Sunday, January 29, 2012

The China Study Part III: Animal Protein, Good or Bad?

Atkins, South Beach, Sugar Busters, and the list goes on. Fad diets will probably always surround us and continue to confuse the general public. Unfortunately, it seems that Campbell is planting the seed for another fad with The China Study (1). Don't get me wrong, as I said in the last post, Campbell is completely right that we need more fruits, vegetables, and whole grains in our diet. We also need less refined foods and meat. However, is there really truth to the claim that all animal protein is slowly killing Americans?

As I mentioned in Part I of this discussion of The China Study, Campbell bases the idea that animal protein is detrimental on a study that linked casein to cancer. On page 104, Campbell states, "casein, and very likely all animal proteins, may be the most relevant cancer-causing substance that we consume (1)." So, it is Campbell's opinion that all animal proteins cause cancer. There is no proof and in the peer-reviewed journal article, a claim about animal protein being a carcinogen is not made (2).

The second major study (3) that Campbell draws his conclusions from was an ecological study that he performed in China. In the study, nutritional intake was compared to cholesterol levels, body weight, and many other factors that may be predictive of chronic disease. The study was very interesting and gave some insight to the idea that a whole foods diet high in plants can lead to a life with less disease. Other than the fact that this type of study cannot prove cause-and-effect, it seemed that it was fairly well designed. Of course there were limitations to the study, but it still produced a lot of interesting information. The biggest concern I had with the design of the study was that blood samples were pooled by commune, age, and sex. Those pools of blood were then used to measure a number of biochemical markers. I asked several Medical Doctors and other people skilled in research about this technique. Not one person failed to raise an eyebrow at this. It seems like a lot of validity would have been lost in dumping everyone's blood sample together and just taking an average. The actual study that was published in the American Journal of Clinical Nutrition, stated that "any inferences concerning cause-and-effect relationships should be considered to be hypothetical only, with validation to be provided by intervention or prospective analytic studies on individuals." In the book that Campbell wrote, he does mention that the study cannot prove cause-and-effect. However, he goes on to basically talk about animal proteins causing disease as if they are hard and true facts. It is very important to remember that the study published in the American Journal of Clinical Nutrition is peer-reviewed; whereas the book that Campbell wrote about the study and other studies is not peer-reviewed. As far as I can remember, there is actually no mention in the actual study that it is best if humans cut out all animal products. Please correct me if I am wrong. In The China Study book, Campbell highly encourages readers to cut out all animal products.

So let's get back to my claim that Campbell's book is starting a fad diet. Why would I go that far? If you look at the data, it shows that the Chinese eat animal protein. They have not cut it out of their diets, they just eat less than Americans. I don't think it is any secret that Americans eat way too much meat and cheese. If most Americans reduced their portion sizes of meat, ate less cheese, and stuck to low fat dairy products, I imagine that there would be much less chronic disease in our country. Notice that I did not say "eliminate" these products from our diets. So if the Chinese haven't eliminated animal products from their diets and their chronic disease rates are so much lower, why must we eliminate animal products from our diet? A serving size of meat is three ounces. How many people eat more than this serving size? Probably most people do. So, maybe our chronic disease rates are so high because people are eating way more than the recommended serving size, not because they're eating any amount of animal products. I believe that any diet that promotes completely cutting out a food group belongs in the "fad diet" category. Animal products provide us with necessary nutrients and we can obtain those nutrients by eating small portions of those products.

One disclaimer I would like to add is cutting out animal products in the case of ethical concern. I support any person's ethical convictions and believe that you can live a healthy life without animal products, as long as you take a few necessary supplements.

3. Campbell, T.C. & Junshi, C. Diet and chronic degenerative diseases: perspectives from Chima. Am J Clin Nutr. 1994; 59 (suppl): 1153S-61S.

Monday, January 23, 2012

The China Study Part II: Where We Agree

Campbell seems to have a passion for disease prevention, public health, and eating well. I share these same passions and this is where we can certainly agree. This post will mostly be about where Campbell and I agree.

