A team of health and nutrition specialists from the University of Bath, working with colleagues from the University of Bristol, Oxford University Hospital Trusts, Maastricht University and the Teagasc Food Research Centre, found that people following a ketogenic diet may experience increased levels of LDL cholesterol, higher levels of apolipoprotein B, and a reduction in certain gut bacteria.
Ketogenic Diet: Not Just Benefits
In their study, published on the open access website Cell Reports Medicine volunteers followed a ketogenic diet for a month, so researchers could study its impact on their bodies.
A ketogenic diet involves drastically reducing carbohydrate intake, replacing it with fats from meat, dairy, cheese, eggs, and other foods like avocados. Previous research has shown that those who stick to the rules lose weight, but also that the diet can cause other health problems such as nutritional deficiencies, digestive problems, kidney stones, and, in the long term, bone problems.
In this new effort, the research team suspected that the diet could also lead to increases in LDL cholesterol levels and possibly other problems. To find out if this might be the case, they conducted a randomized controlled trial recruiting volunteers to follow the diet for a month and then undergo a medical evaluation to determine the changes.
The study involved 53 nonobese adults. One-third followed a ketogenic diet, another third followed a low-sugar diet, and the remaining third followed what the researchers described as a moderate diet to serve as a control.
After a month, all the volunteers were tested. The research team found that the volunteers on the ketogenic diet lost an average of 1.6 kg (3.5 lbs) of fat. They also had 16% higher levels of LDL cholesterol in their blood than the control group and 26% higher levels of apolipoprotein B, a protein known to clog arteries. Those on the low-sugar diet lost an average of 1 kg (2.2 lbs) of fat and had 10% lower LDL cholesterol levels in their blood samples and no change in apolipoprotein B levels.
The researchers noted that volunteers who followed the ketogenic diet also had reduced levels of a type of gut bacteria known to be involved in strengthening the immune system and producing B vitamins.
A long-term ketogenic diet accumulates aged cells in tissues
A strict “ketogenic” diet, popular for weight loss and diabetes, may not be right for everyone, depending on the diet and the person.
A study by researchers at the University of Texas Health Science Center at San Antonio (UT Health San Antonio) found that a long-term, continuous ketogenic diet can induce senescence, or aging, of cells in normal tissues, particularly affecting heart and kidney function. However, an intermittent ketogenic diet, with a planned ketogenic vacation or break, showed no pro-inflammatory effects from aging cells, according to the research.
The findings have significant clinical implications, suggesting that the beneficial effect of a ketogenic diet may be enhanced by planned breaks.
“To put things in perspective, 13 million Americans are on a ketogenic diet and we say you have to stop it, otherwise there could be long-term consequences,” said David Gius.
A ketogenic diet, commonly known as keto-friendly, is a high-fat, low-carb diet that leads to the generation of ketones, a type of chemical that the liver produces when it breaks down fat. While a ketogenic diet improves some health conditions and is popular for weight loss, pro-inflammatory effects have also been reported.
The new study shows that mice fed two different ketogenic diets at different ages induced cellular senescence in multiple organs, including the heart and kidneys. However, this cellular senescence was reversed by a senolytic, or a class of small molecules that can destroy senescent cells, and prevented by intermittent ketogenic diet administration.
“Since cellular senescence has been implicated in the pathology of organ disease, our findings have important clinical implications for understanding the use of a ketogenic diet,” Gius said. “As with other nutritional interventions, ‘taking a ketogenic break’ is necessary.”
Ketogenic Diet Slows Early Stages of Alzheimer’s in Mice
A study by researchers at the University of California, Davis shows that a ketogenic diet significantly delays the early stages of Alzheimer’s-related memory loss in mice. This early memory loss is comparable to the mild cognitive decline in humans that precedes full-blown Alzheimer’s disease. The study was published in Communications Biology.
The ketogenic diet is a low-carb, high-fat, moderate-protein diet that shifts the body’s metabolism from using glucose as the primary fuel source to burning fat and producing ketones for energy. UC Davis researchers previously found that mice lived 13 percent longer on ketogenic diets.
The new study, which follows up on that research, found that the molecule beta-hydroxybutyrate, or BHB, plays a key role in preventing early memory decline. It increases nearly sevenfold on the ketogenic diet.
“The data support the idea that the ketogenic diet in general, and BHB in particular, delays mild cognitive impairment and may delay full-blown Alzheimer’s disease,” said corresponding author Gino Cortopassi, a biochemist and pharmacologist at the UC Davis School of Veterinary Medicine. “The data clearly do not support the idea that this completely eliminates Alzheimer’s disease.”
The scientists gave mice enough BHB to simulate the benefits of a ketogenic diet for seven months.
“We saw the incredible ability of BHB to improve the function of synapses, the tiny structures that connect all the nerve cells in the brain. When nerve cells are better connected, memory problems in mild cognitive impairment improve,” said corresponding author Izumi Maezawa, a professor of pathology at the UC Davis School of Medicine.
Cortopassi noted that BHB is also available as a supplement for humans. He said that a BHB supplement could probably support memory in mice, but that has not yet been proven.
The researchers found that mice on the ketogenic diet showed significant increases in biochemical pathways related to memory formation. The ketogenic diet also appeared to benefit females more than males and led to higher levels of BHB in females.
“If these findings apply to humans, it could be interesting, as women, particularly those carrying the ApoE4 genetic variant, are at significantly higher risk of developing Alzheimer’s,” Cortopassi said.
The research team is optimistic about the potential impact on healthy aging and plans to further explore the topic in future studies.
#Ketogenic #diet #increased #LDL #cholesterol
