Most of us have an ambition of living to a ripe old age. At the same time, many of fear the loss of our mental faculties as we age. For at least some of us, the spectre of dementia looms large in our minds. One potential modifiable risk factor for dementia concerns derangement in blood sugar regulation. Diabetics are noted to be at increased risk of dementia, at least in part as a result of ‘vascular dementia’ (dementia caused by disease of vessels supplying blood to the brain).
Type 2 diabetics have normally secreted a lot of insulin in their lives, and a potential consequences of this is the accumulation of fat around the midriff (sometimes referred to as ‘abdominal’ or ‘central’ obesity). Interestingly, previous research in men found that higher levels of abdominal obesity was associated with an enhanced risk of dementia in later life.
Now, the same association has been found in women. In a study published recently in the journal Neurology, women aged 38-60 were assessed periodically over a 32-year period (starting in 1968) [1]. Women with evidence of abdominal obesity (as adjudged by a waist-to-hip circumference ratio of more than 0.80) in middle age were found to be at more than twice the risk of dementia compared to women with smaller waist-to-hip ratio measurements.
Studies of this nature do not tell us that abdominal obesity causes dementia, only that these two things are associated. Having said that, there is evidence which links insulin (high levels of which are often a feature in abdominal obesity) and the development of dementia. See here for more on this.
The link between dementia, abdominal obesity and insulin mean that there is an argument that moderating insulin secretion may have value in terms of preserving mental function in later life. I know of no better way to achieve this than cutting back on carbohydrate, specifically those that are most disruptive to blood sugar (including many starch carbs such as bread, potato, rice, pasta and breakfast cereals).
References:
1. Gustafson DR, et al. Adiposity indicators and dementia over 32 years in Sweden Neurology 2009;73:1559-1566
Wouldnt cutting out sugar and anything with sugar in it be important also?
Dr. Briffa, I have learned a lot from you blog. Thank you for sharing your insight.
Do you think there is any need for fruits and vegetables in the human diet? I have basically not eaten any vegetation to speak of since August 2008. I feel fine, in fact better than I have felt for 30 years. I am 58. I am doing this to keep my insulin levels steady. I am fearful of dementia. I do still have a bit of abdominal obesity. My waist to hip ratio is .88 which puts me in the risk category. Hopefully my waist will reduce more with time amd my hips don’t shrink with my waist.
Thank you for writing this blog.
You may like to read NHS Choices take on the same story.
It’s pity the NHS don’t yet seem to have appreciated the enormity of the crisis we are facing.
Perhaps they should read
Alzheimer’s Disease Is Type 3 Diabetes—Evidence Reviewed
AD is intrinsically a neuroendocrine disease caused by selective impairments in insulin and IGF signaling mechanisms, including deficiencies in local insulin and IGF production. At the same time, it is essential to recognize that T2DM and T3DM are not solely the end results of insulin/IGF resistance and/or deficiency, because these syndromes are unequivocally accompanied by significant activation of inflammatory mediators, oxidative stress, DNA damage, and mitochondrial dysfunction, which contribute to the degenerative cascade by exacerbating insulin/ IGF resistance.
Does anyone disagree with the idea that unrestricted inflammation, oxidative stress, DNA damage, and mitochondrial dysfunction are not healthy?
Eventually the NHS may recognise that high carbs (starchy, sweet foods and beverages)–fructose –n-6 pufas (corn oil and other veggie and bean oils) are adding to the inflammatory process and that deficiencies in anti inflammatory agents n-3 EPA DHA fish oil, vitamin D3, magnesium, selenium, zinc, B-vitamins, Coenzyme Q10 etc are allowing that inflammatory process to continue uncontrolled.
@ Susan
Robert Lustig certainly thinks so Sugar: The Bitter Truth is a good place to start but You may also find Jimmy Moore’s interview with Richard Johnson worth considering.
Deb
Fruit and veg are very important in the diet as they are an important source of phytonutrients and antioxidants, especially the richly coloured ones such as berries, peppers, tomatoes, etc.
However, in order to maintain good weight, it’s best to avoid those that are high in starch and fructose, such as potatoes, carrots (cooked), yams, bananas, oranges, grapes and dried fruits, too.
Dr. Briffa’s book may go into this more at length or you can read Patrick Holford “Low GL Diet”, available from Amazon.
I’m a Type 1 diabetic. As we don’t secrete any insulin at all, are we at less risk?
@ Terry: Type 1 diabetics usually don’t have Insulin Resistance, so you should by O.K., provided you maintain good BG control so that you don’t glycate yourself to an early death.
Loss of sex hormones (Testosterone in men & Progesterone in women) may also be relevant to AD/LBD/PD. See http://nigeepoo.blogspot.com/2009/11/look-after-your-brain-part-2.html
Deb, I must agree with Joanna. Food is not just about carbs, protein et. Fruits and vegs contain many other factors essential to good health such as antioxidants, minerals, vitamins and probably unknown factors related to health. Many are very low GI such as salads, greens and berries.If you are not eating these what are you eating? Hilda Glickman Nutritionist.
