Research Update: Red Meat And Risk Of Stroke

Red meat consumption and risk of stroke in Swedish men.  American Journal of Clinical Nutrition 2011: 94:417-21.

Objective:  The objective of this study was to examine the association between red meat consumption and risk of stroke in 40,291 Swedish men over a 10 year follow-up period.

Methods: All men filled out a 96 item food frequency questionnaire that assessed usual diet.  This enabled the researchers to compute total red meat, fresh red meat, and processed red meat consumption for the analysis.  Fresh red meat was considered minced pork, beef, or veal.  Processed red meat was considered sausage, hot dogs, salami, ham, and processed cold cuts.  Total red meat was the sum of fresh red meat and processed red meat.

Results: After 10 years of follow up, there were 2,409 new cases of stroke among these men.  Men who consumed more than 2 ounces of processed red meat per day had a 23% increased risk of stroke when compared to men consuming less than ¾ ounce of processed red meat per day. Fresh red meat was not associated with risk of stroke.  Total red meat was associated with a borderline significant 15% increased risk of stroke when comparing men who consumed the most red meat (greater than 5 ounces per day) to men who consumed the least (less than 2 ounces per day).

Discussion: A number of studies have recently shown that fresh red meat is not as strongly associated with risk of cardiovascular disease as once thought.  Processed red meat, on the other hand, is strongly associated with risk of heart disease and stroke.  It is believed that the high levels of nitrates and sodium in the processed red meat are the mechanism behind the increased risk. 

Take Home Message:  It seems like the problem with red meat largely lies in the processing.  I tell my clients to limit portions of red meat to once per week.  Choosing lean and fresh sources of red meat like filet mignon and lean hamburger is a good idea.   Strictly limit the processed red meats like bacon, sausage, hot dogs and fatty deli meats.  Keep in mind that red meat has also been associated with colon cancer incidence so don’t go overboard with the red meat consumption.

Top 5 Strategies To Reduce Your Sodium Consumption

           The impact of sodium on health has been a very hot topic in the nutritional literature of late.  Public health efforts to reduce sodium in our foods are becoming more and more focused.  In years past, sodium restriction was only recommended for those with hypertension.  It is now becoming clear that we all should be limiting our sodium intake.  High sodium diets have been associated with hypertension, stroke, heart disease, osteoporosis and even gastric cancer.  A good goal is 1500 mg of sodium per day.  The typical American gets 3400 mg.  We’ve clearly got some work to do.  Here are the top 5 strategies to reduce your sodium consumption.

1) Limit Processed Food 

The vast majority of the sodium that we consume comes from processed, pre-packaged food.  If you eat most of your food in its natural form, you’ll be reducing your sodium dramatically.  Focus on fresh fruits and vegetables, lean protein sources, vegetable fats like oils and nuts, legumes and whole grains for the majority of your calories and you will significantly reduce your sodium levels.

2) Eat Out Less

            One thing that I always stress to my clients is that when they are deciding on what to eat, the main goal is to pick foods that are healthy for them.  When you eat out at a restaurant, the main goal of the chef is to make the food taste as good as possible, so you’ll want to come back for another visit.  This means you are getting much higher levels of flavor enhancing sugar, salt and fat when you eat out.  Eat as many meals in your home as possible and your salt consumption will plummet.

3) Choose Low Sodium Versions Of Foods When You Can

            Low sodium versions of many foods are available and you can find more and more of them in grocery stores every day.  Admittedly, it does take a little while to get used to the lower sodium level, but after a short period of time you don’t even really notice the difference.  Look for low sodium black beans, soups, turkey breast, turkey bacon, nuts, nut butters, etc.  You can reduce your sodium levels drastically by just making a few changes when low sodium options present themselves.

4) Don’t Add Any Salt To Your Food At The Table

            Even better, don’t even have a salt shaker on your table.

5) Limit Fast Food

            Fast food restaurants are a major source of sodium in the American diet.  Limit fast food to an occasional treat and you’ll reduce your sodium intake dramatically.

