How To Prevent Memory Loss?

Written by Dr. Steve Chaney on . Posted in current health articles, Drugs and Health, Food and Health, Vitamins and Health

 A New Study Shows B Vitamins and Omega-3s May Prevent Memory Loss

Author: Dr. Stephen Chaney

 

how to prevent memory lossWant to know how to prevent memory loss? Every once in a while a breakthrough study comes along that has the potential to change paradigms. A recent study (Jerneren et al, Am J Clin Nutr, 102: 215-221, 2015) looking at the potential of B vitamins and omega-3s to slow brain shrinkage in the elderly is just such a study. It has the potential to forever change the way we think about preserving brain health as we age.

One of the most terrifying aspects of aging is the thought that we might literally lose our minds. On one hand, it seems to be an almost inevitable part of the aging process. Every year millions of older Americans develop mild cognitive impairment, and as they age many of them progress on to dementia or Alzheimer disease. In fact, one recent study (Plassman et al, Ann Neurol, 70: 418-426, 2014) estimated that for individuals 72 and older in the United States every 6 years:

  • 8 million will develop mild cognitive impairment.
  • 4 million will develop dementia.
  • 3 million will develop Alzheimer disease.

Unfortunately, there is no effective drug treatment for preventing this cognitive decline, and there don’t appear to be any promising new drugs on the horizon. So it is only natural to ask whether there are diet and lifestyle changes that might reduce the rate of cognitive decline as we age.

As I discussed in previous issues of “Health Tips From the Professor” there are clinical studies suggesting that B vitamins  and omega-3 fatty acids can both slow the brain shrinkage and cognitive decline associated with aging. Unfortunately, there are also clinical studies that have come up empty. They have found no effect of B vitamins or omega-3 fatty acids on brain shrinkage or cognitive decline. Because of these conflicting clinical results, many experts are simply not ready to endorse natural approaches for preventing cognitive decline.

That’s what makes the current study (Jerneren et al, Am J Clin Nutr, 102: 215-221, 2015) paradigm-changing. If this study is correct, you need both B vitamins and omega-3 fatty acids together to prevent cognitive decline. Neither one will work without the other.

That would explain a lot! The previous studies have not been designed to test the effects of both B vitamins and omega-3 fatty acids simultaneously. Whether or not the diets of previous study participants were adequate with respect to B vitamins and omega-3s was a matter of pure chance. If the diets were adequate in both B vitamins and omega-3s, the study outcome might be positive. If the diets were only adequate in just one or the other, the outcome would almost assuredly be negative.

Why Might B Vitamins and Omega-3s Both Be Required for Brain Health?

It is easy to understand why B vitamins and omega-3s each might be important for preventing cognitive decline individually. Cognitive decline is closely associated with elevated levels of homocysteine, a toxic amino acid metabolite, and multiple clinical studies have shown that the combination of folic acid, vitamin B12 and vitamin B6 is effective at lowering homocysteine levels.

The omega-3 fatty acids are an integral part of the myelin sheath that coats our neurons. You can think of myelin as being like the plastic coating on an electrical wire that allows the electrical current to travel from one end of the wire to the other without shorting out. Myelin plays essentially the same role for our neurons.

But what is the possible connection between B vitamins and omega-3s with regard to brain health? The authors of this study had an interesting hypothesis. It turns out that when homocysteine levels are elevated due to B vitamin deficiency methionine levels and the levels of a number of downstream metabolites, including phosphatidylcholine, are reduced – and phosphatidylcholine is what delivers omega-3 fatty acids to the brain.

If their hypothesis is correct, adequate levels of B vitamins are required to deliver omega-3 fatty acids to the brain. That means that omega-3 fatty acids would only be effective at preventing brain shrinkage and/or cognitive decline in studies where the subjects were receiving adequate B vitamins as well.

Conversely, if we assume, as the authors suggested, that the real role of B vitamins is to assure the presence of enough phosphatidylcholine to deliver omega-3 fatty acids to the brain, B vitamins would be effective only in clinical studies where the subjects were also getting sufficient omega-3s from their diet.

B Vitamins and Omega-3s Together May Be How To Prevent Memory Loss

vitamins help reduce cognitive declineThe study itself included 168 adults over the age of 70 (average age = 77) with mild cognitive impairment at the beginning of the study. Half of them were given a high dose B vitamin supplement (800 ug folic acid, 500 ug vitamin B12, and 20 mg vitamin B6), and the other half were given a placebo.

Brain MRI scans were performed at the beginning of the study and again 2 years later to measure brain volume. Blood levels of omega-3 fatty acids were assessed at the beginning of the study. When the data were analyzed at the end of the study, the subjects with blood omega-3 levels of >590 umole/L were classified as having high omega-3 status, and subjects with blood omega-3 levels <390 umole/L were classified as having low omega-3 status.

The results were pretty striking:

  • B vitamin treatment reduced brain shrinkage by up to 70% over a two year period in adults over the age of 70.
  • The B vitamin treatment was only effective when the subjects were deficient in B vitamins at the beginning of the study, as indicated by elevated homocysteine levels.
  • The B vitamin treatment was also only effective in subjects with high omega-3 status. The B vitamin treatment had no benefit in subjects with low omega-3 status.

What Is The Significance Of This Study?

In today’s scientific world, “gold standard” clinical studies are considered to be those in which a single variable is evaluated in a double-blind, placebo-controlled clinical trial. Unfortunately, this reductionist approach can sometimes lead to misleading and confusing results.

