Abstract
Sugars are foundational to biological life and played essential roles in human evolution and dietary patterns for most of recorded history. The simple sugar glucose is so central to human health that it is one of the World Health Organization's Essential Medicines. Given these facts, it defies both logic and a large body of scientific evidence to claim that sugars and other nutrients that played fundamental roles in the substantial improvements in life- and health-spans over the past century are now suddenly responsible for increments in the prevalence of obesity and chronic non-communicable diseases. Thus, the purpose of this review is to provide a rigorous, evidence-based challenge to 'diet-centrism' and the disease-mongering of dietary sugar. The term 'diet-centrism' describes the naïve tendency of both researchers and the public to attribute a wide-range of negative health outcomes exclusively to dietary factors while neglecting the essential and well-established role of individual differences in nutrient-metabolism. The explicit conflation of dietary intake with both nutritional status and health inherent in 'diet-centrism' contravenes the fact that the human body is a complex biologic system in which the effects of dietary factors are dependent on the current state of that system. Thus, macronutrients cannot have health or metabolic effects independent of the physiologic context of the consuming individual (e.g., physical activity level). Therefore, given the unscientific hyperbole surrounding dietary sugars, I take an adversarial position and present highly-replicated evidence from multiple domains to show that 'diet' is a necessary but trivial factor in metabolic health, and that anti-sugar rhetoric is simply diet-centric disease-mongering engendered by physiologic illiteracy. My position is that dietary sugars are not responsible for obesity or metabolic diseases and that the consumption of simple sugars and sugar-polymers (e.g., starches) up to 75% of total daily caloric intake is innocuous in healthy individuals.

Conflict of interest: None.

Just wrote an article responding to this ridiculous one claiming sugar is healthy. I’ll tweet my response once published.

...anti-sugar rhetoric is simply diet-centric disease-mongering engendered by physiologic illiteracy.

Vitsi varmaan: "Sokeri on välttämätön lääke, ei aiheuta lihavuutta eikä metabolisia sairauksia, on ihan OK jos terve ihminen saa kolme neljäsosaa kaloreistaa sokerista ja tärkkelyksestä".

... Elimistön tärkein tehtävä on turvata aivojen energiansaanti, että aivot pysyvät toiminnassa. Koska jos aivot eivät toimi kunnolla, koko ihminen kuolee, sanoo ravitsemusterapeutti Kirsi Englund Terveystalosta.

Jos ihminen ei saa ravinnostaan ollenkaan hiilihydraatteja eli sokereita, menevät elimistön aineenvaihduntamekanismit hätätilaan. Turvatakseen aivojen toiminnan elimistö alkaa ottamaan lihaksista proteiineja ja rasvakudoksesta rasvahappoja ja muokkaamaan niitä ketoaineiden avulla glukoosiksi.

– Periaatteessa ihminen pärjää ilman sokeria, mutta ei ole välttämättä mitään syytä pyrkiä sellaiseen tilanteeseen, Englund sanoo.

Vähäkuituinen ruokavalio altistaa sairauksille
Trendikkäissä ketoosiruokavalioissa tavoitellaan juuri edellä mainittua elimistön ”hätätilaa” eli ketoosia. Ketoosiruokavalioita noudattaville nopeaksi energianlähteeksi kaupataan toisinaan rasvakahvia tai MTC-öljyjä. Englund ihmettelee, miksi pyörä pitää keksiä uudelleen? Elimistössä kun on jo luontainen mekanismi, hiilihydraattien pilkkominen glukoosiksi, josta saadaan nopeasti energiaa esimerkiksi bussiin pinkaisemiseen.

– Siellähän on kaupalliset intressit myös takana, Englund toteaa.

Rahan menon sijaan Englund kuitenkin pitää ketoosiruokavalioiden suurimpana vaarana suolisto-ongelmia. Suolistomikrobit käyttävät ravinnokseen kuiturakenteita, joita löytyy vain hiilihydraateista. Jos suolistobakteereja ei ruoki kuiduilla, alkaa mikrobiomin koostumus muuttua: hyvät bakteerit häviävät ja tilalle tulee niin sanotusti pahoja bakteereja.

Muutoksen tiedetään altistavan esimerkiksi suolistosairauksille, mutta ne on yhdistetty lukuisiin muihinkin sairauksiin, kuten diabetekseen ja lihavuuteen...

Epilepsy: Although usually not completely devoid of carbs, the classical ketogenic and modified Atkins diet restrict carbs to less than 20 grams per day – providing well below the 100+ grams of glucose needed by the brain. Well-designed trials have shown that strict carb restriction can be very effective in reducing and in some cases eliminating seizures in children and adults.11

Mental health conditions: While research is preliminary, anecdotal evidence, basic neurochemistry studies and a few promising clinical trials have suggested a ketogenic diet may improve symptom control for some mental health conditions. For example, bipolar disorder-which research is showing shares a number of features with epilepsy- may improve on a ketogenic diet.12 Read more in our guide on low-carb and mental health.

Traumatic brain injury (TBI): Trauma to the brain can impair its ability to use glucose efficiently and may lead to elevated blood sugar levels. According to some studies, a carb-free or ketogenic diet may provide an alternative fuel to the brain as it heals, thus giving benefits to people who have sustained TBI’s, although the most promising results to date have been shown in animal research.13

Alzheimers: In Alzheimer’s disease there is documented insulin resistance in the brain that hampers the uptake of glucose for fuel, so much so that some researchers have called Alzheimer’s “Type 3 diabetes.”14 It has been known since the early 1980s, through the use of PET scanning, that brain glucose metabolism is impaired by up to 40% in individuals with Alzheimer’s and the problem shows up on imaging studies of the brain many years before cognitive problems begin to show.15Studies have found, however, that while glucose uptake is impaired in early Alzheimer’s, the brain’s use of ketones for energy is not.16 Two recent notable clinical studies, one in 2012 and one in 2017, showed preliminary but promising results of using a ketogenic diet for people with Alzheimers.17 Two more clinical trials are now underway.

Hunger control: A carbohydrate-free diet suppresses the “hunger hormone” ghrelin that is secreted mainly by the stomach. Ghrelin has multiple impacts in the body but one impact is on the brain’s hypothalmus to regulate appetite control.18 It also travels to the amygdala, the brain’s reward center. This means that in a body burning ketones, the brain is receiving reduced hunger signals, which may enhance weight loss and diabetes control.19 Importantly, although considered high-quality research, these studies are very small. Nevertheless, they provide clinical evidence that helps confirm what many people report after adopting a carb-free diet —they feel much less hungry.