High-protein diet makes me less prone to depression. Why?

March 12, 2008 8:01 AM

I've started a high protein diet and my mood has stabilised a lot. I feel more balanced. What's likely going on? Read on for important info.

I'm a vegetarian and, up until four months ago, ate a carbohydrate-heavy and mostly low-fat diet. I was almost vegan -- no eggs, very little cheese. Mostly grain-based food (bread, cereal, pasta) and beans/pulses.

Now I eat a high-protein diet, eating cheese, Quorn, soya (in various forms), eggs, and so on. I limit myself to around 40-60g of carb a day, which allows for vegetables with meals, and a slice of wholemeal bread for lunch.

I've always wrestled with mild depression in the form of mood swings but, since starting the diet, I've been a lot more balanced. It's almost been a miracle cure. I gave up caffeine a year ago for this very reason and that also helped, but a high protein diet seems to have been the finishing touch.

I've been researching what might be going on. Most obvious is that this is a low-GI diet, so I'm not prone to mood swings caused by rushes of glucose in my blood.

But I also read that having too little cholesterol in your blood can made you depressed, and I wonder if eating a higher quantity of eggs and cheese means I now have more cholesterol.

I'd love to hear anybody's opinions on this, especially if this is something you've experienced too.

posted by deeper red to Health & Fitness (23 answers total)

It's the blood sugar. It sounds trivial, but once you've stabilized that and stop the swings, it's amazing the effect it has.
posted by unixrat at 8:12 AM on March 12, 2008

Placebo?

I've heard people have more energy/feel more focused/feel happier for a huge range of various dietary changes. Examples: cutting out wheat, or eat more whole grains, or cutting out dairy, or adding more dairy, cutting/adding more soy, cutting/adding meat, etc. So whenever someone makes a dietary change it seems that the expected result pretty much...happens.

I'm not a huge believer in the glycemic index, but, it could be that the balance of macronutrients is more suitable to you individually.
posted by red_lotus at 8:25 AM on March 12, 2008 [1 favorite]

Yep, blood sugar. Getting off sugars and starches was the best thing I've done in a long while.
posted by sanka at 8:25 AM on March 12, 2008

There are several amino acids (at least, Tyrosine, Serotonin and Phenylalaline) that are used by the body to make mood elevating (or ameliorating) neurotransmitters.

Here is a Neuropsychopharmacology paper on the subject. The paper is not unequivocal.
posted by OmieWise at 8:30 AM on March 12, 2008

I would also go with enhanced production of neurotransmitters from elevated levels of essential amino acids - specifically tryptophan and tryosine. We've seen improvements in our son's mood when he's taking 5HTP, which is similar to tryptophan. Research has been done on using amino acids to treat depression and other issues. I would not say the research that I have seen is unequivocal (per OmniWise) but it is interesting. Elevated levels of certain amino acids may not affect everyone the same and maybe it's a placebo effect, but it seems to help some people.
posted by GuyZero at 8:43 AM on March 12, 2008

I had the same experience. First I stayed veg and just added whey protein and eggs. I noticed a big increase in both physical and emotional stamina. In fact, I sometimes had too much energy and ate carbohydrate to settle down. My depressive tendencies faded, and a friend actually pointed out that I was more outgoing.

Now I've backed off the whey but eat some chicken almost every day, and while I'm not gorging on protein (probably get less than the RDA), I'm still emotionally sturdier than I was when I was veg.

I increased my protein intake about 2 years ago and the effect has persisted, so I don't think my change is a short-term placebo effect.

I had never heard of the cholesterol-depression link, and it intrigues me. I had my cholesterol measured once as a veg, and it was extremely low (the LDL was 17, for example). I'll have to check it again and see if it has changed.
posted by PatoPata at 9:05 AM on March 12, 2008 [3 favorites]

Response by poster: PatoPata: I'm a committed life-long vegetarian, and that isn't about to change, but I'm starting to realise vegetarianism might not be for everybody. My father suffers badly from depression (it's controlled by medication) and has been a vegetarian since the 80s, when he was in his mid-40s. Prior to that he was a normal person. I've got to wonder if his vegetarianism has something to do with it. Vegetarian diets can be practically 100% carbohydrate if you aren't careful.

