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Boosting Moods with Foods

In my video Plant-Based Diets for Improved Mood and Productivity, I discuss a recent systematic review and meta-analysis of dietary patterns and depression that concluded that a healthy diet pattern was “significantly associated with a reduced odds of depression.” However, out of the 21 studies the researchers were able to find in the medical literature, they were only able to find one randomized controlled trial, the study design that provides the highest level of evidence. It was the study I profiled in my Improving Mood Through Diet video, in which removing meat (including fish and poultry) and eggs improved several mood scores in just two weeks.

We’ve known those eating plant-based diets tend to have healthier mood states—less tension, anxiety, depression, anger, hostility, and fatigue—but we couldn’t tell if it was cause and effect until it was put to the test, which researchers finally did. What could account for such rapid results?

Eating a vegetarian diet gives you a better antioxidant status, which may help with depression, as I discussed in Antioxidants and Depression. Also, as I previously addressed in A Better Way to Boost Serotonin, consumption of even a single carbohydrate-rich meal can improve depression, tension, anger, confusion, sadness, fatigue, alertness, and calmness scores among patients with premenstrual syndrome. But what about long term?

Overweight men and women were randomized into two groups: one following a low-carb, high-fat diet and the other following a high-carb, low-fat diet for a year. By the end of the study, who had less depression, anxiety, anger, hostility, feelings of dejection, tension, fatigue, confusion, fewer mood disturbances, and better vigor? “The sustained improvements in mood in the LF [low-fat] group compared with the LC [low-carb] group are consistent with results from epidemiological studies showing that diets high in carbohydrate and low in fat and protein are associated with lower levels of anxiety and depression and have beneficial effects on psychological well-being.”

The overall amount of fat in the research subjects’ diet didn’t change significantly, though. But the type of fat did. Their arachidonic acid intake fell to zero. Arachidonic acid is an inflammatory omega-6 fatty acid that can adversely affect mental health via a “cascade of neuroinflammation”—that is, it may inflame your brain. High levels of arachidonic acid in the bloodstream have been associated with a greater likelihood of suicidal risk and major depressive episodes, for example. How can we stay away from the stuff? Americans are exposed to arachidonic acid primarily through chicken and eggs. So, when we remove eggs, chicken, and other meat we eliminate preformed arachidonic acid from our diet.

Although high-quality treatment studies examining diet’s impact on depression are scarce, there was the successful two-week trial discussed earlier and, even better, a twenty-two-week study. Overweight or diabetic employees of a major insurance corporation received either weekly group instruction on a whole food, plant-based diet or no diet instruction for five and one-half months. There was no portion size restriction, no calorie counting, no carb counting, and no change in exercise. No meals were provided, but the company cafeteria did start offering daily plant-based options such as lentil soup, minestrone, and bean burritos.

Participants ate no meat, eggs, dairy, oil, or junk, yet they reported greater diet satisfaction compared with the control group participants who had no diet restrictions. More participants in the plant-based intervention group reported improved digestion, increased energy, and better sleep than usual at week 22 compared with the control group. They also reported a significant improvement in physical functioning, general health, vitality, and mental health. The plant-based group beat out controls on nearly every measure.

There were also significant improvements in work productivity, thought to be due in large part to their improvements in health. What this study demonstrated is that a cholesterol-free diet is acceptable, not only in research settings but also in a typical corporate environment, improving quality of life and productivity at little cost. All we needed was a large, controlled trial for confirmation, but we didn’t have such a thing… until now.

A study of ten corporate sites across the country from San Diego, California, to Macon, Georgia, with the same set-up as before found that a plant-based nutrition program in a multi-center, corporate setting improves depression, anxiety, and productivity. Significant improvements were found in depression, anxiety, fatigue, emotional well-being, and daily functioning. “Lifestyle interventions have an increasingly apparent role in physical and mental health, and among the most effective of these is the use of plant-based diets.”

The pilot data on workplace interventions can be found in my videos Slimming the Gecko and Plant-Based Workplace Intervention.

Diet can help at home, too. See:

And, for background on the inflammatory fatty acid arachidonic acid, see my videos Inflammatory Remarks About Arachidonic Acid, Chicken, Eggs, and Inflammation, and Chicken’s Fate Is Sealed.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

41 responses to “Boosting Moods with Foods

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  1. Apparently, there is evidence that chronic systemic inflammation can lead to depression.

