By finding a link to a condition that raises the risk of type 2 diabetes, new research questions the health benefits of ketogenic diets.
Ketogenic diets are low-carbohydrate, high-fat diets that have been shown to reduce weight. They change metabolism so that energy comes from fat instead of sugar.
When researchers in Switzlerland examined what happened to mice in the early stages of a ketogenic diet, they found that the animals showed a poorer ability to regulate blood sugar compared with similar mice on a high-fat, high-carbohydrate diet.
In a paper on their work now published in the Journal of Physiology, they note that “even though [keto diet]-fed animals appear healthy in the fasted state, they exhibit decreased glucose tolerance to a greater extent than [high-fat diet]-fed animals.”
The reason for this, they found, was that the livers of the keto diet-fed mice were not responding as well to insulin. This condition, which is known as insulin resistance, raises the risk of developing type 2 diabetes.
“Diabetes is one of the biggest health issues we face,” says study author Christian Wolfrum, who is with the Institute of Food, Nutrition and Health at ETH Zürich in Switzerland.
Insulin is a hormone that helps the body control levels of blood sugar, or glucose. If blood sugar stays above normal for long periods of time, it becomes a condition called hyperglycemia that can lead to serious health problems. This is the hallmark of diabetes.
In type 1 diabetes, hyperglycemia develops because the pancreas does not make enough insulin. In type 2 diabetes, organs and tissues lose their ability to respond to insulin. The pancreas tries to compensate by making more insulin, but eventually this is not enough and leads to hyperglycemia.
There are a number of ways in which insulin helps control blood glucose levels. One is by signaling to the liver to reduce glucose production, and another is by helping muscles and tissues absorb glucose and convert it into energy.
Insulin resistance is a “
Cells can also become insulin resistant when they need increasing amounts of the hormone to help them use glucose.
However, the researchers found that the main reason for decreased glucose tolerance in the keto diet-fed mice was due to insulin resistance in the liver “rather than impaired glucose clearance and tissue glucose uptake.”
Despite extensive research into the causes of insulin resistance and type 2 diabetes, they are not completely understood.
One thing that scientists do know is that fat-like substances called lipids are “clearly associated with insulin resistance.” Even here, however, many questions remain, such as, “Is the link due to circulating fats or to fat buildup in tissue?”
The lack of carbohydrates makes the body break down fats into fatty acids and then into ketones.
Keto diets are probably among the “most studied” approaches to weight loss of recent times.
A lot of research now backs the idea that keto diets have a sound “physiological and biochemical basis” and can significantly benefit cardiovascular health.
This is welcome news to many physicians, for whom one of the biggest challenges that they face in their daily practices is treating obesity.
However, while keto diets have a proven track record in tackling obesity, some concerns remain. Many of these likely relate to a “broad lack of knowledge about the physiological mechanisms involved.”
The new study helps plug some of this knowledge gap. It suggests that insulin resistance in the liver can develop in the early stages of keto diets. This now needs to be confirmed in humans.
Also, the underlying mechanisms that lead to insulin resistance are still unclear, especially in relation to different diets. This also needs to be explored further, say the researchers.
Another area that needs further research is the effect on the brain of the byproducts of fatty acid breakdown. The researchers’ theory is that the fatty acid byproducts might have important “signaling roles” in the brain.
“Although ketogenic diets are known to be healthy, our findings indicate that there may be an increased risk of insulin resistance with this type of diet that may lead to type 2 diabetes.”