I wonder if we'll read more about this sooner or later.
posted by deeper red at 9:30 AM on March 12, 2008

You might want to give Gary Taubes' Good Calories, Bad Calories a read for answers to some of these questions. I noticed the same effects when I started a low carb, high fat, high protein diet. I've honestly never felt better in my life. A couple of days ago I "cheated" and ate a bunch of junk food. Wow, did I really feel that this stuff was worthwhile at some point? I mean I still ate quite a bit of it but I didn't feel the same enjoyment that I get from a medium rare steak or my low carb chicken curry. It just felt mindless and my mood slipped quite a bit. So I don't think what you're experiencing is unusual at all. Go to any lowcarb bulletin board like forum.lowcarber.org and read what people say about their mood swings and depression disappeared after trying this diet. And good luck!
posted by peacheater at 9:42 AM on March 12, 2008

I've got to wonder if his vegetarianism has something to do with it. Vegetarian diets can be practically 100% carbohydrate if you aren't careful.

I was a vegetarian for 5 or 6 years, and my diet was pretty close to the 100% carb stereotype -- I also ate some dairy, eggs, and tofu, but mostly it was beans/rice/pasta, wash/rinse/repeat. 2 years ago, I switched over to a meat-and-veg-rich, low-starch diet due to Ankylosing Spondylitis. The diet has worked really well for me. It's sort of hard for me to isolate any mood benefits from the physical ones, though... mainly because I'm not in severe pain anymore, so of course my mood is better!

That said, I think there's really something to this diet. To me, it seems as if I have a lot more energy, energy that's more evenly distributed throughout the day. I don't get as low before meals, for example, and I don't get suddenly hungry a couple of hours after I eat. I think it's fair to say that my mood is more balanced, also -- I've always had a hell of a temper, and some of my friends have mentioned that I've been able to control it better during the last 2 years. Maybe that's just because I'm getting older, but it's a data point for you, at least.

I agree with those who suggested some sort of "perfect storm" caused by the combination of steady blood sugar levels and amino/fatty acids. I also take flaxseed oil, and I find that the omega-3s in it also seem to help keep me feeling healthy. If you're not getting any flax and/or hemp in your diet, you should try it for a week or two and see what you think. I usually just knock down a shot of it after dinner, but you can put it in salad dressings and the like if you don't like it straight.
posted by vorfeed at 10:11 AM on March 12, 2008 [2 favorites]

I find it somewhat difficult to digest carbs (varies on the food). This makes me very lethargic and being lethargic usually leads to moodiness. Toss in the blood sugar swing and its not a great combination. I dont have much proof other than eating better usually leads to better moods, at least for me.
posted by damn dirty ape at 10:22 AM on March 12, 2008

Your diet can and will affect your mood, any qualified nutritionist/food scientist will tell you this.

For some reason, people allow the effects of their food to remain a mystery. For some, I think that it allows for better excuse making... "I don't know why I am tired / gaining weight / losing weight / depressed, etc." It reminds me of all those people who don't understand why their mortgages are so expensive now. The information is documented, available and not that hard to understand if you are willing to put the time in. Food science is an advanced field, people.

One of the best things I ever did was invest a couple of hundred bucks in some meetings with a nutritionist (I am an athlete, wanted to understand how to best fuel myself without subscribing to trends or fads). The result of my investment was a significant change in my understanding of how our bodies use different types of fuel. I don't eat like a monk (in fact, I find that I eat a much richer diet now), and if I want to lose a few pounds, I can make it happen like clockwork. If I feel a bit depressed, I can think about my food and usually find the answer.

As for how this relates to vegetarianism - on of the things I learned is how difficult it really is to eat the kind of food your body needs if you are vegetarian - it requires a lot of vigilance. Of all people, those who impose restrictions on their diets are the ones who most need to take an unbiased food-science course or work with a nutritionist - learn from someone who doesn't have an agenda.
posted by chuke at 12:56 PM on March 12, 2008 [3 favorites]

Good Calories, Bad Calories is huge and is more about the science establishment and it's acceptance of the low fat diet as dogma that it is about the actual science of these diets (at least the several hundred pages I read).

Try "The Carbohydrate Addicts Diet" for something more focussed on the protein/carb/mood/energy thing.
posted by jefftang at 1:01 PM on March 12, 2008

I agree that GI has something to do with it. Meals that contain a mix of protein, carbs, and fat help to keep your energy levels stable. The % of each is up for debate, but for example, with the ZONE its 30/40/30.

But, it could also be that you are getting more B vitamins (you didn't mention vitamin supplements before or after). B vitamins are important to healthy brain functioning, especially B12. Since B12 is found in foods of animal origin including meat and milk products, vegetarians can be in need of it (and, those who drink alcohol if that is the case too).
posted by hazel at 2:30 PM on March 12, 2008

Re your dad: He could try following your example to get more protein still be vegetarian. I did it for my last year of vegetarianism, so I certainly wouldn't say that vegetarians should jump ship to get more protein.

