Dietary Supplement May Help Slow Alzheimer’s Progression and Improve Cognitive Outcomes, Small Trial Suggests

Patricia Inacio, PhD avatar

by Patricia Inacio, PhD |

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Abnormalities in the levels of unsaturated fatty acids in the brain might contribute the development of Alzheimer’s disease.

A dietary supplement made with components of foods such as broccoli and peppers plus fish oil may help slow the progression of Alzheimer’s disease and improve memory, sight and mood, a small clinical trial suggests.

The findings paved the way for a larger European trial, called re-MIND, currently recruiting in Ireland, to test the nutritional strategy in 120 patients with mild to moderate Alzheimer’s disease.

“This work follows many years of research into the role of nutrients on brain and ocular health. We know from several large-scale population-based studies that nutrition is a key factor in the development of Alzheimer’s disease, and importantly, what the major nutrients of the brain are. However, attempts to identify an exact combination of nutrients that can positively impact on brain health have failed — until now,” Professor John Nolan, founder of the Nutrition Research Centre Ireland (NRCI) and the study’s author, said in a press release.

“This recent work identified a unique way to enhance the localized nutrients of the brain, and adds to our earlier work, which demonstrated the memory-enhancing effect of carotenoids in the normal population,” he said.

The study, “Nutritional Intervention to Prevent Alzheimer’s Disease: Potential Benefits of Xanthophyll Carotenoids and Omega-3 Fatty Acids Combined,” was published in the Journal of Alzheimer’s Disease.

An increasing number of studies have reported the influence of dietary habits on the risk of Alzheimer’s disease, with a number of observational studies suggesting that maintaining a healthy diet, such as the Japanese and Mediterranean diets, can help reduce the risk of Alzheimer’s.

Among the benefits included in the Mediterranean diet were an improvement in cognitive performance and reduced risk of dementia. However, the specific nutrients in these diets that may help protect the brain from degeneration were not known. To date, the most promising candidates include omega-3 fatty acids, a type of fat found in high concentrations in fish oil, and in fatty fish such salmon and herring.

Consumption of high levels of omega-3 fatty acids, namely omega-3 fatty acid docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), has been suggested to improve cognitive performance and reduce the risk of dementia. However, the scientific evidence is still controversial.

But the benefits may extend to other food (nutrient) sources that include the xanthophyll carotenoids lutein, zeaxanthin, and meso-zeaxanthin. Xanthophylls carotenoids are a class of oxygen-containing carotenoid pigments that give food its characteristic colors, such as those of fruits and vegetables.

Lutein and zeaxanthin are found in spinach, broccoli, peppers, and melon, among others, while meso-zeaxanthin is present in fish.

Researchers at the NRCI together with colleagues at the University Hospital Waterford, Ireland investigated the effects of a dietary supplementation with xanthophyll carotenoids alone — the combo included lutein (10 mg/day), meso-zeaxanthin (10 mg/day) and zeaxanthin (2 mg/day) — or combined with fish oil (containing both DHA and EPA).

A total of 12 patients with mild to moderate Alzheimer’s received xanthophyll carotenoids alone and a group of 13 patients with mild to severe Alzheimer’s the combo of xanthophyll carotenoids plus fish oil. Patients were treated for 18 months.

A group of 15 age-matched control subjects (not diagnosed with Alzheimer’s) received xanthophyll carotenoids alone for six months. Both supplements were given as softgel capsules.

After six months of treatment, the levels of both lutein and meso-zeaxanthin in the blood were significantly higher in the group treated with the combo of xanthophyll carotenoids plus fish oil compared to those who received xanthophyll carotenoids alone (both the control and Alzheimer’s groups).

Patients treated with the combo of xanthophyll carotenoids plus fish oil also had increased levels of the omega-3 fatty acids DHA and EPA when compared to the levels observed at the start of the study.

Alzheimer’s progression assessed at the end of the study (18 months) appeared to diminish in the xanthophyll carotenoids plus fish oil-treated group, while in the group of patients who received the xanthophyll carotenoids alone the disease continued to progress — 42 percent of the patients worsened up to the point where they had to drop the study.

In the xanthophyll carotenoids plus fish oil group, the percentage of patients with severe Alzheimer’s was maintained — 7.69 percent at baseline and at 18 months — while the percentage of patients with moderate disease dropped from 76.92 percent to 61.54 percent.

Caretakers reported improvements in memory, sight, and mood when patients received the combo of xanthophyll carotenoids plus fish oil.

“Given our growing and aging population, we believe our studies will guide further research and perceptions worldwide about the role of nutrition on brain function, especially considering we live in a time where we are all living longer and where the nutritional value of foods continues to decline,” Nolan said.

These initial findings are now being tested in a large double-blind, placebo-controlled clinical trial in Ireland. The re-MIND (Memory Intervention with Nutrition for Dementia) study (ISRCTN11892249) will enroll 120 patients with mild to moderate Alzheimer’s disease to assess the potential of a nutritional combo — three carotenoids (lutein, zeaxanthin and meso-zeaxanthin), omega-3 fatty acids and vitamin E — to slow the progression of Alzheimer’s disease.

“Up-to-date best medical advice suggests that you can lower your risk of AD through moderate alcohol intake, not smoking, being physically and mentally active, and eating a well-balanced diet. Our work shows that diet deficiency is a key component. Science is now helping us understand exactly what nutrients our brains need. It’s a very exciting development,”said Professor Riona Mulcahy from the University Hospital Waterford and a medical consultant to the re-MIND trial.

“The initial trial findings are some of the first to demonstrate meaningful preservation of function in Alzheimer’s disease. If the findings are confirmed in the ongoing larger double-blind study, it could safely transform treatment,” said George Perry, editor of the Journal of Alzheimer’s Disease.