keto diet

Posted on Diet

Switching to a vegan or ketogenic diet rapidly impacts the immune system.

Researchers at the National Institutes of Health observed rapid and distinct immune system changes in a small study of people who switched to a vegan or a ketogenic (also called keto) diet. Scientists closely monitored various biological responses of people sequentially eating vegan and keto diets for two weeks, in random order. They found that the vegan diet prompted responses linked to innate immunity—the body’s non-specific first line of defence against pathogens—while the keto diet prompted responses associated with adaptive immunity—pathogen-specific immunity built through daily life exposure and vaccination. Metabolic changes and shifts in the participants’ microbiomes—communities of bacteria living in the gut—were also observed. More research is needed to determine if these changes are beneficial or detrimental and how they could affect nutritional interventions for diseases such as cancer or inflammatory conditions.

Scientific understanding of how different diets impact the human immune system and microbiome is limited. Therapeutic nutritional interventions—which involve changing the diet to improve health—are poorly understood, and few studies have directly compared the effects of more than one diet. The keto diet is a low-carbohydrate diet that is generally high in fat. The vegan diet eliminates animal products and tends to be high in fibre and low in fat.  

The study was conducted by researchers from the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at the Metabolic Clinical Research Unit in the NIH Clinical Center. The 20 participants were diverse with respect to ethnicity, race, gender, body mass index (BMI), and age. Each person ate as much as desired of one diet (vegan or keto) for two weeks, followed by as much as desired of the other diet for two weeks. People on the vegan diet, which contained about 10% fat and 75% carbohydrates, chose to consume fewer calories than those on the keto diet, which contained about 76% fat and 10% carbohydrates. Blood, urine, and stool were collected for analysis throughout the study period. The effects of the diets were examined using a “multi-omics” approach that analyzed multiple data sets to assess the body’s biochemical, cellular, metabolic, and immune responses, as well as changes to the microbiome. Participants remained on site for the entire month-long study, allowing for careful control of the dietary interventions.

Switching exclusively to the study diets caused notable changes in all participants. The vegan diet significantly impacted pathways linked to the innate immune system, including antiviral responses. On the other hand, the keto diet led to significant increases in biochemical and cellular processes linked to adaptive immunity, such as pathways associated with T and B cells. The keto diet affected levels of more proteins in the blood plasma than the vegan diet and proteins from a wider range of tissues, such as the blood, brain and bone marrow. The vegan diet promoted more red blood cell-linked pathways, including those involved in heme metabolism, which could be due to the higher iron content of this diet. Additionally, both diets produced changes in the participants’ microbiomes, causing shifts in the abundance of gut bacterial species previously linked to the diets. The keto diet was associated with changes in amino acid metabolism—an increase in human metabolic pathways for the production and degradation of amino acids and a reduction in microbial pathways for these processes—which might reflect the higher amounts of protein consumed by people on this diet.

The distinct metabolic and immune system changes caused by the two diets were observed despite the diversity of the participants, which shows that dietary changes consistently affect widespread and interconnected pathways in the body. More study is needed to examine how these nutritional interventions affect specific immune system components. According to the authors, the results of this study demonstrate that the immune system responds surprisingly rapidly to nutritional interventions. The authors suggest that it may be possible to tailor diets to prevent disease or complement disease treatments, such as by slowing processes associated with cancer or neurodegenerative disorders.

Posted on Diet, Weight Loss

A ‘Keto-like’ diet may be linked to a higher risk of heart disease and cardiac events.

Popular weight-loss diet also associated with higher levels of LDL cholesterol
Popular weight-loss diet also associated with higher levels of LDL cholesterol


The ketogenic or “keto” diet, which involves consuming very low amounts of carbohydrates and high amounts of fats, has been gaining popularity. However, a new study presented at the American College of Cardiology’s Annual Scientific Session Together With the World Congress of Cardiology suggests that a “keto-like” diet may be associated with higher blood levels of “bad” cholesterol and a twofold heightened risk of cardiovascular events such as chest pain (angina), blocked arteries requiring stenting, heart attacks and strokes.