I was veg for 25 years. I was mildly and sometimes severely depressed for most of that time. For what it's worth, I seem to be a mesomorph: I have more muscle than other women, and I'm "sturdy," so maybe I naturally need more protein than others might.

This is the thinking that led to me eat chicken after I realized that protein made me feel better:

For health reasons, I can't eat soy protein. The non-soy, all-veg protein powder I found gave me digestive trouble. The next best was whey. My body liked it, but I did a lot of research and couldn't find whey protein that was from grass-fed cows on small farms. I concluded that by buying the whey I was supporting factory farming, which on my personal ethical scale is worse than actually eating an animal that was "humanely" raised on a small farm. The whey is also shipped great distances, while the chicken is local.

I used to raise ducks for their eggs so obviously have no ethical problems with keeping domestic animals on a small scale.

Eating that first piece of chicken was weird, but I was also craving it. I guess everyone has to find their ethical "sweet spot" when it comes to food and health.
posted by PatoPata at 2:46 PM on March 12, 2008

I find it somewhat difficult to digest carbs (varies on the food). This makes me very lethargic and being lethargic usually leads to moodiness.

Me too. I can't eat much in the way of pasta, rice, oatmeal etc without getting headaches, nausea and generally feeling terrible. Bread I can digest fine, especially sourdough or other white bread. Today I had a burrito for lunch, with tons of rice, then promptly got very nauseous and now I have a headache that will be a medium sized migraine in a few hours.

Damn you, tasty burritos!
posted by fshgrl at 5:24 PM on March 12, 2008

It would be quite easy to test the theory of whether this is the low carbs, or the increased protein. Keep the protein, and add in some more carbs. Start feeling shitty again? It's the carbs. Stay happy? The absence of protein was your problem. You can theorize all you want, but if it were me I would want to know, especially since eating low carb can be a really hard thing to do for the long-term.
posted by ch1x0r at 5:28 PM on March 12, 2008 [2 favorites]

Other people have covered the whys behind your experience, but I will add my data point. I was recently vegetarian for about 7 months. I was cranky and depressed for most of that period. I went back to eating meat, roughly every other night, mostly chicken or fish (after reading about fishery depletion, that will probably shift to mostly chicken). My mood improved, my muscle tone improved, my general sense of well-being went right up.

My boyfriend is, like you, a committed lifelong vegetarian (eats dairy and eggs) and I wouldn't try to change that. But it's not a diet that works for all people and it is much harder to be a high-protein vegetarian than an omnivore. Having said that, as you've noticed, it can be done so good on you for making it work.

I guess everyone has to find their ethical "sweet spot" when it comes to food and health.

Quoted for truth.
posted by fuzzbean at 5:49 PM on March 12, 2008 [4 favorites]

I don't have an answer to your question but I am really interested in this. Can you post more specifically about what you eat on a typical day? Quantities, what kind of meals, that sort of thing? Right now I'm imagining you eat blocks of cheese and tofu all day which I'm sure is not correct... I would love to try this without resorting to eating meat if at all possible.
posted by dinkyday at 4:47 AM on March 13, 2008

The people I met that said that vegetarian diets did not work for them or do not work for everybody ate unhealthy vegetarian diets (even though they thought they were eating healthy) and switched to healthier diets with meat. It was not the meat that helped them, it was the better balanced diet. Of course, vegetarian diets can be just as balanced, without things like "protein powder", but I do think it is harder for some people than it is for other people.
See also less grains more greens and the I was vegan for awhile, but... section on veganhealth.org.
posted by davar at 7:05 AM on March 13, 2008 [1 favorite]

Response by poster: he people I met that said that vegetarian diets did not work for them or do not work for everybody ate unhealthy vegetarian diets (even though they thought they were eating healthy) and switched to healthier diets with meat. It was not the meat that helped them, it was the better balanced diet.

Hmmm, I'm not entirely sure this argument adds up. To remind you, I'm a lifelong vegetarian, and have been for around 20 years now. I've also tried being vegan for lengthy periods.

I'm in a situation now of being a vegetarian, and passionately believing vegetarianism is right, but not being able to recommend it to other people.

The reason is that I think an average human diet should contain a very high percentage of protein (60%+), and that vegetarianism struggles to provide that. This is a peculiar point of view but my personal experience points to it being correct.

Soya and cheese aside, even the foods quoted by vegetarians as being high in protein actually contain more carbohydrate than protein in percentage terms. Beans have more carbohydrate in them than they have protein. Cooked peanuts have slightly more protein than carb, but only just. Tofu is the exception, of course, but one can't eat tofu forever. Heck, even eating it for one meal can be a trial sometimes.

