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Overeating may reduce brain function

High caloric intake could raise the risk of memory loss.

Eating too many calories may do more than just expand your midsection. A recent study suggests that high caloric intake over time may actually raise your odds of developing memory loss, or mild cognitive impairment (MCI), later in life.

The study, presented earlier this year at the American Academy of Neurology’s annual meeting, found that consuming between 2,100 and 6,000 calories per day may double the risk of MCI among people age 70 and older. The study involved more than 1,200 men and women, ages 70 to 89, who did not show signs of dementia at the start of the study.

“This study implies that in late life, when you are already at increased risk for cognitive impairment—primarily due to Alzheimer’s disease—increased caloric intake is associated with increased risk of cognitive impairment,” explains Dr. Gad Marshall, a behavioral neurologist at Harvard-affiliated Brigham and Women’s Hospital in Boston.

He adds, however, that it’s not entirely clear what the association is between caloric intake and brain health later in life. Other studies, for example, have shown that in mid-life, a greater body mass index, or BMI—a measure of body fat that uses a ratio between your height and weight—is associated with an accelerated rate of cognitive decline in late-life.

Conversely, a larger BMI in late-life has been associated with slower cognitive decline. “This could be because weight loss late in life is associated with poorer overall medical outcomes for many reasons,” Dr. Marshall says.

To cut calories in your diet

Instead of this

Eat this

Ground chuck
(3 oz, 293 calories)


(3 oz, 127 calories)

Whole milk
(1 cup, 150 calories)

Skim milk (1 cup, 86 calories)

Baked potato, plain
(1 medium, 161 calories)

Spinach, frozen (1/2 cup, 32 calories)

Bagel, toasted
(1 bagel, 354 calories)

Whole wheat toast (1 slice, 77 calories)

Chocolate ice cream
(3.5 oz, 125 calories)

Fresh strawberries (1 cup, 46 calories)

How much is enough?

Determining the caloric intake that’s right for you depends on several factors, such as your age, height, weight, activity level, and overall health. Remember that unless you burn more calories than you consume, you will gain weight. So if you lead a somewhat sedentary lifestyle, it’s even more important to limit your calories.

While many older adults are overweight and need to watch their calories, frail or underweight individuals may be able to boost their caloric intake with diet aids, such as protein drinks.

Researchers emphasize that the findings of this study shouldn’t be interpreted as a recommendation to starve yourself or limit your food intake to a point where you start to miss out on important vitamins and nutrients.

And while this study doesn’t conclude with a particular calorie range considered optimal for brain health, Dr. Marshall suggests that for older adults a daily caloric intake of between 1,526 to 2,142 calories “is likely associated with reduced risk of cognitive impairment late in life.”

Your doctor should help you set a target weight, and a dietitian can help you develop an eating plan with appropriate calorie levels and a healthy mix of nutritious foods.

What kind of calories?

Dr. Marshall notes that it’s not just how many calories but what kind of calories that are important for protection against dementia. In particular, a Mediterranean-style diet, which focuses on fish, vegetables, legumes, olive oil and whole grains, is associated with a decreased risk of developing cognitive impairment later in life as well as decreased progression of cognitive impairment once symptoms are already present.

“DHA, an omega-3 fatty acid, and one of the main components of fish oil, has been shown to help the developing brain and has been used to supplement infant formula,” Dr. Marshall says. “It is true that DHA or generic fish oil have not been found to be helpful in treating people who already have Alzheimer’s disease. While there has not been a similar randomized trial to see if fish oil (compared to placebo) helps prevent Alzheimer’s disease, population studies indicate that it might be helpful in that regard.”

Although it is not proven that fewer and healthier calories will reduce your risk of Alzheimer’s disease, the evidence is reasonably strong. And the evidence that the same formula will protect you against other diseases—like diabetes and heart disease—is even stronger.

Posted by: Dr.Health

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