Kwa kugundua uhusiano na hali ambayo huongeza hatari ya ugonjwa wa kisukari wa aina ya 2, utafiti mpya unauliza faida za kiafya za lishe ya ketogenic. Chakula cha ketogenic ni chakula cha chini ya wanga na mafuta ambayo imeonyeshwa kupunguza uzito. Hizo hubadili kimetaboliki ili nishati itokeze kutoka kwa mafuta badala ya sukari. Watafiti wa Uswisi walipochunguza nini kilichotokea kwa panya katika hatua za mapema za lishe ya ketogenic, waligundua kwamba wanyama walionyesha uwezo duni wa kudhibiti sukari ya damu ikilinganishwa na panya sawa kwenye lishe ya mafuta na wanga. Katika makala yao iliyochapishwa katika jarida la Journal of Physiology, watafiti hao wanasema kwamba ingawa wanyama waliolishwa na keto wanaonekana kuwa na afya nzuri wakati wa kula, wanaonyesha upungufu wa uvumilivu wa sukari kwa kiwango kikubwa kuliko wanyama waliolishwa na keto. Hali hii, inayojulikana kama upinzani wa insulini, huongeza hatari ya kuambukizwa ugonjwa wa kisukari wa aina ya 2. "Ugonjwa wa kisukari ni moja ya matatizo makubwa ya afya tunayoyakabili,"" anasema mwandishi wa utafiti Christian Wolfrum, ambaye ni mtafiti wa Taasisi ya Chakula, Lishe na Afya katika ETH Zurich nchini Uswisi." Insulini ni homoni inayosaidia mwili kudhibiti viwango vya sukari ya damu, au glukosi. Kama sukari ya damu inabaki juu ya kawaida kwa muda mrefu, inakuwa hali inayoitwa hyperglycemia ambayo inaweza kusababisha matatizo makubwa ya afya. Hii ndiyo dalili ya ugonjwa wa kisukari. Katika ugonjwa wa kisukari wa aina ya 1, hyperglycemia hutokea kwa sababu kongosho haifanyi insulini ya kutosha. Katika ugonjwa wa kisukari wa aina ya 2, viungo na tishu hupoteza uwezo wao wa kujibu insulini. Pancreas hujaribu kulipa fidia kwa kutengeneza insulini zaidi, lakini hatimaye hiyo haitoshi na husababisha hyperglycemia. Kuna njia kadhaa ambazo insulini husaidia kudhibiti viwango vya sukari katika damu. Njia ya kwanza ni kwa kuelekeza ishara kwa ini ili kupunguza uzalishaji wa glukosi, na ya pili ni kwa kusaidia misuli na tishu kuchukua glukosi na kuibadilisha kuwa nishati. Insulin upinzani ni mgonjwa wa insulini, ambayo ni ugonjwa wa kuambukizwa na ugonjwa wa kuambukizwa na ugonjwa wa kuambukizwa na ugonjwa wa kuambukizwa na ugonjwa wa kuambukizwa na ugonjwa wa kuambukizwa. Hata hivyo, watafiti walipata kwamba sababu kuu ya kupungua kwa uvumilivu wa glukosi katika panya waliolishwa na keto ilikuwa kutokana na upinzani wa insulini katika ini badala ya kuharibika kwa uondoaji wa glukosi na upatikanaji wa glukosi katika tishu. "Wanasayansi wanajua kwamba ""mafuta"" yana uhusiano wa karibu na upinzani wa insulini, lakini bado kuna maswali mengi kama vile: ""Je, uhusiano huo unatokana na mafuta yanayozunguka au mafuta yanayokusanywa katika tishu?""" Vyakula vya Keto labda ni kati ya mbinu za "kuchunguzwa zaidi" za kupoteza uzito katika nyakati za hivi karibuni. Utafiti mwingi sasa unaunga mkono wazo kwamba vyakula vya keto vina msingi mzuri wa kisaikolojia na biokemia na vinaweza kufaidika sana na afya ya moyo na mishipa. Hii ni habari nzuri kwa madaktari wengi, ambao moja ya changamoto kubwa wanakabiliwa katika mazoezi yao ya kila siku ni kutibu unene. Hata hivyo, ingawa mlo wa keto una rekodi iliyothibitishwa katika kukabiliana na unene wa kupita kiasi, baadhi ya wasiwasi unabaki. Wengi wa haya yaelekea yanahusiana na "ukosefu mkubwa wa maarifa kuhusu taratibu za kisaikolojia zinazohusika". Utafiti mpya husaidia kuziba baadhi ya pengo hili la maarifa. Inasemekana kwamba upinzani wa insulini katika ini unaweza kutokea katika hatua za mapema za mlo wa keto. Sasa jambo hilo linahitaji kuthibitishwa kwa wanadamu. Pia, utaratibu wa msingi unaosababisha upinzani wa insulini bado haujulikani, hasa kuhusiana na lishe tofauti. Watafiti wanasema kwamba jambo hilo pia linahitaji kuchunguzwa zaidi. Sehemu nyingine inayohitaji utafiti zaidi ni athari kwa ubongo ya viungo vinavyotokana na kuharibika kwa asidi za mafuta. Nadharia ya watafiti ni kwamba bidhaa za asidi ya mafuta zinaweza kuwa na "majukumu muhimu ya ishara" katika ubongo. "Hata ingawa vyakula vya ketogenic vinajulikana kuwa na afya, matokeo yetu yanaonyesha kuwa kunaweza kuwa na hatari ya kuongezeka kwa upinzani wa insulini na aina hii ya chakula ambayo inaweza kusababisha ugonjwa wa kisukari wa aina ya 2 """