About 22 percent of North Americans ages 85-89 and 33 percent of those over 90 suffer some degree of dementia (JAMA Neurol, 2022;79(12):1242-1249).
A study from the Chicago Health and Aging Project, which followed 2449 men and women over age 65, suggests that there is a lot that you can do to help protect yourself from dementia (BMJ Neurology, April 13, 2022;377:e068390). The healthful lifestyle factors tracked in this study included diet, physical activity, cognitive activity, not smoking, and avoiding or limiting alcohol (<15g/day for women, <30g/day for men). Higher lifestyle scores were associated with a longer life expectancy, and the higher-scoring participants lived a larger proportion of their remaining years without dementia.
Researchers from the University of Minnesota estimate that “The following modifiable risk factors account for about 40 percent of worldwide dementia, which thus could theoretically be prevented or delayed” (JAMA Netw Open, 2022 Jul 1;5(7):e2219672):
• Lack of physical activity
• Unhealthful diet
• Hypertension
• Smoking
• Heavy drinking
• Hearing impairment
• Obesity
• Depression
• Diabetes
• Low social contact
• Traumatic brain injury
• Air pollution
Anti-Inflammatory Diet to Help Prevent Dementia
Researchers have not proven that diet changes can help to prevent or treat dementia, but strong data associate a pro-inflammatory diet with increased risk for dementia (Neurology, Nov 10, 2021;10.1212). The authors divided 1059 non-demented people, average age 73, into three groups based on high, medium and low inflammatory diet scores. This study is especially important because it analyzed the entire diets and classified 45 different groups of foods into:
• pro-inflammatory foods that raise blood markers of inflammation,
and
• anti-inflammatory foods that lower these same blood markers.
At the end of the three-year study period, 62 of the participants had become demented. Those with the worst inflammatory diet scores were 3.5 times more likely to become demented than those with the best scores.
Each week for three years, the people with the best anti-inflammatory scores had eaten an average of:
• 20 servings of fruit
• 19 servings of vegetables
• 4 servings of beans or other legumes
Those with the worst scores had eaten an average of:
• 9 servings of fruit
• 10 servings of vegetables
• 2 servings of legumes
When Inflammation Causes Problems
You have germs in your body when you are born (Front Microbiol, June 4, 2019), and soon after birth, bacteria increase everywhere on your skin surface, in your respiratory tract and in your entire digestive tract. Most of these germs are good for you and help in many different ways. They help you to digest and absorb nutrients from the food that you eat, and to eliminate waste products. They colonize the linings of your respiratory tract and intestines to help keep harmful germs from growing there.
Germs are not supposed to invade your cells. However, when they do, your immune system recognizes that the germs’ sugar-proteins are different from the sugar-proteins on your own cells. Your immune system produces proteins called antibodies that attach to and try to kill the invading bacteria or virus, cells that literally eat the invading germs, and cytokines that marshal your entire immune system to destroy harmful germs that are trying to invade your body. The visible signs of inflammation — redness, swelling, soreness, fever — tell you that your immune system is working to combat an infection or injury.
As soon as a wound is healed or an infection is gone, your immune system is supposed to dampen down and stop making large amounts of these cells and antibodies. If your immune system does not stop making excessive amounts of cells and proteins to kill germs, these same cells and proteins can attack you to damage:
• your brain to cause dementia
• your arteries to cause plaques to form and break off, leading to heart attacks and strokes
• your DNA in cells to block apoptosis that can lead to cancer
• your liver to cause diabetes
• your own immune system itself, leading to auto-immune diseases such as rheumatoid arthritis
What Makes a Food Pro-Inflammatory or Anti-Inflammatory?
The pro-inflammatory foods turn on your immune system to cause these cells and proteins to attack and damage your own normal cells, while the anti-inflammatory foods dampen down this response to protect your cells from damage from an overactive immune system.
Dementia and heart attacks share the same common pro-inflammatory risk factors (Alzheimer’s and Dementia, Dec 2021;17(12):1914-1922), and the American Heart Association reports that dementia is strongly associated with a pro-inflammatory diet (Stroke, Mar 15, 2021:52(6A);52:e295–e308). Chronic inflammation increases risk for heart disease, diabetes, Alzheimer’s disease, certain cancers, and many other diseases. The more pro-inflammatory foods you eat, the greater your risk for these conditions. The more anti-inflammatory foods you eat, the greater your protection from chronic inflammation and the diseases it causes. Many previous scientific papers have associated risk for dementia with what you eat.
What you eat determines the proportions of good and bad bacteria in your colon. The good bacteria are happy to eat the same food that you eat, while the bad bacteria are not happy with your food supply and try to enter your colon cells, which turns on your immune system and keeps it on to cause excessive inflammation. You can improve the colony of good bacteria in your colon by:
• Eating lots of the anti-inflammatory foods: vegetables, whole grains, beans, seeds, nuts, fruits, and seafood (non-fried)
• Restricting the pro-inflammatory foods such as red meat, processed meats, fried foods, foods with added sugar and all drinks with sugar in them including fruit juices and alcohol.
Most ultra-processed foods are pro-inflammatory even if they are promoted and packaged to appear “healthful.” Many people are confused about a healthful diet because food companies spend so much money advertising that their products are healthful when they are not. Ultra-processed foods usually lack protein, dietary fiber, and micronutrients and also often contain contaminants from industrial processing and packaging. An estimated 73 percent of the U.S. food supply is ultra-processed and usually contains lots of unhealthful ingredients, such as sugar, salt, fat, artificial colors, preservatives, flavorings, sweeteners, and emulsifiers. Ultra-processed foods include frozen meals, soft drinks and “fruit” drinks, hot dogs, cold cuts, most fast foods, sweet or savory packaged snacks, energy bars and drinks, and so forth. Several studies suggest that ultra-processed foods are associated with dementia and decreased mental functioning (JAMA Neurology, Dec. 5, 2022).
My Recommendations
Dementia risk increases with age, and 33 percent of people over 90 are demented. Heart attacks and dementia have almost all of the same risk factors, so everyone should follow the anti-inflammatory lifestyle rules that help to prevent heart attacks, strokes, diabetes and many other diseases:
• Try to exercise every day
• Follow an anti-inflammatory, high-plant diet
• Avoid being overweight
• Avoid or severely limit alcohol
• Avoid smoking and second hand smoke
• Keep your vitamin D levels above 30 ng/mL
