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Flickr/kowitz

There is no one right way to eat for everyone.

We are all different and what works for one person may not work for the next.

I personally advocate consumption of both animals and plants and I think there is plenty of evidence that this is a reasonable way to eat.

However, I often get comments from vegans who think that people should eliminate all animal foods.

They frequently say that I'm giving out dangerous advice, that I must be corrupt and sponsored by the meat and dairy industry, or that I'm simply misinformed and need to read The China Study.

Really… I have nothing against vegans or vegetarians.

If you want to eat in this way for whatever reason and you are feeling good and improving your health, then great! Keep on doing what you're doing.

But I do have a serious problem when proponents of this diet are using lies and fear mongering to try and convince everyone else to eat in the same way.

I'm tired of having to constantly defend my position regarding animal foods, so I decided to summarize what I think are the key problems with vegan diets.

Here are 5 reasons why I think vegan (as in no animal foods at all) diets are a bad idea…

1. Vegans are deficient in many important nutrients.

broccoli
Flickr/Lloyd Davis
Humans are omnivores. We function best eating both animals and plants.

There are some nutrients that can only be gotten from plants (like Vitamin C) and others that can only be gotten from animals.

Vitamin B12 is a water soluble vitamin that is involved in the function of every cell in the body.

It is particularly important in the formation of blood and the function of the brain.

Because B12 is critical for life and isn't found in any amount in plants (except some types of algae), it is by far the most important nutrient that vegans must be concerned with.

In fact, B12 deficiency is very common in vegans, one study showing that a whopping 92% of vegans are deficient in this critical nutrient (1).

But B12 is just the tip of the iceberg… there are other lesser known nutrients that are only found in animal foods and are critical for optimal function of the body.

Here are a few examples:

  • Animal protein contains all the essential amino acids in the right ratios. It is important for muscle mass and bone health, to name a few. Vegans don't get any animal protein, which can have negative effects on body composition (2, 3, 4, 5).
  • Creatine helps form an energy reservoir in cells. Studies show that vegetarians are deficient in creatine, which has harmful effects on muscle and brain function (6, 7, 8).
  • Carnosine is protective against various degenerative processes in the body and may protect against aging. It is found only in animal foods (9, 10, 11).
  • Docosahexaenoic Acid (DHA) is the most active form of Omega-3 fatty acids in the body and primarily found in animal foods. The plant form of Omega-3s, ALA, is inefficiently converted to DHA in the body (12, 13, 14).

Two other nutrients that have been demonized by vegan proponents are saturated fat and cholesterol.

Cholesterol is a crucial molecule in the body and is part of every cell membrane. It is also used to make steroid hormones like testosterone. Studies show that saturated fat intake correlates with increased testosterone levels (15).

Not surprisingly, vegans and vegetarians have much lower testosterone levels than meat eaters (16, 17, 18, 19).