Michael Greger

What Michael says, topic by topic

Vitamina B12

Greger treats B12 as the one supplement that is not optional. In a 2023 article he wrote that B12 comes from microbes rather than plants or animals, that a regular source is mandatory for anyone on a plant based diet, and that he would extend this to everyone from age 65¹. He described a case report of years of psychosis in a vegan who had not taken B12¹.

His dose advice has come down over time. In a podcast posted in 2020 he said he personally took one 2,500 mcg chewable tablet of cyanocobalamin once a week, adding that 2,000 mcg would do². In another podcast episode he explained that a newer study had normalized blood markers with just 50 mcg a day, so he lowered his advice to that daily amount or 2,000 mcg a week³.

His current recommendations page lists at least 2,000 mcg of cyanocobalamin once a week or at least 50 mcg daily, or fortified foods three times a day, and at least 1,000 mcg daily over age 65⁴. He prefers cyanocobalamin to methylcobalamin, and he says algae such as spirulina are not a usable source¹.

What all the experts say about vitamin B12

Vitamin D

Greger’s recommendations page gives a latitude and season chart: 15 to 30 minutes of midday sun (the longer time for darker skin), or 2,000 IU of supplemental vitamin D a day, with the supplement alone in the darker months farther north⁴. The 2011 version of the same advice added that D3 may be preferable to D2 from fungi⁵.

In a 2019 article he explained the 2,000 IU figure: about 1,000 IU brings half of people to the target blood level of 75 nmol/L, while 2,000 IU covers around 85 percent⁶. He wrote that people who are overweight or over 70 may need more, and that routine blood testing is not recommended⁶.

He has also weighed vitamin D trials against the hype. In a 2023 video he reported that more than 20 randomized trials found no benefit for heart attacks, strokes or death, and none for obesity, while trials did support vitamin D for COPD and for treating major depression⁷.

What all the experts say about vitamin D

Omega-3 fats

In a 2018 article Greger wrote that about a tablespoon a day of ground flaxseed or chia covers the short-chain omega-3 ALA⁸. His recommendations, first posted in 2011, also list 250 mg a day of long-chain EPA and DHA from algae or yeast, free of the pollutants found in fish⁵.

He noted in the same 2018 article that these long-chain fats had since failed to prevent or treat heart disease, but said he keeps the advice for the sake of brain health⁹.

On fish, a 2017 podcast episode reported a study of 33 species in which, for most fish, mercury’s harm to children’s IQ outweighed the gain from DHA¹⁰. He concluded that pregnant women can get DHA from microalgae supplements without the contaminants¹⁰.

What all the experts say about omega-3 fats

Aceite

Greger’s position is that whole foods beat their oils. In a 2012 video he likened extra virgin olive oil to fruit juice, with relatively empty calories next to the whole olive, and called nuts and seeds the best source of fat¹¹.

A 2017 article added that refined olive oil impaired artery function after a meal much like other high fat foods, and that extra virgin oil looked closer to neutral¹². He suggested the Mediterranean diet’s benefits may come in spite of the oil, from its vegetables, fruits, beans and nuts¹².

He also counts oil’s calorie load. In his 2019 weight loss lecture he said a tablespoon of oil adds over 100 calories, about the same as two cups of blackberries, which fill the stomach far more¹³.

What all the experts say about oil

Proteínas

In a 2019 article Greger wrote that adults need at most about 0.8 to 0.9 g of protein for each kilogram of healthy weight, roughly ideal weight in pounds times four divided by ten¹⁴. He argued that the 1950s fear of a global protein gap was a mistake, undone by a recalculation of requirements in the 1970s¹⁴.

Another 2019 article discussed a study in which lower protein intake went with less cancer and death in middle age, an effect that seemed to reverse after 65¹⁵. He wrote that the same allowance appears adequate for older people, that extra protein did not boost the gains from strength training in older adults, and pointed to vegetables as linked with better muscle mass¹⁵.

He separates protein sources. A 2013 article noted that animal protein was tied to higher IGF-1, a growth hormone that promotes cancer, and that a mix of non-soy plant proteins was tied to lower levels¹⁶.