Feature Article: Multivitamins: Healthy Or Deadly?

A controversial study by Mursu, et al was published recently in the Archives of Internal Medicine showing that women who took a multivitamin each day had an increased risk of mortality when compared to women who did not.  The results of this investigation ignited a media firestorm, to say the least.  Since then, I have been getting a ton of questions from my clients on whether or not it is safe to take a multivitamin.  I thought I’d use this blog post to examine the study and give a general, research based recommendation regarding multivitamin use.

The Study
The study in question took a look at risk of multivitamin use and mortality in 38,772 women from the Iowa Women’s Health Study (1).  Women were asked via questionnaire if they were using any supplements and if they were to describe what they were taking and how often.  This question was asked 3 different times over a mean follow-up of 19 years.  This was done to reflect changes in supplement use over the years.  Women taking a multivitamin had a 6% increased risk of mortality when compared to women who did not take a multivitamin.  Here are some of the other interesting findings of this investigation:

B6 supplements were associated with a 10% increased risk of death.
Folic acid supplements were associated with a 15% increased risk of death.
Iron supplements were associated with a 10% increased risk of death.
Magnesium supplements were associated with an 8% increased risk of death.
Zinc supplements were associated with an 8% increased risk of death.
Copper supplements were associated with a 45% increased risk of death.

Calcium supplements were associated with an 8% decreased risk of death.

Was this study methodologically sound?
Overall, this study had a sound methodology.  There was a very large sample size, updated measures of supplement use to reflect changes over time, an adequate follow-up and good control of potential confounders.   However, this study had one major flaw: the researchers didn’t exclude sick women.  This is a major problem because someone who gets diagnosed with a serious medical condition is much more likely to initiate multivitamin use.  God forbid you were diagnosed with cancer today; wouldn’t you want to load up on vitamins and supplements to help treat your disease? 

This oversight is problematic because many of those who are diagnosed with these serious diseases will die from them.  This makes it look like people who are supplementing are dying at a higher rate when in fact, they were sicker from the start.  You can eliminate this problem by excluding people who sick at the beginning of your study.

Previous Research

There are a number of well designed studies in recent years that have shown a benefit with multivitamin supplementation.  These studies show that multivitamins help reduce the risk of coronary heart disease, colon cancer and breast cancer.  Vitamin D supplementation is showing a lot of promise and folate supplementation has done much to reduce the incidence of neural tube defect in pregnant women.  We can’t forget these positive outcomes when assessing the benefits and risks of multivitamin supplementation.

So What’s The Bottom Line?

There has been a good amount of research that shows a benefit to multivitamin supplementation and just a few studies that show potential harm.  Considering that there were methodological flaws in some of the research that showed harm, I feel that the benefits of multivitamin supplementation outweigh the risks for most people.  However, to hedge your bets, I recommend taking a good multivitamin (which includes vitamin D) every other day.  This way you are minimizing the risk while retaining the benefit. This is what I do myself and what I recommend to my clients.  Always keep in mind that any kind of supplement will never replace a healthy diet.

References

1) Mursu J, Robien K, Harnack LJ, et at. Dietary supplements and mortality rate in older women.  Archives of Internal Medicine 2011; 171(18):1625-1633.

Research Update: Sugar Consumption And Heart Disease

Low to moderate sugar-sweetened beverage consumption impairs glucose and lipid metabolism and promotes inflammation in healthy young men: A randomized controlled trial. The American Journal of Clinical Nutrition 2011; 94:479-85.

Objective: To examine the association between low to moderate sugar consumption and risk factors for coronary heart disease in 29 healthy young men.

Methods:  This investigation was a crossover trial.  What this means is that the 29 men in this study were put through 6 separate 3 week interventions.  During each 3 week intervention, a 600 ml soft drink beverage was consumed daily with varying sugar content.  Here are the soft drink interventions:

Intervention 1- 40 grams of fructose per day (moderate fructose)

Intervention 2- 80 grams of fructose per day (high fructose)

Intervention 3- 40 grams of glucose per day (moderate glucose)

Intervention 4- 80 grams of glucose per day (high glucose)

Intervention 5- 80 grams of sucrose per day (high sucrose)

Intervention 6- dietary advice to strictly limit fructose.

