By Dr. Mercola
In the United States, nearly 80 million people, or one in four, have diabetes or pre-diabetes. What’s worse, diabetes among children and teens has also skyrocketed.
In the UK, more than one-third of adults are now pre-diabetic,3 and British researchers warn that this will lead to a massive avalanche of type 2 diabetics in upcoming years, which will have serious consequences for health care and life expectancy.
Diabetes Linked to Faster Decline in Memory
One of many debilitating health problems associated with type 2 diabetes is a higher risk for dementia. According to one recent study,4,5,6 diabetes ages your brain about five years faster than normal.
People who are diagnosed with diabetes in their 50s are at a significantly heightened risk for mental decline by the time they’re 70.
Previous research7 has also shown that type 2 diabetics lose more brain volume with age than expected—particularly gray matter. This kind of brain atrophy is yet another contributing factor for dementia.
According to lead author Elizabeth Selvin, PhD, MPH, an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health:8
“The lesson is that to have a healthy brain when you’re 70, you need to eat right and exercise when you’re 50.
There is a substantial cognitive decline associated with diabetes, pre-diabetes and poor glucose control in people with diabetes. And we know how to prevent or delay the diabetes associated with this decline...”
The Importance of Healthy Blood Vessels for Proper Brain Function
A number of different factors play a role in memory decline and dementia. One important factor is the health of your blood vessels, and I’ve previously discussed the links between heart disease and dementia. In fact, the test that predicts your future risk of heart disease is better at predicting your risk of dementia than a specific dementia-risk test.9
In the featured study, diabetics were found to suffer a 19 percent greater decline in mental acuity compared to non-diabetics over the course of 20 years. Those with pre-diabetes were also at a significantly increased risk for memory decline.
The researchers suggest the decline in memory associated with diabetes is due to damage to small blood vessels in the brain. According to co-author A. Richey Sharrett, MD, DrPH:
“There are many ways we can reduce the impact of cerebral blood vessel disease—by prevention or control of diabetes and hypertension, reduction in smoking, increase in exercise and improvements in diet.
Knowing that the risk for cognitive impairments begins with diabetes and other risk factors in mid-life can be a strong motivator for patients and their doctors to adopt and maintain long-term healthy practices.”
The best predictor of type 2 diabetes is being obese or overweight, and in the US one-third of children and teens (aged two to 19), and more than two-thirds of adults are either overweight or obese.
Obesity is usually the result of inappropriate lifestyle choices, such as eating too much processed foods (high in carbs and low in healthy fats), and not fasting enough.
It’s interesting to note that the poorest Americans have the highest obesity rate, and they also tend to eat a diet that is very high in processed foods. This is yet another indication that processed foods play a significant role in metabolic dysfunction, weight gain, and associated health problems like diabetes, heart disease, and dementia.
Diabetes Medication May Do More Harm Than Good
This is why the medical community’s approach to its treatment is not getting anywhere. Contrary to popular belief, treating type 2 diabetes with insulin is actually one of the worst things you can do, as it only exacerbates the underlying problem.
One recent study published in JAMA Internal Medicine11 concluded that insulin therapy in type 2 diabetic patients—especially older diabetics—may indeed do more harm than good. As reported by Medical News Today:12
“In the US, type 2 diabetes is diagnosed when hemoglobin A1c levels reach 6.5 percent or higher. The higher A1c levels are, the greater the risk of other health problems.
Sometimes the condition can be managed through changes in diet, but other patients with type 2 diabetes may need medication - such as insulin or metformin – to help lower their blood sugar levels, and ultimately, reduce the risk of diabetes complications.
But the researchers of this latest study... claim that the benefits of such treatment - particularly for people over the age of 50 – may not always outweigh the negatives.
‘In many cases, insulin treatment may not do anything to add to the person's quality life expectancy,’ says study co-author John S. Yudkin...
‘If people feel that insulin therapy reduces their quality of life by anything more than around 3-4 percent, this will outweigh any potential benefits gained by treatment in almost anyone with type 2 diabetes over around 50 years old.’ ...
For example, they estimate that a person with type 2 diabetes who begins insulin therapy at age 45 and lowers their hemoglobin A1c levels by 1 percent may experience an extra 10 months of healthy life.
But for a patient who starts treatment for type 2 diabetes at age 75, they estimate the therapy may only gain them an additional 3 weeks of healthy life. The researchers say this prompts the question - is 10-15 years of pills or injections with possible side effects worth it?”