A typical vegetarian meal might have a carbohydrate portion in the form of starchy foods (potato, pasta, rice, bread), and then more carbohydrate in the form of vegetables, and then the "protein" part, which itself might be at least 50% carbohydrate! Many, many vegetarian recipes I've seen don't directly involve ANY protein at all, apart from what little is found in the likes of wheat. It's quite alarming when you read a vegetarian cookbook from this point of view. Vegan cookbooks are even worse.
posted by deeper red at 9:05 AM on March 13, 2008

Soya and cheese aside, even the foods quoted by vegetarians as being high in protein actually contain more carbohydrate than protein in percentage terms.

I agree -- this is why I had to quit vegetarianism when I discovered I needed a low-starch diet, even though I loved my veg meals and would have been quite happy to eat that way forever. There just aren't enough non-meat sources of protein that don't contain loads of starchy carbs. The canonical low-starch diet book even has a chapter that says "sorry, but it's almost impossible to follow this diet and be a vegetarian".

At any rate, I think it's a bit of an overstatement to claim that people who quit vegetarianism and start eating meat are benefiting from a "better balanced diet [...] not the meat". The vast majority of people who do this don't make a major change in their diets, other than adding some meat to the things they already eat, so it's a little disingenuous to suggest that the benefit isn't due to the meat! Yes, a better balanced vegetarian diet might also have helped, but that doesn't change what's actually happening here. A balanced, carb-light and protein-heavy diet isn't anywhere close to as easy to maintain as a strict vegetarian as it is when you try a mostly-veg diet with some meat... that's just a fact of nutrition. That sort of diet is a more important health factor for some people than it is for others, and so some people will have more trouble with maintaining healthy vegetarianism than others, no matter how hard they try.

I guess everyone has to find their ethical "sweet spot" when it comes to food and health.

Agreed. There are lots of possible choices, here -- as long as someone is actually thinking about these issues, there's not much reason to freak out over their position on the spectrum.
posted by vorfeed at 11:07 AM on March 13, 2008

If you believe that an average human diet should contain 60% protein, I agree a vegan diet is impossible.
The vast majority of people who do this don't make a major change in their diets, other than adding some meat to the things they already eat
But that's exactly my point! Most people who become vegetarian do not change their diet very much, they just cut out the meat (or replace it with nutritionally almost useless fake meat). That will lead to an unbalanced diet. They will feel better when they add in the meat again. A healthy vegetarian diet (a'la Fuhrman, Esselstyn or even McDougall or Ornish) is very different from a standard American diet.
posted by davar at 1:38 PM on March 13, 2008

But that's exactly my point! Most people who become vegetarian do not change their diet very much, they just cut out the meat (or replace it with nutritionally almost useless fake meat). That will lead to an unbalanced diet. They will feel better when they add in the meat again. A healthy vegetarian diet (a'la Fuhrman, Esselstyn or even McDougall or Ornish) is very different from a standard American diet.

Yes, I agree. However, I don't see how there is any way to phrase that while denying that "meat" is what's making people feel better or not, not "a balanced diet". Especially considering how ridiculously unbalanced the standard American diet is, even with the meat. It's not a general sense of nutritional balance that's the problem, here, it's a specific lack of protein as a percentage of calories. Even a healthy vegetarian diet a la Fuhrman is going to have a high ratio of starch & carbs to protein, that's just the nature of the beast.

For example, when I was vegetarian I was also lifting weights, so I was purposely aiming for a protein-rich lifestyle. I also wasn't eating a standard American diet. I was getting my proteins mainly from beans, nuts, green leafy veg, and other Fuhrman-approved whole foods, but the FitDay percentages still came out bad as often as good, because there wasn't much that was filling and protein-rich but not also full of carbs. And I wasn't aiming for anything even close to 60% protein -- my target was just 20%, and I was still falling short on at least 3 days out of every 5. I started eating a lot of fat-free yogurt (i.e. processed junk) to try and make up the difference. I also had quite a bit of trouble with getting enough calories for weight gain. These days, I eat meat (but I'm still nowhere close to a standard America diet), and I've made noticeable progress in weightlifting without much struggle. To me, the difference is obvious.

Vegetarianism does not provide a good protein ratio, at least not if your idea of good is on the higher end of the scale. Thus, some people do well on veg diets, others do not, and it's not necessarily a failure of "balance".
posted by vorfeed at 8:38 AM on March 14, 2008