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Omega-3 on a plant based diet: what the doctors say
Omega-3 on a plant based diet: what McDougall, Esselstyn, Barnard, Rogers and other doctors say about flax, fish oil and DHA, with sources.
Updated . For education only, not medical advice.
Our view
Omega-3 fats start in plants, not in fish: algae and greens make them, and fish only carry what they ate up the food chain123. The parent omega-3, alpha linolenic acid or ALA, sits in many plant foods, with flax, chia and walnuts the richest45.
This is a debated topic, and we give the most weight to two low-fat voices, Peter Rogers and Jeff Nelson, along with John McDougall, who all say a whole food plant diet needs no omega-3 pill678. Rogers takes no omega-3 at all and treats the pills as a bad idea, partly because the long chain fats in them go rancid so easily69. Nelson reached the same verdict on DHA in 2019 and held it in 2026, calling the dementia warnings aimed at vegans fear marketing on thin evidence710.
The trial record supports their caution: McDougall cited a review of 48 randomized trials that found no clear effect on deaths, heart events or cancer, Rogers pointed to further reviews with the same result, and even Dean Ornish, who takes a plankton supplement, conceded in 2019 that recent trials had weakened the case for it111213. Keeping total fat low also helps the body make its own long chain omega-3 from ALA, a point Nelson, Jeff Novick and T. Colin Campbell each make in their own way141516.
Where they agree
Nearly all of them reject fish as the answer: McDougall calls the need to eat fish a myth, Esselstyn’s FAQ says fish oil is not essential, and Barnard says algae capsules give the same EPA and DHA as fish oil without the fish17182. By 2022 even Ornish said his program’s omega-3 can come from algae rather than fish19.
They also agree on where plant omega-3 is found: Esselstyn names leafy greens and ground flaxseed, Barnard adds chia, and Rip Esselstyn’s beginners’ guide lists flax, chia and walnuts32021. Goldhamer’s center allows a small daily serving of nuts or seeds partly for their omega-322.
Most of them draw the line at oils pressed from these foods: Esselstyn’s FAQ rules out flaxseed oil, Rip Esselstyn calls flax and walnut oil as calorie dense as any other oil, and McDougall says such oil works more like a medicine than a food232425. Novick, Nelson and Campbell agree that a low-fat diet with few omega-6 oils is what lets the body use plant omega-3 well151426.
Where they differ
The doctors split on pills, on how much seed to add, on blood tests, on fish for people who still eat it and on omega-6 fats, and a few views changed over the years8272819.
Pills or no pills
McDougall said in 2024 that people should not take omega-3 supplements, since a whole plant, starch-based diet cannot leave them short8. Rogers and Nelson take the same line, and Campbell said in 2021 that he does not recommend single nutrient pills of any kind6729. Others keep a door open: Goldhamer keeps algae DHA for people who test low and cannot eat nuts, seeds or avocado, and Barnard says some people test first and add vegan EPA and DHA only when their level is low2730. Novick wrote in 2009 that he had nothing against algae DHA but saw no proven need for it31. Ornish is the one who takes it daily, 3 grams from plankton by his 2019 account13.
How much seed
Esselstyn’s FAQ considers a daily one or two tablespoons of ground flax or chia sufficient, Novick’s optional extra was one tablespoon of flax, ground fresh, or a half ounce of walnuts, and Nelson offered a tablespoon of flax for anyone worried183233. At Goldhamer’s center the daily allowance of nuts or seeds is about an ounce22. McDougall is warier: in 2023 he described flax, chia and hemp seeds as roughly 80% fat and said grinding them makes weight gain more likely25. Rogers said in 2024 that ordinary plant foods already give plenty of both kinds of essential fat, leaving no need for rich, fatty sources34.
Testing
Barnard mentions an omega-3 blood test as a way to decide on a supplement30. Goldhamer said in 2026 that what counts as a normal level is disputed and that his center changes the diet first35. Nelson advised against the test altogether in 20197.
Fish and fish oil
Walter Willett told a 2020 panel that most people do well to have fish weekly or twice weekly, since without it their omega-3 intake may run below ideal28. Ornish named fish oil in 2019 as the choice for people who are not vegan, and in an earlier column recommended a fish oil brand while stating he had no financial tie to it1336. The others see harm: Esselstyn’s FAQ warns of bleeding and reports no benefit for heart patients, Rogers says fish oil raises LDL cholesterol, and Barnard notes a link with higher prostate cancer risk in men183730.