After each intervention a variety of blood tests were taken, including LDL particle size, LDL subclass, fasting glucose and high sensitivity C-reactive protein.

Results: The results of this investigation were fascinating:

1) LDL particle size was significantly reduced after both the high fructose and high sucrose intervention.  The smaller the LDL particle, the more likely it is to promote atherosclerosis, which in turn increases the risk of heart disease.

2) A more atherogenic LDL subclass distribution was seen with all of the fructose interventions.  This means that the LDL particles became more likely to promote heart disease.

3) Fasting glucose and high sensitivity C-reactive protein increased significantly after all interventions.  C-reactive protein is a measure of body wide inflammation and has been associated with a variety of diseases, including heart disease.

Discussion:  This is an amazing paper that shows that even a moderate consumption of sugar has the potential to increase risk of heart disease.  LDL particle size, subclass distribution, fasting glucose and high sensitivity C-reactive protein all changed for the worse when consuming even moderate amounts of sugar consistently for only 3 weeks.  These are powerful markers for risk of heart disease.

Take Home Message: Drinking sugar sweetened beverages like soda is not a good idea.  It has been known for years that they provide nothing but empty calories and promote weight gain.  Now the research is beginning to mount that they can cause disease as well.  Sugar sweetened beverages are the largest contributor of sugar in the American diet.  Giving them up entirely is a good first step to improving your health.

If you work with me privately or have read my book, you know how I feel about sugar.  After trans fat, I believe it is the most harmful thing one can eat.  It is a difficult concept to accept, but at the end of the day, humans were never designed to eat sugar.  Cutting down on it, or better yet, eliminating sugar entirely, will cause far reaching and dramatic positive changes in your life that I guarantee will surprise you.

Questions And Answers: Trans Fat

What are trans fats?

Trans fats are man made fats.  They are produced through the commercial hydrogenation of unsaturated oils.  Hydrogen is bubbled through the oil at high pressure in the presence of a nickel catalyst to change the structure of the chemical bonds in the oil from cis to trans.

Why do food manufacturers do this?

Hydrogenation removes essential fatty acids such as linoleic acid and alpha linolenic acid.

These fatty acids tend to oxidize over time, which can turn the fat rancid.  Therefore, a big reason why oils are hydrogenated is to increase the shelf life of the food product.  Hydrogenation also increases the melting point of oil so that the product is solid at 25° Celsius.  This acts to improve the texture and consistency of many commercially prepared foods.  Finally, using this type of oil is cheaper for the manufacturer. 

Where are trans fats found?

Trans fats are generally found in fried foods, margarines and commercially prepared baked goods like cookies, candies and cakes.   Thankfully, recent legislation has banned the use of trans fat in restaurants in many states.  It is getting harder and harder to find them, even in food products that used to contain them a few years ago.  However, they are still used and you need to become aware of which manufacturers continue to use them in their products.

What are the health effects of trans fats?

Trans fats have been shown in the research literature to have a number of negative health effects.  They raise LDL cholesterol and lower HDL cholesterol levels, which can have a devastating impact on risk of heart disease.  Trans fats have also been associated with an increased risk of type 2 diabetes and possibly some cancers.

How do you know if a food contains trans fats?

Labeling laws now require the listing of trans fats on all food products.  This is great, not only because you can readily identify trans fat content, but because many manufacturers are now eliminating trans fat from their products so that they will not be perceived as unhealthy.  However, if a food contains less than 0.5 grams of trans fat in a serving, the manufacturer is legally allowed to list trans fats as zero grams.  This is problematic because even tiny amounts of trans fat are really harmful.  So, after checking the food label under trans fat for zero grams, you’ll also need to check the ingredient list as well.  If you see “partially hydrogenated” before any oil (IE, partially hydrogenated soybean oil) the product contains trans fat.

