Thanks to the publicity surrounding the human genome project, most of us think we know something about genetics. However, genetic science, like nutritional science, is still in its infancy. Until recently, for example, we used to think of genes as set in stone. You either had good genes or bad genes, and they determined whether or not you would get breast cancer, have crooked teeth, or get an astigmatism in your middle age. Modern genetic research has shown us otherwise. It turns out these things are more heavily influenced by nutrition — yours, your parents’, and your grandparents’.
Now, rather than talking about whether or not you “have” a particular gene, genetic scientists talk about how the genes you have are expressed. The study of how inherited genes are “turned on” and “turned off” is called epigenetics.
Dr. Cate Shanahan wrote perhaps my favorite book on the subject, Deep Nutrition: Why Your Genes Need Traditional Food. I recently interviewed Dr. Cate so that she could explain the implications of this emerging science to us in layman’s terms.
Me: How did you first get the idea to write your book, Deep Nutrition? Why did you choose to write it?
Dr. Cate: I started writing when I became overwhelmed by the amount of medical research that did nothing to explain chronic illnesses, or what to do to actually cure them. I wanted the world to know that there was research to support eating a traditional diet, tons of it. A traditional diet had not even been anthropologically defined. This in a time where countless pills to lose weight have all the attention.
The spark was lit at my office in Kalaheo, HI. One busy afternoon a colleague was shaking her head over what to do for a diabetic who’s blood sugars were sky high, over 300, in spite of taking insulin and multiple glucose-lowering pills. The patient was terribly overweight and had just about every diabetic complication, including kidney failure and heart failure. Frustrated, she said “It’s like none of the cells in her body work right.”
I could not get the image of a cell struggling to work properly out of my head. I imagined it’s membrane with complicated protein transporters and ion channels, and its internal chambers and enzymes trying to operate with all that extra sugar swirling around and wondered what the sugar itself might do that could interfere with a cell’s basic functionality.
Something made me crack open my biochemistry book and, skimming through, my finger stopped over a word I used every day but had not thought about what it really meant, glycated.
Your glycated hemoglobin reading is a direct measure of how high your blood sugars are on an average day. A normal person has a level under 5.5. A person with diabetes has a level over 6.0 (in between 5.5 and 6 is called prediabetes). The higher the number, the more likely you are to have premature arterial disease, kidney failure, blindness, and more. For example, if your number is over 8, you are considered extremely high risk.
And here’s the thing that suddenly made all the difference to my understanding of this disease we call diabetes: Glycation is a spontaneous reaction, so our bodies cannot control it.
With this realization came a burst of insight. Because glycation can occur inside and outside a cell, it means a person with high blood sugar would suffer from internal and external cell damage that could potentially interfere with any number of vital cell processes.
At that point, in the year 2002, I had already educated myself about the reality that saturated fat is not the cause of heart disease and understood the role that the oxidized fats in common foods like salad dressing and cereal would play in damaging cell functionality. Now, with this understanding of glycation, I was able to see how eating carbohydrate-rich foods would inevitably cause the damage that would render cells insensitive to not just insulin, and therefore cause diabetes, but to potentially all other hormones! Including thyroid, estrogen, testosterone, and more.
The two reactions, glycation and lipid oxidation, feed off of each other. So a diet high in vegetable oils and glucose/fructose-rich foods — the very diet nutritionists were advising my diabetic patients to follow — would accelerate their disease and lead to the development of new ones. I started a search to see if there was any scientific research to support the idea that oxidation and glycation reactions were the underlying cause of things like hypertension or atherosclerosis or cancer. And of course there was. Tons of it.
By then I felt like I needed to keep track of my findings, so I started writing things down. But it took seven more years to put Deep Nutrition together because I felt like I wanted to incorporate all the amazing things about the inner workings of the human body that could be brought together to tell the story of health and disease simply by understanding how food affects our body at a cellular, even molecular, level.
Here’s a video that beautifully illustrates the complexity of a dynamic, living cell:
Me: Can you briefly explain the concepts of genetic wealth and genetic momentum?
Dr. Cate: Genetic Wealth is the idea that if your parents or grandparents ate traditional and nutrient-rich foods, then you came into the world with genes that could express in an optimal way, and this makes you more likely to look like a supermodel and be an extraordinary athlete. Take Angelina Jolie or Michael Jordan, for instance. They’ve got loads of genetic wealth.
Genetic Momentum describes the fact that, once you have that extraordinary genetic wealth, you don’t have to eat so great to be healthier than the average person. It’s like being born into a kind of royalty. You always have that inheritance around and you don’t need to work at your health in the same way other people do.
These days, for most of us, it was our grandparents or great grandparents who were the last in our line to grow up on a farm or get a nutrient-rich diet. In my case, I have to go back 4 generations to the Irish and Russian farmers who immigrated to NYC where my grandparents on both sides could only eat cheap food; sometimes good things like chopped liver and beef tongue, but often preserves and crackers and other junk. So my grandparents were far healthier than my brother and sisters and I.
The Standard American Diet (SAD) has accelerated the processes of genetic wealth being spent down, genetic momentum petering out, and the current generation getting sick earlier than their parents and grandparents. This is a real, extreme tragedy on the order of end-of-the-world level losses of natural resources. Genetic wealth is a kind of natural resource. And loss of genetic wealth is a more urgent problem than peak oil or the bursting of the housing bubble. But of course nobody is talking about it directly, only indirectly, in terms of increased rates of chronic disease.
