There are a lot of factors that seem to contribute to people getting Alzheimer’s disease. There are unmodifiable risk factors like older age and genetics, and then there are modifiable risk factors. Some will say that lack of exercise, too much alcohol, social isolation, poor quality of relationships, and lack of quality sleep all play a part. But if someone asks me what the single most important contributor is, the answer at this point, especially with all the recent research that has come out, seems pretty obvious.
That’s eating too much sugar, which is a simple way of saying that at the molecular and cellular level, it’s a problem with insulin resistance, inflammation, and oxidative stress that ends up impairing mitochondrial function. Insulin resistance can lead to mitochondrial dysfunction anywhere in the body, but the last place you want it to happen is in your neurons. In Alzheimer’s disease, that’s exactly what happens, and it starts in the neurons that make up your hippocampus, the part of the brain that stores your memories.
How Diet Can Impact Alzheimer’s and Dementia Risk: Understanding the Link Between Sugar, Insulin Resistance, and Brain Health
That’s why the first thing that starts to go in Alzheimer’s is our memories. The neurons here produce metabolic junk in the form of Tau proteins that clump up the insides of the neurons, called neurofibrillary tangles. The neurons also make more junk that gets kicked out of the cell called amyloid plaques.
Regardless, it’s more junk in the trunk. Right now, there’s a lot of research that is specifically teasing out the relationships between sugar, insulin resistance, and type 2 diabetes and how those impact the development of Alzheimer’s. For instance, we know that patients with type 2 diabetes are four times more likely to develop dementia than the general population if you combine both Alzheimer’s and vascular dementia, the second most common type of dementia.
In fact, the prevalence of type 2 diabetes over the years looks very similar to the prevalence of Alzheimer’s over those years, and both of these parallel the amount of sugar consumption during this time period.
Uncovering the Startling Link Between Sugar and Alzheimer’s: Exploring the Historical Roots
Any guesses as to when Alzheimer’s was first discovered? It’s not as long ago as you might think, and I’m going to come back to that in a bit. But here’s another question: When did people start eating a lot of sugar? Because before 1700, sugar was nothing more than a luxury item that could only be afforded by the wealthy and was, therefore, a rare commodity in Europe. It was primarily used as a sweetener in small quantities and reserved for special occasions only. But that all changed as a result of what happened in the 1660s when Britain colonized the West Indies, where there was a lot of sugarcane.
This led to a very dark part of world history. Britain was not the only European country to participate in the slave trade, but it was the most significant. It implemented the plantation system in the West Indies and America and built an empire of sugar on the backs of slaves.
The Sweet Revolution: How Sugar Became a Staple of the European and American Diet
So, back home in Britain and the rest of Europe, the price of sugar fell, and it started to be incorporated into more and more food. Meanwhile, in 1747, another source of sugar was discovered in Europe thanks to German chemist Andreas Margrath, who was the first to identify sugar in beetroots. So, this time period of the late 18th century and early 19th century marked the start of the sugar revolution, and sugar consumption exploded.
It was now a major part of the European diet. Europeans were making all sorts of new kinds of cakes, candies, jams, biscuits, and other pastries. In the United States, sugar consumption began to increase in the late 19th century and early 20th century with the rise of mass-produced processed foods and beverages. And this was turbocharged with the invention of high fructose corn syrup in the 1970s.
When and Where Was the First Case of Alzheimer’s Disease Discovered? Tracing the History of a Global Public Health Challenge
But when and where was the very first case of Alzheimer’s disease? In Germany, in 1906, Dr. Alois Alzheimer had a patient named August Dieter who had profound memory loss and other neurological symptoms. In her brain, at autopsy, it was found to be shrunken down in size, and when her brain tissue was put underneath the microscope, Dr. Alzheimer found abnormal deposits in and around those neurons, and these are now known as the amyloid plaques and neurofibrillary tangles.
But even though it was discovered in 1906, the disease was relatively unknown, as there were fewer than 150 scientific articles published on it before the 1970s. In 1976, there was a landmark scientific editorial written by American neurologist Robert Katzman, who described the disease as a major killer and the most common cause of dementia, a major public health challenge that impacts the entire world.
How Has the Prevalence of Alzheimer’s Disease Changed Over Time and Across the World? Exploring the Latest Research and Projections
Back then, about 12 percent of 85-year-olds would go on to develop Alzheimer’s, but between 1970 and 2014, the prevalence of Alzheimer’s doubled throughout the entire world. Interestingly, in high-income countries like the United States, the overall prevalence is around 6.5 percent and has held steady for the past decade, while in developing countries, it has increased by 50 percent in that time interval. Right now, an estimated 6 million people in the United States have it, and it’s projected to reach 14 million by the year 2050.
