Wednesday, July 31, 2013

Fruits on Paleo

   Are fruits healthy for you? This is another subject where information is all over the map in the Paleo community. The staunch Paleo community maintains that if a food was not part of the human development during the Paleolithic era then it is a food that we should not consume. Since most fruits, the forms that we see them today, did not exist in the Paleolithic era, then they are not part of the Paleo diet. The fruits like dates, grapes, figs, and olives were domesticated around 6000 years ago. The wild fruits that existed in the Paleolithic era were probably much smaller and tasted bitter. The mainstream nutritional advice is of course to consume several helpings of fruits and vegetables per day. I have a friend who tried Paleo for a while, he saw immediate results within couple of months, when his doctor advised him to stop taking statins, but after a while he was simply stuck and did not lose additional weight. It turned out that he was consuming about a pound of grapes per day. He apparently loved grapes and would have large bunch to munch on all day. I have other friends who feel guilty if they did not consume couple of pieces of fruits per day. The general public opinion heavily influenced by mainstream nutritional advice is that fruits are healthy and a good source of vitamins and dietary fiber. They keep us regular and keep things flowing. I have been on Paleo for almost two years. In the past two years, I have consumed very few fruits, I eat seasonal fruits and eat them very sparingly. The lack of fruits have not caused my digestive system to lock up but on the contrary my digestive health has greatly improved with meats, vegetables, fats, and total lack of grains. In this blogpost I will offer my 2 cents about fruits and try to offer middle of the path advice about fruits.

   The fruits like dates, figs, olives, and grapes were probably domesticated around 6000 years ago in the fertile crescent region. The pits of these fruits are found in the archeological findings dating back to 6000 years. The fruits that our hunter gatherer forefathers consumed were wild berries and most often fruits like apples were much smaller in size and tasted bitter. The apple that we see today is probably gone through thousands of natural selections and genetic iterations as humans began to settle down and began domesticating fruits, vegetables, and grains. For the past hundred years as agricultural technology vastly improved, the fruits have gotten much bigger in size and much much sweeter. The agricultural scientists are able to segregate genes and discard the bad genes in producing perfect fruit crops. The important take away is that fruits that we see today in their existing form did not exist in the Paleolithic era. The modern fruits are genetically engineered to produce perfect pest resistant crops to maximize profits and increase shelf life in the supermarkets. The modern fruits are much sweeter and much larger in size than the fruits of maybe hundred years ago. You can see the difference by heading to your local organic farmers market. In most cases organic fruits and vegetables look almost sicker and malnourished compared to the vegetables sold at your local grocery stores, but organic produce does taste and smell better than the regular grocery store produce. See picture below.

 The main problem with fruits is their sugar content. Yes fruits deliver a healthy dose of dietary fiber and vitamins, but they also deliver a potent dose of sugar. The modern society already in the midst of insulin roller coaster does not benefit from the high sugar content of most grocery store fruits. As you can see from the table below that consuming an apple is equivalent to consuming about 6 cubes of sugar. Now imagine consuming 2-3 helpings of fruits and the associated sugar consumption. The old adage "an apple a day keeps a doctor away" may not be true anymore. It is more like an apple a day will give you diabetes. The content of sugar, vitamins, antioxidants, and dietary fiber may exist in all fruits, but like any other food, the content exist on a spectrum. For example, a strawberry maybe healthier than a banana as it contains a whole lot less sugar and more antioxidants. A blueberry may also be more healthier than grapes because of its low sugar content and high antioxidants. The table below list most common fruits and their respective sugar contents. 