    One sialic acid not produced by humans but manufactured by virtually all other mammals is Neu5Gc. In humans ingestion of Neu5Gc contained in red meat and milk provokes an immunolgical response but can be absorbed by human tissue thus resulting in chronic systemic inflammation. Cooked organ meats are reportedly particularly high in Neu5Gc

    A completely vegetarian diet does not contain either (red) meat or dairy foods and – all other things being equal – would naturally be less inflammatory than standard (Western) diets. This might also at least partly explain why vegetarians have better mood states (and less chronic disease generally).

    1. TG thx. Very applicable for me…and too many others with ‘systemic inflammation.’ I’m already WFPB with no animal protein. Even with the meds my doctors admit I have less side effects (or evidence of) then I should and at almost 50 improved blood markers for hormones. I added some flax and sweet potatoes for phytoestrogen and after 2 months many ‘menopause’ symptoms have improved quite a bit. So I gladly turned down HRT and my husband is happy to have house feel less like deep freeze at night LOL!

  2. Thank you Dr. Greger for finding these quality studies. Many accuse your team of “cherry picking” but in reality you use critical thinking to weed out the bad studies and show use the good ones. Thank you for your work.

  3. Chris P
    Agreed. There’s a good Plant Based News video with Dr G. addressing the ‘cherry picking’ argument. Spoiler alert…it doesn’t hold up. Shocking.

  4. On some Doctor’s shows they talk about some studies that show that Vegan people tend to be more depressed. One of the Doctor’s on the show made sure to say that it might not have to be anything about the food we eat. He pointed out that some people that choose to be vegan can be more sensitive to a lot of things that are going on in the world. I know I feel very sad if the only shoes that firt my weird feet are made out of leather.

    1. Wendy, so being plant based/ vegan can lead to increased compassion and better health. I’m sure there’s a drug for that. LOL

      I’m on hunt this year for good winter boots not made from animals. It’s not easy but hopefully as demand and awareness goes up choice will as well. Happy holidays!

      1. I do have weird shaped feet that need a double wide and can other shapes.  I do have leather shoes, but I make sure to thank the cows that have allowed for me to walk well.

        1. No animal is ever killed for their leather , for their furs yes . So my feeling is leather shoes or belts or gloves your not being a hypocrite by using that type of wear . Environmentally speaking it’s quite possible leather is better than man made leathers . Leathers last years longer than the man made leathers and normally have qualities that are hard to reproduce . My leather gloves are going into their seventh winter .

    2. Simple observational studies do show an association between vegetarianism and depression, However, they usually do not examine when people were diagnosed with depression and when those individuals adopted a vegetarian diet.

      I think that most people here would acknowledge that many of us adopt vegetarian diets because we have been dignosed with a health problem of some kind. This might equally well apply to mental health as to physical health problems.

      Indeed the only study I am aware that looked at the dates of adoption of a vegetarian diet and diagnosis of “mental disorders” found:

      “The analysis of the respective ages at adoption of a vegetarian diet and onset of a mental disorder showed that the adoption of the vegetarian diet tends to follow the onset of mental disorders.”

  5. I gave up meat, eggs and dairy in January 2017. I experienced some very positive results. The insomnia I was experiencing totally went away. I had energy and felt great. I took B12 every day in the recommended form. After 8 months or so, I started having problems with my knees, shoulders and fingers. My knees felt unstable when I would pivot or turn. My left shoulder became inflamed making it painful to move my arm in certain directions. Also, my fingers in my left hand became numb and stiff especially in the mornings when I woke. I also had some numbness in one of my toes in my left foot. I suspected I was not getting enough iron or protein, but blood tests said everything was ok. I was eating an entire can of beans (black, pinto, kidney, chick, navy, white, etc)? and a can of veggies (carrots, corn, green beans, spinach, collards, etc) at lunch AND dinner everyday. Sometimes I ate fresh veggies when I had time to prepare. I ate a banana and an apple everyday, too. I ate fresh avocados in guacamole and baked sweet potatoes, too. I felt like I was getting sufficient protein, iron and fiber. I love eating plant based, but my joint ailments have caused me to reluctantly incorporate meat again. As a result, my fingers have improved, but the insomnia is back and I can’t shake depression, though I really have every reason to be happy. Any suggestions for how to prevent the joint issues I experienced on the plant based diet?

    1. A lot of people take MSM 1000 mg capsules and it improves their joint discomfort and pains. It works for me and I am 73. However, Dr. Greger is against taking any kind of supplement. He shows studies that indicate that people who take supplements do not live as long as people who do not take supplements. However, the MSM or Methylsulfonylmethane Sulfur sure has relieved me of joint pain. You can buy it in most health food stores. I buy the Bluebonnet Brand. Don’t tell Dr. Greger though.