What are you recommendations for trans fat?

Avoid it 100%.  Treat it as if it will make you sick and shorten your life, because that is exactly what it has the potential to do.  If I was asked what is the bottom line worst thing that you can eat for your health, I would not hesitate to identify trans fat.

Book Review: Eat To Live

Eat To Live is next up for review.  The author, Dr. Joel Fuhrman, is a Medical Doctor who is board certified as a family physician and has also published some nutrition research. 

Introduction

            The Eat To Live program is based on several premises:

            1) The concept of nutrient density, which in simplest terms, is a foods ratio of nutrients to calories.  If a food delivers a lot of nutrients per serving, it is considered high nutrient density.  If it delivers a small amount of nutrients in a serving, it is low nutrient density.  The focus of Eat To Live is to eat only high nutrient density foods.

            2) All animal products will make you sick.

            3) All sources of dietary fat will make you sick and overweight.

            The book spends a lot of time discussing how nutrition impacts health and disease risk.  The food guidelines are then presented with a couple of 7 day meal plans and a large number of recipes.  The book is well written and an easy read. 

5 Things I Liked About Eat To Live

1) The concept of nutrient density- Eating nutrient dense foods means more fruits and vegetables and less processed junk food.  I’m all for that.

2) Strongly against sugar and refined carbohydrates- I couldn’t agree more.

3) Strongly in favor of fruits and vegetables- Fruits and vegetables are probably the best things you can eat to improve your health and the more the merrier.

4) Against dairy- I’m not convinced that dairy is a natural food for humans.  Those of you who work with me or read my book know this.  I don’t think there is a need for total elimination, but I feel that dairy intake should be now and again rather than a dietary staple.

5) Against snacking- I’ve been telling my clients not to snack for years.  If you are eating a blood sugar stabilizing diet, you should not be hungry in between meals.  Also, keep in mind that if you eat 70 more calories a day than your body needs, you’ll put on 8 pounds in a year and 23 pounds in 3 years.  Snack calories can add up like crazy over time.

What I didn’t agree with in Eat To Live

1) Very little attention was paid to exercise- I am more than convinced that for long term weight loss, cardiovascular exercise and resistance training are pivotal.   The research bears this out, as does my 15 years of working with weight loss clients.  Exercise was barely mentioned in this book and almost seemed to be an optional part of the program.

2) Unrealistic weight loss goals- Several testimonials were presented throughout the book that showed dramatic weight loss.  Some of these cases lost up to 19 pounds in 2 weeks.  Dr. Fuhrman says you should expect to lose 14 pounds in the first 14 days.  I think this is an unrealistic goal.  A pound of fat is 3500 calories.  To lose even 1 pound a week you have to create a caloric/exercise deficit of 500 calories per day.  This is not easy.  If you are losing a pound a week you are doing great.  Going into a program expecting to lose a pound a day will only set you up for failure and disappointment.  Realistic expectations can be the difference between staying with your program and giving up because “it’s not working”.

3) Incomplete evaluation of the current research- Many parts of this book are really well researched.  When describing the dangers of refined carbohydrates, saturated fats, Tran’s fats, etc, excellent research is presented.  The Nurses’ Health Study and the Health Professional Follow-up Study are mentioned several times in these sections.  These are Harvard cohorts and although I’m biased, I believe they represent the very best in epidemiological study design.

However, when Dr Fuhrman starts to mention that all animal protein promotes disease (even lean sources like chicken and fish) and all fat makes you fat (including healthy vegetable oils like olive oil and canola oil), he leaves out results from these cohorts that prove otherwise.  Research in the Nurses’ Health Study and Health Professional Study show that total fat is not associated with weight gain, that vegetable sources of fat reduce risk of disease and that lean sources of protein (including fish, chicken and turkey) are health promoting, particularly when they replace refined carbohydrate in the diet. 

