Summaries of study evidence on various foods. OBJECTIVITY zone.

Mar 252011

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General Information: Wikipedia entry

Studied Uses: General health

General Health

Fructose Evidence Summary - General Health -

Overall Score: -2.25

Behind the Score: The preponderance of studies show various negative effects from fructose consumption, although the score is not staggeringly negative because most studies to date have been animal 1 or in vitro 2 studies, with the notable exception of a small double-blinded parallel-arm study 3 (which showed a link to visceral fat and decreased insulin sensitivity) and a large cohort study 4 (which showed a possible link to gout). Moreover, it’s becoming conventional wisdom that high-fructose corn syrup is unhealthy 5, despite counter-arguments of the Corn Refiners Association. But what about whole fruits, fruit juices and sweeteners like agave nectar? The answer is complicated. (See the “Warnings and Special Notes” and “What Can I Do?” sections below.)

Warnings and Special Notes: A recent in vitro study 6 showed that fructose fed pancreatic cancer cells — so even organic or raw fructose-based sweeteners do not seem like such a “free pass” anymore 7. To minimize fructose, the answer seems simple: Favor low-fructose vegetables and fruits, and avoid high-fructose products. Note: To reduce pesticide and GM food exposure, eat organic fruits and vegetables.

What Now? Further study is definitely warranted, as the pancreatic-cancer study mentioned above was in vitro and did not involve human subjects. In general, most studies performed to date have found fructose has negative effects in animals, in vitro, and in humans.

What Can I Do? Keep eating whole fruits — they are widely acknowledged to have far more benefits than drawbacks. If you’re concerned about sugar intake, refer to the fructose chart and choose fruits that have relatively low amounts. (Note: Cancer patients may want to read the Warnings and Special Notes section above.) Compared to whole fruits, fruit juices contain relatively large amounts of sugars and much less fiber, so choosing whole fruits instead is probably a better choice.

Regarding sweeteners, regular table sugar is about 50 percent glucose and 50 percent fructose. High-fructose corn syrup often has either 42 or 55 percent fructose 8 (plus, it is often made from genetically modified corn), and agave nectar can range from about 56 to 92 percent fructose 9. With regard to fructose-heavy sweeteners such as agave nectar, used in many raw and/or vegan food products, some in moderation may be acceptable unless further studies show definite negative effects. Proponents cite agave nectar’s low glycemic index, which means it doesn’t affect blood glucose as much as table sugar. However, use caution if you have or had cancer. If you would rather avoid agave nectar and fructose in general, there are (imperfect) alternatives, such as stevia and xylitol.