“Our study found that regular consumption of a self-reported diet low in carbohydrates and high in fat was associated with increased levels of LDL cholesterol— or “bad” cholesterol—and a higher risk of heart disease,” said Iulia Iatan, MD, PhD, attending physician-scientist at the Healthy Heart Program Prevention Clinic, St. Paul’s Hospital and University of British Columbia’s Centre for Heart Lung Innovation in Vancouver, Canada, and lead author of the study. “To our knowledge, our study is one of the first to examine the association between this type of dietary pattern and cardiovascular outcomes.”

Carbohydrates are the body’s first “go-to” source for fuel to provide energy for daily life. Low-carbohydrate, high-fat (LCHF) diets, like a keto diet, restrict consumption of carbohydrates (e.g., bread, pasta, rice and other grains, baked goods, potato products such as fries and chips, and high-carbohydrate fruits and vegetables). By depriving the body of carbohydrates, it is forced to start breaking down fat for energy instead. The breakdown of fat in the liver produces ketones, chemicals that the body uses as energy in the absence of carbohydrates—hence the name ketogenic, or “ketone producing.” Proponents of a ketogenic diet generally suggest limiting carbohydrates to 10% of total daily calories, protein to 20% to 30% and obtaining 60% to 80% of daily calories from fat.

Some previous studies have shown that an LCHF diet can lead to elevated levels of LDL cholesterol in some people. While elevated LDL cholesterol is a known risk factor for heart disease (caused by atherosclerosis, a buildup of cholesterol in the coronary arteries), the effects of an LCHF diet on risk for heart disease and stroke have not been well studied, Iatan said.  

For this study, Iatan and her colleagues defined an LCHF diet as consisting of no more than 25% of total daily energy or calories from carbohydrates and more than 45% of total daily calories from fat. They dubbed this an LCHF diet and “keto-like” because it is somewhat higher in carbohydrates and lower in fat than a strict ketogenic diet. They defined a “standard diet” as individuals not meeting these criteria and having more balanced eating habits.

The research team analyzed data from the UK Biobank, a large-scale prospective database with health information from over half a million people living in the United Kingdom who were followed for at least 10 years. Upon enrollment in the biobank, 70,684 participants completed a one-time self-reported 24-hour diet questionnaire and, at the same time, had blood drawn to check their levels of cholesterol. The researchers identified 305 participants whose questionnaire responses indicated that their diet during the 24-hour reporting period met the study’s definition of an LCHF. These participants were matched by age and sex with 1,220 individuals who reported eating a standard diet. This resulted in 73% of the participants in each group being women and the group’s average age was 54 years. Those on an LCHF diet had an average body mass index (BMI) of 27.7; those on a standard diet, 26.7. A BMI of 25 to 30 falls within the overweight range.

Compared with participants on a standard diet, those on an LCHF diet had significantly higher levels of both LDL cholesterol and apolipoprotein B (apoB), the protein component that sits on LDL and other atherogenic lipoprotein particles. Previous studies have shown that elevated apoB may be a better predictor than elevated LDL cholesterol for risk of cardiovascular disease, Iatan said. After an average of 11.8 years of follow-up—and after adjustment for other risk factors for heart disease, such as diabetes, high blood pressure, obesity and smoking—people on an LCHF diet had more than two-times higher risk of having several major cardiovascular events, such as blockages in the arteries that needed to be opened with stenting procedures, heart attack, stroke and peripheral arterial disease. In all, 9.8% of participants on an LCHF diet experienced a new cardiac event, compared with 4.3% of those on a standard diet, a doubling of risk for those on an LCHF diet.

“Among the participants on an LCHF diet, we found that those with the highest levels of LDL cholesterol were at the highest risk for a cardiovascular event,” Iatan said. “Our findings suggest that people who are considering going on an LCHF diet should be aware that doing so could lead to an increase in their levels of LDL cholesterol. Before starting this dietary pattern, they should consult a health care provider. While on the diet, it is recommended they have their cholesterol levels monitored and should try to address other risk factors for heart disease or stroke, such as diabetes, high blood pressure, physical inactivity and smoking.”

The study’s findings also suggest that not everyone responds to an LCHF diet in the same way.

“On average, cholesterol levels tend to rise on this diet, but some people’s cholesterol concentrations can stay the same or go down, depending on several underlying factors,” Iatan said. “There are inter-individual differences in how people respond to this dietary pattern that we don’t fully understand yet. One of our next steps will be to try to identify specific characteristics or genetic markers that can predict how someone will respond to this type of diet.”   

