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Coffee and tea on a plant based diet: what the doctors say
Coffee, tea and caffeine on a plant based diet: what McDougall, Esselstyn, Barnard, Goldhamer and other doctors say, with sources.
Updated . For education only, not medical advice.
Our view
None of the doctors on this site treats coffee or tea as something the body needs; Campbell said in 2021 that coffee is not a drink he recommends, and Barnard called caffeinated drinks unnecessary in 202012. The programs run most strictly leave caffeine out altogether: Ornish’s reversal guidelines dropped it in every form, Esselstyn’s heart program came to exclude it, and Goldhamer’s TrueNorth center serves neither coffee nor tea345.
Where the evidence is argued over, we give more weight to the low-fat clinicians with nothing to sell, and on caffeine most of them, from Esselstyn and Goldhamer to Novick and Rogers, advise against it6578. McDougall, a coffee drinker himself, is the mildest of the group, yet in 2022 he still told poor sleepers and people with high cholesterol to quit or at least brew through a paper filter910. Studies that tie coffee to less disease do exist, and Barnard takes them seriously, while McDougall and Lisle doubt what they show111213.
Where they agree
Almost all of them treat caffeine as a drug rather than a food: Goldhamer, Barnard, Campbell and Chef AJ each describe it as addictive5141516. Goldhamer, Barnard and Lisle all offer the same proof, the headaches people get in the days after they stop171418.
Sleep is the harm they raise most often: McDougall, Barnard, Goldhamer, Rogers and Lisle all say coffee can cost people sleep, and Lisle added that lab studies detect broken sleep after as little as half a cup92192021.
They also agree that what goes into the cup counts: Barnard warned in 2024 that the milk in a latte can matter more than the coffee, Novick wrote in 2013 that blended coffee shop drinks average about 240 calories, and Chef AJ said in 2017 that people who need cream and sugar to get coffee down do not really love it222324.
Where they differ
The doctors part ways on how much harm a daily cup does, on studies that find benefits, on decaf, on brewing, and on whether tea is a better choice14252627.
Avoid it or live with it
Goldhamer said in 2025 that caffeine harms health and should be dropped, Rogers said in 2026 that he gave up coffee years ago and is glad of it, and Pritikin said in 1982 that coffee has no place as an everyday drink172829. Campbell, by contrast, thought in 2021 that many people can drink coffee without much trouble if they keep it moderate, and Barnard said in 2020 that it is not the worst problem in most diets152. Lisle counted caffeine among the minor sins in 2026, and in 2025 described it as a small harm each person weighs against the pleasure3031. Rogers made one exception: a single cup to keep a drowsy driver alert on a long journey20.
Studies that find benefits
Barnard said in 2020 that around five cups a day goes with a lower risk of Alzheimer’s disease, and in 2021 expected coffee to be cleared of blame for heart disease, cancer and diabetes1114. McDougall distrusted such findings in 2022, suggesting they get attention because drinkers welcome flattering news about a habit12. Lisle suspected in 2025 that a doctor who praises coffee is looking at one plant compound rather than at what years of drinking it do13. Campbell granted in 2021 that a couple of studies hint at some benefit, yet still did not recommend it1.
Decaf
Esselstyn’s caution came from a 2010 Italian study in which only caffeinated coffee, not decaf, worsened artery function on the arm cuff test6. McDougall and Pritikin saw decaf as no help for the stomach, since in their account it raises acid as much as regular coffee2529. McDougall also said decaf raised cholesterol even more than regular coffee, and in 2024 gave the figures as about 11% against 10%3233. Ornish’s guidelines, archived in 2011, removed decaf along with regular coffee, and Lisle judged in 2025 that decaf is probably slightly harmful as well334.
Brewing and cholesterol
McDougall explained in 2022 that coffee made by boiling or percolating lifts cholesterol, whereas brewing through paper traps the substances behind it32. A 2024 article on Rip Esselstyn’s PLANTSTRONG site makes the same case against the French press, citing an LDL rise of 6 to 8% after four weeks of five cups a day, and suggests drip or pour-over brewing2635. The same article then recommends switching to tea and presents the brand’s own teas36.
Tea
Tea divides them most: Ornish’s 2011 guidelines let green tea in as the one exception to the caffeine ban, up to two cups a day, and Novick said in 2008 that a few cups of green tea were fine with him2737. Goldhamer serves no tea at his center and said in 2025 that even decaffeinated green tea carries other chemicals that concern him538. Rogers rejected green tea as a wonder food in 2026 and said tea leaves pick up fluoride and aluminum, and Novick reported in 2013 on research that detected lead in all the brewed teas it measured3940. Chef AJ said in 2017 that green tea beats coffee because it has less caffeine, while still calling caffeine an addiction41. Herbal tea has its own warning: Nelson’s wife was hospitalized with acute liver failure in January 2024 after about a month of daily rooibos, and he suggested regular rooibos drinkers think about liver tests now and then4243.
