I was whining to Ellen the other day “Why is it that everything that tastes good is bad for us?” I have had this perception many times in the past, but this time I followed up on it. I mean seriously, everything I read these days highlights the dangers of one food after another, at least of the foods that I think taste good. Even my favorite vegetables are now under fire. I find it strange that the foods and vegetables I dislike are still the stars of the nutrition world – leafy greens, oily fish, fermented cabbage.
I decided to actually research the answer to my casual whine and believe it or not there is a real answer to my perception. I started looking up the function of taste buds. Why do we have them? How do they support our survival?
Taste buds exist for two basic survival reasons: they warn us if the food we are about to eat is rotten and will make us sick, and they override our fullness signals to get us to keep eating way too much so that we will gain weight. The first reason makes obvious sense. The second reason is not sarcasm, but actual truth. Without taste buds we normally stop eating when our stomach and blood sugar signal our brain that we have had enough food to keep us going for a bit. In an environment with adequate food availability, this is ideal for us. We stay sleek and strong enough to enable us to outrun predators and still reproduce. Tropical environments supply these circumstances. Do you ever see natives living their ancestral lifestyle getting overweight while in their prime? No, you don’t.
But what about the lives of the majority of people living in environments that have significant seasonal variations in temperature and food availability? In these environments food is not available all the time. There are months at a time when there is nothing to eat. For these people gaining weight has a huge survival advantage. They can live for months on their stored fat when no food is available to eat. But what could make them want to gain weight when they are in the season where they have enough food? The answer is pleasure – in this case taste pleasure.
Pleasure is a strange survival adaptation our species has developed. The pursuit of pleasure will make us do things that actually are non-survival behaviors as we chase down this feeling we call pleasure. Sex is a great example. Weaker members of a tribe will risk life and limb to briefly acquire a mate even though it means they are likely to get beat up or killed for trying. How is that survival? Other species meet this need for reproductive genetic diversity through instinctual drives cued by scent or plumage. Most other critters do not seem to be driven by the desire for pleasure.
Food consumption is controlled in us the same way. Certain food cues in the form of tastes trigger the addictive pleasure centers in our brain making us disregard our normal survival limits and keep us trying to experience as much pleasure as we can stand. Sweet is the strongest trigger and actually hits the same pleasure center in our brain as cocaine. Fatty salty tastes similarly trigger pleasure reward circuits in our brain. This drive causes us to stuff ourselves way past our present needs when we encounter sweet tastes. Since we can’t use all that food we are eating, we convert it into fat and store it for later.
In a natural environment this is all perfectly timed. In the spring when we need to be strong and fast as we compete for a mate and search for bits of scarce food, the available food sources are leafy greens and bland tubers. There is nothing sweet anywhere available that time of year except the very rare find of a honeybee hive. Sweet tasting foods don’t start appearing in seasonal environments until late summer and autumn. This is precisely when we want to start gaining 20 to 30 extra pounds of fat to carry us through the winter. Those who did not have the pleasure drive for the sweet taste would not overeat and not gain that extra weight. They would not survive the winter starvation time and be able to reproduce the next spring. Notice that the relative sugar intensity and carb load of the fruits and starchy veggies progressively gets more intense as you get closer to winter.
We are geared to gain weight in the fall. Our pleasure seeking taste buds override our natural desire to only eat as much as we need more and more as winter approaches. But what happens when you put all those people designed to survive the winter starvation and never let them starve off the extra weight? What happens when sweets are available all year round? How about sweets, heavy starches, and salty fatty foods all year round? What you get is everything that tastes good is now bad for us because we simply have too much of it available. Eating all those goodies during the holidays would not be such a big deal if we fasted for two or three months afterward, but we don’t.
Even fasting just five days a month would reverse a lot of the evils of our modern diet and lifestyle. The taste buds that were designed to make sure we would survive winter without food have now become a liability in our world of plenty. This threat has been triply amplified by our modern food industry that has used our addictions to design even more intensely addictive products to make big money. So we either have to stop eating anything and everything we love, or we have to accept that these foods will make us inflamed and fat and compensate with times of dietary abstinence to counter balance the effects of these foods. The sweet/salty/fat loving taste buds hooking up to the pleasure/addiction center in our brain was a brilliant survival advantage 100,000 years ago, but it is killing us now.
So what do I say to patients when they say “but I like ice cream and cookies and chips and candy and sandwiches and big fat juicy steaks”? I love them too, but they are still destroying our health. If our intestines were still healthy, then moderation combined with periodic abstinence would probably allow things to work in our body. But once our gut gets inflamed, then every exposure we get to our favorite foods creates significant consequences.
Hippocrates, the father of medicine once said “All disease starts in the gut.” This is certainly true for degenerative diseases. I deal mostly with arthritis and autoimmune issues, but the same diet/gut cause is behind heart disease, cancer, Alzheimer’s, Parkinson’s, liver disease, kidney disease, and so on. If we don’t repair our gut and temper our bad eating habits, we are destined to travel the degenerative disease path. No amount of exercise, nutritional supplements, or miracle drugs can outrun the effects of a bad diet. And as much as we love how it tastes, the standard American diet is really, really bad for us.
The real question is just how far do we have to go to get back on track with our diet to regain our health?