Book Review: Carbohydrates Can Kill

I recently read Carbohydrates Can Kill, by Robert K. Su, M.D., written in 2009.  Per’s rating system, I give it four stars ( I like it).

♦   ♦   ♦

Many developed Western societies have a love affair with carbohydrates, particularly concentrated sugars and highly processed grains and starches.  The U.S. is a good example.  Our skyrocketing rates of overweight and obesity (68% of adults) are testament to that.  Obesity is strongly linked to cancer, high blood pressure, heart attacks, diabetes, strokes, and premature death.  It’s not too much of a stretch to blame carbohydrates for at least a portion of these diseases and others.  Dr. Robert Su thoroughly reviews these connections in Carbohydrates Can Kill.

Blissfully unaware of his prediabetes

Blocked heart arteries are the No.1 cause of death in developed countries.  A growing trend among the experts is to abandon the theory that total and saturated fats cause heart disease, pointing instead to excessive consumption of sugars and processed grains and other starches.  Dr. Su makes a fairly convincing case for the carbohydrate theory of heart disease.  He’s also convinced that carbs cause high blood pressure, dementia, many cancers, diabetes, overweight, perhaps even most diseases. 

This book addresses overweight, adverse health effects of obesity, nutrition and digestion in detail, and numerous scientific studies supporting his ideas.

One of the most interesting things to me was Dr. Su’s personal medical story.  At age 62, he found himself 40 pounds (18 kg) overweight, blood pressure 205/63, and having apparent reversible heart pains (angina) when stressed or exercising.  The combination of salt restriction and exercise didn’t help.  Reducing carbs to 60-70 g/day and continued exercise (walking and stair-climbing) did the trick, helping him lose 30 pounds and controlling angina and high blood pressure.  I expected him at any time to reveal he had a heart attack, stroke, or heart bypass surgery, but he dodged those bullets.  His problems at 62 were a wake-up call.  He didn’t want to end up prematurely dead or disabled, a burden to his family and unable to spend quality time with them.  So he undertook major lifestyle changes.  Very inspirational. 

In addition to a medical degree, Dr. Su has a degree in pharmacy.  He knew he’d be put on multiple drugs if he went to a doctor for treatment of his symptoms.  Like me, he’s wary of drug side effects and wanted to avoid them, opting for diet and exercise instead.  He gambled and won.  I’m sure at least a few others would not be so lucky.

Dr. Su cites evidence that high blood sugars cause inflammation, which can predispose to cancer.  Diabetics do indeed have a higher risk of certain cancers, yet he didn’t mention that diabetics have a lower risk of prostate cancer. 

Dr. Su is anti-alcohol.  The studies are mixed on the overall health effects of alcohol, but the bulk of the studies link low-to-moderate consumption of alcohol with less cardiovascular disease and longer lifespan.  Clearly, heavy drinking can be lethal.

Like all books, CCK isn’t perfect.  First, it could have used better editing to eliminate grammatical errors and wordiness.  Next, I suspect Dr. Su is getting a little ahead of the science when he states that “….most diseases, if not all, are directly or indirectly caused by too much blood sugar.”  If carbohydrates are so deadly (mediated via high blood sugar), why do the Kitavan’s of Melanesia have such low rates of heart attack, stroke, overweight, and diabetes, despite a diet deriving 69% of total calories from carbohydrates?  (Calories from carbohydrates in the U.S. are about 50% of the total.)  Granted, Kitavan’s carbs are mostly unrefined.  Could the Kitavans be genetically protected from carb toxicity? 

So, what do we do if carboydrates are so dangerous?  Dr. Su recommends limiting carb consumption to a maximum of 100 grams a day.  (By way of reference, average U.S. carb consumption is 250 grams a day.)  Simple sugars and highly processed grains and starches should be avoided.  Additionally, he recommends a yearly glucose tolerance test to determine fasting blood sugar, then blood sugar readings every 15-20 minutes after an unspecified meal for two or three hours.  I wonder if a single hemoglobin A1c blood test would suffice.  I agree with Dr. Su that fasting blood sugars should be under 110 mg/dl (6.1 mmol/l)—if not lower—and all blood sugars after meals under 150 mg/dl (8.3 mmol/l).

Dr. Su is a tireless advocate for carbohydrate-restricted eating.  Visit his website:  If his diet and exercise ideas were widely adopted in the U.S., we’d be a healthier country.  This book is a worthy read for anyone with overweight, obesity, diabetes, prediabetes, or otherwise enamored of concentrated sugars and highly processed grains and other starches.  Note that one of every three U.S. adults has prediabetes, including half of all those over 65, and most of them are unaware.

Steve Parker, M.D.


Filed under Book Reviews

11 responses to “Book Review: Carbohydrates Can Kill

  1. 100g of carbs per day is very low. I am with Mark Sisson in that most people do well somewhere between 100-150g

    • Depending on the individual’s build, gender, physical activities, and the state of his beta cells, 100 -150 grams of daily carbohydrate may work well, so long as he consumes more carbohydrates, which are low in both glycemic indices and glycemic loads. In fact, I suggested in my book for an average person with no history of carbohydrate abuse might even do well with 125-175 grams of carbohydrates daily. The key is how these daily carbohydrate foods affect the individual’s blood glucose level. If the BG level spikes beyond 150 mg%, it is a red flag. Generally, I would like to keep the BG level around 100 mg%, or at least, under 120 mg% at all times. So, there is no such thing that one size fits all.

