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Should I Get a Flu Shot?

October 21, 2014 by Dr. Steve Chaney

The Truth About About Flu Shots That Nobody Else Is Telling You

Author: Dr. Stephen Chaney

It is flu season again, and the annual debate about whether everyone should get a flu shot is heating up. On the one hand we are told that the flu shot saves thousands of lives and everyone should be vaccinated. On the other hand we are being told that the flu shot is deadly and we should avoid it. As usual, the truth is somewhere in between.

When you examine the scientific literature it is clear that:

The risks of the flu shot have been greatly exaggerated.
The benefits of the flu shot have been greatly exaggerated.
The medical profession has not leveled with us about the real reason they recommend that everyone get a flu shot.

Flu Shot Side Effects

The greatest fear of vaccination and therefor flu shot side effects for children has been the claim that the flu vaccine causes autism. It is easy to understand how the hypothesis arose that vaccinations and autism might be linked, because the first symptoms of autism usually appear around the time that children are completing their initial series of vaccinations.

However, clinical research has not substantiated that any causal relationship between vaccinations and autism. It isn’t that scientist haven’t looked. A number of clinical studies have looked for a link between vaccinations and autism and have failed to find any. The age of onset and prevalence of autism are virtually identical in vaccinated and unvaccinated children.

However, most vaccines still contain mercury, and mercury is a neurotoxin. So if you are getting your child vaccinated, I recommend that you insist on getting a mercury free vaccine. You may want to inquire about the preservatives and additives in the flu vaccine as well, because some of them are also toxic.

Beyond that the biggest concerns are severe allergic reactions and an autoimmune response called Guillian-Barré syndrome which causes symptoms ranging from muscle weakness and fatigue to partial paralysis. These side effects are real and they are serious, but they are also quite rare. They affect somewhere between 1 in a million to 1 in 100,000 children, depending on the vaccine.

In short, flu shot side effects risks are real, but they have been greatly exaggerated by some in the media.

Let’s Talk Science

It turns out that the benefits of the flu shot have been greatly exaggerated by health professionals and the media as well. However, to properly understand why the messages you hear are a bit misleading you need to understand some scientific jargon, namely the difference between relative risk and absolute risk.

Relative risk describes the effect of an intervention for people with a certain condition. In this case, relative risk would be the effect of the flu shot (intervention) for people who have been infected with the flu virus (condition). Relative risk is often used in media reports because it magnifies the effect of the intervention. In short, it makes the intervention look really good.

Absolute risk describes the effect of an intervention on the probability that you will develop a certain condition. In this case absolute risk would be the effect of the flu shot on you actually getting the flu. Since this takes into account your probability of being infected by the flu virus as well as the relative risk reduction once you have become infected, it is a much smaller number. Absolute risk is a much better measure of the actual benefit you can expect to receive.

Is The Flu Shot Effective?

There is always year to year variation in the severity of the flu and the effectiveness of flu vaccines. In addition, many other viruses that cause flu-like symptoms and are completely unaffected by the flu vaccine.

For example, both enterovirus D68 and the Ebola virus are in the headlines – enterovirus D68 because it has hospitalized so many kids this fall and Ebola virus because it is so deadly. Unfortunately, the flu vaccine has no efficacy against either of those viruses.

In addition, there is also significant variation in both the efficacy and evidence for efficacy in different population groups that is generally not acknowledged during the annual campaigns recommending that everyone should get a flu shot. To better understand that we need to look at the efficacy of the flu shot in each population group individually.

Is The Flu Shot Effective in Children Age 6 Months To 2 Years?

In 2010, the US Advisory Committee on Immunization Practices began recommending flu vaccination for all healthy children older than 6 months. However, in 2012 the Cochrane Collaboration conducted a systematic review of all published clinical studies and concluded that for children in that age group currently licensed flu vaccines “are not significantly more effective than placebo”. [To fully understand the significance of that statement you need to know that the Cochrane Collaboration is an independent, non-profit organization that promotes evidence-based medicine. In fact, in the medical community Cochrane Collaboration systematic reviews are considered to be the gold standard for evidence based medicine.]

