Seaweed therapy: tackling LOAD.

Figure 5. The Nutritional Approach to Combating Alzheimer’s (AD). 

2.4.a. The Role of Omega-3s in Alzheimer’s Prevention.

The intricate nature of Alzheimer's Disease (AD) poses a formidable challenge due to its multifaceted characteristics. However, nutritional supplementation offers a potentially straightforward preventive measure against late-onset Alzheimer’s disease (LOAD). Various cohort and meta-analyses studies on fish consumption, along with clinical trials exploring the effects of highly enriched EPA [Eicosapentaenoic acid (C20:5, ω-3; EPA], DPA [Docosapentaenoic acid (C22:5, ω-3; DPA], or DHA [Docosahexaenoic acid (C22:6, ω-3; DHA] preparations, suggest that both dietary fish intake and fish oil supplementation have protective effects against LOAD. Notably, individuals with high fish intake exhibit a comparable risk of dementia to regular fatty fish consumers, supporting the protective role of fish consumption. Clinical trials have demonstrated significant improvements in memory functions and cognitive decline in individuals receiving DHA treatment. These findings underscore the importance of individual ω-3 VLC-PUFAs (EPA, DPA, and DHA) in combating LOAD, highlighting their unique mechanisms of action, particularly their anti-inflammatory properties.

2.4.b. Genetic Factors in Alzheimer’s: The African Predisposition.

The role of ω-6 VLC-PUFAs, particularly Arachidonic acid [Arachidonic acid (C20:4, ω-6; ARA], emerges as a significant factor in LOAD based on meta-analyses and cohort studies. The interplay between ARA and DGLA [Dihomo-γ-Linolenic acid (C20:3, ω-6; DGLA], regulated by delta-5 desaturase (∆5D; FADS1-gene), is crucial in LOAD pathogenesis and is influenced by common ‘Fatty Acid Desaturase’ (FAD) polymorphisms. African American populations, characterized by higher frequencies of genotypes associated with increased ARA levels, exhibit heightened susceptibility to inflammatory reactions, potentially exacerbating the risk of LOAD compared to Caucasian populations. This genetic predisposition underscores the importance of understanding population-specific genetic profiles in LOAD susceptibility. An imbalanced [ω-6/ω-3] ratio in the modern Western diet might be driving the escalating global incidence of LOAD, as evidenced by low levels of ω-3 VLC-PUFAs in various regions.

Figure 6 illustrates alarmingly low levels of ω-3 VLC-PUFAs in Sub-Saharan Africa, South America (excluding Chile), and Asian mainland nations, underscoring the global deficiency of these essential fatty acids and necessitating focused public health initiatives and policies, including dietary ω-3 supplementation through seaweed consumption.

Figure 6. Global and regional mean seafood consumption levels of dietary ω-3 polyunsaturated fat intake (mg/day) for adults aged ≥20 years in 2010 (Modified: Micha et al 2014).

2.3. Zinc Deficiency: A Hidden Risk for Alzheimer’s.

The enzymatic conversion of ‘essential fatty acids’ (EFAs) like ALA [α-Linolenic acid (C18:3, ω-3; ALA] and LA [Linoleic acid (C18:2, ω-6; LA], towards anti-inflammatory ω-3 VLC-PUFAs like EPA, DPA, and DHA, crucial in LOAD pathogenesis, is regulated by delta-6 desaturase (∆6D; FADS2-gene) and reliant on adequate zinc (Zn2+) concentrations. Zinc deficiency, exacerbated by factors such as insulin and protein deficiencies, correlates with reduced ∆6 desaturase activity and subsequently diminished concentrations of ω-3 VLC-PUFAs, potentially heightening LOAD susceptibility. Geographical distribution patterns highlight the urgency for targeted interventions, particularly in regions with high zinc deficiency rates, to mitigate LOAD risk associated with impaired ∆6D activity. A deficiency in zinc reduces concentrations of crucial ω-3 VLC-PUFAs, increasing susceptibility to LOAD (Figure 7).

Figure 13: The brown seaweed Sargassum natans (Phaeophyceae), considered a pest due to its rampant growth (Figure 10b), particularly in the Caribbean (Resiere et al., 2018).

4.3: Clinical Benefits of Seaweed-Derived ω-3 for AD.

Blending Ulva lactuca and Sargassum natans optimizes the intake of EPA, DPA, and DHA, crucial for brain health, and is essential to harness the complementary effects of these fatty acids, as highlighted in Table 2. Ulva lactuca provides significant EPA and DPA content, while Sargassum natans offers substantial EPA and DHA quantities, crucial for optimal brain function. Clinical studies highlight the need for dietary supplementation with seaweed-derived ω-3 VLC-PUFAs, given the global scarcity of fish oils. Seaweeds can convert inflammatory ω-6 fatty acids into anti-inflammatory ω-3 fatty acids, addressing the imbalance in modern diets that contributes to AD. Public health initiatives should focus on integrating seaweed-based supplements to prevent neurodegenerative diseases like AD.

Table 2. Fatty acid lipid composition of the green seaweed Ulva lactuca (Chlorophyta) and Sargassum natans(Phaeophyceae) measured by GCMS-measurements. Mean ± Std (n=4). Abbreviation: n.d. = not detected with @: detection limit 0.022 μg FA per g dry matter (≈0.001%). Abbreviations: “SFA”: (Saturated Fatty Acids); “MUFA”: (Monounsaturated Fatty Acid); “PUFA”: (Polyunsaturated Fatty Acids) (Source: van Ginneken et al 2011).

4.4: Optimal Brain Health: The Nutritional Power of Seaweeds.

Moreover, Ulva lactuca and Sargassum natans provide not only ω-3 VLC-PUFAs but also a spectrum of vitamins and essential minerals, further supporting cognitive health as outlined in table 3. Ulva lactuca and Sargassum natans are rich in vitamins and minerals essential for brain function, including vitamins A, B1, B2, B3, B6, B9, B12, C, D, E, and K, and micro-elements like calcium, manganese, iron, copper, zinc, and selenium. These nutrients support cognitive health and prevent AD.

Table 3: Comparative Overview of Vitamins, Micro-, and Trace-Elements in Ulva lactuca (Chlorophyta), other Ulva Species, and Sargassum natans (Phaeophyceae).