Plant-Based DHA Vs. Fish Oil: Which Is Better?

DHA stands for docosahexaenoic acid, a long-chain omega-3 polyunsaturated fatty acid that can be found in the human brain, retina, and skin. The body can make DHA in very small amounts, so it’s important to include sources of DHA in the diet. DHA is abundant in fish, shellfish, some algae, and genetically engineered plants.

Although there is no set recommendation for the amount of DHA you need each day, The Global Organization for EPA and DHA Omega-3s (GOED) suggests consuming 500 milligrams of DHA on a daily basis. 

Plant-Based DHA vs. Fish Oil

Fish oil comes from the fat of fish tissues, and it’s generally extracted from fatty fish, like herring, tuna, anchovies, or mackerel. Occasionally, it’s derived from the liver of a fish, like in the case of cod liver oil.  According to the National Institutes of Health, about 19 million Americans take some form of fish oil supplement.

Fish oil usually contains the two types of omega-3s found in fish, DHA and EPA (Eicosapentaenoic acid). The National Institute of Health states that most fish oil supplements contain 180 mg EPA and 120 mg DHA, but these numbers can vary.

Vegan and vegetarian DHA supplements are made from algae and usually provide around 100–300 mg DHA. In addition, algal oil supplements are typically more expensive than fish oil. 

Benefits of DHA

There are very few studies on the benefits of plant-based DHA, but the scientific literature on fish oil is abundant. A review of the research found that ingestion of micro-algae oil led to significant increases in blood levels of DHA.

Therefore, it can be assumed that the benefits associated with fish oil may also apply to plant-based DHA. Those strengths are numerous, including:

May Fight Inflammation

Omega-3s are rich in antioxidants, which may help fight inflammation. Chronic inflammation is prevalent in many serious diseases, leading to extensive research on the role of omega-3s in reducing inflammation. Animal and human studies show the correlation between DHA and anti-inflammatory effects.

May Contribute to a Healthy Heart

A review of the literature shows a correlation between increased consumption of omega-3s from fish or fish oil supplements and a decreased rate of death by cardiac events. The American Heart Association recommends eating fish at least twice a week for a healthy heart.

In addition, “there is strong evidence supporting omega-3s’ ability to lower triglycerides and increase HDL (the “good” cholesterol),” says Colleen Wysocki Woods, MS, RDN & Owner of ZEST Nutrition.

May Prevent Cancer

Due to their anti-inflammatory properties, omega-3s are being studied for their potential cancer prevention abilities.

Research suggests that omega-3 supplementation might reduce instances of non-melanoma skin cancer. A randomized controlled trial in participants with breast cancer found that taking fish oil supplements had anti-inflammatory properties that may prove beneficial for the immune system.

 May Relieve Arthritis 

“For those suffering from rheumatoid arthritis, there is some evidence that fish oil may help relieve the pain, stiffness, and tenderness in the joints,” says Woods. In a randomized controlled trial with 60 people with rheumatoid arthritis, researchers found significant improvement in several arthritis markers after three months of omega-3 supplementation.

The patients experienced an improvement in joint stiffness, pain severity, swollen joints, and physical function. “Omega-3s have anti-inflammatory properties, which may explain why inflammation-induced pain tends to subside when fish oil is consumed,” adds Woods.

May Contribute to a Healthy Pregnancy

“There is continuing research looking at the effects of fish oil supplements on prenatal health for developing fetuses,” says Woods. “Taking omega-3 supplements such as fish oil with DHA decreases the risk of pre-term birth by 11% and the risk of low birth weight by 10%, according to a systematic review," she adds. DHA may also help with infant brain development and vision.

Potential Concerns

According to Woods, there is some evidence of fish oil being detrimental to certain health conditions. “For instance, a recent analysis suggested that for those with elevated triglycerides, fish oil may actually increase their risk of atrial fibrillation, or AFib,” she says. It’s important to consult with a physician before taking any supplements.

Plant-based DHA can also be costly. “It may be more cost-effective to eat fish two to three times a week or take a single fish oil supplement than to purchase algal oil,” adds Woods.  

A Word From Verywell 

“Oily fish two to three times a week is the best choice [for DHA], filling in the non-fish days with a fish oil supplement if your physician approves it,” says Woods. “If you’re a strict vegan and don’t want to include fish in your diet, try agal oil,” she suggests.

If you’re confused about which fish oil to choose or have any hesitation in adding it to your diet, consult with a healthcare provider.