We have known for many years that having a big belly is associated with increased risk for heart attacks, diabetes, certain cancers, high blood pressure, high cholesterol, disability and premature death. We now also have data that links having a large belly to increased risk for dementia, including Alzheimer's disease, a debilitating way to spend your last years. According to World Health Organization (WHO), more than 24 million people in the world live with dementia, with 4.6 million new cases each year.
A recent study of African Americans showed that having a larger waist circumference in mid-life is associated with a greater rate of memory loss over six years than in those who just had more body fat overall (higher BMI) or those who were not overweight (TJ Am Geriatr Soc, June 2017;65(6):1282-1288). Those who reduced their belly fat circumference in middle age had improved results in memory tests and decision making. These results agree with many other studies, including one of 2,817 middle-aged men and women that showed that those with big bellies had significantly lower scores in tests used to measure executive function and the ability to make wise decisions (J Nutr Health Aging, Feb 2015;19(2):183-9).
Large Bellies Predict Memory Loss
In one study, people with protruding bellies in middle age were 3.6 times more likely than those without excess belly fat to develop memory loss and dementia later in life (Cell Reports, Oct 8, 2013). Another study of 1,049 men and women showed that those with excess belly fat are three times more likely to suffer from dementia (Neurology, September 30, 2008;71(14):1057-1064).
A study of more than 700 apparently healthy men and women, average age 60, found that those with more belly fat on CT scans had significantly smaller brains shown in MRIs (Annals of Neurology, August, 2010;68(2):136–144). Many other studies also associate abdominal obesity with smaller brains (Neurobiology of Aging, Feb 2014;35(2):378-386).
Many studies associate abdominal obesity with increased risk for strokes, a common cause of dementia. A study of 41,837 women, aged 55-69, showed that those with abdominal obesity were at markedly increased risk for stroke (Stroke, May 1, 1990;21:701-706) and another study of 1137 men and women showed the same results (Stroke, 2008;39:3145-3151).
Belly Fat Is Far Worse than Fat Anywhere Else
Having a lot of fat in your belly generally means that you have excess fat in your liver. Fat in the liver causes high blood sugar levels, which can lead to heart attacks, strokes, diabetes, cancers, arthritis, sleep disorders, depression, sexual dysfunction and osteoporosis as well as dementia. Everybody's blood sugar rises after they eat. However, when blood sugar rises too high, sugar attaches to the surface membranes of cells everywhere in your body, including your brain. Once attached, the sugar cannot get off and eventually destroys the cells.
• When your blood sugar rises after you eat, your pancreas releases insulin which lowers high blood sugar levels by driving sugar from your bloodstream into your liver.
• If your liver is full of fat, your liver cannot accept the sugar and blood sugar levels go higher and higher to cause and increase damage to every type of cell in your body.
Why Sugared Drinks are Linked to Dementia
All drinks with sugar in them are associated with increased risk for strokes and dementia (Stroke, April 20, 2017). The highest rises in blood sugar usually come after taking sugared drinks, including fruit juices. Solid foods take time to pass from your stomach into your intestines because the pyloric valve at the end of your stomach closes when you eat and allows only a liquid soup to pass into your intestines. An apple or any other solid food can take as long as five hours to reach your intestines, while sugar in liquid form passes right through the stomach into the intestines to cause a rapid rise in blood sugar.
• If you can pinch more than two inches of fat under the skin near your belly button, you are at high risk for having too much fat in your liver, high blood sugar levels after meals and increased risk for dementia.
• The only two places your body can move sugar from your bloodstream are into your liver or your muscles.
• If you have a lot of fat in your liver, the excess sugar in your bloodstream cannot be removed rapidly so it will attach to and destroy cells everywhere in your body.
• You can work to get fat out of your liver by avoiding sugared drinks, sugar-added foods, red meat, processed meats and fried foods. See Get Rid of Fat in Liver. You should eat lots of vegetables, fruits and nuts. I believe that the most effective way to lose excess fat is intermittent fasting.
• You get excess fat out of your muscles by exercising. Contracting muscles can draw sugar out of your bloodstream without even needing insulin to do so.
• You can have very high blood sugar levels after eating and still have normal fasting blood sugar levels below 100 nmol/L. The new definition of diabetes is having a blood sugar level above 140 nmol/L one hour after eating a meal. If you have a large belly and your doctor tells you that you are not diabetic based on your fasting blood sugar test, ask to have the test repeated one hour after you eat.