Using Multicountry Ecological and Observational Studies to Determine Dietary Risk Factors for Alzheimer's Disease
J Am Coll Nutr. 2016 Jul;35(5):476-89. doi: 10.1080/07315724.2016.1161566.
William B Grant 1
Chart of 10 countries
Rates of Alzheimer's disease (AD) are rising worldwide. The most important risk factors seem to be linked to diet. For example, when Japan made the nutrition transition from the traditional Japanese diet to the Western diet, AD rates rose from 1% in 1985 to 7% in 2008. Foods protective against AD include fruits, vegetables, grains, low-fat dairy products, legumes, and fish, whereas risk factors include meat, sweets, and high-fat dairy products. The evidence comes from ecological and observational studies as well as investigations of the mechanisms whereby dietary factors affect risk. The mechanisms linking dietary risk factors to AD are fairly well known and include increased oxidative stress from metal ions such as copper as well as from advanced glycation end products associated with high-temperature cooking, increased homocysteine concentrations, and cholesterol and its effects on amyloid beta, insulin resistance, and obesity. Lower 25-hydroxyvitamin D concentrations also are associated with increased risk of AD. In addition to reviewing the journal literature, a new ecological study was conducted using AD prevalence from
10 countries (Brazil, Chile, Cuba, Egypt, India, Mongolia, Nigeria, Republic of Korea, Sri Lanka, and the United States) along with dietary supply data 5, 10, and 15 years before the prevalence data. Dietary supply of meat or animal products less milk 5 years before AD prevalence had the highest correlations with AD prevalence in this study.
Thus, reducing meat consumption could significantly reduce the risk of
- AD as well as of
- several cancers,
- iabetes mellitus type 2,
- stroke, and,
- likely, chronic kidney disease.
Teaching points
• Single-country ecological data can be used to find links between diet and AD because the national diet changes, such as during the nutrition transition to a Western diet.
• Multicountry ecological studies can be used to find links between dietary factors and risk of AD.
• Prospective observational studies are useful in linking dietary components and patterns to risk of AD.
• The most important dietary link to AD appears to be meat consumption, with eggs and high-fat dairy also contributing.
• Diets high in grains, fruits, vegetables, and fish are associated with reduced risk of AD, but these factors cannot counter the effects of meat, eggs, and high-fat dairy.
• Higher vitamin D status is associated with reduced risk of AD.
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VitaminDWiki - Alzheimers-Cognition - Overview
- FACT: Cognitive decline is 19X more likely if low vitamin D
- FACT: Dementia is associated with low vitamin D levels.
- FACT: Alzheimer’s Dementia 2.3X more likely in elderly if low vitamin D – Dec 2022
- FACT: Dementia is associated with low vitamin D - many studies
- FACT: Alzheimer's Disease is 4X less likely if high vitamin D
- FACT: Every single risk factor listed for Alzheimer's Disease is also a risk factor for low vitamin D levels
- FACT: Elderly cognition gets worse as the elderly vitamin D levels get even lower (while in senior homes)
- OBSERVATION: Reports of increased vitamin D levels result in improved cognition
- OBSERVATION: Alzheimer’s patients 3X more likely to have a malfunctioning vitamin D receptor gene – 2012
- OBSERVATION: Alzheimer's Disease has been seen to halt when vitamin D was added.
- OBSERVATION: Alzheimer’s is associated with all 7 of the genes which restrict vitamin D
- OBSERVATION: 39 vitamin D and Alz. or Cognition intervention trials as of Sept 2018
- OBSERVATION: 2 Meta-analysis in 2012 agreed that Alzheimer's Disease. associated with low vitamin D
- OBSERVATION: 50X increase in Alzheimer's while decrease in vitamin D
- OBSERVATION: Vitamin D reduces Alzheimer’s disease in 11 ways
- OBSERVATION: Alzheimer’s cognition improved by 4,000 IU of vitamin D
- OBSERVATION: Plaque removed in mice by equiv. of 14,000 IU daily
- OBSERVATION: DDT (which decreases Vit D) increases risk of Alzheimer's by up to 3.8X
- OBSERVATION: 2% of people have 2 copies of the poor gene reference: Alz Org
- OBSERVATION: Genes do not change rapidly enough to account for the huge increase in incidence
- OBSERVATION: End of Alzheimer's videos, transcripts and many studies protocol has been very successful
- It adjusts Vitamin D, B-12, Iron, Omega-3, food, etc, and can now be done at home.
- FACT: Vitamin D is extremely low cost and has very very few side effects
- CONCLUSION: Everyone concerned about cognitive decline or Alzheimer's Disease should take vitamin D
- PREDICTION MET: By 2024 Omega-3 and high dose Vitamin D will be found to reverse Alzheimer's in humans
There are 13+ Alzheimer’s meta-analyses in VitaminDWiki
There are 97+ Alzheimer’s studies in VitaminDWiki
Dementia is associated with low vitamin D - many studies 50+ studies
16+ studies in both categories Cognitive and Omega-3
Increased Meat consumption in Japan - chart
Chapter 26 - Japanese Perspectives on Dietary Patterns and Risk of Dementia - 2015
Download the PDF from Sci-Hub via VitaminDWiki
Increased Dementia Deaths in Japan - Chart
place of death trends among patients with dementia in Japan: a population-based observational study - 2019
Download the PDF from VitaminDWiki
The Dementia-Diet Link Grows Stronger: Processed Meats Linked To Higher Risk - 2021
- "In a recent study published in the American Journal of Clinical Nutrition, and the first-large scale study of its kind, scientists found that a 25g serving of processed meat a day correlates to a 44 percent increased risk in developing dementia."