More reasons to maintain a healthy weight

Being overweight is not harmless – excess fat is the major factor responsible for insulin resistance and resultant type 2 diabetes, and a risk factor for a plethora of conditions including heart disease, stroke, hypertension, high cholesterol, liver disease, gallbladder disease, respiratory problems, arthritis, and infertility.1  Being overweight is thought to be responsible for over 100,000 new cancer cases each year in the U.S. alone, and both overweight and obesity are associated with a greater risk of death from all causes. 

Recent findings in the field of obesity research have given us two more reasons to keep one’s weight in check. 

  1. Excess weight may restrict blood flow to certain areas of the brain, impairing brain function and possibly fueling more overeating.
  2. Even just a few extra pounds on someone with a “normal” BMI may increase risk of death from heart disease.

1.  Brain function

brain

Obesity in mid-life is already known to increase the later risk of dementia, suggesting that excess weight has detrimental effects on the brain.2  The high blood pressure, arterial stiffness, and insulin resistance that come with excess weight could be the factors that harm the brain.

In this particular study, the researchers compared overweight and normal weight subjects (average BMI 28.43 and 21.79, respectively) using an imaging technique that measures blood flow in specific areas of the brain.  They focused on the prefrontal cortex, an area of the brain that governs focus, impulse control, and executive function (which includes decision-making, planning, and working toward goals).

In overweight subjects compared to normal subjects, they saw a decrease in blood flow to the brain overall, and also specifically to the prefrontal cortex.  Because of the unique functions of the prefrontal cortex in regulating impulse control, they concluded that excess weight has the potential for driving further overeating by reducing blood flow to this area.3

Conversely, another recent study has found that losing weight can improve memory.   Subjects underwent memory, concentration, and problem solving tests before and 12 weeks after bariatric surgery.  Memory performance had improved after 12 weeks.  Importantly, the baseline tests also revealed that the obese subjects and cognitive impairment. Of course, bariatric surgery is not a safe way to lose weight, but this study makes the point that the brain begins to work more effectively when excess fat begins to disappear.4

2.  Risk of death from coronary artery disease

heartObesity is a known risk factor for heart disease, but a new meta-analysis has reported that a little “excess belly fat” can increase the risk of death from coronary artery disease even for people whose body mass index (BMI) is in the normal range.   BMI is an imperfect indicator of the health risks associated with obesity, taking only height and weight, and not body fat percentage or fat distribution, into account. Many scientists believe that waist circumference and/or waist-to-hip ratio are better measures of overweight and obesity.  Certainly, these are better indicators of visceral fat, which is more metabolically active and thought to be more harmful. Nevertheless, both high BMI and large waist circumference are associated with increased risk of death.  

The meta-analysis included data on over 15,000 coronary artery disease patients, and found that those who had “central obesity” (which was evaluated based on waist circumference and waist-to-hip ratio) are at a greater risk of death.  This was true not only for obese patients, but normal weight patients as well.  In obese patients, central obesity increased risk by 93%, and in normal weight patients by 70%.5

In order to enjoy excellent health, in addition to eating high-nutrient foods, we must also strive to respond appropriately to the signals of true hunger so that we avoid overeating.  Too many calories, even from healthy natural foods, will translate into excess fat on the body and therefore health risks.

It should be noted that eating right gives you the ability to lose food addictions and be in better control of your cravings, but food is all around us and people can still overeat for recreation.  

 

References:

1. U.S. Centers for Disease Control and Prevention. Overweight and Obesity: Health Consequences. http://www.cdc.gov/obesity/causes/health.html 

2. Fitzpatrick AL, Kuller LH, Lopez OL, et al. Midlife and late-life obesity and the risk of dementia: cardiovascular health study. Arch Neurol. 2009 Mar;66(3):336-42.

3. Willeumier KC, Taylor DV, Amen DG. Elevated BMI Is associated With Decreased Blood Flow in the Prefrontal Cortex Using SPECT Imaging in Healthy Adults. Obesity (2011) 19, 1095–1097

4. Gunstad J, Strain G, Devlin MJ, et al. Improved memory function 12 weeks after bariatric surgery. Surg Obes Relat Dis. 2010 Oct 30. [Epub ahead of print]

5. Coutinho T, Goel K, Corrêa de Sá D, et al. Central obesity and survival in subjects with coronary artery disease a systematic review of the literature and collaborative analysis with individual subject data. J Am Coll Cardiol. 2011 May 10;57(19):1877-86.

 

Being just overweight, not obese, still shortens lifespan

It is becoming more widely known that obesity can lead to a premature death – but what about those who fall in between healthy weight and obese?  A new study suggests that even “a few extra pounds” can be dangerous.

This comes just a few months after a large study that concluded that waist circumference was associated with risk of death from all causes. These two studies used different methods of measurement, but they agree on a very important point – even a small amount of excess weight increases the risk of death. In the waist circumference study, even people who had a normal body mass index (BMI; calculated based on height and weight) were at greater risk of death if they had a 4-inch larger waist compared to others in their BMI category – that four extra inches of abdominal fat translated into a 16% (men) and 25% (women) increase in mortality risk over a nine year period.

Last week, another article was published in the New England Journal of Medicine in which the researchers analyzed risk of death from all causes according to BMI. The data they analyzed came from 19 different studies and included 1.46 million people across the U.S., Europe and Australia. The results were dramatic. The risk of death from all causes was elevated just above the ‘normal’ BMI category and continued to climb as BMI increased. Those who were overweight but not obese were still at risk.