What all the experts say about protein

Calcium, dairy and bones

Greger’s recommendations call for at least 600 mg of calcium a day from plant foods, preferably from low-oxalate greens, which in his list means every green other than spinach, chard and beet greens⁴.

He is wary of calcium pills. In a 2018 article he reviewed trials in which women who started calcium supplements had more heart attacks or strokes, possibly because of the blood calcium spikes pills cause, and noted that most bone health groups now advise getting calcium from food¹⁷.

On vegans, a 2022 video reported a 30 percent higher fracture risk, mostly wrist and arm, in a large study¹⁸. He noted that the excess risk disappeared among vegans getting at least 525 mg of calcium a day, and said more milk and dairy is not linked to fewer hip fractures¹⁹.

What all the experts say about calcium, dairy and bones

Iodine

Greger’s recommendations advise a 150 mcg daily iodine supplement for people who do not eat seaweed or use iodized salt, and warn against hijiki for its arsenic and kelp for its excess iodine⁴.

In a 2025 article he explained that the usual sources are iodized salt and dairy, and that people who drop both without eating sea vegetables can run short²⁰. He noted that few plant milks are fortified with iodine and that many prenatal vitamins lack it²⁰.

A second 2025 article named seaweed as the most concentrated source. He gave rough daily amounts such as two nori sheets, which he says he nibbles as a snack, or a teaspoon of dulse flakes, and kept his advice against kelp²¹.

What all the experts say about iodine

Calorie density

Calorie density is central to Greger’s weight loss teaching. In his 2019 lecture he defined it as how many calories a given amount of food holds and said stretch receptors in the stomach signal fullness by volume²². He gave the example that a stomach full of strawberry ice cream could supply a whole day’s calories, while the same calories from strawberries would take 44 cups²³.

In a 2020 video he argued that humans evolved to seek the densest foods, that natural foods tested stayed under about 500 calories per pound, and that people lose the ability to tell differences above that range²⁴. He said the food industry exploits this by stripping crops down to nearly pure sugar and oil²⁵.

What all the experts say about calorie density

Nuts, seeds and avocado

Nuts and seeds are part of Greger’s Daily Dozen checklist, which has separate categories for flaxseeds and for nuts and seeds²⁶. His advice is about a quarter cup of nuts or seeds a day, or two tablespoons of nut or seed butter²⁷.

In a 2012 video he reviewed trials in which adding nuts to people’s diets caused far less weight gain than the calories predicted²⁸. He added that in population studies the slimmest people ate the most nuts²⁹. A 2026 article reported that nuts beat even vegetables for lower risk of premature death in a comparison of a dozen food groups³⁰.

What all the experts say about nuts, seeds and avocado

Soja

Greger is broadly in favor of soy but sets a ceiling. In a 2013 article he noted that studies found five to ten servings a day raised IGF-1 while two to three did not, and concluded that soy is an excellent choice at no more than three to five servings a day³¹.

In a 2014 article he cited a review in which women who ate the most soy had 29 percent fewer breast cancer deaths and 36 percent fewer recurrences³². In 2025 he wrote that soy appears harmless for people whose thyroid works normally, as long as they get enough iodine³³.

What all the experts say about soy

Salt

In a 2019 article Greger wrote that cutting salt by half a teaspoon a day, through skipping salty foods and adding none at the table, might prevent about a fifth of stroke deaths (22 percent) and 16 percent of fatal heart attacks³⁴. He noted that most salt comes from processed foods and that, for adults aged 20 to 50, chicken is the top source of sodium because of the salt injected into the meat³⁴.

In 2025 he called dietary salt the leading dietary risk factor for death worldwide and said ideally no salt should be added at all³⁵.

What all the experts say about salt

Sugar

In a 2024 article Greger traced how sugar industry lobbying kept a numeric limit out of US dietary guidelines for decades, until the 2015 to 2020 guidelines set added sugar below 10 percent of calories³⁶. He wrote that there is no requirement for added sugar at all, and noted moves by the American Heart Association and UK advisers toward lower limits³⁷.

