Ketone-Rich Diets May Reduce Alzheimer’s Disease Risk

In the early stages of development, Alzheimer’s disease (AD) causes overactive brain functioning, potentially as a result of the loss of inhibitory – GABAergic – interneurons that control the signaling of other neurons in the circuit. Interneurons require more energy compared with other neurons, which makes them more susceptible to degeneration upon encountering the Alzheimer’s disease protein – amyloid beta. Research has shown the negative impact of amyloid beta interaction , revealing its ability to damage mitochondria by interfering with SIRT3 – a protective protein.

Impaired mitochondrial function and abnormal neuronal network activity are thought to be some of the early signs of the development of Alzheimer’s disease, however, how mitochondrial alterations contribute to the abnormal activity in neural circuits and their connection to AD remains unknown.

SIRT3 in Mice with Alzheimer’s Disease 

In a recent study published in the Journal of Neuroscience, Aiwu Chang, PhD, and her colleagues investigated the function of the mitochondrial protein by genetically reducing the levels of SIRT3 in mouse models of Alzheimer’s disease. Per their findings, mice with low levels of SIRT3 experienced a significantly higher mortality rate, more violent seizures, and increased interneuron death compared with mice from the standard Alzheimer’s disease model as well as the control group. Both male and female mice were observed to die prematurely before 5 months of age.

On the other hand, mice with reduced levels of SIRT3 who consumed a ketone-rich diet experienced fewer seizures and were less likely to die. Consuming the fatty acid also increased levels of SIRT3 in these mice.  “When comparing male mice among different genotypes, SIRT3 haploinsufficiency renders GABAergic interneurons in the cerebral cortex vulnerable to degeneration and associated neuronal network hyperexcitability,” researchers wrote.

In short, SIRT3 proteins work to preserve GABAergic interneurons and protect cerebral circuits against hyperexcitability; this neuroprotective mechanism can potentially be reinforced by dietary ketone intake.

Ketone Consumption for Risk Reduction

The latest findings implicate that the consumption of ketones may be a way of protecting interneurons and delaying the progression of Alzheimer’s disease. By preserving mitochondrial function, SIRT3 protects interneurons against amyloid beta-induced dysfunction ad degeneration in mice with Alzheimer’s disease. According to Dr. Chang and her team, “the neuronal network dysfunction that occurs in Alzheimer’s disease can be partially reversed by physiological, dietary, and pharmacological interventions to increase SIRT3 expression and enhance the functionality of GABAergic interneurons.”

Due to the growing popularity of the ketogenic diet – which can support weight loss, diabetes management, and several other health conditions – there is an increased awareness and availability of ketone-rich foods. Limiting carbohydrate consumptions and incorporating ketone-rich foods such as seafood, low carb vegetables, high-quality meat and poultry, and eggs into the diet may prove to have neuroprotective effects.

The study’s findings implicate the potential benefit of ketone consumption; however, the results need to be verified in human studies before any recommendations can be made. Further research is necessary to determine whether a ketogenic diet in humans may reduce Alzheimer’s disease risk and to what degree.

Rising Rates of Uninsured Americans Threaten Health Outcomes

Changes in the prevalence of health insurance coverage and the distribution of coverage types are closely tied to shifts in economic trends, demographic composition and policy changes affecting access to care. Within the United States, a lack of health insurance coverage has been a persistent problem, despite the introduction of the Affordable Care Act (ACA) in 2010. Although these policy changes led to the growth of the share of insured Americans, current trends reveal that coverage is yet again on the decline.

Recently released by the Census Bureau, the 2018 Health Insurance Coverage in the United States report presents the state of health insurance coverage in the United States in 2018, revealing worrying changes in insurance trends between 2017 and 2018.

Decline in Number of Insured Individuals

According to the latest data from the Census Bureau, the percentage of Americans without health insurance rose for the first time in nearly a decade. In 2018, the rate of individuals without coverage increased to 8.5% – up 0.5% from the previous year – which is the equivalent of 27.5 million uninsured Americans. Overall, the percentage of people with health insurance coverage for all or part of 2018 in the United States was 91.5%, compared with 92.1% in 2017. The decline was also evidenced in the number of insured children – which dropped by 425,000.

Who Are the Uninsured?

Most members of the uninsured population come from low-income families, with at least one worker in the family, and tend to live in states with limited access to Medicaid. In 2018, 45% of uninsured non-elderly adults remained uninsured due to the high cost of health care coverage. Many members of the uninsured population do not have access to insurance through their employment, while others remain ineligible for financial assistance for coverage.

The growing uninsured, low-income population faces not only a lack of access to health care, but also unaffordable medical bills, which translate to medical debt. In 2018, uninsured non-elderly adults were twice as likely as their insured counterparts to have issues paying their medical bills.

The latest data also reports a significant increase in the share of Hispanic individuals without health insurance coverage, which grew to 8.7% from the prior year – the most significant change in any racial group. People of color faced a higher risk of being uninsured than their non-Hispanic white counterparts; while they make up 43% of the total non-elderly U.S. population, people of color account for over half of all non-elderly uninsured Americans, according to data from the Kaiser Family Foundation.