4) Inclusion of many high glycemic load foods.   One of the goals of any healthy diet is to limit high glycemic load foods.  There is no mention of the concept of glycemic load in this book and the meal plans allows for daily consumption of white potatoes, fruit juice, dried fruit and you are even allowed 100 calories of cookies or candy each day if you want.  These high glyemic load carbs would be particularly damaging to the blood sugar since this diet is so low in fat and protein, which act to attenuate the glycemic response.

5) Overgeneralization of the macronutrients. Dr. Furman says that all fats and all animal protein are unhealthy and will lead to disease and overweight.  I beg to differ.  Some fats are bad for you and some are actually quite good for you.  Trans fat and saturated fat should be avoided while poly- and monounsaturated fat have been shown to reduce risk of chronic disease.  They also serve to lower the glyemic load of the diet when they replace refined carbohydrate foods and can improve health in this way as well. 

Fatty sources of animal protein like steak, sausage, hot dogs and bacon are indeed unhealthy choices and should be strictly limited.  However, fish, chicken, eggs and turkey are great choices that can actually reduce your risk of disease when they replace refined carbohydrate foods in the diet and thus act to lower the overall glycemic load of the diet.  Eating lean protein also promotes satiety, which is a big reason why my weight loss clients are not hungry between meals.

Is Eat To Live Worth Reading?

Absolutely.  If you are interested in nutrition as a profession or for your own personal health, read as many books as you can.   I think it is important to get as many different perspectives as possible.  In Eat To Live you will learn a lot of great things about the benefits of fruits, vegetables, whole grains and legumes.  You’ll also learn a lot about the dangers of refined carbohydrates, saturated fat and Trans fat. 

Will you lose weight?  I think you will, at least in the short term.  This is a really low calorie diet.  However, low fat diets are just too hard to stay on for any length of time and the research shows that most weight lost on low fat diets is regained after about a year.  Just keep in mind as you read this that a healthy diet also includes a bit more protein (even some lean animal protein like chicken, eggs, fish and turkey) and a lot more healthy fat (like olive oil, canola oil, nuts, avocado, etc).  Also keep in mind that if you truly want to lose weight and keep it off, exercise is a huge part of the equation.  We all collectively must learn to accept this basic truth.

Research Update: Green Tea And Serum Cholesterol

Green tea intake lowers fasting serum total and LDL cholesterol in adults: A meta-analysis of 14 randomized clinical trials.

The American Journal of Clinical Nutrition 2011; 94:601-10.

Objective: To examine the association between green tea consumption and serum cholesterol.

Methods:  This article is a meta-analysis.  The literature was extensively searched for all research on the affects of green tea on serum cholesterol.  The analysis included 14 studies and a summary estimate was calculated.  There were a total of 1,136 subjects from the 14 studies included in this meta-analysis.

Results: Green tea significantly lowered total cholesterol by 7.2 mg/dl and significantly lowered LDL cholesterol by 2.2 mg/dl.  There was no association between green tea consumption and HDL cholesterol.

Discussion:  This is a pretty impressive finding that could have a nice effect on your risk of coronary heart disease, the number one killer in the U.S.  It is hypothesized that every 1% drop in serum cholesterol lowers risk of coronary heart disease by 3%.  Green tea is produce from the leaves of the plant Camellia Sinensis.  Green tea leaves contain antioxidants, vitamins, minerals and polyphenols.   The researchers believed that substances in green tea lower serum cholesterol by inhibiting key enzymes involved in cholesterol synthesis and by reducing intestinal absorption of cholesterol.   About half of the 14 studies used green tea beverages as the intervention and the other half used green tea dietary supplements in pill form.  No major adverse health effects were reported in any of the studies.

Take Home Message: If you are trying to reduce your total and LDL cholesterol, green tea may be another simple yet effective strategy.  The studies included in this meta-analysis used a variety of doses and the authors didn’t have recommendations regarding the amounts necessary to produce the desired effect.  There were no major adverse health effects reported, so it looks like a cup or 2 a day of green tea may be a safe and effective way to lower cholesterol.