Which Supplements May Help Slow the Progression of Alzheimer’s Disease?
A Summary of Evidence From the Past 5 Years
Supplements cannot replace medication
Supplements should only be used as supportive nutrition
Maintaining healthy lifestyle habits remains the most important foundation
When Alzheimer’s disease (commonly known as “dementia”) is mentioned, many people feel a heavy sense of concern. It affects not only individuals, but also families and society as a whole.
According to the China Alzheimer’s Disease Report 2024, it is estimated that by 2021, the number of patients with Alzheimer’s disease (AD) and other types of dementia in China had reached 16.99 million, with a prevalence of 1,194.2 per 100,000 people and a mortality rate of 34.6 per 100,000. Both prevalence and mortality rates are higher in women than in men.
As interest grows in non-pharmacological approaches—such as nutritional support—for chronic diseases, research on whether dietary supplements can influence the progression of Alzheimer’s disease has increased significantly. This article summarizes key findings from studies published over the past five years.
Stages of Cognitive Decline
Many people are familiar with Alzheimer’s disease, but age-related neurodegenerative conditions progress through multiple stages.
Mild Cognitive Impairment (MCI)
This is an intermediate stage between normal aging and dementia. Individuals show measurable cognitive decline (such as memory loss), but daily functioning is largely preserved.
Approximately 63–70% of MCI patients eventually progress to Alzheimer’s disease.
Dementia
Dementia is a general term describing a group of syndromes characterized by global cognitive decline, including Alzheimer’s disease, vascular dementia, and others.
Alzheimer’s disease accounts for 60–70% of all dementia cases.
Alzheimer’s Disease (AD)
A neurodegenerative disease characterized by amyloid-β (Aβ) plaques and tau protein tangles. It progresses through several stages:
Preclinical stage: Aβ accumulation is present (detectable via PET or CSF tests), but no symptoms
Prodromal stage: Mild cognitive symptoms without meeting dementia criteria
Dementia stage: Severe cognitive impairment requiring assistance with daily life
Important Notes on the Evidence
The studies discussed below focus on supplemental intake beyond normal dietary consumption. In many cases, the doses used exceed recommended dietary intakes and cannot realistically be achieved through diet alone.
Because of large differences in dosage, duration, and cognitive assessment methods, it is difficult to conduct unified quantitative meta-analyses. Therefore, a “vote-counting” approach is used to describe overall trends. This method has clear limitations and should be interpreted cautiously—it reflects direction, not certainty.
1. Omega-3 Fatty Acids (Especially DHA)
More consistent benefits in patients with Mild Cognitive Impairment
Supplementation with omega-3 fatty acids—particularly DHA—has shown some positive effects on cognitive function across different stages of cognitive decline, though results are not universally positive.
Overall, studies reporting beneficial outcomes account for approximately 66% of the evidence, with stronger effects observed in individuals with MCI rather than established Alzheimer’s disease.
2. Folic Acid
High doses benefit Alzheimer’s patients; low doses benefit MCI patients
Folic acid (vitamin B9) is an essential nutrient. Moderate-to-high quality evidence suggests that folic acid supplementation may help improve cognitive symptoms in both Alzheimer’s disease and MCI, but required doses differ significantly.
A quantitative analysis of 22 randomized controlled trials involving 3,604 participants found:
For Alzheimer’s patients:
Daily supplementation above 3 mg (3,000 μg) improved cognitive function; doses below this level showed no effect.
For MCI patients:
Daily supplementation ≤400 μg significantly improved cognitive function; higher doses did not provide additional benefits.
For context:
Pregnant women are typically recommended an additional 200 μg/day
Lactating women: 150 μg/day
The tolerable upper intake level (UL) for adults is 1,000 μg/day
The effective dose used in Alzheimer’s studies (3 mg/day) is very high and should only be considered under medical supervision, as long-term high-dose folic acid intake may carry risks, including a potential increased cancer risk.
3. Probiotics
Positive findings, but evidence remains limited
The concept of the gut–brain axis has gained popularity, leading to studies on whether probiotic supplementation can improve Alzheimer’s symptoms. However, overall evidence quality remains relatively low.
A meta-analysis of 4 randomized controlled trials (251 participants) showed that probiotic supplementation improved cognitive function in Alzheimer’s patients aged 65 and older, though results varied widely.
The probiotic strains used included Lactobacillus acidophilus, Bifidobacterium, and Lactobacillus plantarum.
Three studies used multi-strain formulations
One small study (30 participants) used a single strain (Bifidobacterium longum R0175) and showed better results
Due to small sample size and limited geographic diversity, these findings require larger trials for confirmation.
Another meta-analysis involving 3,910 patients also suggested cognitive benefits, but failed to identify optimal strains, dosages, or intervention duration.
It is important to note that probiotic effects vary greatly by strain. Multi-strain formulas are not necessarily superior, as microbial competition may reduce effectiveness.
4. Carotenoids
Benefits observed in healthy middle-aged and older adults, but not in dementia patients
Carotenoids are natural pigments with antioxidant properties that may help protect brain health and slow cognitive decline.
A meta-analysis of 9 randomized controlled trials (4,402 adults aged 45–78) found that carotenoid supplementation significantly improved multiple cognitive domains, particularly executive function and episodic memory.
Studied carotenoids included:
β-carotene
Lutein
Zeaxanthin
Astaxanthin
Doses ranged from 0.5 to 50 mg/day, with intervention durations from 2 weeks to 12 months.
Among them, lutein showed the most consistent benefits. A daily dose of 12 mg significantly improved verbal fluency and working memory. Lutein’s advantage lies in its ability to cross the blood–brain barrier and accumulate in the cerebral cortex. Combined supplementation with lutein and zeaxanthin may offer additional benefits.
These findings apply to generally healthy middle-aged and older adults, not patients with Alzheimer’s disease.
5. Combination Supplementation
Some positive results, but no optimal formula established
Several randomized controlled trials have explored combined supplementation strategies:
Omega-3 (especially DHA) + folic acid
Effective in patients with Mild Cognitive Impairment
Lutein + DHA
Shown to slow disease progression in Alzheimer’s patients
However, these results are based on individual trials, and no optimal dosage ratios or standardized protocols have been established. Further large-scale studies are needed.
Final Takeaway
Dietary supplements may play a supportive role in slowing cognitive decline, particularly in early stages, but they cannot replace medical treatment. The strongest foundation remains a combination of appropriate medical care, healthy lifestyle habits, and evidence-based nutritional support.
About Jiabeikang
Jiabeikang provides professional dietary supplement customization and wholesale services for global brands. Our product range includes DHA & Omega-3 fish oil, folic acid, probiotics, carotenoids, lutein, and other evidence-based nutrition solutions.
With OEM / ODM and private label capabilities, Jiabeikang supports formula development, packaging, labeling, and large-scale production.
Today, we proudly serve clients in more than 100 countries worldwide, helping partners build competitive, compliant, and market-ready supplement brands.