronic diseases associated with immune dysfunction and inflammation, including

  • High blood pressure
  • Arthritis
  • Atherosclerosis
  • Depression
  • Diabetes mellitus
  • Myocardial infarction
  • Thrombosis
  • some types of cancer

11 DHA has a supportive effect in the treatment of depression

DHA may help to reduce the development of mood-related problems, including depression. In some studies, scientists have been able to establish a link between depression and a low intake of essential omega-3 fatty acids.

In one study, the test subjects, all of whom suffered from depression, were instructed to increase their fish consumption over a period of five years. The results showed that aggressive behavior patterns and depression occurred less frequently. In societies where more fish is consumed in general, depression typically occurs less frequently. Overall, the correlation between the incidence of major depression and fish consumption in different countries suggests that people tend to suffer less from depression when they consume more fish.

Which foods contain DHA?

Which foods contain particularly high levels of DHA? Docosahexaenoic acid is mainly found in fatty cold-water fish, including sardines, salmon, mackerel, tuna, shellfish and herring. DHA is also found in breast milk and is available in smaller amounts in meat and eggs.

DHA in food

These are the best sources of DHA: 

  • Salmon
  • Atlantic herring
  • Coalfish
  • various trout species
  • Sardines
  • Pacific rock oyster
  • Mackerel
  • Sea bass
  • Tuna
  • Oysters
  • Shrimps
  • Scallops
  • Cod
  • Egg yolk
  • Minced beef

Women who are pregnant or planning a pregnancy should not consume high amounts of albacore tuna, shark, tilefish, swordfish or king mackerel due to high levels of mercury. It is recommended that pregnant women consume no more than 170g per week of these fish and instead switch to salmon and sardines to meet their omega-3 requirements.

Shellfish also provide a good portion of DHA. However, they are also often contaminated and should therefore rarely be included in the diet. They also often trigger allergic reactions. It is therefore better to opt for the healthier option and cover your DHA requirements with wild-caught fish. Another safe option is to take standardized food supplements, which are guaranteed to be free from harmful substances or contamination.

DHA preparations and their dosage

DHA supplements are available in various forms, for example as fish oil, krill oil, cod oil and as vegetarian products with algae oil.

  • Fish oil capsules contain both docosahexaenoic acid and eicosapentaenoic acid (EPA). When choosing a fish oil supplement, you should first look at the amount of omega-3 acids it contains per portion. The most important factor here is the proportion of EPA and DHA. The higher the proportion, the better the supplement can work. In general, high-quality supplements contain a higher concentration than others.
  • Algae contain docosahexaenoic acid, but no EPA. Algae supplements are a good alternative for vegans and vegetarians with a DHA deficiency if they do not want to take fish oil. 

How much omega-3 do you need per day?

The recommended intake of omega-3 fatty acids (DHA and EPA combined) can be achieved through dietary supplements and/or increased consumption of oily fish. If you regularly eat oily fish several times a week, your need for omega-3 supplements will be reduced or even eliminated. The "Dietary Guidelines for Americans" states: "For the general population, it is recommended to consume about 8 ounces [about 240 g] of fish and seafood per week. This corresponds to an average intake of 250 mg EPA and DHA per day." Pregnant or breastfeeding women should consume at least 240 to 340 g of various seafood and fish per week, mainly varieties with a low mercury content (e.g. salmon or sardines).

With regard to supplements, the daily dose depends on your age and current state of health:

  • combination preparation (DHA and EPA) is recommended for healthy adults at a dosage of 250 mg/day. The maximum dose that still provides health benefits is approximately 500 mg. DHA supplements are generally considered safe. However, you should not take more than 2 g (2000 mg) per day. There are no other health benefits from such a high dose.
  • To prevent cardiovascular disease300 to 600 mg of DHA and EPA per day are recommended.
  • Pregnant and breastfeeding women are recommended to take between 300 and 900 mg of DHA and EPA (combined). Some prenatal vitamin supplements contain DHA/EPA, but by no means all of them. During pregnancy, women need about 200 mg of docosahexaenoic acid daily for healthy fetal growth.
  • Children up to the age of 24 months require 10 to 12 mg DHA per kg body weight. The daily requirement for older children is up to 250 mg.
  • People suffering from memory loss, trauma or other cognitive impairments were given between 900 and 1700 mg docosahexaenoic acid in studies to boost cognitive function.

Why you should use a high-quality fish oil supplement

  • High-quality fish oil supplements contain omega 3 in the form of triglycerides. This is the form with the highest bioavailability and therefore the most valuable for the body.
  • Fish often has a high heavy metal load, but also fish oil preparations of lower quality. These may be contaminated with PCBs, heavy metals, dioxins and furans. To be sure that the product has not been contaminated by toxins, you should read the label carefully and check the purity information.
  • Only high-quality fish oil supplements keep well: if the composition is not right, mistakes have been made in the manufacturing process or the products have not been stored properly (i.e. exposed to extreme temperatures and humidity), fish oil supplements of lower quality tend to become rancid and oxidize.

High-quality fish oil with DHA

DHA and EPA fish oil

There are two main types of polyunsaturated fatty acids: omega-3 and omega-6. 

Although there are various omega-3 fatty acids, scientific research focuses on three:

  • Alpha-linolenic acid (ALA)
  • Eicosapentaenoic acid (EPA)
  • Docosahexaenoic acid (DHA)

ALA is the type of omega-3 found in flaxseed and walnuts. However, the acid cannot be easily converted into DHA by the body. It therefore has less positive effects on human health.

More important, however, are the fatty acids contained in omega 3: EPA and DHA. EPA is a long-chain n-3 fatty acid and is found together with DHA in oily fish. Most fish oil capsules contain both DHA and EPA. 

