Is a Low Carb Diet Really Healthier for You? Blood Test Results After 30 Days on a Low Carb Diet

If you are a carb-lover like me, any news that avoiding carbohydrates is better for health is hard to take. Most American meals are somehow based on carbohydrates: pasta, pizza, bread, rice, etc. Eating low carb or no carb is so hard and takes tremendous discipline.

Last month, I managed to stick to a low carb diet for 30 days. It felt like a “no carb” diet because the only carbs I ate were oatmeal, whole fruit smoothies, an occasional amount of quinoa and any small amounts of carbs that happened to be in things like tomatoes, corn, or salad dressing. I didn’t eat a single slice of bread, not one bite of pasta. Hardest of all, I ate no sugars except for fruit and any small amounts that might have been in salad dressing. I ate tons of salad greens and vegetables, lean proteins like fish, turkey and chicken, healthy raw nuts, fruits and oatmeal. That was about it.

At the end of the 30 days, I wanted to scientifically quantify whether this type of diet is healthier or not. So, I had a blood sample drawn and analyzed to measure my cholesterol, blood sugar and other basic indicators of health. (It took so much discipline to eat this diet for 30 days that I was terrified some mixup would happen at the lab and they would lose the sample. Fortunately, all went well.)

I compared the results to the blood sample drawn at my annual physical a few months ago. At that point, I would describe my diet as “normal American.” It was not the unhealthiest diet (I rarely eat fried foods or red meat) but not the healthiest either (I have a weakness for sugar and carbs and don’t eat as many vegetables as I should.)

*Note: I am not a medical doctor and none of the information below is intended to be medical advice. It is only a report of my own experience. Always consult your doctor for advice specific to your own situation.

In general

Both before and after my diet, my basic blood indicators were all in the “normal” range. Likely, most busy physicians would take a quick look at the results and say, “Well, you were healthy before and you are still healthy. Congratulations!”

Looking a little more deeply

However, when you start digging in to specific numbers on the tests, some interesting results appear.

Factors Improved

So now, for those of us who resist low-carb diets, the bad news. There are several ways that a low carb diet improves health.

Lower Cholesterol

This was a little bit of a shocker to me. In general, I had been eating more meats than normal (lean proteins like turkey and fish mostly) yet my cholesterol went down! While most of us know that eating too much meat and saturated fats raises cholesterol, how many of us know that eating too many carbohydrates does the same thing?

Lower Glucose

With diabetes such a frequent health concern, we all should pay attention to our blood glucose levels. Not surprisingly, on a low carb diet, where you are ingesting fewer sugars than normal, the blood glucose level falls. In my case, it fell to the very lowest end of normal.

Decreased Bilirubin

While distinguishing differences in liver enzymes when both are in the “normal” range is almost pointless, it does make sense that when the body is having an easier time digesting healthful foods, the liver does not have to work as hard. A lowered bilirubin level generally means that the liver is functioning well.

Confusing Factors

The results below are counterintuitive to me. I am not sure how to interpret them and will have to ask my doctor at our next visit. Based on some online research, there are numerous ways to interpret these results.

Lower HDL Cholesterol

I am fortunate to generally have a positive level of HDL (“good”) cholesterol. It was interesting to see that while my total cholesterol dropped 19% and LDL (“bad”) cholesterol dropped 24%, my good cholesterol also dropped—by nearly 20%! I assume this might be related to the decreased acetyl co-A production issue mentioned above. Lowered HDL was also found in patients in this study of ketogenic diets. There is not a lot of research done about HDL so it is hard to say what this impact means. My HDL levels were still very good, even with the reduction so I am not worried.

Increased Triglycerides

The biggest shock was seeing my triglyceride levels increase by 23%! In general, you don’t want your triglyceride levels to increase as this is a risk factor for heart disease and other problems. Many studies of low carbohydrate diets only report that participants lowered triglyceride levels. Anecdotally, however, it seems that some people on low carb diets experience at least a temporary increase in triglyceride levels, which could reflect the body using fats as a source of energy. While we use terms like “burn off that fat” or “melt that fat” when we think about losing weight or exercising, what I was not connecting is that the body essentially has to process stored fat (through a process called ketosis) and get it out of the body. So, the fat has to circulate in the blood to get out and can be detected in your tests. One source I read indicated that this diet-induced triglyceride increase is not dangerous in the same way that increased triglycerides due to over-consumption of bad fats is and that the triglyceride levels fall over time as fat is eliminated from the body. I am not sure if this is a bad or good indicator of health.

Decreased White Blood Cell Count

My white blood cell count dropped 39% between the two diets! We have been conditioned to associate white blood cell counts with strong immune systems and the ability to fight off disease. So, a falling white blood cell count does not sound like a good thing! However, some additional research showed anecdotal evidence that white blood cell counts often fall when people are on ketogenic diets. Some researchers indicate that obesity and/or consumption of diets rich in saturated fats, trans fats and high glycemic index foods promote inflammation in the body and raise white blood cell counts. Therefore, when you start eating healthier, you see decreased inflammation and perhaps lower white blood cell counts. However, another study looking at ketogenic diets in children suggests that the lowered white blood cell count could also indicate a nutritional deficiency, such as Vitamin D.

Increased AST and ALT Liver Enzymes

While some of my liver enzymes were decreased on the low-carb diet, generally showing the liver having an easier time processing food, others were not so positive. My AST and ALT liver enzymes increased by 20% and 17% respectively. Anecdotal evidence suggests this may be connected to ketosis and that the liver has to work harder to process the body’s fat stores as a supply of energy than it does to process carbohydrates. Some suggest that over time, ketosis eventually results in lowered and better liver enzyme levels.

Other blood factors

I had a number of tiny changes in my blood factors that could be interpreted to show signs of dehydration and possible iron deficiency. I had never really thought much about iron before so I hope to talk about that in a future post. The changes were small but it does highlight that you have to be careful when you undertake any drastic dietary changes. Each body is different and has different dietary requirements for optimal health.

So, overall, how do I answer the question, “Is a low carb diet healthier?” I think the answer is that medical science is still catching up with popular dieting trends and the results aren’t fully understood yet. Most of us eat way too many carbohydrates and can have better health if we eat less of them and more of the healthy stuff like vegetables and lean proteins. However, we don’t need to cut out all carbohydrates completely and if we do, it might not be good for us. Eating more of the good kind of carbohydrates (whole grains) and less of the bad kind (simple sugars and candies) is another area we need to work on.

Have you experimented with low carb diets? Did you see any of the above health effects? After seeing this evidence, are you more or less convinced of the merit of low carb diets? Please share in the comments.