Summary: This is one of the groups at greatest risk for developing severe complications to the flu, so it is disappointing that the flu vaccine is not more effective for this group. I will talk about the best way to protect this group below.

Is The Flu Shot Safe & Effective in Healthy Children Age 2 To 7 Years?

This is the age group for which immunization makes the greatest sense, and the nasal spray gives the best results for this group. According to the 2012 Cochrane Collaboration review the flu shot reduces the relative risk of the flu by 48% and the nasal spray with attenuated live virus reduces the relative risk by 83%.

Since around 16% of unvaccinated children catch the flu in an average year this translates to an absolute risk reduction of 3.6% for the flu shot and 17% for the nasal spray. That is a smaller number, but still significant. This, of course, varies from year to year dependent on how well the vaccine matches the strains of virus that are actually circulating through the population.

Summary: The science behind vaccination for this group has shifted significantly in the past few years. The evidence for the efficacy of the flu shot in this age group has increased while the evidence for harm has deceased. The fear of the flu shot causing autism has been largely disproven by recent clinical studies. That leaves severe allergic reactions and the Guillian-Barré syndrome as the major complications of the flu vaccination.

Proponents of the flu vaccinations have estimated that if all children in this age range were vaccinated, around 200 would develop severe complications to the flu shot, and if all children in this age range were unvaccinated 20,000 would develop severe complications from the flu. I have not been able to independently substantiate those statistics. We also need to keep in mind that in those rare years, such as during the 1976 swine flu epidemic, when approximately 1 in 100,000 vaccinated children developed Guillian-Barré syndrome the incidence of severe complications to the flu shot could have reached the 2-3,000 range if the vaccination program had not been terminated early.

I realize that this is an emotional issue for parents, and there is no perfect answer. However, at present the weight of evidence is slightly in favor of vaccination for this age group.

Is The Flu Shot Effective in Healthy Children Age 8 To 18 Years?

According to a recent meta-analysis of all available clinical studies (Oosterholm et al, The Lancet Infectious Diseases, 12: 36-44, 2012), we simply don’t know whether the flu vaccine will be effective in this age group because no reliable studies have been conducted.

Even worse than that, we may never know whether the flu shot offers any protection for this age group because of a Catch 22 situation in modern clinical research. Once a particular treatment becomes “the standard of care” it is considered unethical to withhold that treatment in a clinical trial. Since the CDC is now recommending the flu shot for everyone over age 2, it would be considered unethical to conduct a clinical trial in which half the population received flu shots and half did not.

Summary: I suspect that the flu shot may offer some protection in this age group, but there is no convincing clinical evidence to support that belief at present and for the foreseeable future.

Is The Flu Shot Effective in Healthy Adults Age 18 To 65 Years?

Here the answer is yes. According to a 2012 meta-analysis of 31 published clinical studies (Oosterholm et al, The Lancet Infectious Diseases) the flu shot gives an impressive 75% reduction in the relative risk of catching the flu. However, in an average year only 4% of this population will catch the flu if unvaccinated, so the absolute risk reduction is a modest 3%.

This is also the group that has the least to fear from the flu. Only about 1 in 100 people in this age range develop severe complications as a result of getting the flu, and these are usually the people with severe diseases and/or compromised immune systems. For most healthy adults in this age range, the flu is merely a one or two day inconvenience.

Summary: For healthy adults in this age range the flu vaccine offers only a modest decrease in the absolute risk of catching the flu, and this group has a relatively low risk of developing severe complications from the flu. If the self interest of this group were the only consideration, it is hard to understand the insistence of the medical community that everyone in this age range get a flu shot. It would appear to be a matter of personal choice.

Is The Flu Shot Effective in Seniors Age 65 And Older?

Flu shot proponents will tell you that flu shots cut the risk of death in this group by 50% based on a meta-analysis published in 2002 (Vu et al, Vaccine, 20: 1831-1836, 2002).

However, more recent research has come to the opposite conclusion. A recent meta-analysis (Oosterholm et al, The Lancet Infectious Diseases, 12: 36-44, 2012) concluded “Evidence for protection in adults aged 65 years or older is lacking”. The 2010 Cochrane Collaboration systematic review concluded “Due to the poor quality of available evidence, any conclusions regarding the affects of influenza vaccines for people aged 65 years or older cannot be drawn.”