An undeniable truth that Campbell discusses in The China Study is the fact that diseases such as heart disease, cancer, and diabetes are too rampant and something needs to be done. Lifestyle is a huge factor that impacts disease risk. Unfortunately, many people and some health professionals would rather blame genetics and rely heavily on medication to lower risk. While genetics certainly play a role in disease risk, the impact of lifestyle is quite dramatic, yet often ignored. It is easy to become complacent and not equate the food on your plate to disease risk, but everything we eat day-in and day-out is setting us up for health or debilitating disease. Remember that not everyone dies suddenly. Often, people live for decades with body aches, angina (chest pain), loss of sight, loss of limbs, painful surgeries, and the list goes on and on. That is what poor nutrition and lack of exercise do to a person. So, its not all about genetics and its not all about life or death. Your quality of life is heavily determined by what does or does not enter your mouth and how much you move. Of course, some people will need medication no matter what they do and it is important to take medication as directed. However, lifestyle can impact the amount you are taking and how effective the medication is.

On page 233 of The China Study, Campbell makes this statement:

"Much of this focus on genes, however, misses a simple but crucial point: not all genes are fully expressed all the time. If they aren't activated or expressed, they remain biochemically dormant. Dormant genes do not have any effect on our health. This is obvious to most scientists, and many laypeople, but the significance of this idea is seldom understood. What happens to cause some genes to remain dormant, and others to express themselves? The answer: environment, especially diet."

I am very deficient when it comes to understanding genetics, but I thought this was a very great and interesting way of explaining why lifestyle is so crucial. If anyone has more knowledge about genetics and would like to comment on the excerpt, I would love to hear it!

Nutrition is a vital ingredient to a healthy life. Another point that Campbell spent a lot of time discussing was that people do not eat enough fruits, vegetables, and whole grains. Adults need a minimum of three to five vegetables daily and two to four fruits. I am guilty of not always meeting my vegetable needs and I actually felt inspired to take the personal challenge of increasing my vegetables after reading this book. Fruits and vegetables are loaded with antioxidants, fiber, phytonutrients, vitamins, and minerals. They are so powerful at helping to reduce disease risk and are not consumed enough in America. Whole grains are also under-consumed whereas refined carbohydrates are abundantly eaten. Refined carbohydrates are stripped of many important nutrients and also tend to raise blood sugar more quickly due to their lack of fiber.

With the exception of just a few nutrients, Campbell believes firmly that nutrients should come from whole foods and not a pill. (The nutrients that he claims we should get from a pill are available in animal products.) This is an important point. We cannot replicate the many phytonutrients found in foods and we have yet to even identify most of them. Getting your fruits and vegetables will never be as easy as popping a pill. Vitamin supplements will not replace disease-protection that fruits and vegetables provide. I do not agree that we should take pills to replace the vitamins that are lost by avoiding animal products. Instead, I believe we should get those from small servings of meat and dairy. While I do believe that much is lost by depending on supplements to get the nutrients found in fruits and vegetables, vitamin supplements are sometimes needed for "insurance". I believe that it is important to take prenatal vitamins, especially because folate is actually more bioavailable in the synthetic form. Also, children may benefit from a multi-vitamin if they do not eat a good variety of foods. This is not to say that these vitamins replace what we find in plants, but they are helpful to reinforce some very pertinent needs. There are also other disease states and conditions that require specific vitamin supplementation; however, those should be overseen by a Medical Doctor and Registered Dietitian.

Another major area where Campbell and I agree is that Americans are consuming way too much meat. I don't know who could really argue with this. A serving of meat is three ounces. Most restaurants serve steaks in portion sizes that are at least double the proper portion size. Plates should be mostly full of plant foods and have a small portion of meat. Instead, plates are full of meat with a sprig of green. The amount of meat being consumed in America is really hurting our health. The part where we disagree is that I believe meat has a place in a small part of the plate. Campbell believes that meat should be avoided completely.

In general, Campbell and I share the same sentiment that we all need to eat healthier.

Sunday, January 15, 2012

The China Study Part I: Is Drinking Milk Damaging Your Health?

After completing The China Study by T. Colin Campbell, PhD and Thomas M. Campbell II, MD, I decided to discuss it over a few posts (1). Honestly, I feel like I could write a book about this book, but I will try to just hit the major highlights. The first topic I would like to write about concerns the question, "Are milk and other dairy products harmful to your health?"