A limitation of the study is that participants provided dietary information at only one point in time, which should be considered when interpreting the study findings, Iatan said. Moreover, self-reports of food consumption can be inaccurate, though Iatan said this questionnaire has been extensively validated.    

Because the study was observational, it can only show an association between the diet and an increased risk for major cardiac events, not a causal relationship. However, Iatan said the findings merit further research in prospectively designed studies, especially when approximately 1 in 5 Americans report being on a low-carb, keto-like or full keto diet.

Posted on Diet, Weight Loss

Keto vs vegan: Study of popular diets finds over fourfold difference in carbon footprints

Keto and paleo diets were found to be the least sustainable -- and have the lowest diet quality scores -- of the six popular diets examined
Keto and paleo diets were found to be the least sustainable — and have the lowest diet quality scores — of the six popular diets examined

This may be tough to swallow for those on keto or paleo diets.

A new study from Tulane University which compared popular diets on both nutritional quality and environmental impact, found that the keto and paleo diets, as eaten by American adults, scored among the lowest on overall nutrition quality and were among the highest on carbon emissions.

The keto diet, which prioritizes high fat and low carbs, was estimated to generate almost 3 kg of carbon dioxide for every 1,000 calories consumed. The paleo diet, which eschews grains and beans in favour of meats, nuts and vegetables, received the next lowest diet quality score and also had a high carbon footprint, at 2.6 kg of carbon dioxide per 1,000 calories.

The study, published in The American Journal of Clinical Nutrition, compiled diet quality scores using data from more than 16,000 adult diets collected by the CDC’s National Health and Nutrition Examination Survey. Individual diets were assigned point values based on the federal Healthy Eating Index and average scores were calculated for those eating each type of diet.

The study’s senior author Diego Rose, professor and nutrition program director at Tulane University School of Public Health and Tropical Medicine, said that while researchers have examined the nutritional impact of keto and paleo diets, this is the first study to measure the carbon footprints of each diet, as consumed by U.S. adults, and compare them to other common diets.

“We suspected the negative climate impacts because they’re meat-centric, but no one had really compared all these diets – as they are chosen by individuals, instead of prescribed by experts – to each other using a common framework,” Rose said.

On the other end of the spectrum, a vegan diet was found to be the least impactful on climate, generating 0.7 kg of carbon dioxide per 1,000 calories consumed, less than a quarter of the impact of the keto diet. The vegan diet was followed by vegetarian and pescatarian diets in increasing impact.

The pescatarian diet scored highest on nutritional quality of the diets analyzed, with vegetarian and vegan diets following behind.

The omnivore diet – the most common diet, represented by 86% of survey participants – sat squarely in the middle of the pack of both quality and sustainability. Based on the findings, if a third of those on omnivore diets began eating a vegetarian diet, on average for any given day, it would be equivalent to eliminating 340 million passenger vehicle miles.

Notably, however, when those on omnivorous diets opted for the plant-forward Mediterranean or fatty meat-limiting DASH diet versions, both carbon footprints and nutritional quality scores improved.

“Climate change is arguably one of the most pressing problems of our time, and a lot of people are interested in moving to a plant- based diet,” Rose said. “Based on our results, that would reduce your footprint and be generally healthy. Our research also shows there’s a way to improve your health and footprint without giving up meat entirely.”

A 2021 United Nations-backed study found that 34% of greenhouse gas emissions come from the food system. The major share of those emissions come from food production, with beef being responsible for 8-10 times more emissions than chicken production and over 20 times more emissions than nut and legume production.

While the environmental impacts of specific foods have been studied extensively, Rose said this study was important because “it considers how individuals select popular diets that are composed of a wide variety of foods.”

Going forward, Rose still has questions about how to encourage eating habits that are better for people and the planet.

“I think the next question is how would different policies affect outcomes and how could those move us toward healthier, more environmentally friendly diets?” Rose said.

Posted on Multiple Sclerosis

The Keto diet improves multiple sclerosis symptoms

Keto diet improves multiple sclerosis symptoms - YouTube


A new preliminary study reports a ketogenic diet significantly improves the quality of life and health scores for people with multiple sclerosis (MS). Given the lack of safe and effective therapies for MS, this is very encouraging to have a lifestyle-based therapy that can make a positive difference in the lives of people with MS.