Tot Sugar    Sugar Cubes
Lime100 g1 medium0.4 g0.1
Avocados100 g1 medium0.9 g0.15
Lemon100 g1 serving2.5 g0.5
Tomatos100 g1 medium 2.8 g0.5
Strawberries147 g1 cup full7.0 g1.5
Figs100 g1 serving7.0 g1.5
Blueberries100 g1 cup full7.3 g1.5
Plum100 g1 serving7.5 g1.5
Pineapple112 g1 serving9.0 g2.5
Pears100 g1 small pear9.0 g3
Apricots100 g1 serving10 g2.8
Cantaloupe160 g1 cup cubed13 g3
Peach (Large)184 g1 Large Peach15 g3.5
Mango100 g1/2 Mango15 g5
Banana (Large)140 g1 Large Banana17 g4.5
Watermelon280 g1 Large slice18 g5.5
Red Seedless Grapes126 g1 serving20 g5
Naval Orange270 g1 Large orange23 g6
Apple223 g1 Large Apple23 g6

   As you can see from the above table that fruits like lemon, lime, avocados, strawberries, and tomato are very low in sugar content and should not be avoided. The low sugar content fruits are also good source of vitamin C and and contain good antioxidant qualities. However, most fruits are very high in sugar. Also the sugar content of a fruit goes up several folds the riper it gets, as sunlight and aging (rotting) will convert complex carbohydrates (starches) to simple sugar. The quantities given above are based on one sensible serving, but most often fruits are over eaten because of their sweetness and feel good factor. My friend who was not losing weight was munching on almost a pound of grapes throughout the day. No wonder he had trouble losing weight. As blood sugar rises, insulin gets released, the function of insulin is to store away fat and deal with metabolizing the sugar in the body. Once the sugar burns away body feels hungry and we end up eating more sugary foods and the insulin cycle continues. Fruits with their high sugar content contribute to this insulin cycle. The way to achieve good optimal health is to control this sugar/insulin roller coaster. The foods eaten on Paleo diet do not cause the blood sugar to rise and fall, they keep the blood sugar steady and burn over a longer period of time than sugars. The hunter gathers walked around several miles per day foraging for food. They ate meats, fats, and vegetables. Their blood sugar remained constant and provided energy over a longer part of the day. Most often meats and fats were not available on the daily basis, in that period the hunter gathers resorted to foraging for wild berries, nuts, seeds, and wild fruits. They probably did not have the luxury to walk up and grab a giant peach that we see in our super markets. As mentioned above the wild fruits are most often much smaller in size.

   Coming back to our original question; are fruits healthy for you? The answer is to adopt the middle path. If you are overweight and are trying to lose weight then avoid sweet fruits like bananas or mangos. Eating high sugary fruits will keep your insulin levels high and hinder the burning of fats. If you are lean and are at your ideal weight and also lead an active life style, then enjoy a piece of fruit. You are probably able to burn it off, but remember, that sugar is sugar. It does not matter where it comes from. Sugar simply does not burn cleanly in the body as fats and proteins are metabolized. Fruits are seasonal, so if you are going to enjoy fruits then have them when they are in season. I try not to eat a fruit that is ripe. I enjoy a white peach that has plenty of crunch. I also eat a banana once in a while (during travels) that is not ripe. The less ripe a fruit, lower the sugar content. Ripening of a fruit converts the starches to sugars and the fruit becomes sweeter. I probably consume fruits twice per week and in very moderate quantities. I receive my vitamins, minerals, and dietary fiber from meats, fats, and vegetables. I love blueberries and most often during lunch a small box of blueberries is enough for me. The final take away is that fruits consumption should be limited. Most of the fruits that we see today were domesticated only few thousand years ago, and only within the last hundred years they have been genetically engineered to produce perfect crops. When you walk in to a supermarket and notice that all the peaches are of the same size and color, an alarm should go up in your head. Nature is very random, wild fruits and vegetables are never uniform and homogenous. I have an apple tree in my back yard, it gives plenty of fruit in the summer. The apples always vary in size and color. Some are deformed and some are perfectly round. The fruit that is not strong to withstand weather simply falls off and only the strong good fruit survives. The Darwinian natural selection works in front of us. My advice don't make fruits your ultimate health saviors; meats, fats, and vegetables are much better for you and will provide all the nourishment (energy, vitamins, minerals, and dietary fiber) that a healthy body requires.