@Terry
Diabetes UK Sept 2009 say
Life expectancy is reduced, on average, by:
— more than 20 years in people with Type 1 diabetes
However I don’t know where DiabetesUK sourced that information.
It’s possible better modern management of the condition, particularly with low carbohydrate diets has improved that depressing statistic.
Late onset Alzheimer’s is the most common form. Dying younger avoids it.
This graph shows a 15% increase in Alzheimer’s incidence over the 10yrs from age 74 to 84 with incidence over age 85 rising even higher to over 50%.
While the evidence for Type 2 Diabetes increasing risk for Alzheimer’s is solid, I’ve not found much good evidence for the same level of risk for Type 1.
There are some rat/mice studies using rat/mice Alzheimer model type animals that indicate a greater risk potential BUT, rats/mice brains have less sophisticated, less developed astrocytes. Astrocytes are the only brain cell that perform β-oxidation of fatty acids. Astrocytes use fatty acids to synthesise ketone bodies that are supplied to neurons. So eating low carbohydrate, higher fat diets offers greater neuroprotection via astrocyte provision of ketones supporting neurones under crisis.
Diabetes patients have a greater rate of decline in cognitive function so even more important for them keep neuroprotective astrocytes supplied with medium chain fatty acids such as from coconut oil readily available as emergency fuel supply.
Alzheimer’s disease risk factors, obesity, diabetes, and hyperinsulinemia are all reduced with a diet of unprocessed, fresh food in which refined carbohydrates are eliminated or significantly reduced. Ensuring Vitamin D3 25(OH)D level stays above 125nmol/l and omega 3 levels are kept optimum, helps reduce inflammation.
The astrocytes I mentioned earlier communicate with neurones using calcium. Improving Vitamin D status optimises dietary calcium uptake, but increased calcium may need counterbalancing with extra magnesium and adequate vitamin K2 to ensure the calcium goes/stays where required.
I was busy when I last posted and so didn’t have time to check the source for the DIABETESUK quote.
Life expectancy is reduced, on average, by:
— more than 20 years in people with Type 1 diabetes
— up to 10 years in people with Type 2 diabetes.
(73)
the reference at 73 is to
Turning the Corner: Improving Diabetes Care
Report from Dr Sue Roberts National Clinical Director for Diabetes to the Secretary of State for Health
Where is says
Life expectancy is reduced, on average, by:
— More than 15 years in people with Type 1 diabetes
— Between 5 and 7 years in people with Type 2 diabetes (at age 55 years)
I don’t quite understand why they enhanced the figures at the reference they quote.
The single most comprehensive and widely researched book on the subject that I’ve ever read is Gary Taubes’ ‘Diet Delusion’ (aka Good Calories, Bad Calories). He traces the pathway of over-secretion of insulin to the Western diseases including obesity, diabetes, high triglycerides, Alzheimer’s, cancer and ageing in scientific yet highly readable detail. Also includes a fascinating section on whether or not fruits and vegetables are actually essential in the human diet if all the necessary parts of other natural foods (meats) are being consumed with particular reference to the Inuit community who appear to survive solely on flesh foods without suffering deficiencies or scurvy.
The Inuit diet is interesting as is the Yukip. Particularly interesting is the consequence when Eskimo meets ‘west’. In this theres’ is similar to the plight of ethnic Australians in that when the strictly native diet is dispensed with and western dietary influences are adopted then obesity, diabetes, and heaven knows what other chronic illnesses manifest themselves with rapidity.
One observation of curiosity to me is that native Australians would get a lot of exposure to Sun and not a lot of opportunity to eat fish whereas Eskimo peoples would get a lot of opportunity to eat cold water fish rich in marine derived omega 3 and limited (and seasonally variable) opportunity for sun-bathing.
Second dimension of equal curiosity is the anticipated contrast in consumption of soluble fibre.
Third are the visual clues to contrasting historical evolutionary pathways. If folks look quite different, what may be the subtle differences in physiology? Are their metabolic workings and functional nutritional needs exactly like those of white Europeans?
Evidently, vitamin C remains is functionally important and Eskimo peoples get theirs from “muktuk”, the skin of beluga whales. I believe it is native practice to forage for plant foods in the short season of availability.
It is the reported rapidity of degeneration that is alarming when western dietary influences replace native ones. The contrasts may be revealing for the culprits of causality; sugar and carbohydrates look like prime candidates. However, it could be unwise to rich to conclusions without regard for understanding the physiological forces behind the pathway to ill-health and without fully understanding the interplay of other nutritional influences.
Something that stands against enlightenment is that not all the science we are fed can be relied upon to be either valid or unbiased.
Personally, I think the 21st century health scandal is the contrasting (with dietary evolution) availability of omega 6 PUFA refined vegetable oils that are highly represented in ‘processed’ foods. A network of 22 scientists thinks along similar lines were alarmed at proposed EU food legislation. Dr Briffa blogged, about the breaking news of the petiton back in October.
What irks me is the the EU food regulator EFSA and our own Food Standards Agency will adopt a seemingly erroneous stance on saturated fat and willfully promote the migration to increased consumption of (w6 PUFA rich) margarines.