Blood pressure, sleep and changing views
The older warnings were broader: in 1982 Pritikin linked caffeine with ulcers, fibrocystic breast disease and higher blood pressure, and Novick’s 2002 article reported trials where caffeine equal to about one cup made arteries stiffer and pushed blood pressure up for several hours29447. By 2023 Barnard described the rise in blood pressure as modest and shrinking as people get used to caffeine, while Rogers in 2026 still connected caffeine with hypertension and insulin resistance4546. Even the numbers on sleep differ: Goldhamer put the half-life of caffeine at about seven hours in 2025, while Chef AJ had given a figure of 17 hours in 20161947.
What each expert says
JMJohn McDougall
In a 2022 video McDougall counted coffee among his own favorite drugs, a morning stimulant whose price is poor sleep and, for heavy users, the jitters9. He warned that coffee, decaf included, drives up stomach acid, and that the body bounces back within two or three days of stopping2510. For bad sleep or high cholesterol he told people to stop, or failing that, to brew through paper10.
In a lecture posted in 2014 Esselstyn said he is wary of caffeine, persuaded by a 2010 Italian study in which young volunteers took caffeinated and decaf coffee in turn and only the caffeinated kind impaired artery function6. His 2014 paper on 198 heart patients notes that caffeine was later removed from the program4.
Campbell said in a 2021 interview that coffee and tea are concentrated extracts of a plant that fail to meet the body’s need for water, and he called coffee a diuretic4849. He thought caffeine can hook people while many can still live with moderate coffee, and he does not recommend it151.
Barnard does not drink coffee and in 2020 called the evidence mixed, with possible protection against Alzheimer’s disease on one side and heart rhythm trouble, poor sleep and mood swings on the other112. In 2021 he described a daily cycle of highs and withdrawal headaches, and in 2024 said the small lift caffeine gives the metabolism fades as the body adapts1422.
Ornish’s reversal guidelines, archived in 2011, removed every source of caffeine, including regular and decaf coffee, tea, cocoa and chocolate, because in the program’s view it disturbs meditation and relaxation3. Green tea was the one exception, capped at two cups a day for its polyphenols27.
Goldhamer said in 2025 that caffeine is a strongly addictive stimulant of the nervous system that also acts on the gut microbiome and hormones, and that water is the best drink5. He sees short sleep as a main reason people struggle with weight, and even a morning cup as a threat to sleep19.
In a 2026 lecture Rogers said caffeine imitates the stress response and raises cortisol, and cited studies in which a 250 mg dose lowered blood flow to the brain by about 22 to 30%508. He started drinking coffee as an exhausted surgical intern and has since given it up28.
Novick urged readers in 2002 to avoid caffeine, citing a Finnish cohort in which four or more cups a day doubled the risk of rheumatoid arthritis and a trial in which moderate caffeine cut insulin sensitivity by 15%7. He is gentler on tea, accepting a few cups of green tea, decaffeinated if needed, while advising short brewing and modest amounts because of lead3740.
Nelson told in a 2024 video how his wife developed acute liver failure after drinking rooibos tea every day for about a month, with no other cause found and a published case report tying the tea to liver injury4251. He blamed toxic weeds picked along with some rooibos and asked for a warning label43.
A 2024 article on Rip Esselstyn’s PLANTSTRONG site warns that French press coffee lets through oily compounds, cafestol and kahweol, that raise LDL cholesterol and that paper filters catch2635. The article goes on to offer PLANTSTRONG teas as the alternative36.
Chef AJ calls caffeine a drug and not a food, and said in 2016 that she went through withdrawal twice before she was free of it52. In 2017 she said most people drink caffeine because they are hooked or short of sleep, and that the reason for needing it is what deserves fixing16.
In a 2022 talk on her group’s rheumatoid arthritis study, Kahleova explained that after a few weeks on a low-fat vegan diet, coffee was one of the foods removed for three weeks and then brought back one at a time to spot pain triggers53. Some participants found going without coffee hard, she said, but they managed it54.
Pritikin told McDougall in 1982 that coffee, regular or decaf, sharply raises stomach acid and is tied to ulcers and fibrocystic breast disease, so it should not be a beverage29. He told people with high blood pressure to avoid both caffeine and alcohol44.
Lisle said in 2025 that no one knows how much decaf harms the brain, rated caffeine an unlikely main cause of dementia but a small contributor to brain aging, and left the choice to each person’s own weighing of costs and benefits5531. He pointed to withdrawal headaches and measurable sleep loss as signs of a real drug effect1821.
None of these doctors calls coffee or tea necessary, and most of the clinicians who run strict programs leave caffeine out354. For anyone keeping a daily cup, McDougall’s advice was a paper filter, and Barnard and Novick both pointed at the milk, sugar and syrups that turn coffee into dessert102223. Whether to cut back, switch to decaf or tea, or stop, and how that fits any heart, stomach, sleep or blood pressure problem, are questions 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.