The lack of protection of the flu virus in seniors is most likely due to the fact that, in many cases, their immune systems have weakened with age.

Summary: This is another group where you would most like to see protection by the flu shot, because this group is likely to suffer severe complications and death from the flu, so it is disappointing that the flu vaccine is not more effective for this group.

Who Has Most To Fear From The Flu?

When you hear that the flu shot significantly reduces the risk of severe complications and death from the flu, you should know that the risks are not spread evenly over the population. The very young are at risk because their immune systems haven’t fully developed. The very old are at risk because their immune systems have weakened with age and they may already be in precarious health because of other diseases. And, of course, anyone at any age who is in precarious health because of disease or who has a compromised immune system is at risk as well.

Why Do Health Professionals Recommend That Everyone Get A Flu Shot?

If you are a healthy adult in the 18-65 age range, your risk of severe complications and death is from the flu is very low. It is not zero, but it is low. So why are health professionals so insistent that you need to get a flu shot?

The reason is straight forward, but it is not the reason that they are giving you. It is a public health measure, pure and simple.

The very young, the very old, the sick and the infirm are the ones most likely to develop severe complications and die from a flu infection. However, the flu shot doesn’t offer them much protection because their immune systems are often compromised. The best way to protect those groups is to immunize everyone else. If the flu virus can’t gain a foothold in the rest of the population, those at greatest risk will never be exposed to the flu.

So the constant warnings that you need to get a flu shot is less about protecting you than it is about protecting those whom you might infect. Now you know the truth. If you decide to get a flu shot it will be for the right reason, not the reason you are being given by the medical profession.

In a similar vein, many health departments are warning about hospitalizations and deaths from enterovirus D68 infections and urging people to get flu shots. They are not telling people that the flu shot has no efficacy against enterovirus D68.

I understand the concept that the rare combination of the regular flu and enterovirus D68 infection in the same patient would be particularly deadly. But, I also believe in truth in advertising. The medical profession needs to level with people about why they are recommending flu shots, not use scare tactics that make promises the flu shot can’t deliver.

Should I Get A Flu Shot?

As you can see, your decision about whether or not the flu shot is the right thing for you is not an easy one. Both the benefits and risks of the flu shot have been greatly exaggerated in the media. I have tried not to be an advocate either for or against flu vaccinations. I have evaluated the scientific literature and tried to give you the unvarnished truth. It is now up to you to make an educated decision – one that is right for you.

My personal decision about the flu shot is influenced by my father’s example. He dutifully got his flu shot every year, and every year he came down with the flu shortly after getting the flu shot. I’ve seen the same phenomenon with several of my friends who work at area hospitals and are required to get an annual flu shot. I know that the experts claim you can’t get the flu from the flu shot. I don’t know about that. I only know what I have observed.

In addition, I do not have young children or elderly parents at home who might be compromised if I were to develop even a mild case of the flu. So I chose to follow the kind of lifestyle that keeps my immune system strong rather than relying on a flu shot to protect me from the flu. That immune-healthy lifestyle, of course, will be a topic for a future “Health Tips From the Professor”.

The Bottom Line:

Both the effectiveness and risks of the flu shot have been greatly exaggerated.
The flu shot has no proven effectiveness in children ages 6 months to 2 years, children aged 8-18 years and seniors 65 years and older.
In children, aged 2 to 7, nasal sprays with partially inactive flu virus give a 17% decrease in absolute risk of catching the flu. Side effects of the flu vaccine in this population group are severe allergic reactions and an autoimmune response called Guillian-Barré syndrome. Both severe complications from the flu virus and side effects of the flu vaccine are very rare, but complications from the flu virus are several fold more common than side effects from the vaccine.
Fears that the flu vaccine could trigger autism have not been validated by clinical studies. However, mercury is a neurotoxin so I recommend that you insist on mercury-free vaccines for your children. You may also wish to inquire about other preservatives and additives in the vaccine, because some of them are toxic.
In healthy adults, aged 18 to 65, flu shots give a 3% decrease in absolute risk of catching the flu. This is also the population group with the lowest risk of severe complications from the flu. For most adults in this age group the flu is nothing more than a one or two day inconvenience.
The groups most likely to develop severe complications and die from flu infections are the very young, the very old, and the sick. They are also the groups least likely to benefit from the flu shot because their immune systems are weak.
If you are a healthy adult in the 18 to 65 age group, the constant warnings that you need to get a flu shot is less about protecting you than it is about protecting those whom you might infect if you catch the flu. It is a public health measure to protect the very young, the very old, and the sick. Now you know the truth. If you decide to get a flu shot it will be for the right reason, not the reason you have been given by the health profession.
In addition, the flu shot has no efficacy against either enterovirus D68 or Ebola virus. Although both of these viruses are real concerns, neither is a justification for recommending that people get flu shots.
As for me, I am influenced by the example of my father who got the flu from the flu shot every year. I chose to follow the kind of lifestyle that keeps my immune system strong rather than relying on a flu shot to protect me from the flu. That, of course, will be a topic for a future “Health Tips From the Professor”.

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.

Best Diet For Weight Loss

September 23, 2014 by Dr. Steve Chaney

The Diet Wars Heat Up Again

Author: Dr. Stephen Chaney

What is the best diet for weight loss? One week the headlines say that low-carbohydrate diets are better. The next week it’s low-fat diets that are better. There is even the occasional headline proclaiming that it doesn’t matter which diet you follow as long as you control your calories. It is no wonder that you are confused.

It is unusual, however, to have conflicting headlines within the same week, but that is exactly what happened last week. Let me take you behind the headlines to the actual clinical studies and help you sort through the conflicting headlines.

Are Low-Carbohydrate Diets Best For Weight Loss?

The manuscript behind this headline was published September 2nd in the Annals of Internal Medicine (Bazzano et al, Annals of Internal Medicine, 161: 309-318, 2014). This study was designed to determine which was the best diet for weight loss, low carb diet or low fat diet. The study recruited 148 overweight participants (mean age, 46.8, 88% female, 51% black) and randomly assigned them to either a low-fat diet or low-carbohydrate diet.

The participants on the low-fat diet were instructed to consume <30% of their calories from fat, while the participants on the low-carbohydrate diet were told to limit carbohydrates to <40 g/day. Neither group was told to limit calories. They met with a dietitian 10 times during the 12-month study and received information on dietary fiber (target = 25 g/day) and healthy fats (target = <7% saturated fat and little or no trans fats).

At the end of 12 months the low-carbohydrate diet resulted in significantly greater…

Weight loss (7.7 pounds)…

Decrease in triglyceride levels…

Increase in HDL cholesterol…

Decrease in the ratio of total to HDL Cholesterol…

…than the low-fat diet. In short, the results suggested that the low-carbohydrate diet was not only better than the low-fat diet for weight loss, but that it was also more effective in reducing risk factors for cardiovascular disease.

Case closed, you might be tempted to say. The low carb diet is the best the diet for weight loss. But there have been lots of other studies that have come to the opposite conclusion. So we have to ask the question: “Is this study significantly better than all of the studies that have failed to find any difference between the low-fat and low-carbohydrate diets with respect to weight loss and cardiovascular risk?”

What Are The Strengths & Weaknesses Of the Study?

Strengths of the Study: This was a very well designed study. In particular:

Dietitians met with the participants at multiple times during the program to assure adherence to the diet, which was very good.

The study utilized multiple dietary recalls, both during the week and on weekends.

The study had a diverse population.

