Paleo Diet Side Effects

Time to clear up some misconceptions about the Paleo diet. An article I just read on the Live Strong website by Corinne Shaw, asks if the Paleo diet has side effects, then proceeds to answer that question. I agree, it is important to know if there are any side effects of any eating plan and it’s important to know what can be done about them. However according to my research there really aren’t any negative side effects, if the diet is followed correctly. And I also believe that the author, who has done her research, has gotten some misinformation. Let’s see where the Paleo diet stands.

First is the overview, a description of the basic diet which is accurate.  Here also is the introduction of the idea of side effects.

… eating program based on the belief that humans are best adapted to the foods consumed thousands of years ago. Featuring fresh fruits, lean meats, seafood, vegetables, fruits, nuts and seeds, the caveman diet mimics the menu of early hunter-gatherers while shunning neolithic foods, such as dairy products, grains, legumes, tubers and refined sugar. Although the diet may offer some health perks, it may also result in undesirable side effects in the long term. Consult your physician before adopting a caveman diet…

What side effects could she be referring to? She lists osteoporosis, kidney problems, high cholesterol and constipation. Let’s look at each of these.


Because the caveman diet excludes many high-calcium foods, such as dairy, tofu, fortified cereals, calcium-enriched beverages and soy milk, it may provide insufficient levels of calcium, a mineral essential for bone health. To maintain strong bones and reduce your risk of osteoporosis, the National Osteoporosis Foundation recommends that adults under 50 years old get 1,000 mg of calcium daily, and adults over 50 get 1,200 mg daily. On the caveman diet, you may need to eat ample amounts of leafy green vegetables and bone-in fish to meet your calcium requirement.

There is too much hype about calcium. You cannot turn on the TV without seeing an ad for yogurt without being told how much calcium is in it. Yes, calcium is important as long as you get it with other minerals and vitamins such as magnesium, potassium and Vitamin D. But calcium is not the definitive word on strong bones. In fact too much calcium can cause bone loss. Having said that, the Paleo diet would have been filled with foods that contain exactly the right amount of calcium. And if you want to avoid osteoporosis, then the food to avoid is dairy. Studies have been done looking at the consumption of dairy in different countries. Countries where the most dairy is consumed had higher incidence of hip fractures. In countries with the lowest consumption, hip fractures were virtually unknown. Not getting enough calcium from the diet does not seem to be an issue.

Kidney Problems

The caveman diet is based on high-protein foods, like lean meats and seafood, and may result in an excessively high protein intake. According to a paper published ….”high-protein diets can reduce calcium absorption and cause kidney stones, especially when carbohydrate intake is also low”. adds that high protein intakes may cause or worsen kidney problems because protein metabolism creates waste products that place stress on the kidneys. Consuming a caveman diet that emphasizes fruits and vegetables over animal products may help prevent kidney problems.

The above statement is a myth that is not supported by the facts. Eating a high protein diet does not cause kidney problems. In fact a paleo diet may actually prevent kidney problems. From

Although protein restricted diets are helpful for people who have kidney disease, eating meat does not cause kidney problems… Furthermore, the fat-soluble vitamins and saturated fatty acids found in animal foods are pivotal for properly functioning kidneys …

Many experts attempt to explain how meat supposedly “acidifies” the blood, leading to greater mineral loss in the urine is also incorrect. Theoretically, the sulfur and phosphorus in meat can form an acid when placed in water, but that does not mean that is what happens in the body.

Actually, meat provides complete proteins and vitamin D (if the fat or skin is eaten), both of which are needed to maintain proper acid-alkaline balance in the body. Furthermore, in a diet that includes enough magnesium and vitamin B6 and restricts simple sugars, one has little to fear from kidney stones …

What else is there to say? Do not worry about kidney problems if you are going paleo!

High Cholesterol

Because the caveman diet emphasizes foods high in cholesterol and saturated fat, such as meat, shellfish, organ meats and eggs, it may raise your blood cholesterol to high levels. As explains, high cholesterol can result in plaque deposits in your arteries, causing decreased blood flow and raising your risk of a heart attack or stroke. If you follow the caveman diet, have your cholesterol level monitored by your physician and limit your consumption of high-cholesterol foods and those high in saturated fat.