He draws a line between added sugar and fruit. In a 2016 article he cited studies in which fructose from added sugars, but not from fruit, was linked with high blood pressure, and in which keeping fruit in a diet led to more weight loss³⁸.

What all the experts say about sugar

Starches

For Greger the form of a starch matters. In a 2019 article he explained that resistant starch escapes digestion and feeds gut bacteria much as fiber does; cooling cooked pasta or potatoes raises it only slightly, from about 3 to 4 percent, and beans are the richer source³⁹. He added that berries eaten with a starchy meal can block the enzyme that breaks starch down⁴⁰.

In a 2017 article he reported that brown rice ground into flour produced twice the blood sugar and insulin rise of the same rice eaten whole, one reason he ranks intact grains above flour products⁴¹.

What all the experts say about starches

Fasting

Greger has examined intermittent fasting closely and come away unconvinced. In a 2024 article he wrote that the hoped-for advantages over plain daily calorie cutting, such as avoiding the metabolic slowdown or making a diet easier to keep, had not been borne out, and that the largest and longest alternate-day trial suggested it may be harder to sustain⁴².

A companion 2024 article described a year-long trial in which alternate-day fasters lost as much body fat as daily calorie restrictors yet ended with LDL cholesterol 10 percent higher, a result he counted as a serious strike against the method⁴³. He wrote that anyone who tries it anyway should get their cholesterol checked to make sure it falls along with their weight⁴⁴.

What all the experts say about fasting

Supplements

Beyond a few specific nutrients, Greger is skeptical of supplements. In a 2015 article he reviewed a decade-long Harvard trial and a meta-analysis of 21 trials in which multivitamins made no difference to heart attacks, strokes or death, and an evidence review for the US Preventive Services Task Force that found no consistent benefit for heart disease, cancer or lifespan⁴⁵. He concluded that, vitamins D and B12 aside, people should aim to get their nutrients from produce rather than pills⁴⁶.

His recommendations have since grown a little: his current page also covers iodine for people who eat no seaweed or iodized salt, and his earlier list included algae-based long-chain omega-3⁴⁵.

What all the experts say about supplements

Hierro

In a 2017 article Greger wrote that people on plant based diets are no more likely than others to have iron deficiency anemia, and tend to take in more iron overall⁴⁷. He argued that the plant (non-heme) form, though less well absorbed, may be the safer one, citing estimates that each daily milligram of heme iron from meat raises coronary heart disease risk by 27 percent, type 2 diabetes risk by 16 percent and cancer risk by up to 12 percent⁴⁸.

He named beans and other legumes, whole grains, dark leafy greens, dried fruit, nuts and seeds as the healthiest places to get iron⁴⁹.

What all the experts say about iron

Fish and eggs

On eggs, a 2015 article took apart egg industry funded studies that found no harm to artery function in people whose cholesterol was already very high. Greger likened their logic to tossing a lit match into burning gasoline, seeing the flames no higher, and calling matches safe⁵⁰. He wrote that for someone already eating healthily, two eggs could raise cholesterol by about 20 points⁵¹.

On fish, a 2019 article noted that trials of fish fats had failed to help heart disease, depression or cognitive decline, and that some studies even linked higher fish intake with slower thinking, possibly because of mercury and PCBs in seafood⁵². His 2017 podcast on omega-3 made a similar point about mercury and children’s IQ¹⁰.

What all the experts say about fish and eggs

Fibra

Greger calls fiber the nutrient most Americans lack. In a 2015 article he wrote that fewer than 3 percent reach the minimum adequate intake, that the average is about 15 grams a day against a minimum of 31.5, and that fiber exists only in plants, none in meat, dairy or eggs⁵³.

In a 2017 article he cited data in which every extra 7 grams of fiber a day went with 7 percent lower stroke risk, an amount he said a serving of whole grain pasta plus an apple would supply⁵⁴.

What all the experts say about fiber

Fruit

Fruit is a fixed part of Greger’s Daily Dozen: at least one serving of berries and three of other fruits every day⁵⁵. In a 2017 article he cited a global analysis that ranked eating too little fruit as possibly the leading dietary risk factor for death worldwide, with about 4.9 million lives a year at stake⁵⁶.