Take autism, for example. Why is autism so common? I don’t think vaccines are the reason for the vast vast majority of cases, since subtle signs of autism can be seen before vaccination in the majority. I think the reason has to do with loss of genetic wealth. We know that children with autism exhibit DNA mutations that their parents and grandparents did not have. Why? Because in the absence of necessary nutrients, DNA cannot even duplicate itself properly and permanent mutations develop.
(Here’s an article on one kind of genetic mutation (DNA deletions) associated with autism.)
Fortunately, most disease is not due to permanent letter mutations and therefore a good diet can rehabilitate a lot of genetic disease that is only a result of altered genetic expression. To put your high-school biology to work, it’s the idea of genotype versus phenotype. You might have the genes that make you prone to, for example, breast cancer (the BRCA1 mutation), but you might not get the disease if you eat right because the gene expression can revert back to normal.
Me: In other words, most disease is not hard-wired into our genetic code. Rather, it surfaces as the result of genetic expression — something that can be altered with nutrient-dense, traditional food. In the book, you spend a while unpacking the idea of “second sibling syndrome” in order to demonstrate how siblings with nearly identical genetic inheritance can express those genes differently. What is “second sibling syndrome”?
Dr. Cate: It’s the set of consequences that come from a kind of gestational sibling rivalry. These days, most mothers can not nourish themselves optimally before conception or during pregnancy. And close-birth spacing exaggerates the differences in health between siblings. There’s benefits and drawbacks to being first.
The first born gets first dibs at all the nutrients in mom’s body (minerals from bone, fatty acids from brain, etc etc). So there are definite advantages to being first if your mom did not follow an optimal diet. If baby number two is born in short order, mom’s body will likely be depleted of one or more nutrients for baby number two because baby number one took all she could spare. This relative deficiency means baby number one usually has a wider jaw and higher cheekbones than number two, for instance.
These days, being baby number one has a special disadvantage of its own because most women eat far to many carbs. This often makes their bodies relatively hormone insensitive, which means that their uterus will not perform optimally the first time around. And that performance can impact baby’s skeletal growth and symmetry. For baby number two, uterine blood vessels and hormone receptors and other infrastructure have all be laid down, and the uterus grows faster for number two. Because of this, baby number two is often more biradially symmetrical and has features indicative of optimal hormone sensitivity compared to number one.
You can see examples of the trend here.
Me: You recommend people eat according to the Four Pillars Of World Cuisine in order to improve their genetic expression and help create genetic wealth. What are the Four Pillars, and why do you recommend them?
Dr. Cate: A traditional diet can help genes function better, and you will pass that improved function in the form of optimized growth down to your children. The Four Pillars of World Cuisine define the key components of a traditional diet.
When I started writing, there was no agreed-upon consensus as to what our ancestors ate. There was no paleo-diet movement where people could come together and hash out the most logical answers to the simple, central question. There were only a few scattered books and most still clung to the idea that the natural world is stingy with her resources, so food, and especially fat, was hard to come by. I had read A Revolution in Eating and Health and The Rise of Civilization and The Original Affluent Society, and all pointed to an easy abundance that people could simply collect when they chose to.
So we started with an anthropologic approach. We can assume our ancestors’ relationship with nature would have been the same 100,000 ago it would be today, that is, we would search for seasonal foods and use all that we possibly could. So we defined the Four Pillars very simplistically. We started with the idea that people would eat whatever didn’t make them immediately sick, and prepare or store it however they could. No matter where people live, we all have the same sorts of resources: Local plants and animals, and the firewood and storage chambers that would retard or facilitate decay during storage. We also eat food fresh sometimes. So we broke it all down into four common practices and procedures that we found common to all the traditional cuisines and cultures we studied and came up with these.
- Fresh food
- Fermented and Sprouted foods
- Meat on the Bone
- Organ meats
Each has special health-promoting benefits that are unique to their category. And since our genes evolved with constant exposure to these foods, as we did with vitamin C, we evolved a dependency on them that is uniquely human.
Me: Why did you write your follow up book, Food Rules?
Dr. Cate: After researching and writing Deep Nutrition, I found myself dispensing a whole bunch of little tidbits to more and more patients. When Michael Pollan’s Food Rules came out, saying: Eat food, Not too much, Mostly vegetables, I thought I had to respond.
With Luke’s help, I compiled my in-clinic advice to my patients into a much more practical, much more health promoting set of rules that help people to recognize the healthiest foods available in stores, cook them to optimally preserve or enhance their nutrients, and be mindful of how to coordinate eating with sleep and activity to optimize the health-promoting power of your meals. Plus I’ve got a bonus section, Doctor’s Orders, that helps people navigate the healthcare system, avoiding the worst drugs and asking your doctor for the most important tests. Many of the tables and the appendix are made to be xeroxed easily to take shopping with you.
Me: How do you think Food Rules can help the average eater? Do they need to read Deep Nutrition first?
Dr. Cate: Food Rules is a nutritional amuse bouche. Deep Nutrition is a main course. And like an amuse bouche, I designed it to not to replace Deep Nutrition, but to accompany and complement it. I have heard from patients (and you can read in the reviews on Amazon) that it was extremely helpful even though they’d read Deep Nutrition more than once.
I wrote Food Rules so that one could read a rule or two or three during the morning constitutional—if that’s the only place one has a moment to read. One woman read it while sunning on the beach and went on to give her kitchen a healthy makeover and lose 40 pounds and get off a handful of prescriptions.
Because its such an easy, quick, readable guide it makes a wonderful gift for the busy people in your life!
Me: Do you have any questions for Dr. Cate? If so, ask them in the comments!