The Link Between Sugar, Insulin Resistance, and Chronic Diseases: How Your Diet Impacts Your Health
Let’s talk a little bit about fructose and how it impacts your brain. Even though your brain weighs only three pounds, it is still the body’s biggest utilizer of energy, consuming 20% of all the glucose floating around in your bloodstream at any given moment. But what does the brain do with fructose? Let’s say you eat sugar – that’s your trigger molecule. It’s sucrose, a disaccharide that has two monosaccharides.
One of those monosaccharides is glucose, and the other is fructose. High fructose corn syrup is composed of a mixture of individual glucose and fructose molecules. Regardless of whether you’re consuming sucrose or high fructose corn syrup, it goes down into the intestines, gets absorbed there, and is delivered to the liver. Fructose is metabolized in the liver, and one of the byproducts is uric acid, which then travels out of the liver and makes its way to the brain, where it leads to microscopic inflammation.
More inflammation means more oxidative stress. The more oxidative stress that cells have, the sicker they become, sometimes to the point of causing cellular death. But if you overwhelm the liver’s sugar capacity – let’s say you eat a donut or go to Starbucks and drink a venti frap with extra syrup – well, guess what happens then? A sizable portion of that fructose load actually makes its way out of the liver.
In essence, it spills over into the bloodstream and then makes its way to the brain. Now fructose directly impacts the brain. And if you thought what uric acid did to the brain was bad, check this out: fructose alters brain metabolism in a few key ways. One of them is what it does to the astrocytes, the cells that nourish the neurons.
How Does Fructose Affect Your Brain? Exploring the Link Between Sugar, Glycation, and Oxidative Stress
Specifically, fructose does something called glycation and oxidative stress. Glycation is essentially the sugar molecule combining with the amino acid portion of a protein, which leads to the formation of AGES (Advanced Glycolated End Products), which is what ages you. The glycation process is also known as the Maillard reaction. It’s also known as caramelization or browning.
Both glucose and fructose cause glycation, but fructose does it seven times the rate of glucose. Basically, your brain becomes caramelized if you eat too much fructose. So, in that sense, you kind of are what you eat. Fructose generates 100 times the number of oxygen radicals compared to glucose, and all this means oxidative stress. This oxidative stress means that the mitochondria become sicker and eventually dysfunctional.
How does fructose affect brain function and cognitive abilities?
When these mitochondria start failing at their job, the cells start to die off. And if that’s not bad enough, fructose also messes with two trophic growth factors that help the brain develop and organize connections: leptin and BDNF (brain-derived neurotrophic factor). You could think of these two proteins as fertilizer or like Miracle-Gro that allows our neurons to break off the old branches and form new ones.
Fructose, because it induces insulin resistance and causes high insulin levels, ends up impairing leptin’s ability to do its job. This leads to cognitive deficits or cognitive impairments. Now, you may or may not know that beta-hydroxybutyrate is the ketone that is generated either from exercise, intermittent fasting, or from a ketogenic diet. And beta-hydroxybutyrate actually increases BDNF activity, which helps lay down new connections in the hippocampus.
How does fructose consumption impact Alzheimer’s risk, and what lifestyle factors have been linked to a decreased risk of the disease?
The hippocampus is the memory center of our brain, and it’s also the first part of the brain that deteriorates in Alzheimer’s. As it turns out, fructose impairs BDNF activity, and interestingly enough, various studies have shown that exercise, a ketogenic diet, intermittent fasting, and eating unprocessed food have all been linked with a decreased risk of Alzheimer’s.
This is why when you look at the blue zones of the world where people live the longest, healthiest lives, like in Japan, Italy, Greece, Costa Rica, and Loma Linda, California, what do they all have in common? They eat mostly unprocessed food with very little sugar in their diet. They’re also physically active and have good social relationships and a good sense of community.
And when you take a look at the map of the United States and see which states have the highest rates of diabetes, most of them are in the South, Southeast, and Appalachian area. These also happen to be the states with the highest rates of obesity, and these states, for the most part, have the highest rates of Alzheimer’s.
Embracing change: Making positive shifts for a healthier tomorrow.
So, what is the common thread between Type 2 diabetes, obesity, and Alzheimer’s? Too much sugar and insulin resistance. So, if you really want to know the best way that you can prevent these diseases, it really boils down to what you eat. But there are other important factors as well, like exercise, having good relationships, getting good sleep, and there you have it.
In conclusion, we have seen how excess sugar consumption and insulin resistance can lead to a host of health problems, including Type 2 diabetes, obesity, and Alzheimer’s disease. By focusing on a diet that is low in sugar and high in unprocessed foods, along with regular exercise and good lifestyle habits, we can significantly reduce our risk of developing these conditions. So, let’s take care of our bodies and minds by making healthy choices and living our best lives possible.