Lifestyle Changes Are as Effective as Medicine for Preventing Type 2 Diabetes
Just like obesity, type 2 diabetes is primarily controlled and prevented through diet and exercise. Avoiding sugar (and processed fructose in particular) is imperative for preventing insulin/leptin resistance. Exercise is also important for normalizing your insulin and leptin sensitivity.
I’ve often said that lifestyle changes can be just as, if not more, effective than drugs, and studies have repeatedly confirmed this view. Most recently, a meta-analysis published in Diabetologia13 found that diet and exercise lowers blood sugar levels and prevents diabetes in pre-diabetics as effectively as diabetic medications in both genders. As reported by MedicineNet.com:14
“The researchers reviewed data from more than 7,400 women and 5,500 men in 12 studies. Men and women with prediabetes who made lifestyle changes were 40 percent less likely to progress to diabetes after one year, and 37 percent less likely to progress after three years, compared to those who did not make lifestyle changes, the study found.
Men and women with prediabetes who made lifestyle changes also lost more weight and had greater reductions in blood sugar levels, the researchers said... ‘Clinically, these findings highlight an important issue.
Despite differences in age of onset, detection and burden of type 2 diabetes between men and women, the effectiveness of preventive interventions in people with prediabetes is not influenced by gender,’ the researchers explained...”
The Importance of Magnesium for Glucose and Insulin Balance
Magnesium deficiency is also worth mentioning, as it plays an important role in glucose and insulin homeostasis.15 Magnesium is also required to activate tyrosine kinase, an enzyme that functions as an “on” or “off” switch in many cellular functions and is required for the proper function of your insulin receptors. Studies,16,17,18 from around the world universally agree that in order to optimize your metabolism and keep your risk for type 2 diabetes low, you need to consume adequate magnesium.
One 2013 study involving pre-diabetics found that most had inadequate magnesium intake, and those with the highest magnesium intake reduced their risk for blood sugar and metabolic problems by a whopping 71 percent.19 Current government guidelines for magnesium intake among adults call for 300 to 420 mg per day,7 but research suggests many would benefit from a much higher intake—about 700 mg per day or more.
Type 3 Diabetes, or ‘Brain Diabetes,’ May Be Responsible for Alzheimer’s Disease
A growing body of research suggests there’s a powerful connection between your diet and your risk of Alzheimer's disease20 via similar pathways that cause type 2 diabetes. Alzheimer's disease was tentatively dubbed "type 3 diabetes" in early 2005 when researchers learned that, in addition to the pancreas, your brain also produces insulin. This brain insulin is actually necessary for the survival of your brain cells.
A drop in insulin production in your brain may contribute to the degeneration of your brain cells, and studies have found that people with lower levels of insulin and insulin receptors in their brain often have Alzheimer's disease. Researchers have discovered that insulin actually does far more than regulate your blood sugar. It also helps with neuron glucose-uptake, and the regulation of neurotransmitters like acetylcholine, which are crucial for memory and learning. This is why reducing the level of insulin in your brain impairs your cognition.
It's becoming increasingly clear that the same pathological process that leads to insulin resistance and type 2 diabetes may also hold true for your brain. As you over-indulge on sugar and grains, your brain becomes overwhelmed by the consistently high levels of glucose and insulin that blunts its insulin signaling, leading to impairments in your thinking and memory abilities, eventually causing permanent brain damage.
Additionally, when your liver is busy processing fructose (which your liver turns into fat), it severely hampers its ability to make cholesterol, an essential building block of your brain that is crucial for optimal brain function. Indeed, mounting evidence supports the notion that significantly reducing fructose consumption is a very important step you can take to prevent Alzheimer's disease.
Prevention and Treatment Guidelines for Diabetes
It’s becoming quite clear that to protect your brain and prevent cognitive decline, it’s important to address any underlying insulin/leptin resistance and/or type 2 diabetes. Fortunately, type 2 diabetes is curable, and in the vast majority of cases does not require any form of medication. The following nutrition and lifestyle modifications should be the foundation of your diabetes prevention and treatment plan.
Also, make sure to monitor your FASTING insulin level. This is every bit as important as monitoring your fasting blood sugar. You'll want your fasting insulin level to be between 2 and 4. The higher your level, the greater your insulin resistance and the more aggressive you need to be in your treatment plan, especially when it comes to altering your diet.