Posted on Autism, Epilepsy

New dietary treatment for epilepsy well tolerated and reduced seizures – useful for the autism community

The first clinical trial of a new dietary treatment for children and adults with severe forms of epilepsy, co-developed by UCL researchers and based on the ketogenic diet, has been successfully completed.

For the study, published in Brain Communications, clinicians evaluated the use of K.Vita®, (also known as Betashot), an oral liquid dietary supplement developed by UCL in collaboration with Royal Holloway, University of London, and Vitaflo International Ltd.

The ketogenic diet (KD) consists of high-fat, low-carbohydrate and adequate protein consumption and mimics the fasting state, altering the metabolism to use body fat as the primary fuel source. This switch from carbohydrates to fat for body fuel is known as ketosis.

It is widely used to treat drug resistant epilepsies. However, the highly restrictive diet, which can cause constipation, low blood sugar, and stomach problems, can have poor compliance and is not suitable for everyone. Some KD supplements are also known to be unappetising.

K.Vita is based on novel findings by UCL researchers*, who discovered a different underlying mechanism to explain why the KD is effective against epilepsy; in developing a new treatment, researchers also sought to reduce the adverse side effects caused by KD.

Corresponding author Professor Matthew Walker (UCL Queen Square Institute of Neurology) said: “The ketogenic diet has been used for 100 years to treat epilepsy, helping reduce seizures in both children and adults.

“It has long been thought the diet was effective due to its production of ketones**, however we now believe the increase in levels of the fatty acid, decanoic acid, also produced by the diet, may provide the powerful antiseizure effects.

“In this study we evaluated a newly developed medium chain triglyceride (type of dietary fat) supplement, designed to increase levels of decanoic acid, while also reducing the adverse side effects, and to be more palatable.”

For the feasibility trial, researchers wanted to establish participants’ tolerance (side effects such as bloating or cramps) to the treatment, acceptability (flavour, texture, taste) and compliance (how easy it is to use K.Vita at the advised quantity, as part of their daily diet).

As secondary outcomes, they also monitored the frequency of epileptic seizures or paroxysmal events (fits, attacks, convulsions) and whether ketone production was decreased.

In total, 35 children (aged 3 to 18) with genetically caused epilepsy and known to be unresponsive to drugs, and 26 adults with drug-resistant epilepsy*** (DRE), were given K.Vita liquid supplements (a drink), to be taken with meals. They were also asked to limit high-refined sugary food and beverages from their diets.

The trial lasted 12 weeks with K.Vita treatments increasing incrementally over time, taking into account individuals’ tolerance to the treatment.

In total, 23/35 (66%) children and 18/26 (69%) adults completed the trial i.e they were continuing to take K.Vita at 12 weeks. Gastrointestinal disturbances were the primary reason for discontinuation, and their incidence decreased over time

Over three-quarters of participants/caregivers reported favourably on sensory attributes, such as taste, texture and appearance, and ease of use.

In regards to the secondary outcomes, there was a mean 50% reduction in seizures or paroxysmal events, and fewer than 10% of people on the diet produced significant ketones.

Commenting on the findings, Professor Walker, who is also a consultant neurologist at the National Hospital for Neurology and Neurosurgery, said: “Our study provides early evidence of the tolerability and effectiveness of a new dietary supplement in severe drug-resistant epilepsies in adults and children and provides a further treatment option in these devastating conditions.

“It also offers an alternative, more liberal, diet for those who cannot tolerate or do not have access to ketogenic diets.”

He added: “While this study was not designed to include enough patients to fully assess the supplement’s effects on seizures, it is exciting to report that there was a statistically significant reduction in the number of seizures in the group overall after three months of treatment.

“Furthermore, high ketone levels were not observed in over 90% of the participants. This indicates that the effect of the diet was independent from ketosis; this is important because high ketone levels in the ketogenic diets contribute to both short- and longer-term side effects.”

First author, Dr Natasha Schoeler, Research Dietitian at UCL Great Ormond Street Institute of Child Health, commented: “This novel dietary approach for epilepsy management involves following the principles of a healthy balanced diet alongside use of K.Vita, allowing greater dietary freedom compared to ketogenic diets. Our approach also requires much less input from a specialist dietician than is required by traditional ketogenic diets, and so may allow more widespread access to people with drug-resistant epilepsy.”

Researchers say larger, controlled studies of K.Vita are now needed to determine the precise epilepsies and conditions in which the supplement is most effective.