For example, I once attended a session in which a world renowned expert was giving his talk on colon cancer. He said, “I can show you, unequivocally, that colon cancer risk is significantly decreased by a lifestyle that includes a high-fiber diet, a low-fat diet, adequate calcium, adequate B-vitamins, exercise and weight control. But I can’t show you that any one of them, by themselves, is effective.”

The question that came to me as I heard him speak was: “What’s the message that a responsible scientist or responsible health professional should be giving to their patients or the people that they’re advising?” You’ve heard experts saying: “Don’t worry about the fat” “Don’t worry about calcium.” “Don’t worry about B-vitamins.” “Don’t worry about fiber.” “None of them can be shown to decrease the risk of colon cancer.” Is that the message that we should be giving people? Or should we really be saying what that doctor said many years ago – that a lifestyle that includes all of those things significantly decreases the risk of colon cancer?

Similarly, in a recent “Health Tips From the Professor” I shared a study, Alzheimers Hope, showing that a holistic program involving exercise, a healthy diet, socialization and memory training significantly reduced cognitive decline in the elderly. Once again, it has been very difficult to reproducibly show that any of those interventions individually prevent cognitive decline.

That is what makes the current study so exciting. It is a single study, and it is a relatively small study. It definitely needs to be repeated. However, it has the potential to be a paradigm-shifting study.

Previous studies looking at the effect of B vitamins and omega-3s on brain shrinkage and/or cognitive decline have been inconsistent. Many have shown a benefit, but some have not. But, until now, none of the studies have looked at B vitamins and omega-3s together. If this study is correct, all future studies should examine the effect of both B vitamins and omega-3s together. The paradigm will have been forever changed.

Does It Matter?

The important question is whether this is just an academic discussion or does it really matter? If most older adults were getting adequate amounts of omega-3s and B vitamins in their diet, this would merely be an academic discussion. Unfortunately, that is not the case.

omega-3s help prevent cognitive declineOur oceans and rivers are becoming more and more polluted, and many people are avoiding fish because of concerns about heavy metal or PCB contamination. There is also an increasing emphasis on eating “sustainable” fish. That usually means the fish are farm raised, and farm raised fish are the most likely to be contaminated with PCBs, which is unfortunate. For example, I recently went to a nice restaurant that had a delicious sounding salmon dish on their menu. They could guarantee that the salmon was sustainably raised, but they couldn’t guarantee it was PCB-free. I chose not to eat the salmon.

It is no wonder that many adults aren’t getting enough omega-3s in their diet. In a recent “Health Tips From the Professor,” Do women get enough omeg-3 during pregnancy I reported a study showing that a shocking 75% of pregnant and lactating Canadian women were not getting enough omega-3s in their diet! Other studies suggest those of us in the United States don’t do much better.

We don’t do much better with respect to B vitamins either. For example:

  • The most frequent cause of B12 deficiency is the age related loss of the ability to absorb vitamin B12 in the upper intestine. This affects 10-30% of people over the age of 50.
  • Chronic use of acid-suppressing medications such as Prilosec, Nexium, Tagamet, Pepcid and Zantac also decreases B12 absorption and increases the risk of B12 deficiency. Millions of Americans use those drugs on a daily basis.
  • Overall, B12 deficiency has been estimated to affect about 40% of people over 60 years of age.
  • Deficiency of the enzyme methylenetetrahydrofolate reductase (MTHFR) substantially increases the requirement for folic acid. About 10% of the US population has this enzyme deficiency.
  • About 25% of Americans have low blood levels of B6

Clearly, this is not just an academic argument. Millions of older Americans are deficient in B vitamins or omega-3s or both.

 

The Bottom Line

  • A recently published study looked at the effect of high dose B vitamin supplementation on brain shrinkage over a two year periods in adults over 70 (average age 77) with mild cognitive impairment at the beginning of the study. This study differed from all previous studies in that it also measured omega-3 fatty acid levels in the blood at the beginning of the study to assess omega-3 status.
  • B vitamin treatment reduced brain shrinkage by up to 70% over the two year period compared to placebo.
  • The B vitamin treatment was only effective when the subjects were deficient in B vitamins at the beginning of the study, as indicated by elevated homocysteine levels.
  • The B vitamin treatment was also only effective in subjects with high omega-3 status at the beginning of the study. If they had low omega-3 status, the B vitamin supplementation was ineffective.
  • This study has the potential to forever shift the paradigm for preventing cognitive decline in the elderly. Past studies have looked at the effect of B vitamins and omega-3s at reducing cognitive decline separately, and these studies have been inconsistent. If this study is correct, consistent benefits will only be seen when both B vitamins and omega-3 fatty acids are present at adequate levels.
  • This is a concern because millions of older Americans are deficient in B vitamins or omega-3s or both.
  • How to prevent memory loss? Of course, B vitamins and omega-3s are just part of a holistic approach for preventing cognitive decline. Weight control, exercise, a healthy diet, adequate sleep, socialization, and memory training (mental exercise) are also important if we want to retail our full mental capacity into our 90s and beyond.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (2)

  • karen klemm

    |

    why can i not make a copy of this e-mail please tell me

    Reply

    • Dr. Steve Chaney

      |

      Dear Karen,

      I am not tech savy enough to answer that question, but all of the emails that subscribers like you receive are archived at https://healthtipsfromtheprofessor.com. Just type a key word from the article title into the search box to pull up the article. From there you can either copy the article or the URL for the article depending on what you want to do with the article. I only ask that you not modify the article in any way before you pass it along.

      Dr. Chaney

      Reply

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Latest Article

A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

For more details read the article above.

 

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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