He does not limit fruit because of its sugar. Another 2017 article described a trial in which people with type 2 diabetes told to cut back on fruit saw no change in their blood sugar control or weight⁵⁷. In the same piece he reported that half a cup of blueberries, though not a quarter cup, offset the drop in blood antioxidants after a sugary cereal breakfast⁵⁸.

What all the experts say about fruit

Vegetables and greens

Vegetables make up the largest share of Greger’s Daily Dozen: at least one half-cup serving of cruciferous vegetables such as broccoli, cabbage or kale, plus two servings of greens and two of other vegetables each day⁵⁹. He gives cruciferous vegetables their own box because sulforaphane comes almost only from that family, so other greens cannot stand in for them⁶⁰. When he pictures a plate, vegetables take half of it, with grains and legumes a quarter each⁶¹.

The global analysis he cited in 2017 put the lives that a higher vegetable intake could save at 1.8 million a year⁶².

What all the experts say about vegetables and greens

Beans and lentils

Legumes get three daily servings in Greger’s Daily Dozen, a serving being half a cup of cooked beans, split peas, lentils or tofu, or a quarter cup of hummus⁶³. In a 2022 article he called them perhaps the cheapest source of nutrition, noted that bean eaters had less heart disease even after adjusting for meat intake, and cited a Costa Rican study in which one daily serving went with 38 percent fewer heart attacks⁶⁴. He added that controlled trials show beans lower LDL cholesterol⁶⁵.

His summary in a 2017 article was “the more beans, the better”, in whatever form people eat them⁶⁶.

What all the experts say about beans and lentils

Whole grains, bread and flour

Greger’s Daily Dozen calls for at least three servings of whole grains a day, such as half a cup of oatmeal, brown rice, quinoa or pasta, or one slice of bread⁶⁷. He prefers grains intact to ground: in a 2017 article he explained that unground grains carry food particles down to the colon for gut bacteria, and that brown rice flour doubled the blood sugar and insulin response of whole brown rice⁶⁸.

In a 2016 article he wrote that for nearly everyone without a gluten disorder, wheat, barley and rye, the grains that contain gluten, are protective, tied to lower rates of heart disease, cancer, diabetes and obesity⁶⁹.

What all the experts say about whole grains, bread and flour

Potatoes

Greger is lukewarm on white potatoes. In a 2026 article he wrote that, French fries aside, potato eaters live about as long as people who skip them, which he saw as a missed chance for a whole plant food⁷⁰. A 2025 article reviewed Harvard cohort data linking baked, boiled or mashed potatoes with a small rise in diabetes risk, with fries close to five times worse⁷¹.

For people who like potatoes, he reported that chilling them after cooking, and adding about a tablespoon of vinegar, can blunt the rise in blood sugar and insulin⁷².

What all the experts say about potatoes

Meat

In the traffic light system Greger set out in a 2021 article, unprocessed animal foods are yellow light foods to keep to a minimum, and processed meats are red light foods to avoid⁷³. His rule of thumb is that a diet improves as whole plant foods replace processed and animal foods⁷⁴.

On processed meat, a 2026 article explained that its Group 1 carcinogen label reflects how strong the evidence is, not how big the risk is, and that each 50 grams a day, about one hot dog, raises colorectal cancer risk by 18 percent⁷⁵. He estimated that dropping one daily serving of processed meat could cut that cancer risk by about a fifth⁷⁶.

What all the experts say about meat

Low-fat eating

Greger thinks today’s idea of low fat is generous. In a 2024 podcast he said a diet with 20 percent of calories from fat only counts as low fat next to the modern average, since for most of human history our ancestors probably got around 10 percent of calories from fat⁷⁷.

In his 2019 weight loss lecture he summed up one strategy as dropping added fats, describing studies in which people secretly given a relatively low fat diet lost body fat while eating freely, and gained it when extra fats and oils were slipped into the same meals⁷⁸. A 2023 article reported a study in which cutting fat led to about 80 percent more body fat loss than cutting the same calories from carbohydrate⁷⁹.