Furthermore, the report reveals a drop in the rate of children with health insurance coverage. More children were uninsured in 2018 than in the prior year; approximately 4.3 million children were uninsured last year – up from 425,000 in 2017. The decline in the share of lower-income children covered by Medicaid or the Children’s Health Insurance Program is in part due to the decreasing accessibility of these programs and rising costs of health insurance coverage.

Private Health Insurance Remains Steady

In 2018, private health insurance continued to be more prevalent than public health coverage and covered over 67% of the population. Employer-based insurance remains the most common form of private health insurance, covering 55.1% of the population. While the percentage of individuals with private health coverage did not statistically change within the past year, there was a notable decline in the number of people covered by Medicaid as the program becomes less accessible due to policy changes. However, the share of individuals covered by Medicare increased between 2017 and 2018 as a result of the growing aged population.

The recent trends revealed in the latest Census Bureau report show that the insurance coverage gains afforded by the Affordable Care Act are receding. Despite nationwide declines in poverty and unemployment rates, this is the first increase in the number of Americans without health insurance coverage to occur since 2009 and since the ACA was passed in 2010. While a variety of proposed public policy solutions are currently being contested, an increase in uninsured individuals threatens improvements in access to care as well as overall population health outcomes and requires urgent repair.

Can a Healthy Lifestyle Reduce Genetic Risk for Dementia?

A combination of genetic and lifestyle factors can play a role in determining an individual’s risk of Alzheimer’s disease and other types of dementia. Although most cases occur in older adults in whom multiple genes influence overall risk, high levels of LDL cholesterol, diabetes, atherosclerosis, and other health factors can further elevate risk. While some risk factors may be difficult to mitigate, others are easily modifiable – for example, weight and lipid management through a combination of lifestyle changes.

A growing body of evidence suggests that individuals who lead a healthy lifestyle – avoid smoking tobacco, engage in regular physical activity, and consume a health diet – have a lower risk of developing dementia. Previous research has investigated the impact of lifestyle factors on many other health conditions such as cardiovascular disease, however, the extent to which these variables can influence dementia risk is unknown. A new study published online in JAMA, uses data from a large population-based cohort to investigate whether adherence to a healthy lifestyle can offset existing genetic risk for dementia.

Association of Lifestyle Habits with Dementia Risk

Led by Ilianna Lourida, PhD from the University of Exeter Medical School, a team of researchers conducted a retrospective cohort study of nearly 200,000 European adults aged 60 and above to investigate whether a healthy lifestyle is associated with a reduced risk of dementia – regardless of genetic factors. At baseline, none of the participants had cognitive impairment or dementia. The main outcome was the incidence of all-cause dementia identified through hospital records.

Researchers calculated a polygenic risk score comprised of common genetic variants linked to Alzheimer’s disease and dementia risk, as well as a weighted healthy lifestyle score – which included smoking status, physical activity levels, dietary patterns, and alcohol consumption.

Healthy Lifestyle May Reduce Dementia Incidence

A total of 196,383 participants with a mean age of 64.1 were followed for a median of 8 years, during which there were 1,769 cases of incident all-cause dementia. Overall, over 68% of the cohort had followed a healthy lifestyle, 23.6% followed an intermediate lifestyle, and 8.2% followed an unfavorable lifestyle. Researchers found that 20% of individuals had high polygenic risk scores, 60% had intermediate-risk scores, and 20% had low-risk scores.

Of those with a high genetic risk, 1.23% developed dementia, compared with 0.63% of participants with low genetic risk. Meanwhile, participants with both a high genetic risk and unfavorable lifestyle developed dementia at a rate of 1.78% compared with 0.56% of participants with low genetic risk and a favorable lifestyle. Researchers found no significant interaction between genetic risk and lifestyle factors. Among individuals with high genetic risk, 1.13% of those leading a healthy lifestyle developed dementia, in comparison with the 1.78% with unfavorable lifestyle.

Risk Reduction

Dr. Lourida and her team found that an unfavorable lifestyle coupled with high genetic risk was significantly associated with a higher risk for developing dementia in older adults without pre-existing cognitive impairment. Meanwhile, a healthy lifestyle was associated with a lower dementia risk even among participants with a high genetic risk. While there was no significant interaction between genetic risk and a healthy lifestyle, a favorable lifestyle was associated with reduced dementia risk regardless of genetic factors.

Overall, the authors found an absolute risk reduction for dementia among the high genetic risk group of 0.65% associated with leading a favorable lifestyle.

The study’s authors acknowledged the trial’s limitations. Firstly, the lifestyle score used in calculations was not independently validated to indicate a high-risk lifestyle outside of trial conditions. Furthermore, there was a possibility of unmeasured confounding and reverse causation. In addition, lifestyle factors were self-reported and some cases of dementia might not have been recorded in medical records or death registers. Nonetheless, the study expands on current knowledge of neurodegenerative diseases and their connection to lifestyle choices.

“This risk reduction implies that, if lifestyle is causal, 1 case of dementia would be prevented for each 121 individuals per 10 years with high genetic risk who improved their lifestyle from unfavorable to favorable,” authors wrote. Aside from the many mental and physical health benefits associated with leading a health-conscious lifestyle, doing so may also contribute to lowering dementia risk by reducing oxidative damage, having anti-thrombotic and anti-inflammatory effects as well as increasing cerebral blood flow. Thus, it is important to encourage patients to follow a favorable lifestyle and support lifestyle interventions when necessary, especially in cases of high genetic risk.