Neither the Mente review nor the Framingham study would support FSA policy that ‘where possible polyunsaturated fats and monostaurated fats should be substituted for saturated fats’. And when challenged they carry on as if neither body of work existed.
.. And westerners used to refer to indigenous peoples living subsistence existences, happy and healthy on it, as primitive?
But for a little enlightenment we could be both healthy and happy – have our cake and eat it, so to speak. It is only the corporate agenda, perhaps coupled with institutional bias, that gets in the way.
You are a torchbearer John. Thanks also to Ted.
@ Juliet,
Early on in Taubes book he makes the point that the extent of complexification inherent to modern science stands in the way of testing our theories against fairly simple observations. I’d be inclined to agree.
I’m with you – Diet Delusion is an excellent contribution. I must advance with reading past halfway. ..
Thank you. I have really enjoyed reading this and I think a lot of interesting points have been raised, and I have not, as yet, read Diet Delusion and will definitely do so. The work of Professor Michael Crawford on the importance of the Omega 3 essential fatty acids and in particular his book ‘Nutrition and Evolution’ is well worth a read. In this book he writes ‘……it is obvious that throughout human evolution, man relied on wild foods. His physiology was initially adapted by, and is still adapted to , wild not modern foods. In Northern Europe and America, as little as 0.006 per cent of his time has been spent on the modern foods created by the enclosure of animals and even less since the industrial revolution. In Western countries we have developed animal proteins but the wrong kind of fats and neglected those that are needed for the nervous and vascular systems’. In her book ‘The Jungle Effect’ Daphne Miller,M.D, looks at the healthiest diets from around the world and looks at indigenous diet components. She cites that ‘Eskimo tribes who live near the North Pole offer us an extreme example of how meat quality can make a difference in the overall nutritional value of a diet. Despite their high protein (50 percent) and fat (30-40 percent) diet, Eskimos who ate this indigenous diet had some of the lowest rates of heart disease and cancer in the world……….. These same nutrition researchers were surprised to discover that the Eskimos also had adequate amounts of essential nutrients such as B vitamins and vitamin C…..It turns out fish and caribou were the main sources ….. the caribou were passing on nutrients from the scrubby lichen and moss that they munch and the fish by eating other fish and sea vegetables. So it seems that being a lover of meaty and fatty is not so bad – just as long as the animal sources for these foods have dined on the right things.’ Sadly, of course intensively reared feed lot animals fed large quantities of corn to make them grow fast, far from dine on the right things for theirs or our health. The work of Weston A Price is always worth a revisit. Price has shown how the movement to refined carbohydrates of primitive peoples evicted from their traditional homes and who ceased to grow or find their old foods and lived instead on European bought produce – white bread, refined cereals,sugar, jam and tinned fruit was nutritionally a disastrous change for them.
Thanks for the post, John, and great thread all.
Jill, you’ve added to my reading list, thanks. Do you blog?
Rick Potts, Humanitys’ Descent: Consequences of Ecological Instability recently dropped onto my reading list and a copy is winging its’ way to me now.
Ted,
I had just visited your link to AD is T3DM-evidence reviewed.
I’ll be honest the review stretches my abilities somewhat. But I deduce you are mirroring an opinion that Alzheimers Disease (AD) and type 2 diabetes arise from a pathway that has much in common.
From manifestation to cause the pathway for (AD) tracks back via neuro-endocrine dysfunction, through endocrine dysfunction, back through autocrine dysfunction and is traceable to dietary inputs, right?
The pathway to dysfunction at these hierarchical physiological regulatory levels is a consequence of inflammation. Inflammation disrupts the capacity of cells to communicate by limiting or influencing what biochemical signals can reach the cell? Several chronic conditions may be attributable to inflammation?
Inflammation is a satisfactory immune response to defend against unwanted invaders, BUT, the kind of inflammation you highlight does not arise from a bona-fide immune response. Instead it arises from unchecked insulin responses and certain autocrine system biochemical mediators called eicosanoids? Some postulate that eicosanoids can go out of balance from permutations of ingesting too much of certain oils (ones rich in omega 6 polyunsaturated fatty acids) and not ingesting enough of marine derived omega 3 polyunsaturated fatty acids (PUFAs).
It is the balance of these that is important, right?
Going back one hundred years the balance has (detrimentally) shifted considerably, and groups of scientists calling themselves Paleo-anthropologists postulate that even the balance apparent 100 years ago is significantly out of balance with that of our human dietary evolutionary past – something I read in The True You Diet.
So, there is paleo-anthropological evidence pointing at diet, particularly at PUFA ratios and imbalances, there is what’s going on before our eyes allied to epidemiological evidence, and a comprehension of a physiological pathway that also links to diet – yet such comprehension is not evident in delivery of health-care?
Two observations; (1) no wonder folks felt so irked that PUFA (omega 6) rich margarines were being marketed off the back of the Food Standards Agencies anti-saturated fat message and (2) – It’ll take more than Gerry Robinson ‘to fix the NHS’.
Chris ,
Not a blogger yet – but definitely on my ‘to do’ list for 2010. I very much appreciate all the information shared here.