Cutting Calories may Boost Memory

In a recent study, older adults who reduced their calorie intake by about 30 percent performed better on memory tests.

Some animal studies suggest that low-calorie diets rich in unsaturated-fatty acids, like nuts, avocados and olive oil, may be beneficial for brain function in aging rats. In this latest study, published in the Proceedings of the National Academy of Sciences, researchers aimed to determine if these same effects apply to humans.

The authors studied 50 older adults (average age: 60) whose weight ranged from healthy to overweight. The participants were divided into three groups. One group reduced their calorie intake by up to 30 percent. The second group increased their unsaturated fatty acids intake by up to 20 percent, and the third group served as the control and did not change their eating habits.

The researchers tested the participants' memory at the beginning and end of the three-month-long study. They found that verbal memory scores significantly increased an average of 20 percent by the end of the study in the reduced-calorie group. These memory improvements were also associated with decreases in insulin levels and C-reactive protein (a marker of inflammation). No significant changes in memory were reported in the other two groups.

Although these early results are promising, additional well-designed trials are needed to fully understand how a low-calorie diet may affect brain functioning.

For more information about a low-calorie diet, please visit Natural Standard's Health & Wellness database.

Comments

[Alexis]

It's very interesting that only the calorie-reduced group noticed improvements in memory. There is so much talk about how foods, such as olive oil, improve cognition. So I would definitely be interested in further studies about specific food groups versus calories in general.

[stacy ray]

Interesting that the subjects who showed the memory benefit ranged from healthy to overweight. I'm thinking that a 30-percent calorie reduction is pretty stiff for those subjects who are at a healthy weight already, and that it's intriguing that all subjects - - overweight or not -- showed the benefit in greater memory.

Still, score more points for a low-fat diet! But let's not ignore the other half of the equation: an active lifestyle. Even if you follow a healthy diet and are at a healthy weight, being active is essential to keeping your body functioning now and as you age, as well as preventing major chronic health problems, such as diabetes, heart disease and some cancers.

[Marley]

These findings add to growing evidence that calorie restriction can benefit health and longevity. However, it is important to note that this shouldn't prompt already skinny seniors to start dieting. Older people who lose too much weight increase their risk of falls and fractures. Moreover, eating less isn't the only way to get this effect. Exercise appears to exert similar effects on brain function by boosting insulin sensitivity and fighting inflammation.

[Noel]

Experts believe that, as Floel's study suggests, increased inflammation and a drop in insulin sensitivity (which is known as insulin resistance), may help explain why obesity and type 2 diabetes have been linked to worse mental performance and a greater risk of Alzheimer's disease.

[Beatrice]

Most studies in humans have looked at people who choose to sharply reduce their calorie intake long-term. This research has found clear signs of reduced cardiovascular disease risk and perhaps slower aging in these individuals. Nonetheless, it's important to note that this kind of lifestyle change isn't easy and is best done with professional help. The trick is to create a state of under-nutrition without malnutrition, and it's not a completely straightforward thing to do.

[leah]

How does consuming less calories affect aging?

[DoctaNo]

Researchers who study caloric restriction have two main theories on how it might slow aging. One argument is that eating less slows down metabolism, so that the body produces fewer free radicals, which are byproducts of oxygen metabolism that can harm body tissues. Another is that reducing calorie intake keeps cells under a constant low level of stress, which makes them better able to cope with higher levels of stress when it comes along, similar to how the moderate stress induced by exercise can improve people's health.

[GB]

I am not 100% sold on this. Were the patients just cutting calories, or were they exercising too? Most people who start eating healthily probably try to become healthy in more than one way. So if these patients were more active, I think that would be the reason for improved memory benefit.

[Jack]

This post is really a good one in respect of health issues and general awareness. Thanks for the information

[Jack]

Really great article! You provide lots of information. Thanks for sharing with us.

[Geston]

This is very interesting. Why memory tests? Why not cholesterol lowering effects of the monosaturated fat in these foods?

[Mimi]

I would say that the probable mechanism this works is via the reduction of cholesterol thus, reducing clogged arteries that would have reduced blood flow to the brain. This is my proposed mechanism based on the fact that avocado, like the other foods, contains ingredients that aid in the reduction of cholesterol.

[Mano]

I don't see the connection between being overweight and memory performance. I do agree with the decrease in insulin. Obesity has been associated with a decrease in insulin sensitivity, which results in an increase in insulin consumption.

[Brandi]

Being overweight does not benefit anything in the body, and now even the memory is being affected. It would be really interesting to know who exactly this is occurring in. Maybe it's that they aren't eating healthy things that strengthen the memory and the body's health.

[Megan]

In the study, they looked into the weight and age of the patients. Through this information and their eating habits, they decided if their caloric intake was affecting their memory. A big confounding variable in this study is the patient's past medical history. Since these patients are around the age of 60, they could have had other conditions that played a role in their memory.

[HST]

Good point, Megan. I would almost 100-percent guarantee that because the patients were older, their past medical histories played a significant role in the outcome measures.

[Jones]

I am not sure if it was the same study but another one similar was reported on ABC News with Charlie Gibson. The theory the researchers suggests is that consuming fewer calories will cause body to produce less insulin, and with less insulin, brain cells will communicate better.

[Elle]

Jones,

I came across another article where a researcher said women who cut calories are more sensitive to the blood sugar-regulating hormone insulin and had drops in the inflammation-associated molecule C-reactive protein. And both factors have been linked to an improvement in brain function.

[Santos]

It is important that healthcare providers take this serious and watch out for those elderly patients who are not even overweight but are looking for an excuse to go on a diet. The elderly should be reminded that if they lose too much weight, they are at a higher risk of falls and fractures. There are other lifestyle changes that can be implemented to improve memory.

[Ines]

Are these people being evaluated right after they eat large amounts of calories? It could be that they are tired from the food intake and aren't able to properly concentrate. After eating, blood flow is redirected to the digestive system instead of the brain.

[Rhea]

Maybe cutting calories allowed the patient to be more active and have more energy. By becoming more active, the patients had greater blood flow to the brain, and memory was one factor that was positively affected.

[Emma]

All of this is, of course, unrelated if the adults are already eating healthy, well-balanced meals. We cannot assume that simply cutting calories is going to dramatically change an outcome. These types of results will be more important in patients who are not already eating in a healthful way.

[JZ]

I'm curious if any of the people in this calorie-cutting study had parents with Alzheimer's, or if they carried the APOE gene themselves (strongly linked to development of AD) -- especially in light of the recent BU School of Medicine study where people who had a parent with Alzheimer's developed visual and verbal memory loss at an earlier age than their AD parent did. And did any of the patients in this study carry the APOE gene? Cutting calories may help with memory if the AD/APOE connection isn't there.

[MHD]

This study does not seem like it has evaluated all the possible causes of memory boosting. What were the subjects eating even though they cut their calories? It has been reported that DHEA in some types of fish, namely salmon, increase memory retention in adults and children. Could it be possible that these "low-calorie" subjects were actually eating healthier, more wholesome foods that incorporated high levels of DHEA into their diets? I think this study needs further evaluation.

[shelly]

Even though the outcome of the study is interesting; it still leaves a lot of questions. How many calories did the participants already consume prior to the study? What is the ration of overweight subjects versus normal-weight subjects in the study groups compared to the control? What are their exercise habits? All of these concerns need to be address in order for readers to determine whether or not the findings are relevant. Because if the participants consume a normal calories intake (1200-2200kcal) daily, cutting 20-30% might put these subjects at risk for deficiencies; at which point the risk might outweighs the benefits.