“Eat more fruits and vegetables” – A very common advice from our physicians. But do fruits and vegetables go hand in hand?
Modern fruit is sweet. The sweetness in fruits is due to its sucrose (we call it ‘Table Sugar’) content which is a mixture of glucose and fructose. After ingestion, when sucrose degrades in the intestine it provides glucose and fructose.
Glucose and fructose have the same chemical formula; however, our body handle them differently.
Glucose is absorbed from the gut straight to the muscle or brain and influence on insulin. A small amount of glucose is stored as a form of glycogen (by a process called gluconeogenesis by the liver) in the liver and muscle, so that our body can use it whenever blood glucose level falls. And any extra glucose stores as fat.
Fructose on the other hand goes directly in the liver and breakdown into a waste product called uric acid. Uric acid depletes ATP level, and suppresses mitochondrial energy production; so, we lack energy, feel hungry, and forage for foods. This is how sugar causes more food cravings.
Small amounts of fructose are also get converted into liver glycogen. Too much fructose is associated with non-alcoholic fatty liver disease.
Some pioneering research work by Dr. Richard Johnson’s group shows a link between fructose intake, elevated uric acid levels, and high blood pressure, as well as increased cardiorenal risks.
Uric acid crystal deposition in the joints cause painful arthritis, called gout. Uric acid inhibits nitric oxide produced by endothelial cells that lines our blood vessels. Nitric oxide is necessary to maintain blood supply to the brain, to maintain blood pressure and healthy heart, and to protect our immune system.
Uric acid is also involved in the development of insulin resistance in the liver and muscle.
Thus, it does not seem like a good idea to eat ‘more fruits’, except some unconventional fruits, such as avocados, tomatoes, and nuts, as eating more fruits will also increase sugar intake. Fruits are advertised heavily due to their vitamins, minerals, and phytonutrients contents, as well as antioxidant properties. However, there is no nutrients that can not be found in vegetables which will provide all nutritional benefits of fruits without overdosing sugar.
Moreover, modern fruit is processed and no longer natural, it’s been manipulated to have high sugar content, sprayed with fertilizers during agriculture, and preservatives to increase shelf-life and transportability. Fruit juice has the same sugar without the fiber content and sometimes contain additives and preservatives. Commercial dried fruits are just concentrated sugar with added chemicals and preservatives.
Fruit is not bad, however conventional sweet fruits are not necessarily be taken every day. The sugar in the high fiber fruit may absorb slowly, however the total sugar load and so does the glycemic load would be same as low fiber sweet fruits. A handful of wild berries, and avocados are probably what our physician or dietician recommends having more.
References
1. Johnson, R. J., Segal, M. S., Sautin, Y., Nakagawa, T., Feig, D. I., Kang, D. H., ... & Sánchez-Lozada, L. G. (2007). Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease, and cardiovascular disease. The American journal of clinical nutrition, 86(4), 899-906.
2. Gary Fettke - https://www.youtube.com/watch?v=L6LL92Zs5L0
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