Lectins, Leptin and the China Study
I have just reviewed a most interesting book called The China Study at Amazon.
This book, touted as the most comprehensive study of nutrition ever conducted, is indeed a treasure trove of useful information. The first point that I particularly liked is that the author is not a reductionist. He understands that the idea of trying to reduce the value of foods to one food type or one nutrient is deeply flawed. Let me give you an example: there is some good evidence that tomato-derived lycopene has a great many health benefits, but that does not mean that the solution to all that ails us is a diet consisting solely of tomatoes. I was once asked to see a person who had a genuine problem with a series of food sensitivities: a well-meaning but poorly educated practitioner had put her on a diet of lettuce leaves, rice and spring water. Several months later I saw her because of profound weight loss and malnutrition. The problem was a lack of balance in the dietary approach, and failing to see the big picture.
T. Colin Campbell is definitely one who sees the big picture, both in terms of his own research, and the broader context. He rightly points out that trying to divorce nutrition from the whole diet and lifestyle is a fundamental mistake.
I noticed something rather interesting, which I have just seen picked up by another reviewer: there seems to be a strongly positive correlation between wheat consumption and the risk of sustaining a myocardial infarction.
The reason that I perked up on seeing this is that I have just been analyzing a paper from Lund in Sweden. The investigators’ fundamental premise is that the rise of agriculture and the consumption of cereals might be the underlying explanation for many of the diseases of affluence. The researchers did a study of pigs, and showed that by putting them on a cereal-free diet, the pigs’ insulin resistance, blood pressure and C-reactive protein all fell, which are excellent markers of cardiovascular health. They went even further and provided a biochemical explanation, pointing out that for all its many benefits, agriculture is exposing our bodies to novel lectins: plant proteins that bind to specific carbohydrate groups on cell membranes. (We met lectins in my previous posting on blood types). These lectins seem to have the worst type of biochemical properties that enable them to block the action of a key metabolic hormone called leptin. First discovered in 1994, leptin produces a satiety signal, telling your brain to stop eating. In some animals it may also cause insulin resistance. Leptin was very hot news a few years ago, because if an animal or a person is resistant to leptin, they become morbidly obese. So a number of pharmaceutical companies tried to develop obesity treatments based on leptin. Sadly, to date all of them have failed. It is not surprising that nutritional interventions based on modulating leptin have also been disappointing. At last count there were over 260 hormones and neurotransmitters involved in the maintenance of body-weight. So trying to manipulate just one of them is hardly likely to be crowned with success.
As I have said in other posts, there will always be someone, somewhere, who will respond to any kind of eating or life plan. The trick is in predicting who will respond to what, and in that we are still scratching our heads. So if you want an approach that has the highest overall chance of success at maintaining and improving your health, rather than just focusing on pounds, I’m going to repeat my advice from an earlier posting:
1. It is important for you to maintain your energy balance, between input and output
2. Calories do count
3. What you include in your diet is as important as what you exclude: we are designed to consume not just rice and lettuce, but an array of other nutrients.
4. Make only moderate dietary changes at any time: making big dietary changes can be a pretty violent attack on your body and your mind
5. Avoid the “trans-fatty acids”
6. Try to consume some omega-3 fatty acids every single day
7. Eat fewer simple carbohydrates
8. Use weight management and exercise strategies that enhance your overall health and well-being
9. Take more exercise: even small amounts can have a big effect.
And now I am going to add a tentative number 10:
10. If your weight and metabolic parameters are still not as they should be, discuss a gradual reduction of cereal intake with your health care provider, and how to ensure that you still get the amount of fiber that you need. Depending upon your own genetic make-up that may be the missing piece.
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