- Swap out processed foods, all forms of sugar—particularly fructose—as well as all grains, for whole, fresh food. A primary reason for the failure of conventional diabetes treatment over the last 50 years has to do with seriously flawed dietary recommendations. Refined fructose, grains, and other sugar forming starchy carbohydrates are largely responsible for your body's adverse insulin reactions, and all sugars and grains—even "healthful" grains such as whole, organic ones—need to be drastically reduced.
If you’re insulin/leptin resistant, have diabetes, high blood pressure, heart disease, or are overweight, you’d be wise to limit your total fructose intake to 15 grams per day until your insulin/leptin resistance has resolved. This includes about 80 percent of Americans. For all others, I recommend limiting your daily fructose consumption to 25 grams or less, to maintain optimal health.
The easiest way to accomplish this is by swapping processed foods for whole, ideally organic foods. This means cooking from scratch with fresh ingredients. Processed foods are the main source of all the primary culprits, including high fructose corn syrup and other sugars, processed grains, trans fats, artificial sweeteners, and other synthetic additives that may aggravate metabolic dysfunction.
Besides fructose, trans fat (NOT saturated fat) increases your risk for diabetes21 by interfering with your insulin receptors. Recent research22,23 also demonstrates that trans fat has a distinct adverse impact on memory, courtesy of the oxidative stress and brain inflammation these fats produce.
Healthy saturated fats do not have any of these adverse effects on your health. Since you’re cutting out a lot of energy (carbs) from your diet when you reduce sugars and grains, you need to replace them with something. The ideal replacement is a combination of:
- Low-to-moderate amount of high-quality protein. Substantial amounts of protein can be found in meat, fish, eggs, dairy products, legumes, and nuts. When selecting animal-based protein, be sure to opt for organically raised, grass-fed or pastured meats, eggs, and dairy, to avoid potential health complications caused by genetically engineered animal feed and pesticides.
Most Americans eat far too much protein, so be mindful of the amount. I believe it is the rare person who really needs more than one-half gram of protein per pound of lean body mass. Those that are aggressively exercising or competing and pregnant women should have about 25 percent more, but most people rarely need more than 40-70 grams of protein a day.
To determine your lean body mass, find out your percent body fat and subtract from 100. This means that if you have 20 percent body fat, you have 80 percent lean body mass. Just multiply that by your current weight to get your lean body mass in pounds or kilos. To determine whether you’re getting too much protein, simply calculate your lean body mass as described above, then write down everything you’re eating for a few days, and calculate the amount of daily protein from all sources.
Again, you’re aiming for one-half gram of protein per pound of lean body mass, which would place most people in the range of 40 to 70 grams of protein per day. If you’re currently averaging a lot more than that, adjust downward accordingly. You could use the chart below or simply Google the food you want to know and you will quickly find the grams of protein in the food.
Red meat, pork, poultry, and seafood average 6-9 grams of protein per ounce.
An ideal amount for most people would be a 3-ounce serving of meat or seafood (not 9- or 12-ounce steaks!), which will provide about 18-27 grams of protein
Eggs contain about 6-8 grams of protein per egg. So an omelet made from two eggs would give you about 12-16 grams of protein.
If you add cheese, you need to calculate that protein in as well (check the label of your cheese)
Seeds and nuts contain on average 4-8 grams of protein per quarter cup Cooked beans average about 7-8 grams per half cup Cooked grains average 5-7 grams per cup Most vegetables contain about 1-2 grams of protein per ounce
- As much high-quality healthy fat as you want (saturated24 and monounsaturated). For optimal health, most people need upwards of 50-85 percent of their daily calories in the form of healthy fats. Good sources include coconut and coconut oil, avocados, butter, nuts, and animal fats. (Remember, fat is high in calories while being small in terms of volume. So when you look at your plate, the largest portion would be vegetables.)
- As many non-starchy vegetables as you want
- Exercise regularly and intensely. Studies have shown that exercise, even without weight loss, increases insulin sensitivity.25 High intensity interval training (HIIT), which is a central component of my Peak Fitness program, has been shown to improve insulin sensitivity by as much as 24 percent in just four weeks. Exercise also prompts nerve cells to release brain-derived neurotrophic factor (BDNF), which triggers other chemicals that promote neural health, and directly benefits cognitive functions, including learning. A number of studies have also shown that exercise can promote growth of new brain cells, enlarge your memory center, improve IQ scores, and help prevent brain deterioration associated with aging.