Weaknesses of the Study:

The study did not control calories. In fact, the caloric intake was ~160 calories/day greater for the low-fat group than the low-carbohydrate group for at least the first 6 months of the study. That alone would be enough to account for the 7.7 pounds difference in weight loss.The reason for the higher caloric intake of low-fat group is not known. It could be due to the lower palatability of the low-carbohydrate diet. Alternatively, it could be due to the lower satiety of the low-fat diet. It was low in both fat and protein, both of which contribute to satiety (the feeling of fullness after we eat).
The study did not specify the type of carbohydrates consumed. The dietitians instructed the participants on the type of fat they should be eating, but not the type of carbohydrate. That was a significant omission. Diets high in sugars and refined carbohydrates provide less satiety and adversely affect cardiovascular risk factors compared to diets where the carbohydrate comes primarily from fresh fruits, vegetables and legumes.
The study did not control protein intake. In fact, the low-fat group consumed significantly less protein than the low-carbohydrate group. As I pointed out in a previous “Health Tips From the Professor” High Protein Diets and Weight Loss , higher protein intakes are essential for maintaining muscle mass during weight loss. That is important because loss of muscle mass can decrease metabolic rate (the rate at which we burn calories 24 hours a day – even at rest).

The amount of protein consumed by the low-carbohydrate group was close to the amount shown to maintain muscle mass during weight loss, while the amount of protein consumed by the low-fat group was close to the amount associated with loss of muscle mass during weight loss. That was reflected in the results. The low-fat group lost muscle mass while the low carbohydrate group actually gained muscle mass. The resulting difference in muscle probably meant that the low-carbohydrate group was burning more calories on a daily basis than the low-fat group.

In short, this is a good study, but it has important flaws. It is not a game changer.

Do Low-Carbohydrate & Low-Fat Diets Result In Identical Weight Loss?

The study behind this headline was published in the September 3rd edition of the Journal of the American Medical Association (Johnson et al, JAMA, 312: 923-933, 2014). This study was a meta-analysis that combined the results of 48 studies with 7286 participants. When the authors combined the data from all of the published studies there was no difference in weight loss for the low-fat and low-carbohydrate diets over a one or two year period.

The strength of the study is that it combines the results of multiple studies. That increases the statistical power of the observations and smoothes over the effect of outlier studies, such as the one described above. This is the study I would trust.

What Do The Experts Say?

Dr. Walter Willett, Chair of the Department of Nutrition at the Harvard School of Public Health was quoted as saying: “…some people [would] do well on either diet. The key issue for each person is finding a way of eating that is healthy and can be maintained for the long term.”

Dr. Bradley Johnson (the author of the meta-analysis) was quoted as saying: “The take home message is that people should choose a diet they can adhere to…”

The Bottom Line

1) Ignore the recent headlines suggesting that low-carbohydrate diets may be more effective than low-fat diets for weight loss. When you control for calories and protein intake there is no difference between the two diets with respect to long term weight loss.

2) You can also ignore the headlines telling you that low-carbohydrate diets are better for cardiovascular health. You don’t need to avoid carbohydrates to have a healthy heart. You just need to make healthy carbohydrate choices – fruits, vegetables, legumes and whole grains instead of refined flour products and sugary junk food.

3) Experts will tell you that the best diet is a healthy diet that you can stick with long term.

4) My personal recommendations are to avoid extremes (either low-fat or low-carbohydrate). Instead:

Aim for moderate amounts of healthy fats and healthy carbohydrates.

Don’t ignore protein. Make sure you get enough protein to maintain your muscle mass.

Control calories by reducing portion sizes and choosing healthy snacks.

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.

Is Alkaline Water Better For You?

September 16, 2014 by Dr. Steve Chaney

Facts About Water

Author: Dr. Stephen Chaney

Is alkaline water better for you? It’s bad enough that some people are paying a premium price for bottled water that isn’t required to be any better than tap water, but the latest fads appear to be things like “alkaline” water and “ionized” water. And these “super” waters come with a really hefty price tag.

If you believed the hype behind these products, you would think that they are revolutionary advances that will cure all sorts of ills. But the truth is these enticing claims are completely bogus. They contradict the basic laws of chemistry and biochemistry.

More importantly, there are no good quality clinical studies showing that they work!

What Is Alkaline Water?

Let’s start with alkaline water – but first a bit of background information.

Pure water has a pH of around 7, which is neutral. However, if the water is exposed to air for any length of time it picks up CO2 from the atmosphere. The CO2 dissolves in the water and is converted to carbonic acid making most sources of pure water slightly acidic.

