Processed foods, low-carb diets linked to depression


Studies document that consumption of processed foods increase odds of depression, and not only that, but those high protein, high fat diets (high in animal products) are also linked with more depression. The diet to protect against depression – that is simple, a high nutrient, plant-based diet outlined in my books, Eat for Health and Eat to Live

In one study, middle-aged subjects were categorized by their dietary patterns based on how much “whole” or “processed” food they consumed. The high processed foods group was characterized by high intake of sweetened desserts, fried food, processed meat, refined grains, and high-fat dairy products. Five years later, the researchers evaluated how many of the subjects had reported depression symptoms.

Subjects who ate the most whole foods had the lowest odds of depression, and those who ate the most processed foods had the highest odds of depression – 60% increased odds compared to those who ate the least amount of processed foods.1

Another study compared the effects of low-fat plant-based diet and low-carbohydrate animal-product-rich diet on mood in overweight women. Although both groups lost similar amounts of weight over one year, measures of mental health and mood only improved in the low-fat group. The low-carb dieters eating more fat and animal products had higher depression scores. The authors also cited previous human studies in which high protein, low-carbohydrate diets have resulted in cognitive impairment.2

A third study measured scores of depression before and after removing meat, poultry, and fish from subjects normally eating a typical American diet. Indicators of depression significantly decreased after removing all the animal products and shifting to a plant-based diet for 2 weeks. 3

Nutrition is crucial for regulating mood – high oxidative stress in the brain and low levels of several micronutrients have also been linked to depression.4  

These studies are a reminder that what we eat affects not only our physical health but our mental health as well. Combine great diet with light therapy, exercise, sufficient Vitamin D and the right fatty acid balance for the brain, and you have my protocol to beat depression



1. Akbaraly TN et al. Dietary pattern and depressive symptoms in middle age. Br J Psychiatry. 2009 Nov;195(5):408-13.

2. Brinkworth et al. Long-term Effects of a Very Low-Carbohydrate Diet

and a Low-Fat Diet on Mood and Cognitive Function. Arch Intern Med. 2009;169(20):1873-1880

3. Beezhold BL et al. Preliminary evidence that vegetarian diet improves mood. American Public Health Association 2009 National Meeting, Abstract 206464. 

4. Leung BM, Kaplan BJ. Perinatal depression: prevalence, risks, and the nutrition link--a review of the literature. J Am Diet Assoc. 2009 Sep;109(9):1566-75.


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Comments (8) Read through and enter the discussion with the form at the end
Rick Ernst - November 13, 2009 1:52 AM

Let me understand this. Our predecessors throughout history ate animals. You're saying they were all depressed? How did they advance from prehistoric to modern days through all that depression? I eat much meat, avoid processed carbs, and am doing just fine. This entire article does not ring true.

Based on my experience, carbs are the kiss of death, create short term energy spurts, and then throw people into depression. Cokes, cookies, cakes, sugar, flour, rice, potatoes (processed white foods) need to basically go away and need to be replaced with more protein, fat, vegetables, fruits, and clean water.

I don't get where you are coming from with this article.

Victor - November 13, 2009 11:42 AM

I can attest to this type diet. I went on a cleanse fast for a few days, then started eating all sorts of frozen vegitables. I ate Only steamed Veggitables and fruit for 3 weeks, and on average, I lost 10 pounds a week.

I would have lost more if I would have been motivated to continue the diet.

Deana Ferreri - November 13, 2009 2:00 PM

Keep in mind that the amount of animal products consumed by our ancestors would pale in comparison to what the typical American consumes today. They were eating for survival, not for recreation.

Your comments on processed foods agree with the first study mentioned in the blog post.

carfree - November 13, 2009 3:51 PM

Gee, Rick, how did you read "odds of depression", and "linked to depression", and then claim that Dr. fuhrman implied that ALL meat eaters were depressed? Your argument is disingenuous, his is not.

Monty - November 16, 2009 3:24 PM

The only need for animal products is for primitive societies in cold climates to survive the winter when plant foods are not available. The level of intelligence in these societies is very low and the life expectancy is very short.

Sam - November 18, 2009 6:01 PM

Hey Rick!

"Our predecessors throughout history ate animals."
So what were their health conditions? Life spans? Quality of life? Were they eating for survival or looking to optimize their health potential? I prefer looking to modern day examples of healthy, long lived societies and modern nutritional science.

"carbs are the kiss of death". Ah, a grand fallacy of the low-carb movement. Carbohydrate is the favored fuel source. I agree with you in eliminating processed carbohydrate. But since you are basing your post on your experience, please tell me what I'm supposed to anticipate as I drop 8-10 bananas in a blender with other assorted fruits (mango, pineapple, papaya, strawberry, blueberry, etc)? A diet high in carbs AND fat is the problem. Excess fat inhibits the bodies ability to efficiently process and use carbohydrate. Low-carbers choose to eliminate the carb and get their energy from fat. Someone like myself chooses to eliminate the fat and focus on nutrition natural to primate physiology beginning with high fruit & vegetation. There are several examples of long lived, pristinely healthy societies living according to this type of diet (read Health at 100). Can you show me similar (lifespan beyond 90, full health, etc) examples based on low-carb?

OweEng2 - December 9, 2009 4:08 AM

Medical Research and Studies these days are becoming more and more weird. I mean, I for one eat a lot of animal products though I don't feel depressed at all. Well, Maybe because I go to the gym regularly and exercise at least 30 minutes each and everyday of my life.

Amy - October 22, 2010 12:29 PM

I believe it. From my own experience, when I switched from eating a lot of processed foods to more healthy natural foods my moods became a lot better.

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