Alzheimer's - the case for prevention
Alzheimer's and other dementias are dreadful diseases. They are also expensive. Just how expensive was revealed by the Alzheimer's Society last February in its Dementia UK report . The cost to the UK is £17 billion a year, or about £25,000 a year for each of the UK's 700,000 sufferers of late onset dementia. The number of sufferers is meanwhile projected to rise to 940,110 by 2021, according to the report, and to 1,735,087 by 2051.
In response to the looming dementia crisis the Society makes seven recommendations, each eminently sensible. But something essential is missing: prevention. There is a host of cost effective, scientifically robust steps that could be taken to hugely reduce the incidence of dementia and keep elderly people in full charge of their cognitive faculties, especially in the areas of diet, nutrition and lifestyle. Applied systematically, these measures have the potential to transform the entire Alzheimer's risk landscape.
The brain is a fatty organ, and it works best when it is fed the right kinds of oil and fat. It responds especially badly to the industrial trans fats found principally in hydrogenated oil, as Martha Clare Morris reported in 2003  following a study of 815 people over 65: the 20 percent with the highest trans fat consumption were four times as likely to develop Alzheimer's than the 20 percent with the lowest trans fat consumption.
The same study found that the 20 percent with the lowest consumption of unsaturated vegetable oils were five times likelier to develop Alzheimer's than the 20 percent with the greatest consumption. Combine the two effects, and someone eating a diet high in trans fat and low in polyunsaturated fat is nine times more susceptible to Alzheimer's than someone eating a low trans fat, high polyunsaturated fat diet.
A 1999 study by Solfrizzi  is one of many that shows the beneficial effect of monounsaturated oil, especially the oleic acid found in olive oil. It hypothesizes that as people age, their brain chemistry requires more monounsaturated fat to prevent degeneration: "High MUFA intake per se could suggest preservation of cognitive functions in healthy elderly people. This effect could be related to the role of fatty acids in maintaining the structural integrity of neuronal membranes."
Omega-3 oils, and especially the long chain EPA and DHA essential fatty acids, are a prerequisite of healthy brain function and have successfully been used to treat depression, ADHD and other disabling mental conditions . Evidence published in the Journal of Neuroscience in 2005  shows that these oils reduce the buildup of the amyloid plaque associated with Alzheimer's in mice, and by extension may also do so in humans.
This supposition was supported in an October 2006 by Y Freund-Levi in the Archives of Neurology : a one year study of 204 Alzheimer's sufferers showed that the decline of very early stage patients was significantly slowed by taking omega-3 supplements. "It seems that not only is DHA an important structural component of brain cells but DHA and its metabolites seem to exert a preventive effect against development of brain cell death.", commented Dr Freund-Levi. "These positive findings now indicate that early treatment with omega 3 can help to reduce memory decline in patients experiencing the early symptoms of Alzheimer's."
Another food with a strongly protective effect is turmeric, the base spice of every curry, rich in the oily chemical curcumin. Curcumin triggers our defence mechanisms against free radicals, a constant cause of cellular damage and a key part of the entire aging process. A host of evidence demonstrates the benefits of curcumin not only to Alzheimer's but to a broad range of pathologies from Crohn's disease to psoriasis . This view is supported by the low incidence of Alzheimer's in India. One 2001 study from Neurology of a rural population at Ballabgarh, India, found a 0.3 percent incidence, "among the lowest ever reported" . This is equivalent to 4.7 per 1000 person-years when adjusted to the US age distribution - compared to 17.5 per 1000 person-years in a reference US population.
The risk of dementia is also strongly correlated with levels of homocysteine - a rogue amino acid associated with low levels of folic acid and vitamin B12 - as recorded in the American Journal of Clinical Nutrition in February 2007 . Thus treatment with B12 is protective in such cases: "Higher plasma vitamin B12 may reduce the risk of homocysteine-associated dementia or CIND (cognitive impairment without dementia)." Vitamin D is also protective against dementia, as shown in a 2006 study of 80 participants, half with mild Alzheimers and half without , which concluded that "vitamin D deficiency was associated with low mood and with impairment on two of four measures of cognitive performance."
Protection is also conferred by the polyphenol anti-oxidants found in fruit and vegetables, as shown in 2006 in a paper by Qi Dai  based on a study of 1836 Japanese Americans. Those who drank juices at least three times a week were a quarter as likely to contract Alzheimer's as those who drank juices less than once a week: "Fruit and vegetable juices may play an important role in delaying the onset of Alzheimer's disease, particularly among those who are at high risk for the disease. These results may lead to a new avenue of inquiry in the prevention of Alzheimer's disease."
The same dietary changes that reduce the risk of Alzheimer's would also be strongly beneficial for cardiovascular health, reducing heart disease and stroke. Mental and cardiovascular health are, indeed, strongly correlated, as shown by a study of 1,500 Finns over a 21 year period by Miia Kivipelto of the Karolinska Institute in Stockholm . "Midlife obesity, high total cholesterol level, and high systolic blood pressure were all significant risk factors for dementia", each doubling the risk, "and they increased the risk additively" so that people with all three risk factors together were 6.2 more likely to succumb to dementia.