This assertion that eating foods that contain cholesterol cause heart disease is incorrect. It has been shown that the consumption of high fat foods has no impact on cholesterol (and here).  In fact it may be carbohydrates and damaged vegetable oils that are some of the culprits.  This idea that eating fat causes heart disease has probably caused more heart problems than any other piece of misinformation. Again from

You are probably aware that there are many myths that portray fat and cholesterol as one of the worst foods you can consume. Please understand that these myths are actually harming your health.

Not only is cholesterol most likely not going to destroy your health (as you have been led to believe), but it is also not the cause of heart disease.

So go ahead and have that nice juicy steak, broccoli on the side with butter. Just hold the potato!


The caveman diet excludes some common sources of dietary fiber, such as whole grains, legumes and tubers, potentially reducing your intake of fiber. Along with improving constipation and promoting regular bowel movements, fiber plays a role in maintaining intestinal health, controlling blood sugar levels, lowering your cholesterol and potentially protecting against colorectal cancer. To avoid the effects of insufficient fiber on the caveman diet, consume ample amounts of high-fiber fruits, vegetables and nuts …. Click here to read the entire article

Here is another over-hyped idea, that dietary fiber from grains and legumes is needed for good digestion. A Paleo diet contains enough fiber for regularity and good digestion.  On a personal note – I have been following the paleo diet for a year. I have noticed several beneficial “side effects”. I am extremely regular, going one to two times per day and I have virtually no gas or bloating. When I ate grains, it was a non-stop toot fest.

So, the upshot is that a Paleo diet has none of the side effects listed above. In fact I would say that side effects from the Paleo diet amount to benefits. I can find no down side to the ancestral diet at all.

What is your opinion?


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4 Responses to Paleo Diet Side Effects

  1. Stephanie July 10, 2011 at 2:14 pm

    If you have not already done so, please leave a link to this article as a comment to the LiveStrong article. As someone who writes for LiveStrong, I can assure you they’ll be happy to have this info available for their readers.

    • Lila July 10, 2011 at 4:40 pm

      Thanks for the reply, Stephanie and the advice. I just tried to leave my comment and I couldn’t I will try again later.

  2. Dana July 10, 2011 at 3:26 pm

    The other thing about meat being “acid” in the body has to do with the protein molecule’s greater amount of hydrogen, plus the presence of nitrogen in that molecule where it does not exist in the fat or carbohydrate molecule. The idea is that the body has to use calcium to “buffer” the acid formed from meat-eating. Well… no, not really. See, animal protein comes with its own buffer: the amino acid glutamine (not to be confused with glutamic acid or glutamates). Glutamine is a conditionally essential amino acid, meaning sometimes we can make it and sometimes we can’t. When we’re sick, we’re less likely to make our own. In any case, it’s necessary in enough bodily processes that it’s a good idea to also consume some for backup.

    In any case, glutamine’s nifty. It is pivotal in the kidney for turning excess hydrogen and nitrogen into ammonia. Presto, your pH is normal and you just pee out the excess.

    Not all proteins have glutamine in them. Plant proteins are notoriously glutamine-poor. Wheat has a fair amount; so does spinach. No one is going to want to eat enough spinach to meet all their protein needs; even if you could choke down that much plant matter in one day, the oxalic acid would do its own damage to your bones. And I don’t think I need to tell anybody here what’s wrong with getting all your protein from wheat.

    Studies are beginning to surface, in fact, correlating a high intake of PLANT protein with bone loss later in life. I don’t one hundred percent trust them yet as most of them (if not all) appear to be observational studies–but I can see how such a thing would happen, and it certainly explains why some vegans go back to meat-eating after suffering bone loss and weird fractures on their former diet. Just ask Lierre Keith. She’ll give you an earful.

    • Lila July 10, 2011 at 5:04 pm

      I came across that info too, about plant proteins causing bone loss. But I already had too much to write and so it didn’t get in to the article. But thanks for posting it here. I have vegan friends who sometimes look at me as a pariah since I won’t give up meat (as if I could!). But we just agree to disagree. At some point I expect they will start paying attention to me. :)