      1. supplements can be very helpful. You don’t have to hide it from us. Thank you for telling which brand you use. 1000mg, once a day or more?


        Research suggests that as people age, their ability to absorb or process protein may decline. To compensate for this loss, protein requirements may increase with age. Megumi Tsubota-Utsugi, PhD, MPH, RD, of the National Institute of Health and Nutrition in Japan, and her colleagues in Tohoku University and Teikyo University, Japan, wondered whether protein intake might affect the functional capabilities of older adults. They designed a study to investigate the relationship between protein intake and future decline in higher-level functional capacity in older community-dwelling adults in Japan. Their analysis included 1,007 individuals with an average age of 67.4 years who completed food questionnaires at the start of the study and seven years later. Participants were divided into four groups (quartiles) according to their intake levels of total, animal, and plant protein. Tests of higher-level functional capacity included social and intellectual aspects as well as measures related to activities of daily living.
        Men in the highest quartile of animal protein intake had a 39 percent decreased chance of experiencing higher-level functional decline than those in the lowest quartile. These associations were not seen in women. No consistent association was observed between plant protein intake and future higher-level functional decline in either sex.

        1. I’m using some 9 essential amino tablets every day and a TBS or 2 of gelatin each day.

          The essential aminos have tended to strengthen musculature and the gelatin helps with joints…tendons…etc.

          I consider the aminos as a “cleaner” protein source…and the gelatin is from grass-fed cattle.

          As you get older…it’s being able to continue to function and get around that counts. Also there are certain supplements that can help strengthen bone structure.

          Don’t be like my neighbor who fell down broke his hip and now resides in a nursing home. Men have a poorer outcome than women when this happens.

          Past 65 things change…but they don’t want to acknowledge this here. That is why I have several sources for health info.

          * this post might just disappear

    2. I was looking at canned beans yesterday since i didn’t have time to soak beans for my evening meal (or spend 3 hours cooking them) but all of them contained significant amounts of salt (some also contained sugar and citric acid).

      According to

      “Many foods contain excessive salt and other preservatives to promote longer shelf lives. For some people, excess consumption of salt may result in inflammation of their joints. It may be worth trying to reduce your salt intake to as modest an amount as is reasonable.”

      it also notes
      “High amounts of sugar in your diet result in an increase in AGEs, which can result in inflammation.”

      You might want to consider dropping the canned (and packaged) foods and just go for fresh or frozen instead.

    3. It’s probably the beans, seriously. Drop those completely for a month. You should not be eating legumes every day. Replace with other grains- quinoa, millet amaranth, rice… you get the picture- but not the same thing day in day out.And what is this ‘can’ thing? Are you seriously eating out of cans?

      1. Why do you say that we should not be eating legumes every day?

        One study found that “the legume food group showed 7-8% reduction in mortality hazard ratio for every 20g increase in daily intake with or without controlling for ethnicity (RR 0.92; 95% CI 0.85-0.99 and RR 0.93; 95% CI 0.87-0.99, respectively).”

        That suggests to me that daily legume intake might be a very good thing.

        1. It’s a phytates issue, Tom. And if you are also eating a lot of beet and kale you want to watch the oxalate load. You might not be one of those wringing their hands over phytic acid but why court trouble? Just ring the changes and ensure your body is not getting the same food every day…  because that is also the route to allergy, and then you can’t eat the thing at all.

          1. Thanks, I understand your point now.

            I agree that high phytate intake, in the context of a very limited diet eaten by poor people with no access to a range of other foods, is unhealthy. Studies in South Asia and Africa bear this out. Phytates inhibit iron, calcium, zince etc absorption. However, vitamin C-containing foods boost iron absorption and leavened breads (compared to the unleavened breads often eaten in South Asia etc) reduce total phytate consumption. Beans tend to be high in iron and zinc anyway which counteracts the reduced iron availability consequent upon phytate consumption. So do whole grains.

            Also, there is no evidence – AFAIK – that (adult) vegetarians in wealthy Western countries suffer adverse health effects such as zinc deficiency from regular high phytate consumption.
            “Despite the apparent lower bioavailability of zinc, copper, manganese, and selenium in vegetarian diets because of the high contents of phytic acid and/or dietary fiber and the low content of flesh foods in the diet, the trace element status of most adult vegetarians appears to be adequate.