Another important approach to preventing dementia is to keep older people lively and mentally active. In June 2003 the New England Journal of Medicine  published a study of 269 healthy adults between 75 and 85 over a 21 year period, which found that "reading, playing board games, playing musical instruments, and dancing were associated with a reduced risk of dementia", with the most mentally active experiencing a 75 percent reduction in their risk of dementia. "It seems that remaining mentally agile makes the brain more healthy and more likely to resist illness, just as physical exercise can protect the body from disease", said lead author Dr. Joe Verghese. Numerous other studies have confirmed these findings.
Loneliness is another important factor, as a study by Professor Robert Wilson, professor of neuropsychology at Rush University Medical Centre, revealed in February 2007 . His study of 823 older people in the Chicago area found that the risk of Alzheimers "was more than doubled in lonely persons" compared with those who were not lonely. "Loneliness was associated with lower level of cognition at baseline and with more rapid cognitive decline during follow-up", his team also found.
In recent months the Alzheimer's Society has finally accepted the need to assess the potential benefits of low-cost, effective preventative measures. However the overwhelming majority of its efforts are still aimed at securing drug therapies (many of dubious efficacy and with undesirable side effects) and adequate care for sufferers. Disproportionate medical research funding is also applied to patentable genetic technologies such as the role of inherited genetic predispositions, and the use of genetically modified cell transplants to produce Nerve Growth Factor .
But the greatest disgrace is that the growing compendium of medical knowledge about diet, nutrition, lifestyle and dementia has produced no policy response from Government. It is hard not to question whether it suits the Government to have the elderly population die relatively young. All the measures that would slow or prevent the onset of dementias would also extend life, especially through improved cardiovascular health, and thus increase pension, benefit, housing and other health costs.
But with the cost of Alzheimer's and other dementias projected to rise to alarming levels in the absence of preventative action, a rethink could (sooner or later) be on the way. Meanwhile all of us can do our own bit - in our own diets and lifestyles - to keep ourselves clear of the dementia danger zone.
Oliver Tickell is a writer and campaigner on health and environmental issues. He is the founder of the tfX campaign against trans fat and architect of the Kyoto2 proposals for an effective Climate Protocol.
1. "Dementia UK", Alzheimer's Society: London. Knapp, M., Prince, M. et al., 2007.
2. "Dietary Fats and the Risk of Incident Alzheimer Disease", Archives of Neurology, February 2003.
3. "High monounsaturated fatty acids intake protects against age-related cognitive decline", Neurology Vol 52, May 1999, pp1563-1569, by Solfrizzi et al.
4. "A Diet Enriched with the Omega-3 Fatty Acid Docosahexaenoic Acid Reduces Amyloid Burden in an Aged Alzheimer Mouse Model". Journal of Neuroscience, March 23, 2005, 25(12):3032-3040. Giselle P. Lim et al.
5. "Omega-3 fatty acids in ADHD and related neurodevelopmental disorders". Int Rev Psychiat, 2006, 18(2) 155-172. Richardson, A.J. "The Oxford-Durham Study: a randomized controlled trial of dietary supplementation with fatty acids in children with developmental coordinaton disorder". Paediatrics 2005, 115(5), 1360-1366. Richardson, A.J. and Montgomery, P.
6. "Omega-3 fatty acid treatment in 174 patients with mild to moderate Alzheimer disease: OmegAD study: a randomized double-blind trial." Archives of Neurology 2006 Oct; 63(10):1402-8. Freund-Levi Y et al.
7. "Curcumin: Getting Back to the Roots". Ann. N.Y. Acad. Sci. 1056: 206-217 (2005). Shishir Shishodia et al.
8. "Obesity and vascular risk factors at midlife and the risk of dementia and Alzheimer disease". Arch Neurol. 2005 Oct;62(10):1556-60. Kivipelto M. et al.
9. "Incidence of Alzheimer's disease in a rural community in India: the Indo-US study". Neurology 2001 Sep 25;57(6):985-9. Chandra V. et al.
10. "Homocysteine, B vitamins, and the incidence of dementia and cognitive impairment: results from the Sacramento Area Latino Study on Aging". Am J Clin Nutr. 2007 Feb;85(2):511-7.Haan M. N. et al.
11. "Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults". American Journal of Geriatric Psychiatry 2006 Dec;14(12):1032-40. Wilkins C. H. et al.
12. "Fruit and vegetable juices and Alzheimer's disease: the Kame Project". American Journal of Medicine 2006 Sep;119(9):751-9. Dai Q. et al.
13. "Leisure Activities and the Risk of Dementia in the Elderly". NEJM Volume 348:2508-2516 June 19, 2003 Number 25. Joe Verghese, M.D., et al.
14. "Loneliness and Risk of Alzheimer Disease", Archives of General Psychiatry 2007; Vol. 64: pp. 234-240, by Robert S. Wilson, et al.
15. "New treatment for Alzheimer's", The Sunday Times, April 24, 2005. Jonathan Leake and Nick Fielding.