Updated: Oct 1, 2020
Dr Michael Fenech of the University of South Australia is known for his work in nutrigenomics and personalised diets according to your genome. Here are some free lectures by him (available on youtube: (“Nutritional Genomics: History, Principles and Nutrient x Gene Interactions”) https://www.youtube.com/watch?v=9OZCwCZGZq8
So can we avoid, slow down or reverse the negative aspects of ageing using diet and exercise? Dr Fenech says that there is much that can be done, although there is a strong genetic association between having a double copy of the Apo E4 gene and developing Alzheimers disease.
Alzheimers involves changes in neurons caused by the development of amyloid plaques and neurofibrillary tangles. One copy of the ApoE4 gene increases your risk by six times, and a double copy increases the risk by twelve times. There are also certain genetic mutations which can increase risk of Alzheimers one hundredfold.
Prevention is undoubtedly better then cure (which seems to be elusive at the moment although slowing is definitely possible). Unfortunately there are no early symptoms of brain degeneration and often by the time there are signs then damage is done. Brain atrophy starts around the age of 30! Tests can be carried out for glucose uptake to the brain and for the amount of amyloid in the brain. However, these tests are not routine and would usually only be carried out if there are signs of early Alzheimers.
Higher intakes of folate and betacarotene are associated with greater glucose use in the brain. Vitamin D, Vitamin 12 and the omega three fatty acid EPA are associated with less amyloid in the brain. Early supplementation with vitamins B6, folate and B12 is often effective in stalling brain atrophy but it only works if omega 3 fatty acids are low in the diet. There are interactions between certain genotypes and vitamin B12. If you have a certain gene mutation then vitamin B12 supplementation is very effective.
To minimise risk of Alkzheimers choose a diet rich in fruit and vegetables, oily fish, folate, vitamin D, vitamin B12 and omega three fatty acids. However, if you are an ApoE4 carrier then the most effective protection is physical exercise.
Nutrient Food Source
Vitamin B6 • Pork, poultry, fish, bread. wholegrain cereals – such as oatmeal, wheatgerm and brown rice, eggs, vegetables, soy beans, peanuts, milk, potatoes, some fortified breakfast cereals
Vitamin B12 • Meat, salmon, other fish, milk, cheese, eggs, some fortified breakfast cereals.
Folate (also known as vitamin B9) • Broccoli, brussels sprouts, liver
Folic acid is the synthetic form of (but avoid this during pregnancy),
folate added to supplement spinach, asparagus, peas, chickpeas, fortified
foods. breakfast cereals
Omega 3 oils Oily fish (best source), white fish, oysters, vegetable oils, rapeseed and linseed (flaxseed), nuts (walnuts, pecans and hazelnuts) and green leafy vegetables.
Vitamin D The best source There is also some in:
is exposure to sunlight on your • oily fish, foods fortified with Vit. D eg
body. margarine, orange juice, soy milk and
cereals, beef liver, cheese, egg yolk. Betacarotene -
a phytonutrient responsible for Sweet potatoes, carrots, dark leafy
orange colour of some vegetables greens, butternut pumpkin, orange coloured it is converted to vitamin A melons and fruits, lettuce, red capsicum,
in the body. apricots, broccoli, and peas.