A new study suggests that intensive diet and lifestyle changes can not only prevent cognitive decline related to Alzheimer’s disease, but also potentially improve the condition of people in its early stages.

This study differs from the dozens that came before it on one point: while a healthy lifestyle had been shown to reduce the risk of Alzheimer’s, nothing substantial about reversing damage had been proven until now. This study did just that, but because little evidence‑based information is available, its researchers say that more studies are needed to bolster the conclusion they reached with more data.

Fifty‑one patients participated in the study, which lasted 20 weeks.

The scientists adopted a “holistic” approach, treating Alzheimer’s with a variety of interventions that had been shown to potentially reduce risk. These interventions were intensive and exhaustive. They think that this approach could be one reason why their results differ from previous studies that employed more moderate interventions.

The 51 study subjects, whose average age was 73.5 years, were in the early stages of Alzheimer’s disease, and all had been diagnosed with mild cognitive impairment or early dementia. Twenty‑six were randomly assigned to the intervention group, and the rest to the control group.

The interventions involved:

Support to transform these interventions into habits was given in person and at Zoom appointments.

To establish a baseline and measure progress, participants completed four standard tests used to measure cognitive performance in Food and Drug Administration (FDA) drug trials. The results varied by test but generally showed that the intervention group improved or stayed the same while the control group stayed the same or worsened.

The researchers, who hailed from institutions in the United States, United Kingdom, Finland, and Sweden, also examined participants’ blood and microbiomes. The biomarker pTau 181 showed little change between the controls and the intervention group, but researchers found improvements in another marker that measures the ratio of two forms of the amyloid beta protein, which forms the plaques in the brain that are hallmarks of Alzheimer’s disease.

Measurements associated with cardiac and metabolic health, such as cholesterol, A1c, hemoglobin, and others, also improved. The intervention group’s microbiome changed, with populations of beneficial bacteria increasing and those thought to be associated with Alzheimer’s disease decreasing.

What’s more, there was a dose‑response effect in both biomarkers and cognitive tests: the degree of change was positively associated with adherence to lifestyle interventions.

The next step would be a larger study to see if the results can be replicated.

Increasing evidence links lifestyle factors to the onset and progression of dementia, including Alzheimer’s. These factors include unhealthy diets, sedentary lifestyle, emotional stress, and social isolation.

The Lancet Commission on dementia prevention, intervention, and care named twelve modifiable risk factors that together account for approximately 40% of worldwide dementias. Many of these factors (hypertension, smoking, depression, type 2 diabetes, obesity, physical inactivity, and social isolation) are also risk factors for coronary artery disease and other chronic conditions, as they share many of the same underlying biological mechanisms.

These mechanisms include chronic inflammation, oxidative stress, insulin resistance, telomere shortening, and sympathetic nervous system hyperactivity, among others.

In a large prospective study in adults 65 years or older in Chicago, the risk of developing Alzheimer’s disease was 38% lower in participants with high vegetable intake compared to those with lower vegetable intake, and 60% lower in those who consumed omega‑3 fatty acids at least once a week. On the other hand, saturated and trans fat consumption more than doubled the risk of developing Alzheimer’s.

A systematic review and meta‑analysis of 243 observational prospective studies and 153 randomized controlled trials found a similar association between these and similar risk factors and onset of the disease.

Most of the studies found that:

For example, the Finnish Geriatric Intervention Study (FINGER), which originally focused on slowing Alzheimer’s, yielded a 13‑20% decrease in participants’ rates of cardiovascular disease events.