Do Blood Pressure Medications Cause Memory Loss?

Written by Dr. Steve Chaney on . Posted in Uncategorized

Is The Cure Worse Than The Disease?

Author: Dr. Stephen Chaney

 

Do blood pressure medications cause memory lossHigh blood pressure has been called a silent killer. This is because it is possible to go for years with high blood pressure and not even know it. Even worse, the consequences of untreated high blood pressure can be catastrophic – stroke, heart attack, congestive heart failure, kidney failure – the list goes on and on.  But, what about when high blood pressure is treated?  Do blood pressure medications cause memory loss?

Because of that, the standard medical recommendation for years has been to:

  • Have your blood pressure tested frequently (at least once a year if your blood pressure is in the normal range and more frequently if it is elevated).
  • If your blood pressure is elevated, get on a blood pressure medication and try to keep your blood pressure as close to normal as possible.

But, is this always the best advice? Maybe not, particularly when we consider the confusing effects of blood pressure on cognitive function.

We have known for years that untreated high blood pressure in middle aged individuals significantly increases the probability that they will suffer cognitive decline in their later years (for example, R. F. Gottesman et al, JAMA Neurology, 71: 1218-1227, 2014).

Conversely, when we look at the elderly as a group we find that those with the lowest blood pressure actually have a higher risk of cognitive decline than those with the highest blood pressure (for example, B. Sabayan et al, Journal of the American Geriatric Society, 60: 2014-2019, 2012).

How can we reconcile such conflicting data on the correlation between blood pressure and cognitive decline in the elderly? Could it possibly be that it was the blood pressure drugs rather than blood pressure itself that was causing cognitive decline in the elderly?

Do Blood Pressure Medications Cause Memory Loss?

blood pressure medicationsA group of scientists in Italy set up a clinical study to determine whether blood pressure or use of blood pressure drugs better correlated with cognitive decline in elderly patients who already have some degree of cognitive impairment (E. Mossello et al, JAMA Internal Medicine, doi: 10.1001/jamainternmed.2014.8164).

They enrolled 172 patients from 2 outpatient memory clinics in the study. The average age of the participants was 79 and all of them had some degree of cognitive impairment (68% with dementia and 32% with mild cognitive impairment). 70% of the study participants were on blood pressure drugs. Their blood pressure was measured on a daily basis, and they were tested for cognitive function at the beginning of the study and 9 months later.

The results of the study concerning:

  • Those with the lowest blood pressure had the highest rate of cognitive decline over the 9 month period. These results were similar to several previous clinical trials with the elderly.
  • The association between low blood pressure and cognitive decline was only seen in those subjects on blood pressure medications. Low blood pressure did not increase the risk of cognitive decline in unmedicated subjects.

There are, of course, some significant limitations to this study:

  • It is a small study of short duration.
  • It is the first study of its kind. It needs to be repeated.
  • It was done in an elderly population who already suffered from cognitive decline. We don’t yet know to what extent these conclusions will apply to younger people and to people without cognitive impairment.

Is The Cure Worse Than The Disease?

However, this study does raise a huge red flag that needs to be evaluated very carefully. It raises the issue of whether aggressive drug treatment to bring blood pressure under control may, under some conditions, cause more problems than it cures. It is not unlike the study a few years ago showing that aggressive treatment to lower blood sugar levels in type 2 diabetics actually increased the death rate (C. J. Currie et al, The Lancet, 375: 481-489, 2010).

It turns out that increased risk of cognitive decline is just one of several risks associated with aggressive drug treatment to lower blood pressure. Because of that realization an expert panel recently recommended that the threshold for the use of blood pressure drugs be raised from 130/90 to 140/90 for adults under 60 and to 150/90 for adults over 60.

Do blood pressure medications cause memory loss?  It’s not that high blood pressure has suddenly become healthier. Rather, the experts realized that the risks of aggressive drug treatment to lower moderately elevated blood pressure outweighed the benefits. The cure was worse than the disease!

Is There Another Option?

dash dietThe answer is a resounding yes, and we have known about it for years. It is called the DASH (Dietary Approaches To Stop Hypertension) diet. It is recommended by the American Heart Association, the National Heart, Lung & Blood Institute, the USDA 2010 Dietary Guidelines for Americans and the US Guidelines for Treatment of High Blood Pressure). Coupled with a few simple lifestyle changes it has been shown to be as effective as drugs at reducing high blood pressure, without the side effects of the drugs.

You can find the details of the DASH diet here (http://dashdiet.org/), but in simple terms, it is low in fat, high in fresh fruits and vegetable, fiber and low fat dairy products. The recommended lifestyle changes are weight control, restricted sodium intake and exercise.

Although not all experts agree, I personally recommend that you also make sure that you are getting the DV for calcium, magnesium and vitamin D from food and supplements and consider supplementing with long chain omega-3 fatty acids and polyphenols – especially resveratrol and related polyphenols from grape skins and seeds.

 

The Bottom Line

  • High blood pressure is a silent killer because people often don’t know they have it. If left untreated it can cause stroke, heart attack, congestive heart failure and kidney failure.
  • However, a recent study suggested that aggressive drug treatment to treat high blood pressure in the elderly can increase the rate of cognitive decline.
  • Because of this and other risks associated with aggressive drug treatment for high blood pressure, especially in the elderly, an expert panel recently recommended that the threshold for the use of blood pressure drugs be raised from 130/90 to 140/90 for adults under 60 and to 150/90 for adults over 60.
  • It’s not that high blood pressure has suddenly become healthier. Rather, the experts realized that the risks of aggressive drug treatment to lower moderately elevated blood pressure outweighed the benefits. The cure was worse than the disease!
  • Fortunately, there is another option, namely the DASH diet. The DASH diet, along with a few simple lifestyle modifications, has been shown to be as effective as drugs at reducing high blood pressure without the side effects of high blood pressure medications. Both the American Heart Association and the National Heart, Lung and Blood Institute recommend that the DASH diet and lifestyle changes be tried first, before considering use of blood pressure medications.
  • Although not all experts agree, I personally recommend that you also make sure that you are getting the DV for calcium, magnesium and vitamin D from food and supplements and consider supplementing with long chain omega-3 fatty acids and polyphenols – especially resveratrol and related polyphenols from grape skins and seeds.
  • Finally, high blood pressure is dangerous. Don’t ignore it. Get your blood pressure tested regularly. If it is elevated, talk with your doctor about the best combination of diet, and lifestyle change and whether medications are absolutely necessary to keep your blood pressure under control.

 

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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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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