- Improve your omega-3 to omega-6 ratio. Today’s Western diet has far too many processed and damaged omega-6 fats, and is far too little omega-3 fats.26 The main sources of omega-6 fats are corn, soy, canola, safflower, peanut, and sunflower oil (the first two of which are typically genetically engineered as well, which further complicates matters). Our bodies evolved for an optimal of approximately 1:1 ratio of omega-6 to omega-3.
However, our ratio has deteriorated to between 20:1 and 50:1 in favor of omega-6. This lopsided ratio has seriously adverse health consequences. To remedy this, reduce your consumption of vegetable oils (this means not cooking with them, and avoiding processed foods), and increase your intake of animal-based omega-3, such as krill oil. Vegetable-based omega-3 is also found in flaxseed oil and walnut oil, and it’s good to include these in your diet as well. Just know they cannot take the place of animal-based omega-3s.
- Maintain optimal vitamin D levels year-round. New evidence strongly supports the notion that vitamin D is highly beneficial for both type 1 and type 2 diabetes. Recent research has also confirmed the link between vitamin D deficiency and dementia. The ideal way to optimize your vitamin D level is by getting regular sun exposure, or by using a tanning bed. As a last resort, consider oral supplementation with regular vitamin D monitoring, to confirm that you are taking enough vitamin D to get your blood levels into the therapeutic range of 50-70 ng/ml. Also please note that if you take supplemental vitamin D, you create an increased demand for vitamin K2 and magnesium.
- Get adequate high-quality sleep every night. Insufficient sleep appears to raise stress and blood sugar, encouraging insulin and leptin resistance and weight gain. In one 10-year-long study27 of 70,000 diabetes-free women, researchers found that women who slept less than five hours or more than nine hours each night were 34 percent more likely to develop diabetes symptoms than women who slept seven to eight hours each night.
Sleep loss has also been linked to severe brain damage. Sleep is actually necessary for maintaining metabolic homeostasis in your brain, and without sufficient sleep, neuron degeneration sets in. Sleep deprivation causes disruption of certain synaptic connections that can impair your brain's ability for learning, memory formation, and other cognitive functions. It also accelerates onset of Alzheimer's disease. If you are having problems with your sleep, try the suggestions in my article “33 Secrets to a Good Night’s Sleep.”
- Maintain a healthy body weight. If you incorporate the diet and lifestyle changes suggested above you will greatly improve your insulin and leptin sensitivity, and a healthy body weight will follow in time. Determining your ideal body weight depends on a variety of factors, including frame size, age, activity level, and genetics. As a general guideline, you might find a hip-to-waist size index chart helpful. This is far better than BMI for evaluating whether or not you may have a weight problem, as BMI fails to factor in both how muscular you are, and your intra-abdominal fat mass (the dangerous visceral fat that accumulates around your inner organs), which is a potent indicator of leptin sensitivity and associated health problems.
- Incorporate intermittent fasting. If you have carefully followed the diet and exercise guidelines and still aren’t making sufficient progress with your weight or overall health, I strongly recommend incorporating intermittent fasting. It’s by far the most effective way I know of to shed unwanted fat, resolve insulin resistance, and eliminate your sugar cravings. Intermittent fasting has also been identified as a potent ally for the prevention and perhaps even treatment of dementia. Ketones are released as a byproduct of burning fat, and ketones (not glucose) are actually the preferred fuel for your brain. Keep up your intermittent fasting schedule until your insulin/leptin resistance improves (or your weight, blood pressure, cholesterol ratios, or diabetes normalizes). After that, you only need to do it “as needed” to maintain your healthy state.
- Optimize your gut health. Your gut is a living ecosystem, full of both good bacteria and bad. Multiple studies have shown that obese people have different intestinal bacteria than lean people. The more good bacteria you have, the stronger your immune system will be and the better your body will function overall. Gut bacteria has been found to affect your brain function, and play a role in the development of diabetes as well. Fortunately, optimizing your gut flora is relatively easy. You can reseed your body with good bacteria by regularly eating fermented foods (like natto, raw organic cheese, miso, and cultured vegetables) or by taking a high-quality probiotic supplement.