What all the experts say about low-fat eating

Grasa saturada

Greger backs the guidelines that push saturated fat down. In a 2016 article he traced the media claim that butter was back to a dairy industry campaign begun in 2008 to change how health professionals view milk fat, and noted that US heart associations advise keeping saturated fat to 5 or 6 percent of calories⁸⁰. He worked out that this leaves room for roughly two pats of butter plus a couple of cheese cubes a day, so about 90 percent of the diet would have to be free of foods containing saturated fat⁸¹. He listed cheese, ice cream, chicken, desserts and pork as the top US sources⁸².

On coconut oil, a 2021 article concluded that the evidence does not support its healthy image and that it should be treated like animal saturated fat, while whole coconut, with its fiber and protein, is a different case⁸³.

What all the experts say about saturated fat

Cholesterol

Greger argues for keeping LDL cholesterol low for life. In a 2026 article he described autopsy studies that found fatty streaks in the arteries of every teenager examined, and said the treatment is to lower LDL by cutting saturated fat and dietary cholesterol, which in practice means eating few eggs, little meat, dairy or junk food⁸⁴. He cited people born with a PCSK9 gene variant that keeps their LDL about 40 percent lower from birth, who had 88 percent less coronary heart disease, and concluded that how long LDL stays low matters as much as how low it goes⁸⁵.

He discounts HDL as a target. In a 2022 article he wrote that genetic studies have shown high HDL is no longer considered protective, while a lifelong lower LDL does cut heart disease⁸⁶.

What all the experts say about cholesterol

Carbohydrates and low-carb diets

Greger rejects ketogenic and low-carb diets. In a 2023 article he wrote that the carbohydrate–insulin theory behind keto had been experimentally falsified, and described a study in which cutting 800 calories of carbohydrate burned 53 grams of body fat a day against 89 grams when the same calories came from fat⁸⁷. He said the faster drop on the scale with low-carb eating is mostly water and lean tissue, as glycogen stores drain away⁸⁸.

In a 2024 article he quoted reviews linking low-carb diets with higher overall mortality, poorer artery function and worsening coronary disease, and judged a whole food plant based diet more effective for weight loss⁸⁹.

What all the experts say about carbohydrates and low-carb diets

Gluten and wheat

Greger accepts that gluten sensitivity is real but uncommon. In a 2016 article he put wheat allergy at about 1 in 1,000 people, celiac disease near 1 in 100 and gluten sensitivity just above 1 percent⁹⁰. He wrote that there is no evidence a gluten-free diet helps the general population, and that a month without gluten may even harm gut bacteria and immune function⁹¹.

In a companion 2016 article he set out an order of steps for people who suspect a problem: a formal test for celiac disease first, then a healthier diet with more whole plant foods, then ruling out other gut causes, and only then a gluten-free trial⁹². He noted that gluten-free products cost about three times as much and that gluten-free junk food is now everywhere⁹³.

What all the experts say about gluten and wheat

Coffee, tea and caffeine

In a 2017 article Greger reviewed the largest diet and health study ever run, in which older coffee drinkers had a modestly lower risk of death, about 10 to 15 percent at six or more cups a day; since another study found higher death rates under age 55 at that intake, he suggested keeping to four cups a day at most⁹⁴. He listed people who may want to avoid caffeine, such as those with glaucoma, epilepsy or trouble sleeping, and reported that coffee causes more acid reflux than tea⁹⁵.

His view grew more cautious later. In a 2023 article he noted that people genetically inclined to drink more coffee were not protected from diabetes, depression or Alzheimer’s, which suggests the population links may come from other habits, and that slow caffeine metabolizers may respond differently⁹⁶.

What all the experts say about coffee, tea and caffeine

Alcohol

Greger sees no safe level of drinking. In a 2022 article he cited estimates that alcohol causes about 5.8 percent of cancer deaths in the organs it affects, mostly head, neck and digestive cancers among men and mostly breast cancer among women, with breast cancer risk rising even at low intakes⁹⁷. He wrote that no level of alcohol appears completely safe as far as cancer goes⁹⁸.

A second 2022 article addressed the J-shaped curve in which moderate drinkers seem to outlive abstainers. He explained that most studies counted former drinkers who had quit because of illness as abstainers; once researchers corrected this, the apparent protection vanished and the link became a straight line in which more drinking meant more deaths⁹⁹.