Campbell hits this topic hard and fast in The China Study as he explains that milk products cause cancer. Throughout the book he encourages his readers to cut out all milk products and all animal products, for that matter. By the end of the book, the general idea is that if you eat any animal products, you are setting yourself up for major health failure whether it be from diabetes, cancer, heart disease, auto-immune diseases, etc.

Campbell's idea that milk products are dangerous originated from a study that examined rats which were fed different amounts of casein (a milk protein) and observed markers of early preneoplastic liver lesions (PNL)(2). Preneoplastic basically means that there is a very good chance this will eventually form into cancer. In the study, it was found that a minimum of 6-8% dietary casein was needed for proper weight gain. When rats were fed a diet 10% or less casein, there were negligible PNL; however, a diet of 12% or more casein showed a significant increase in PNL.

So what does all of this mean?

1. First of all, if you consume an 1800 calorie diet, you would have to drink about 7 cups of milk daily (or dairy equivalent) in order to ingest more than the 12% casein maximum threshold. Granted, casein does exist in very small amounts in processed foods. Most people don't come any where near 7 cups of milk daily, so chances are, you still won't exceed the 12% casein threshold even if you have a little bit of yogurt and some casein in processed foods. Of course, you should always strive to eat more whole foods and less processed foods.

2. We can certainly learn a lot by studying rats; however, it is impossible to directly extrapolate these results to humans. It even says this in the discussion section of the study.

3. What does this mean for breast milk? We know from countless human studies that breastfeeding has numerous benefits for babies and mothers. Breast milk does have less casein than cow's milk, but it still has casein and babies drink it all day long! Campbell does express the importance of breastfeeding and cautions about stopping too early. So, why is the casein in breast milk okay for babies, but Campbell believes that the casein from cow's milk is harmful? He doesn't address this question in the book.

4. It must be said that casein was given to the rats in isolation as well. When we drink milk, it is within the milk among a complex series of nutrients. We know that combining certain nutrients with other nutrients changes the way we absorb them, use them in our bodies, etc. It is a little difficult to compare casein given in isolation to rats versus humans drinking a glass of milk.

5. I am certainly no expert on cancer; however, I do know that it is a complex disease affected by a multitude of factors. I find it difficult to believe that we can easily isolate one little nutrient that causes cancer. Campbell actually has a whole chapter on "reductionism", taking specific nutrients, studying them, and making health claims about them. He disagrees with this practice and explains the complexity of nutrition and health. So, why does he make an exception for casein?

6. Campbell believes that, because casein causes cancer in his opinion, all animal protein must do the same. This is a wild extrapolation.

In summary, the data from the study done on casein and PNL suggests that you don't need to empty all of your milk cartons. It seems that moderation wins again! Drinking 7 cups of milk is a lot of calories, so I wouldn't suggest doing that anyway. Drink milk in moderation!

1. Campbell, T.C. & Campbell, T.M. The China Study. BenBella Books, Dallas, TX, 2006.
2. Dunaif, G.E. & Campbell, T.C. Dietary Protein Level and Aflatoxin B1-Induced Preneoplastic Hepatic Lesions in the Rat1. J, Nutr. 117: 1298-1302, 1987.

Monday, January 2, 2012

Prevent and Reverse Heart Disease: My Thoughts and Opinions

I recently read Caldwell B. Esselstyn, Jr., M.D.'s book called Prevent and Reverse Heart Disease. The China Study by T. Colin Campbell with Thomas M. Campbell II is next on my reading list; however, in retrospect, I realize that I should have read it first. Esselstyn's book is primarily centered on his study, involving 24 subjects, and Campbell's epidemiological study in China. There are several points that I really can't begin to discuss until I read Campbell's book, but I'll do my best to review Esselstyn's book and then will fill in the gaps later.