On the other hand, if metal salts are dissolved in the water it generally becomes slightly alkaline.

Is Alkaline Water Better For You?

Here are some questions you might ask when deciphering if alkaline water is better for you than plain water:

1) What Are the Benefits of Drinking Alkaline Water?

In the 1930s Otto Warburg, one of the founders of modern biochemistry, showed that cancer cells were much more dependent on glucose (blood sugar) as an energy source than were most other cells in the body and that cancer cells metabolized glucose in a way that made the cancer cells very acidic.

That information languished for many years, but interest in the “Warburg Hypothesis” has been revived in recent years by studies showing that cancer cells can be selectively killed by limiting their source of glucose.

So, what are the benefits of drinking alkaline water? In theory, making the body more alkaline would also slow the growth of the cancer cells. There is some evidence to support that hypothesis, but the evidence is still relatively weak.

It is the same with the other proposed health benefits of alkalinizing the body. There is some evidence in the literature, but it is not yet convincing. As a scientist I’m keeping an open mind, but I’m not ready to “bet the farm” on it.

2) Can Alkaline Water Alkalinize the Body?

Here the answer is a clear cut NO! In fact, this hypothesis wins my “Flying Pig” award for the month!

The body has a very strong buffer system and some elaborate metabolic controls to maintain a near-constant neutral pH. More importantly, water is such a weak buffer that it has almost no effect on body pH!

Alkaline Foods

If you really want to alkalinize your body you can do that by eating more of the alkaline foods (most fruits, including citrus fruits, and most vegetables, peas, beans, lentils, seeds & nuts) and less of the acidic foods (grains, especially refined grains, meat, especially red meat, fish, poultry and eggs).

I’ve seen some experts recommend 60% alkaline foods and 40% acidic foods. I can’t vouch for the validity of that recommendation in terms of the benefits of alkalinizing the body, but there are lots of other good reasons to eat more fresh fruits and vegetables and less red meat and refined carbohydrates.

Is Ionized Water Beneficial?

Ionized water is an even sillier concept from a chemical point of view.

It is very difficult to ionize pure water and the ions that you do create quickly recombine to give you pure water again without any change in pH or physical properties.

If you add sodium chloride (table salt) to the water you can get electrolysis that creates a slightly alkaline pH at one electrode and a slightly acidic pH at the other electrode.

However, as soon as you turn off the current, these pH changes rapidly disappear. Even if you were somehow able to capture some of the alkaline or acidic water remember that water alone has almost no effect on body pH.

Never Underestimate The Placebo Effect

But, what about all of those glowing testimonials that you have heard?

You need to remember that the placebo effect is near 50% when it comes to pain or a feeling of well being.

You can’t repeal the laws of chemistry and biochemistry. Water is, after all, just water!

Good science trumps good testimonials any day. Never, never underestimate the placebo effect.

The Bottom Line

Don’t waste your money on alkaline water or ionized water. Water is a very poor buffer and has almost no effect on the pH of our bodies.

There may be some health benefits to keeping our bodies in a more alkaline state, but the best way to do that is to eat more alkaline foods and less acid foods (http://www.webmd.com/diet/alkaline-diets).

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.

Do Omega-3s Slow Cognitive Decline?

September 9, 2014 by Dr. Steve Chaney

Why Omega-3s Should Be Part Of Your Holistic Brain Health Program

Author: Dr. Stephen Chaney

Who wouldn’t want to avoid dementia and Alzheimer’s in our later years? There is a ton of advice on the internet about “magic” solutions to keep our brains sharp well into our 90s. Unfortunately, most of that advice is contradicted by other claims on the internet that those solutions don’t work. What should a person do if they want to keep their brain healthy?

Two weeks ago I talked about a study showing that a holistic approach, which to me includes healthy diet, weight control, exercise, supplementation, socialization and memory training, significantly reduces cognitive decline in the elderly (Is There Hope For Alzheimer’s?).

Last week I sorted out the conflicting advice about B vitamins and cognitive decline (Do B Vitamins Slow Cognitive Decline?). More importantly, I told you who would benefit from B vitamin supplementation and who would not.