Supplements containing EPA are not recommended for infants or young children. There is a risk that the balance between DHA and EPA is disturbed during early development.

The use of DHA

Docosahexaenoic acid is needed in the body for many processes. Among other things, it improves the ability to learn, inhibits inflammation and protects the heart. A lack of DHA, on the other hand, leads to learning difficulties and a decline in cognitive abilities in old age and increases the risk of developing Alzheimer's disease.

Research suggests that an adequate intake of DHA protects infants, children and adults from many ailments and diseases. Sufficient intake reduces the risk of certain health problems.

Complaints and diseases:

  • Heart disease - DHA can reduce the risk of the number one cause of death in industrialized countries: cardiovascular disease
  • Tiredness
  • Poor memory
  • Poor immune defense
  • Eczema, dry skin
  • Hair loss
  • Poor blood circulation
  • Depression and behavioral problems
  • Fertility problems (man and woman)
  • In children, the following conditions are associated with a lack of DHA: ADHD, mood-related problems such as depression, fetal alcohol syndrome, phenylketonuria, cystic fibrosis and aggressive behavioral problems or other behavioral problems 

DHA in infant formula

In the past, DHA was not usually included in infant formula. Now, almost all brands sold in the US are fortified with docosahexaenoic acid and arachidonic acid (ARA). This is good news considering that these fatty acids are an important part of a baby's diet. 

What is ARA and what is it used for? ARA is a long-chain polyunsaturated fatty acid that is normally obtained from foods such as fish (or fish oils), algae and mushrooms, eggs and human breast milk. Like DHA, ARA is needed in the brain and eyes of infants and supports healthy development.

Why does infant formula contain DHA? Docosahexaenoic acid contained in infant formula is said to support cognitive development, protect against learning disabilities and support visual development and healthy immune function. Breast milk naturally contains the fatty acids DHA and ARA. The addition of these fatty acids to infant milk is intended to help the infant's development. Studies in the past have produced mixed results when it comes to the benefits of infant formula enriched with docosahexaenoic acid. Many studies have confirmed the many benefits, but not all.

Docosahexaenoic acid is also contained in some supplements/vitamin supplements for children. 

DHA in prenatal vitamins

Do you need prenatal vitamins that contain DHA? If your vitamin supplement does not contain DHA/ EPA, you should take additional fish oil to meet your needs. Look for a quality product that contains at least 200 mg of DHA. Some manufacturers offer products that are specially tailored to the needs of pregnant women. These usually contain 300 to 400 mg DHA/ EPA as a combination. You can easily cover your requirements with such a preparation.

Supplying the body with DHA - DHA-rich recipes

Consuming DHA and EPA directly from food and/or through supplements is considered "the only practical way to increase the levels of these fatty acids in the body."

The best way to cover your DHA requirement is with oily fish and seafood. The latter contain particularly high levels of EPA and DHA, but are less contaminated with mercury. This also applies to salmon, anchovies, herring, albacore, sardines, Pacific oysters, trout and mackerel from the Atlantic and Pacific.

Many fish that contain a lot of docosahexaenoic acid are only slightly contaminated with mercury. However, this is by no means the case for all varieties. The FDA and other organizations repeatedly emphasize that the benefits of eating fish containing DHA outweigh the risks due to mercury contamination. Although eating DHA-containing fish will cause you to also ingest mercury, the recommendation is that healthy people (without known mercury toxicity) should eat several servings of fish per week. The World Health Organization recommends one to two portions of fish per week. One portion should provide between 200 and 500 mg of DHA and EPA.

Certain nuts and seeds (such as flaxseed and walnuts) also provide some omega-3 fatty acids, but mainly the shorter chain n-3 fatty acid called ALA, which the human body is not very good at converting into docosahexaenoic acid. ALA can be converted to EPA and then to DHA, but the conversion capacity (which mainly takes place in the liver) is very limited. Fish contain long-chain n-3 fatty acids (also known as omega-3 fatty acids), which do not require the same conversion as short-chain omega-3 fatty acids.

Some research suggests that consuming 150 to 300 mg of ALA per day generally has a positive effect on health. Note that ALA is also found in vegetable oils such as linseed, soybean and rapeseed oils. However, these oils are refined in the manufacturing process and are therefore not recommended.

Precautions and side effects

Fish oil capsules containing docosahexaenoic acid can cause side effects such as diarrhea, stomach upset, belching, unpleasant taste, bad breath, heartburn, nausea, gastrointestinal discomfort, headaches and foul-smelling sweat.

Fish oil supplements can also increase the risk of excessive bleeding and lower blood pressure. When taking omega-3 containing supplements, including fish oil, interactions with other medications may occur.

Concluding remarks

  • What is DHA and what is it needed for? Docosahexaenoic acid is an omega-3 polyunsaturated fatty acid that is important for optimal brain health and function at any age. The many positive effects of DHA include a healthy nervous system, healthy hair and skin, a reduced risk of cardiovascular disease and cancer, and a stronger immune system.
  • Symptoms of docosahexaenoic acid deficiency can include fatigue, dry skin, poor memory, poor circulation, hair loss, heart problems, learning disabilities, mood-related problems and behavioral problems.
  • The best way to increase your DHA intake is to eat fatty cold-water fish every week and take high-quality supplements (fish oil or algae).
  • The best food sources of docosahexaenoic acid include sardines, salmon, mackerel, tuna, trout, redfish and herring. Adults should eat 240 g of oily fish per week to get enough docosahexaenoic acid (240 to 360 g for pregnant and breastfeeding women).
  • If you opt for an omega-3 supplement with DHA and EPA, take a daily dose that together provides around 250-500 mg DHA/EPA.

 


 

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