When berries were not in season, the next best thing was fresh picked fruit from the local fruit stand (plus the occasional “fresh picked” apple from the neighbor’s apple orchard). What would drive us to reach for that fruit? Sweet, many fruits are sweet and we love sweet. Not all fruits are sweet. The structural part of any plant that contains its seeds is considered to be its fruit… so cucumbers are fruits, pumpkins are fruits, many of the things we think of as vegetables are in fact fruits, but they are not sweet. What makes the sweet fruits sweet is a type of sugar called fructose. It is almost twice as sweet as the more common sugar our bodies burn as fuel – glucose. Plants are mostly made of glucoses bound together to form starches and woody fibers. We can digest the starches back to glucose to feed our bodies, but only certain bacteria can break down the woody fibers.
So when we are desperate for that sweet taste, what we are really chasing after most of the time is fructose. Table sugar (the white granulated stuff) is half fructose and half glucose. As our demand for more and more sweet taste has increased we have developed sugar with higher fructose percentages like high fructose corn syrup, or the current darling of the “health food industry” – Agave syrup. So is this good or not? We like it, but as I have discussed in previous newsletters we can not trust our taste buds any more.
My first input on fructose came while I was in Chiropractic school. I was a “good vegetarian” at the time (meaning I balanced my foods to make sure I got enough of the right balance of essential proteins) and didn’t eat crap carbohydrates. The concept of glycemic index had just been developed and fructose had been found to have a very low glycemic index. At the time it was thought this would make fructose the best sugar choice for diabetics. (This myth continues even today.) At the time, fructose had just become easily available in health food stores so I started using it to cook with. A few months later I took my first comprehensive muscle testing class. One of the findings mentioned in that class was that fructose tested up bad on everyone – they didn’t know why, but avoid it. I started avoiding the store bought concentrated white crystalline stuff at that point.
About a dozen years later I started studying metabolic typing and looking much more deeply into how food affects metabolism. In those studies I came across and interesting study that had been done on prisoners over a long period of time that had been largely ignored. The large group of prisoners was split into two groups after being well studied for their health parameters. The only difference between the two groups was that one group got normal prison food made with normal table sugar (sucrose – which is half fructose) and the other had their food made with glucose (with no fructose). The food tasted the same and they ate the same. They followed the health of these prisoners for many years. The sucrose group had the usual number of problems with heart disease, diabetes, and the usual degenerative diseases. The glucose group did not. .. interesting.
Fast forward to today, fifteen years later… hundreds of studies have been done on sugar and fructose metabolism and hundreds more on anti-oxidant and healthful nutrient properties of fruits and vegetables. The picture gets more and more complex, but some pieces are starting to shine out. There are now over 10,000 phytonutrients that have been found in our fruits and vegetables. The old One-a-day vitamin tablet with its 10 vitamins now looks ridiculously inadequate. Every day some new nutrient is found in plant sources that helps prevent some disease or enhance some metabolic process in our bodies. It is overwhelmingly clear that we are designed to eat plants – lots of plants. But what about sweet fruits?… what about fructose?
Fructose bypasses the normal sugar processing in the body and goes straight to the liver where it is almost immediately turned into triglycerides (active fats). Normally triglycerides are used by your muscles for energy. Excess (as in high fructose consumption) is stored as fat – first in your liver (causing fatty liver) then in your fat cells. Fructose also disturbs your normal glucose metabolism causing insulin resistance. This leads to hardening of the arteries, heart disease, and diabetes. Fructose disrupts several hormone pathways that tell you when to stop eating so you actually end up hungrier when you use foods high in fructose (the only 2 things they have found that help this is increased magnesium levels and lots of vegetables). Fructose increases the dangerous kinds of cholesterol particles in your blood. Fructose increases oxidative damage (aging) in your body. Excess fructose is bad stuff. However, this process is a consequence of excess. In low levels fructose is actually beneficial.
So the big question – how much fructose is safe and even beneficial? Through most of human history we have consumed 6 – 25 grams of fructose per day. Current estimates say we could likely tolerate up to around 40 grams a day. In terms of sweet fruits that comes out to two to four servings of fruit per day. This varies a lot depending upon the fruit. A large apple or pear runs around 14 grams of fructose while an orange will only have 5. Averaging a number of fruits I come up with a safe level of around 5 to 6 cups of fresh fruit per day. But what about fructose in the form of table sugar or high fructose corn syrup? At 135 pounds of straight sugar consumption (fruit not included) per year, that works out to 170 grams of sugar per day and half or more of that is fructose…way too much.
So where does that leave us? Fruit is a vital source of phytonutrients of all sorts. Phytonutrients fight the diseases of aging. Fruit also contains fructose so we have to limit our fruit consumption to around 5 to 6 cups per day. At the same time, this fruit should be part of our minimum of 8 to 12 cups of vegetables and fruits each day. Be attentive to pesticide levels in fruits. Some fruits and vegetables should be purchased from organic sources only – see health challenge.
So fruit is good for us, but like all things – in moderation. Fructose from other sources has nothing good to say for itself and should be avoided. If you want sweet then use stevia or my blend of stevia and erythritol in the office…no wasted calories and no fructose. If you need the bulk and properties of sugar for baking then use dextrose (I ordered mine through Elliott’s Health Food). This is the commercial form of glucose used in baking and contains no fructose. In general though, the idea is to fill your body with healthful vegetables and fruit and then supplement that with small amounts of healthy and clean protein (meats, fish, eggs, nuts, seeds, and legumes) and a little healthy fat (avocados, olive oil, coconut oil, and nut oils). Throw in abundant amounts of spices and you have a diet fit for a healthy king.