In part three of this series I’m going to help you sort out the conflicting information on omega-3s and cognitive decline. Then I will sum up what a holistic brain health program might look like for you.

Why Might Omega-3s Slow Cognitive Decline?

There are lots of reasons to believe that omega-3 fatty acids are important for brain health and might, therefore, slow cognitive decline. For example:

Omega-3 fatty acids improve blood flow to the brain.

The omega-3 fatty acid DHA is an important part of the myelin sheath, the protective coating for every neuron in our body.

DHA is also converted to a neuroprotective agent that protects the brain from oxidative stress.

The Confusing Evidence About Omega-3s And Cognitive Decline

The data about omega-3s and cognitive function to date have been confusing. Most observational studies have reported better cognitive functioning and lower incidence of Alzheimer’s disease in populations that consume large amounts of fatty fish rich in omega-3s. There is also some evidence that omega-3 supplementation improves cognitive function for patients with mild cognitive impairment or very mild Alzheimer’s disease. However, most short-term, randomized, placebo-controlled studies have found no effect of omega-3 supplementation on cognitive functioning for patients who already have mild to moderate Alzheimer’s disease.

It had been assumed for years that by the time one already had Alzheimer’s it was too late for omega-3s to exert a protective effect. However, some recent studies have suggested a possible genetic explanation for the conflicting information on omega-3s and cognitive decline.

There is a genetic variant of the ApoE gene called ApoE4 that dramatically increases the risk of Alzheimer’s disease. Around 20-25% of the general population and 40-50% of Alzheimer’s patients have this genotype. Several recent studies have suggested that omega-3s may protect against cognitive decline only in people who do not carry the ApoE4 genotype. The current study (Daiello et al, Alzheimer’s & Dementia, doi: 10.1016/j.jalz.2014.02.005) was designed to test this hypothesis.

Do Omega-3s Slow Cognitive Decline?

This was a very well designed study. The investigators enrolled 819 older adults (average age 75, range 55-90) in the study and followed them for 3 to 4 years. 229 of the participants had normal cognition at enrollment, 337 had mild cognitive impairment and 193 had Alzheimer’s disease. All participants were tested for ApoE genotype.

The study participants were tested at baseline and every 6 months with two tests of cognitive function – the Alzheimer’s Disease Assessment Scale (ADAS) and the Mini-Mental State Examination (MMSE). MRI tests were also done at baseline and every 6 months to assess brain volume.

The participants were asked about fish oil supplement use at each of those times. Only those who reported taking fish oil supplements at every examination were considered fish oil supplement users (117), and only those who never consumed fish oil supplements were considered non-users (682).

The results were pretty interesting:

Fish oil supplements significantly decreased cognitive decline and brain shrinkage in the ApoE4 negative population, but not in the ApoE4 positive population.

The beneficial effects of fish oil supplementation were only seen in the population with normal cognition at the time the study started. Those benefits were not significant in the populations with mild cognitive impairment or Alzheimer’s disease.

Unfortunately, the study was not large enough to perform a statistic analysis of the ApoE positive and negative subpopulations of the groups with mild cognitive impairment or Alzheimer’s disease, so it was not possible to tell whether omega-3s might have been beneficial in people with mild cognitive impairment or Alzheimer’s disease who are ApoE4 negative.

The authors concluded that their results “highlight the need for future research on the effects of long-term fish oil supplement use on cognitive aging and dementia prevention in middle-aged and older adults”.

They also highlighted a major reason why so many previous studies have failed to find a link between omega-3s and cognitive decline when they said “Studies on cognitive aging that don’t screen subjects for ApoE4 are doomed to failure”.

Putting It All Together: Holistic Approaches For Preserving Brain Health

When I began this series three weeks ago with Is There Hope For Alzheimer’s? , I talked about the importance of holistic approaches. I referred back to a cancer expert who said that he could prove that a holistic lifestyle approach significantly reduced the risk of colon cancer, but he couldn’t prove that any individual lifestyle change had any effect on colon cancer risk.