I think we can all agree that Americans eat way too much fat, meat, and refined grains while not eating enough fruits, vegetables, and whole grains. Esselstyn really harps on this and I agree with him. If we all reduced our portions of meat, replaced our refined grains with whole grains, cut down on the desserts, and filled our plates with more fruits and vegetables, we would certainly be a lot healthier. I would also be willing to bet that chronic diseases would be diagnosed with much less frequency. I even agree that it wouldn't hurt to eat a vegetarian meal here and there. Meat does not need to be the center of every meal.

Despite the fact that Esselstyn and I agree on some points, I would not recommend this book for several reasons. First of all, Esselstyn bases most of his beliefs on his study, which contained only 24 subjects, and Campbell's China Study. Given the small sample size of his study it is hard to put much faith in the outcomes. My second major criticism of the book is that Esselstyn adamantly promotes a vegan diet. I have never been a supporter of a vegan diet unless a patient is following it due to religious or ethical reasons. Based on available science, I do not believe that there are any health reasons to follow such a strict diet. Because Vitamin B12 is only naturally found in animal products, you would need a supplement to insure you were getting adequate amounts of Vitamin B12. Any diet that is lacking in an essential nutrient makes me very leery.

Certainly, decreasing animal products in the diet would result in a decreased total blood cholesterol; however, do we really need to play the "how low can you go" game? Many things in life, including the human body, are about balance. Cholesterol is essential to the body, but too much can be a bad thing. Effort should be focused on maintaining a balance, not on racing to see who can achieve the lowest possible cholesterol level. That being said, I cannot agree that eliminating animal products is the answer. Animal products, including meat and dairy, provide us with a host of important nutrients that keep us healthy and thriving. Because this is a blog post and not a book, I won't go into all of the details.

Speaking of cholesterol levels, Esselstyn states that if you can achieve a total cholesterol of less than 150 mg/dL, you will not develop heart disease. He says that even if you smoke, are obese, have a family history of heart disease, or hypertension, you will still not develop heart disease. Any of you who have any experience with heart disease patients probably just experienced your jaw dropping. I have personally worked with numerous patients who had total cholesterol levels well below 150 mg/dL, yet they still had a heart attack. Not that this has been backed up by a study, but I would rather see a patient with a total cholesterol of 180 mg/dL and be a non-smoker than to have a total cholesterol of 130 mg/dL and light up 5 times each day.

Esselstyn also promotes a diet very low in dietary fat. Again, while I do agree that Americans eat too much fat, I don't agree that we should aim to ingest as little fat as humanly possible. Fat is necessary for absorption of fat soluble vitamins, satiety, synthesis and repair of vital cell parts, and other important functions. Research has also shown that omega-3 fatty acids decrease inflammation, which is a key factor in preventing heart disease. Research also supports that a diet rich in omega-3 fatty acids helps to decrease the risk of dementia and Alzheimer's disease. In fact, it can even help to delay the progression of dementia and Alzheimer's disease after the onset. Esselstyn actually states that his diet could possibly save a person from senile-impairment. I am not sure how he came to this conclusion as he sites no research. He even says that you should avoid avocados and nuts (although he does mention that you can have some nuts if you do not have heart disease). Although he pushes a plant-based diet, he denies the diet of some very nutrient-dense plant foods that other experts believe to be healthy. In fact, there is plenty of research showing the benefits of nuts, especially walnuts. Furthermore, the American Heart Association actually recommends two servings of fatty fish each week due to its disease protective benefits.

If you ever want to celebrate your birthday with a little cake, you won't be able to follow this diet completely. Esselstyn does not believe in moderation or the occasional treat. For this reason, I feel that his diet is totally unrealistic for the average person to follow, including myself! Although I know that ice cream isn't good for me, I don't see the harm in an occasional splurge. I believe in keeping treats to a minimum and watching the serving size. But, to think I could never make Christmas cookies with my kids or treat them to ice cream on a hot summer day makes me a little sad.

I have a list of notes that I took while reading this book and I have much more to say; however, I am trying not to turn this into a book! I leave you all with this: this book did not sway my stance on nutrition. A balanced diet that contains fruits, vegetables, whole grains, dairy, meat, fish, beans, and nuts is healthy as shown by science. I did not feel that this book produced any compelling evidence that proves otherwise. As I said, I will be reading
The China Study next and will look forward to reporting on the text.