Oct

29

This month in the American Journal of Clinical Nutrition…

“Taylor MK, et al. – Cross-sectional analyses were performed to evaluate the association of dietary glycemic measures with the cerebral amyloid burden and cognitive performance in cognitively normal older adults. The researchers found an association between high-glycemic diet and greater cerebral amyloid burden, which suggested diet as a potential modifiable behavior for cerebral amyloid accumulation and subsequent Alzheimer’s disease risk.“

Amyloid plaguing is the cause of Alzheimer’s disease. In the literature this is now being  referred to as type III diabetes, this article from the American Journal of Clinical Nutrition makes it even clearer why. This is indeed a modifiable behavioral risk factor, as simply reducing  carbohydrate intake markedly reduces this risk. This also reduces risk for diabetes, hypertension, stroke and heart disease, all disorders associated with obesity, which, is also caused by a high glycemic diet. If you have a tendency to overeat carbohydrates, staying full on proteins and (healthy) fats will help.

Mar

11

Various 2012 studies further clarified how excessively sweet, unhealthy foods affect the brain. An animal study out of UCLA found that diets high in fructose can impair cognitive function, which is reversible with omega-3 fatty acid supplementation. High fructose consumption can induce some signs of metabolic syndrome in the brain and can disrupt the signaling of the insulin receptors and reduce the action of insulin in the brain. Other work published in JAMA suggests that fructose consumption modulates the neurophysiologic pathways involved in appetite regulation and encourages overeating. An October 2012 study published in the Journal of Alzheimer’s Disease reported that a diet high in carbohydrates and sugar raises the risk for mild cognitive impairment in the elderly, while a diet high in fat and protein may reduce this risk. Logical yet simple enough, an “optimal balance” of carbohydrates, fat, and protein may help maintain neuronal integrity and optimal cognitive function, particularly in the elderly.

Mounting evidence in 2012 reinforces that high consumption of red meat increases stroke risk. The largest meta-analysis to date looking at the atherogenic effects of red meat found that the risk for total stroke increased by up to 13% for each increase in a single serving of fresh, processed, and total amount of red meat consumed per day. Earlier in the year another study found that processed and unprocessed red meat is associated with a higher risk for stroke, while poultry was associated with a reduced risk. One study found that a diet high in fruits, vegetables, grains, and fish led to a 30% lower depression risk compared with a meat based diet. But, as pointed out last year, meat quality is a factor: Moderate consumption of unprocessed, free-range antibiotic free red meat may actually protect against depression and anxiety. Much of the livestock in the United States is raised on industrial feedlots, which increases saturated fat and decreases very important good fatty acids, whereas pasture-raised animals have a much healthier fatty acid profile.

Information derived from Medscape.

 

Jan

7

A study conducted in Spain reported that consumption of both polyunsaturated fatty acids, (found in nuts, seeds, fish, and leafy green vegetables), and monounsaturated fatty acids, (found in olive oil, avocados, and nuts), decreases the risk for depression over time. However, there were clear dose-response relationships between dietary intake of trans fats and depression risk, whereas other data support an association between trans fats and ischemic stroke risk. Trans fats are found extensively in processed foods, including many commercial chocolates, (hence, check that label when considering dietary intake of chocolate. Also, only the highest levels of dark cocoa contain healthy antioxidants, not milk chocolate). A deficiency in polyunsaturated fatty acids has been linked to attention deficit/hyperactivity disorder in children. Thanks to their high levels of polyunsaturated fatty acids, namely omega-3 fatty acids, fish can help fend off numerous diseases of the brain. A 2010 study correlated fish consumption with a lower risk for psychotic symptoms, and concurrent work suggested that fish oil may help prevent psychosis in high-risk individuals. Although data are conflicting, new research shows that the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid are beneficial in depression and postpartum depression, respectively, and other research suggests that omega-3 deficiency may be a risk factor for suicide. Oily, cold-water fish, such as salmon, herring, and mackerel, have the highest omega-3 levels. Keep in mind that Atlantic fish have elevated levels of mercury and PCB’s compared to Alaskan/Pacific fish, and that farm raised fish contain very little healthy omega 3 fatty acids, due to the confined breeding of farm raised fish.

Dec

19

2012 Neurology Game Changers, Which Foods Are Best for the Brain?

Dietary advice is common practice in cardiology and primary care, but recently food and drink have become important considerations for neurologists, too. Diet is inextricably linked to conditions such as heart disease, obesity, and diabetes. However, what we consume also seems to have significant implications for the brain: Unhealthy diets may increase risk for psychiatric and neurologic conditions, such as depression and dementia, whereas healthy diets may be protective. 2012 saw coffee and berries warding off dementia, caffeine supplements improving motor function in Parkinson’s and the Mediterranean diet reducing the odds of developing Parkinson’s. Lycopene-rich tomatoes and the flavanones in citrus fruits were found to protect against ischemic stroke. As for what not to eat, a study published in January in Stroke supported previous work linking red meat consumption with higher stroke risk, while diets high in carbohydrates and sugar reportedly raise the risk for mild cognitive impairment and dementia in the elderly. A 2009 study published in the Archives of General Psychiatry found that people who follow Mediterranean dietary patterns — that is, a diet high in fruits, vegetables, nuts, whole grains, fish, and unsaturated fat, (common in olive oil and other plant oils) — are up to 30% less likely to develop depression than those who typically consume meatier, dairy-heavy fare. The olive oil-inclined also show a lower risk for ischemic stroke and are less likely to develop mild cognitive impairment and Alzheimer disease, particularly when they engage in higher levels of physical activity.

All data derived from Medscape, 2012.

Jun

7

I am not a big advocate of fad diets by any means.  Quite simply, they don’t work.  You usually lose some weight initially, about half of which is water and fat, and the rest, very desirable and difficult to replace muscle tissue.  After the diet you go back to your old eating habits, and back comes the weight you lost, only now you have less muscle tissue burning calories for you so it is even easier to become even fatter still. While the Atkins diet is not without flaw, Dr. Atkins was well ahead of his time.  The diet focuses on protein as the mainstay for caloric intake, with dramatic carbohydrate reduction.  The diet’s main pitfall was in allowing almost any type of fat in the diet. The problem with dieting, (calorie restriction), is that it is really important whether your calories come from protein, fat or carbs.  Your body can obtain needed fats and carbs very easily from your existing stores, exception being omega 3 fatty acids, (EFA, for essential fatty acids), you cannot make these and need to get them from your diet. As such I believe fish oil supplementation to be wise.  Protein however, if not in the diet, your body will obtain from lean muscle tissue.  Think of your body’s muscle cells as factories and your fat cells as warehouses.  The more muscle you breakdown for needed protein, the less factories you have so the less calories you will burn, meaning more calories for storage for the warehouses, as fat. This concept is what makes the Atkins style diet shine. Your body requires protein every few hours.  Not a two pound steak, but protein.  If you give your body this needed protein the carbs and fat come from storage, you lose weight, not just weight, but fat, and maintain needed lean muscle.  If you are significantly overweight this is even more important.  If you are obese there is a marked likelihood that you are insulin resistant.  When this happens it is almost impossible to lose weight without extreme calorie restriction.  Once again, the Atkins style diet is extremely effective in this case and the way to reduce insulin sensitivity.  Body mass index, (BMI), calculators can easily be found on the internet to quickly calculate your BMI.  A BMI over 30 is clinically obese. Over 40 is morbidly obese. Obesity is typically associated with diabetes, hypertension, metabolic syndrome and sever cardiovascular risk.  If you are considering a diet and currently have health risks you should always be supervised by a doctor.