            The study cited in my previous post suggests the opposite conclusion, ie that daily legume consumption is beneficial

            I agree that a varied diet is advisable but i don’t see a problem with daily legume consumption as such as long as it is accompanied by fruits and other vegetable foodss. Many people in South and Central America appear to consume rice and beans twice a day without any obvious ill effects.

            Dr Greger has a number of videos etc on the phytate anti-nutrient stories found on the net

            1. Thanks for this. I agree with you on the rice issue despite the rice-arsenic hysteria.  But therein resides the problem in citing the well being of social/ethnic groups that may well have self selected for limited diets over centuries. IE the survivors are of course those who do well on a diet of say, one limited food group- sweet potatoes being an oft cited example. Every one else died off.

          2. Gillian – on the beets, kale, oxalates and kidney stone issue, my understanding is that high phytate consumtion inhibits kidney stone formation anyway but:

            “In general, certain foods increase the risk for stones, but only in people who have a genetic or medical vulnerability. People whose diets are high in animal protein and low in fiber and fluids may be at higher risk for stones. A number of foods contain oxalic acid, but there is no proof that such foods make any major contribution to calcium oxalate stones in people who do not have other risk factors.”

            Dr Greger has some useful information on both oxalates and kidney stones.

            1. Thanks for that.   I meant to refer to the phytates issue as separate from the oxalates one. I take your point with oxalates but what about phytic acid and mineral absorption?

            2. Thanks TG as always for your very helpful posts. I learn so much from yourself and other contributors on here!

              I read the labels on new brands of beans (and tomatoes) out of interest and have noticed huge diffetences in the amounts of sodium they contain. One brand of organic beans here contained 1000 mg sodium per serving !! This is rare though.. most brands, organic or not contain little. Tomatoes vary, and I check before buying.

              I do eat beans/lentils daily, and I confess that my diet is limited and repetitive. So far though, my doc says my iron has never been better (at 25 now after hovering at anemic 12 for years), and calcium is perfect, right on down the line. I am the dr’s office poster child for bloodwork lol so maybe I am just lucky to be eating the ‘right’ limited fare, or just lucky.

      2. Hi Gilliam,

        I eat a variety of beans. I also eat quinoa and other whole grains, but beans are my staple. I don’t literally eat “out of the can”, but most of my beans are purchased canned goods. I tried cooking fresh beans but I’d throw away so much because I don’t want to eat the same kind over several days. I guess I need to find recipes for small batch cooking.

        1. I cook up a big batch of black/red/brown rice and (dried) beans or other legumes – plus mushrooms and vegetable to taste – and then store it in separate meal size containers in the freezer.

          Pyrex or equivalent glass containers work well for freezer storage and you can take them direct from the freezer to the microwave for reheating

    4. Hi there. That is tough decision to make. A few thoughts I have, were the canned beans and veggies you were eating, no salt added? I would check the sodium content and consider no salt added beans and veggies or switch to fresh or frozen beans and veggies. Also, do an inventory of your diet and make sure there wasn’t any added sugar or low quality carbs- white flour etc. You also might not need so much protein. High protein diets can be somewhat inflammatory. You may have actually had more protein in your diet with all those beans than from a small amount of meat. A can of beans is about 3 servings right there and that is how many Dr. Greger recommends in a day.

      Were you given any specific diagnosis as to what the joint pain was? If it was thought to be arthritis or something specific, we can look into treating the cause. If you search around for “joint pain” and “inflammation” there is a lot of information which might help you.

      Here are a few things that might help your joint pain:

      I hope that helps.

      1. Thank you! I was probably getting 7 servings of protein each day!! In my effort to prevent a deficiency I guess I went overboard. That could be the culprit along with the can linings. Thank you!

    1. Not clear why beans from a can should be considered “dead.” In fact, nutritionally they’re no different than dried beans you cook yourself.

      Re the excess salt, everyone who eats canned beans should rinse them thoroughly beforehand. This gets rid of much, if not all, of the salt. And don’t eat or drink the can’s liquid. Yes, I know about aquafaba. Just say no to that.

      1. Yes, I drain and rinse until the water stops bubbling, which I understand is an indicator that the salt is mostly gone. I’m wondering if the BP lining in the cans is somehow introducing toxins that could be causing my joint issues.

  6. My joint pain & arthritis in my hands has noticeably disappeared since I have eliminated 90% of my dairy products & cut consumption of chicken bout 90%. I love eggs but have cut consumption about 50%
    I’ve lost a few pounds & feel healthier with more energy.

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