Omega-6 fats
In 2017 Campbell called omega-6 pro-inflammatory and said vegan diets heavy in added oil carry far too much of it, while at 10 to 15% fat from whole foods the ratio stops mattering2616. Novick listed omega-6 oils such as corn and safflower among the things that block the body’s conversion of ALA15. Willett disagrees, calling the idea that omega-6 is inflammatory a myth and linking polyunsaturated fats with lower mortality in his cohorts38.
Changed and commercial views
Ornish’s position moved: around 2015 he was naming a fish oil brand, in 2019 he still offered fish oil to non-vegans, and by 2022 he described his program as more vegan, with algae in place of fish361319. Nelson’s view has not moved between his 2019 video and a 2026 VegSource video710. A 2025 PLANTSTRONG supplement episode featured the head of Complement, whose algae omega-3 capsules contain oil, and the post carried a discount code for them3940.
What each expert says
JMJohn McDougall
McDougall ranks the belief that people need fish for omega-3 as a myth, after the protein and calcium myths17. He classes concentrated omega-3 as medicine rather than food, since it slows clotting and dampens the immune system, with gains against clots and arthritis but costs in bleeding, infection and cancer41. In 2024 he told people not to take these supplements8.
In 2012 Esselstyn said omega-3 shortage is not a real problem and named greens and flaxseed meal as his patients’ sources3. His 2014 heart study paper told patients to add flaxseed meal for both omega-3 and omega-642. His FAQ, read in 2026, calls fish oil unnecessary and rules out flaxseed oil1823.
Campbell looks at total fat and the omega-6 to omega-3 balance rather than at omega-3 alone, and says the balance stops mattering on a whole food diet of 10 to 15% fat16. Asked in 2021 about algae pills, he answered that he advises no pills of a single nutrient29. In 2025 he added that he was not keen of omega-3 taken by itself as a pill43.
Barnard calls ALA the parent omega-3 and points to chia, flax and leafy greens, whose small fat content is largely omega-3420. He accepts vegan EPA and DHA from algae for people who test low, and notes the link between fish oil and prostate cancer230. His group’s page draws on the EPIC study, where vegan women showed higher blood levels of long chain omega-3 than women who ate fish44.
In 2019 Ornish said omega-3 now looked less useful than once believed but still helps keep the heart rhythm steady, and said his own daily intake is 3 grams from plankton13. An older column of his recommended plankton capsules with DHA and EPA for vegans36. By 2022 he said omega-3 in his program can come from algae instead of fish19.
Goldhamer said in 2017 that a DHA supplement may be needed by people who avoid nuts and seeds or convert poorly, but not by everyone45. In 2025 he presented algae DHA as a fallback, not a habit, adding that pills can cause more harm than benefit27. His center offers vegan DHA only occasionally, he said in 202646.
Rogers said in a 2024 video that he takes no omega-3 and thinks the pills are a bad idea6. He argues that fish oil cuts triglycerides while pushing up LDL and total cholesterol, and that EPA and DHA oxidize readily, which is why fish oil must be kept cold and dark3747. In his view everyday plant foods supply all the omega-3 a person needs34.
Novick’s column, first written in 1999 and updated in 2020, grants that the body converts ALA poorly but says a low-fat, minimally processed plant diet covers what vegans need of EPA and DHA with no direct source1532. In 2015 he dismissed purslane as a key omega-3 food, because a spoonful of flax or chia reaches the men’s adequate intake for much less energy48.
Nelson, a health writer by his own description and not a physician, concluded in 2019 that no one living healthily needs DHA pills and urged men to weigh studies linking them to cancer risk749. He favors a low-fat diet with little omega-6 so the body can make EPA and DHA from plant omega-314. His 2026 VegSource video kept that view while saying it did not claim the pills cause dementia10.
Rip Esselstyn’s guide for beginners points to flax, chia and walnuts for omega-3, and he named walnuts his favorite nut in a 2022 show2150. He rejects flax and walnut oil as calorie dense like any oil24. A 2025 PLANTSTRONG episode hosted a supplement maker who defended the oil in his algae omega-3 capsules39.
On a 2020 panel Willett recommended fish once or twice a week for most people to reach ideal omega-3 intake28. He also dismissed as a myth the claim that omega-6 fats inflame the body38.
We get omega-3 from greens and other whole plant foods, with ground flax or chia as an easy extra, and we skip fish, fish oil and pressed seed oils, as most of these doctors advise233433. We keep total fat low, which these doctors see as the way to let the body make its own long chain omega-31415. Whether a pill or a blood test makes sense for you is where they differ, so that is a question for your own doctor. This page is education, not medical advice.
Each small number links to its reference below: the video at the exact second, or the page where it was said.