The situation is very similar when we talk about preserving cognitive function. Over the past three weeks I have identified many things that can reduce the risk of cognitive decline – healthy diets, exercise, socialization, mental exercise, maintaining a healthy weight, B vitamins and omega-3 fatty acids. If we follow a holistic lifestyle that combines all of these things, we are likely to dramatically increase our probability of maintaining a healthy brain well into our golden years.

However, holistic lifestyle changes are difficult. I know some of you will want to take a simpler approach. You are going to ask:

1) Are there some individual lifestyle changes that are certain to slow cognitive decline on their own?

The answer is probably not. Maintaining a healthy weight comes close. However, some evidence suggests that it is not obesity itself that increases the risk of dementia. It is the insulin resistance and elevated blood sugar associated with obesity – and not everyone with obesity has insulin resistance and elevated blood sugar levels. So for some people obesity may not increase their risk of dementia. For those people weight loss might not reduce their risk of dementia.

2) Are there some lifestyle changes I don’t need to make if my diet is OK?

The study I described in last week’s Health Tips From the Professor found that B vitamin supplementation only reduced the risk of cognitive decline for people who were B vitamin deficient.

So one might assume that you could get a simple test for B vitamin deficiency and determine whether B vitamin supplementation would be beneficial or not. But which test should you get? Who is at risk? Is it the 5-10% of the population with elevated homocysteine levels, the 10% of the population with a deficiency of methylenetetrahydrofolate reductase (MTHFR), the 25% of the population with low blood levels of B6 or the 40% of the population over 60 with B12 deficiency? We simply don’t know.

3) Is it even worth bothering making lifestyle changes if I’m genetically predisposed to developing Alzheimer’s?

This week’s study found that omega-3s reduced the risk of cognitive decline only in people who did not have the ApoE4 genotype. Does that mean that you should rush out and test yourself for ApoE4?

Here the answer is a clear no. In the first place, we have no idea how the ApoE4 genotype affects the other lifestyle changes that slow cognitive decline.

In addition, there is another, very important reason why most experts, including the professor, decline being tested for ApoE4. The ApoE4 genotype dramatically increases your risk of developing Alzheimer’s disease, and there is no proven treatment for reducing that risk if you are ApoE4 positive. Who wants to know that they are at increased risk of developing Alzheimer’s if there is nothing they can do about it?

The Bottom Line

1) This study suggests that supplementation with omega-3s (fish oil) significantly reduces cognitive decline and brain shrinkage in older adults (average age 75).

2) The effect of fish oil supplementation on cognitive decline and brain shrinkage was only seen in people who lacked the ApoE4 genotype. Fish oil supplementation was ineffective in people who were ApoE4 positive.

3) The study showed that fish oil supplementation was effective at reducing cognitive decline and brain shrinkage in older adults with normal brain function who were ApoE4 negative, but the study was not large enough to determine whether it was also effective in older adults with cognitive decline or Alzheimer’s disease who were ApoE4 negative. Further research is needed to clarify this important point.

4) This was a relatively well designed study, but it was a small study. Larger, long-term studies are needed to confirm these results. More importantly, based on the results of this study, future studies will need to screen participants for ApoE4 status to assure that there is a large group of ApoE4 negative participants. This would provide enough statistical power to clearly determine whether fish oil supplementation can also benefit people who already have symptoms of cognitive decline or Alzheimer’s and are ApoE4 negative.

5) Even though ApoE4 status influences the effectiveness of fish oil supplementation on slowing cognitive decline, you probably don’t want to rush out and get yourself tested for ApoE4. We don’t know whether ApoE4 status influences other lifestyle changes that slow cognitive decline. More importantly, the ApoE4 genotype dramatically increases the risk of developing Alzheimer’s disease, and there is currently no proven treatment for reducing that risk if you are ApoE4. Who wants to know that they are at increased risk of developing Alzheimer’s if there is nothing you they do about it?

6) Finally, don’t rely solely on supplementation with B vitamins or omega-3s to reduce your risk of cognitive decline. Your chances of reducing cognitive decline are best with a holistic approach that includes healthy diet, exercise, socialization, mental exercises, maintaining a healthy weight, B vitamins and omega-3 fatty acids.

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.