What all the experts say about alcohol

Chocolate

Greger separates cocoa from chocolate. In a 2017 article he called chocolate one of the most calorie-dense foods, and reported a six-year study of more than 10,000 people in which eating chocolate went with steady weight gain, plus a trial in which four squares a day added a few pounds¹⁰⁰. He wrote that cocoa powder beats even dark chocolate because it carries the plant compounds without the saturated fat, and suggested stirring it into a smoothie¹⁰¹.

What all the experts say about chocolate

Juicing and smoothies

Greger favors whole fruit over juice, and smoothies over juicing. In a 2016 article he cited Harvard data linking whole fruit with lower type 2 diabetes risk and fruit juice with higher risk, and explained that juicing strips out not only fiber but the many plant compounds bound to it¹⁰². He concluded that people who like to drink their produce may do better with smoothies¹⁰³.

He has noted a limit even there. A 2017 article described a study in which apples blended into a puree, like apple juice, made blood sugar dip below its starting level in the hours afterward, unlike whole apples¹⁰⁴. Another 2017 article said blending greens may help nutrient absorption while leaving fiber-bound compounds intact for the colon¹⁰⁵.

What all the experts say about juicing and smoothies

Organic food and pesticides

In a 2017 article Greger wrote that organic crops carry fewer pesticide residues, more antioxidant compounds and only about half the cadmium of conventional crops, though conventional residues are usually under legal limits¹⁰⁶. He warned that “Organic junk food is still junk food”¹⁰⁷.

His bottom line was that the benefit of eating conventional fruit and vegetables far outweighs any small pesticide risk: choosing organic is fine, but worry about pesticides should never stop anyone eating plenty of produce¹⁰⁸.

What all the experts say about organic food and pesticides

Mediterranean diet

Greger sees the Mediterranean diet as better than the Western diet but not the best option. In a 2017 article he described the Lyon Diet Heart Study, in which heart attack survivors advised to eat a Mediterranean-style diet cut their yearly risk of another attack from about 4 percent to 1 percent, mainly by eating more bread and fruit and less meat, butter and cream¹⁰⁹. He contrasted it with Caldwell Esselstyn’s case series, in which only one of 177 heart patients who kept to a whole plant food diet had a major event from worsening disease, while noting that Esselstyn’s study was not randomized¹¹⁰¹¹¹.

As noted under oil, he has also suggested the diet’s benefits may come in spite of its olive oil¹².

What all the experts say about mediterranean diet

Weight loss

Greger’s weight loss teaching puts food quality ahead of portion control. In a 2024 article he described a randomized community trial in which people with obesity were told to eat a whole food plant based diet as much as they liked, with no push to exercise more¹¹². They lost about 18 pounds in three months and 26 by six months and kept it off for the year, which he said was the greatest weight loss recorded at 6 and 12 months by any trial that did not limit calories or require exercise¹¹³.

His 2019 lecture framed this through calorie density and through cutting added fats, both covered above²²⁷⁸.

What all the experts say about weight loss

Cravings and food addiction

In a 2014 article Greger compared refined sugar with cocaine: people chewed coca leaves for thousands of years without addiction, and problems began when the active part was isolated and concentrated; likewise, he wrote, nobody binges on bananas¹¹⁴. He cited brain imaging in which heavier people showed lower dopamine sensitivity, a pattern also seen in cocaine addicts and alcoholics, and said the drive that once led our ancestors to fruit has become a liability now that sugar comes refined¹¹⁵.

What all the experts say about cravings and food addiction

Exercise

Greger counts exercise in his Daily Dozen: about 90 minutes a day of moderate activity such as brisk walking, or 40 minutes of vigorous activity¹¹⁶. In a 2020 article he explained the figure, writing that official guidelines of 150 minutes a week reflect what authorities think people will do, while a meta-analysis found an hour a day of brisk walking good and 90 minutes better¹¹⁷. He reported that an hour-long daily walk may cut mortality by about 24 percent¹¹⁸.