      • Dr. Su, many thanks for clarifying that. I’m sorry if I misrepresented your position. Indeed, it’s very difficult to tell an individual’s degree of current beta cell function and insulin resistance.


  2. Emily Deans

    I emailed Dr. Su with some Kitavan references – yet I am notnsure what he thinks. Dr. Eases may think they are adapted to a high carb diet, yet that seems unlikely given the response of most from the pacific islands to a refined Western diet… I still think it is the toxins, not the macronutrient ratio, until the liver is damaged, then who knows?

    • Dr. Deans, it could also be “okay ” to eat a high carb diet until the mass of beta cells goes out.functions. One of the other points that I had mentioned to you is the total glycemic index of the high carb diet the Kitavans are eating. The other is the Kitavan people’s physical activities. Last year, I gave a presentation to my alumni association at DC. In question and answer, a Johns Hopkins endocrinologist agreed with my assertions that carbohydrate are killing. But, he pointed out that our ancestors probably could tolerate the carbohydrate foods better than we do today, because, in the agricultural era, they had to work hard physically all day long without a stop other than the break for meals. They probably did not allow the their BG level rise so much before the BG was spent. In addition, he forgot that we have refined carbohydrates so much, which posse high glycemic indices and glycemic loads. Since we cannot handle carbohydrates like our ancestors did, the best way to avoid illness is to restrict carbohydrates.

      • Hear Dr. Su’s interview of Dr. Emily Deans at this link:

        She discusses diet and mental health and disorders.


      • Since I replied to Dr. Deans’ question, several of my podcast listeners and readers of my book (thank you, Dr. Parker, for your book review!) asked me about my thoughts on why Kitavans can consume high carbohydrate diet (300 grams from carbohydrates out of a total of 1200 grams from yam, sweet potato, and taro), which consists of a whop 69% of their daily calorie intake. But, we take a close look at the data in Dr. Staffan Lindeberg’s article, the amount of their daily total calorie intake was 2,197 Kcal. At the same time, the daily calorie intake for the average America man was at least 2,500 Kcal with an average daily amount of carbohydrates (55%) at 1,375 Kcal or 343.75 grams. As mentioned in my previous reply, the quality of carbohydrates consumed by the Kitavans and the Americans is remarkably different. Apparently, the one for the Kitavans was low in glycemic index, in comparison to the one for the Americans. I have had any data on the Kitavans’ blood glucose. I suspect that theirs were lower and less erratic than the Americans’.
        Based on my preliminary review, the Kitavan diet is lower in both total daily calorie and carbohydrate consumption, in comparison to the typical western (American) diet. Thus, they are lean and healthier.

      • You make a lot of sense, Dr. Su.


  3. Dr, Parker: No problem at all. Every individual has his own history in how his beta cells have dealt with blood glucose since the inception of his fetal life, or even his embryonic stage. I totally agree with you that it is impractical and, perhaps, unwise, to set a firm range of daily carbohydrate consumption and certain types of carbohydrates for every individual, because no two individuals would respond to the same regimens. This is one of the reasons that I hope insurance plans will eventually realize that they will benefit themselves in a long run if they cover a semi-annual or annual series of blood glucose tests for educating the individual about how his foods impact his blood glucose, at the same time, for early detecting the potential of becoming diabetic for disease prevention.

  4. I smiled when i saw Dr. Parker’s review of my book, “Next, I suspect Dr. Su is getting a little ahead of the science when he states that “….most diseases, if not all, are directly or indirectly caused by too much blood sugar.” Well, I hope he was complementing me on my foresight. After reviewing more than 1,100 articles in a very broad spectrum at the end of Spring 2008 when I completed the manuscript of my book for the publisher, I had already had a good picture of how hyperglycemia is involved in the development of many diseases. Since that, I have reviewed many more articles that either reiterate my findings or discover the relationship that I have suspected. I believe in the next decade, the science will eventually “catch up” with my observation.
    Recently, Dr. Lu Cai wrote me that he is invited to The 2nd Zhongshan International Diabetes Forum for a lecture. In his e-mail to me, “…..I believe that you have had a very good vision for the research regarding diabetic complications. You see after we discussed diabetes and cancer, there will be a meeting in China to specifically talk about it……”
    I sincerely hope we all continue to keep an eye on the role of hyperglycemia, which should not referred to the FBS and 2-hrPTT only, but should be referred to hyperglycemia at any time, 24 hours a day. Please keep in mind, hyperglycemia is inflammatory and pro-inflammatory.

  5. Dr. Su, I especially appreciated your discussion of heart disease as related to hyperglycemia and hemoglobin A1c levels. Even mild elevations above normal or average are associated with worse cardiac outcomes. More cardiologists and primary care physicians need to be aware. Even coronary heart disease is considered an inflammatory condition these days, a major paradigm shift over the last two decades.