He still ranks diet first: in the same article he noted that physical inactivity sits fifth among US risk factors for death, with diet the greatest killer¹¹⁹.

What all the experts say about exercise

Heart disease

Greger treats heart disease as largely preventable and partly reversible. In a 2019 article he wrote that nearly all children on the standard American diet have fatty streaks in their arteries by age ten, so for most adults the real choice is whether to reverse disease they likely already have¹²⁰. He described studies in which heart patients put on plant based diets saw plaque start to regress, with better blood flow to the heart muscle after just three weeks, without drugs or surgery¹²¹.

In a 2026 article he contrasted healthy lifestyle choices, which may remove about 90 percent of heart attack risk, with drugs, which may cut it by 20 to 30 percent, and put the difference down to how many years LDL stays low¹²².

What all the experts say about heart disease

High blood pressure

Greger argues that high blood pressure is common but not natural. In a 2017 article he cited a study of a thousand people in rural Kenya whose blood pressure did not climb with age as it does in the West, and even improved¹²³. He noted that high blood pressure is the world’s leading risk factor for death, killing about nine million people a year¹²⁴.

In a 2016 article he reported data on 89,000 Californian Adventists in which hypertension fell step by step as diets became more plant based: vegetarians had under half the rate of regular meat eaters, and vegans about a quarter¹²⁵. In the same piece he reviewed hibiscus tea trials, in which two strong cups each morning matched a starting dose of a common blood pressure drug¹²⁶.

What all the experts say about high blood pressure

Diabetes

In a 2023 article Greger wrote that the case for plant based eating against diabetes has never been stronger¹²⁷. He described a 12-week randomized trial in Asia in which people with type 2 diabetes ate a plant based diet centered on brown rice with no portion limits; those who stuck with it lowered their A1c by 0.9 percent, which he likened to the effect of a leading diabetes drug¹²⁸. He also cited a report of eight diabetics whose falling kidney function stopped declining after they switched to a supplemented vegan diet¹²⁹.

In a 2024 article he noted that most studies find the lowest type 2 diabetes risk among vegans, and listed possible reasons beyond body weight, such as more fiber and plant protein and less heme iron and saturated fat¹³⁰.

What all the experts say about diabetes

Cancer

In a 2026 article Greger argued that cancer prevention should rest on plants rather than pills. He noted that the common cancers grow for 20 years or more before diagnosis, and that compounds in foods such as berries, greens and broccoli have been shown, in laboratory studies, to act on each of the ten recognized hallmarks of cancer¹³¹. He stressed that he means eating whole plant foods, not taking extracts or purified compounds¹³².

He has singled out specific risks as well: processed meat for colorectal cancer, as noted under meat, and alcohol, for which he sees no safe level⁷⁵⁹⁸.

What all the experts say about cancer

Dementia and the brain

In a 2022 article Greger reviewed how dementia rose in Japan as meat and animal fat intake rose by about 500 percent, and cited cross-country data in which meat was the dietary factor most tied to Alzheimer’s, with eggs and high-fat dairy playing a part too¹³³. He acknowledged that no randomized trials have tested meat and brain decline directly¹³⁴.

In a 2023 video on healthy aging he described the MIND diet, rich in berries, greens and other plant foods and low in meat and saturated fat, whose strictest followers had 53 percent less Alzheimer’s risk¹³⁵. He added that meat eaters, poultry and fish eaters included, had over twice the dementia rate of vegetarians in the research he cited¹³⁶.

What all the experts say about dementia and the brain

Longevity and aging

In the same 2023 video Greger cited research on over 400,000 people in which replacing 3 percent of calories from animal protein with plant protein went with 10 percent lower mortality, about an extra year of life, with egg protein the worst offender¹³⁷. He pointed to the Adventist vegetarians of Loma Linda, California, perhaps the longest-lived formally studied population, who live about 6 to 10 years longer than other Californians¹³⁸.

He separates a whole food plant based diet from simply being vegan, saying a vegan diet can be very unhealthy and that the word only describes what someone avoids¹³⁹.

What all the experts say about longevity and aging

Each small number links to its reference at the bottom of the page: the video at the exact second, or the page where it was said.