Compared to individuals with BMI of 20-24.9, the increased risk of death was

  • 13% for those with BMI 25.0-29.9
  • 44% for those with BMI 30.0-34.9
  • 88% for those with BMI 35.0-39.9
  • 251% for those with BMI 40.0-49.9[1]

Of course, the risk is greater with more excess weight, but the key finding is that even with a moderate amount of excess weight, there is a significant increase in the risk of death.

Sixty-eight percent of Americans are overweight or obese, and about half of this group fall into the overweight but not obese category. These studies would therefore suggest that 68% of Americans are dying prematurely because of their excess weight. The prevalence of processed foods and junk food has gotten most Americans completely out of touch with hunger and satiety signals. Nutrient-dense eating, resulting in the recognition of true hunger, is an effective method for reaching and maintaining a healthy weight.

 

Reference:
1. Berrington de Gonzalez, A., et al., Body-mass index and mortality among 1.46 million white adults. N Engl J Med, 2010. 363(23): p. 2211-9.

 

Green and orange vegetable consumption - an indicator of longevity

No matter how many different dietary theories there are out there, pretty much everyone agrees that vegetables are “good for you”. But how good they truly are has been debated – there are plenty of observational studies linking vegetable consumption to favorable health outcomes, but other studies have made headlines by casting doubt on how powerful plant foods are for preventing disease. The data from these observational studies is often flawed simply because the majority of people in the Western world don’t eat enough vegetables to have a measurable impact on their risk of chronic disease – only about 25% of Americans eat the recommended three one-cup servings of vegetables each day.[1] Also, total vegetable consumption isn’t necessarily an accurate indicator of the healthfulness of one’s diet, since some vegetables are far more nutrient-dense than others. Of course, long-term controlled trials of consumption of a high-nutrient vegetable-based (nutritarian) diet have not yet been published (with the Nutritional Research Project, I aim to fill this gap in the medical literature). Some long-term observational studies, however, do provide clear, high-quality data demonstrating that vegetable consumption is an important factor in chronic disease prevention – a recent study on serum α-carotene levels and risk of death provides such data.

Carrots - Flickr: ccharmon

Alpha-carotene is one of over six-hundred different carotenoids, a family of antioxidants that also includes β-carotene, lycopene, lutein, zeaxanthin, and astaxanthin. Carotenoids help to defend the body’s tissues against oxidative damage, which is a natural byproduct of our oxygen-dependent metabolism. [2] Oxidative damage to DNA, proteins, and lipids is a known contributor to chronic disease and an accepted mechanism of aging. The body’s defenses against oxidative damage consist of naturally produced as well as diet-derived antioxidant molecules.

Many prospective studies in the past few years have supported the epidemiologic association between plasma carotenoids and reduced risk of disease and/or death. [3-6] However, these studies didn’t differentiate between carotenoids from food and those from supplements. Carotenoid supplements have failed to duplicate this effect in clinical trials. In fact, supplemental carotenoids are likely to be harmful. A recent meta-analysis of several trials found a 7% increase in mortality risk in subjects taking β-carotene supplements. [7, 8] Also, high serum β-carotene has been associated with decreased lung cancer risk, but β-carotene supplements may increase the risk of lung cancer, especially in smokers.[9] Attempting to duplicate the beneficial effects of carotenoid-rich foods with isolated nutrients is foolish - it completely neglects the contribution of additional and/or synergistic effects of other nutrients contained in those foods.

Beta-carotene is the most widely studied carotenoid, but α-carotene more accurately reflects vegetable intake because α-carotene is not present in most multivitamins and supplements. It is also an excellent marker of high-nutrient vegetable intake, since dark green and orange colored vegetables are the richest sources of alpha carotene. Green vegetables are the highest in overall nutrient density, and of course they are the foods richest in alpha carotene.

This study measured baseline serum α-carotene and tracked deaths in the 15,318 participants over a fourteen-year follow-up period. After controlling for potential confounding factors, the researchers found a significant trend – increasing serum α-carotene associated with decreased risk of death from all causes. Those with the highest serum α-carotene had a 39% decrease in risk of death compared to those with the lowest serum α-carotene. Similar relationships were found between serum α-carotene and risk of death from cardiovascular disease, all causes other than CVD, and cancer.

Serum α-carotene % Decrease in risk of death from all causes
0-1 µg/dl (Reference group)
2-3 µg/dl 23%
4-5 µg/dl (average 4.79 µg/dl) 27%
6-8 µg/dl 34%
≥9 µg/dl  39%

Alpha-carotene itself does provide significant antioxidant benefit –but more importantly α-carotene is a marker of the thousands of additional compounds, working synergistically to keep the body healthy present in green and orange vegetables. [10]

These results suggest that not only quantity of vegetable consumption, but the type of vegetables consumed has a major impact on health. This is the main principle behind the nutritarian diet – eating according to nutrient density. This large, long term study gives much support to the concept of nutritarianism, as many foods high in α-carotene tend to be high in micronutrients overall – the foods that make up the base of the nutritarian food pyramid. And of course keep in mind, even in the highest alpha carotene group in this study, the levels of vegetable consumption as a percent of total calories are likely not nearly as high as in someone following a nutritarian diet. Also, the serum level of alpha carotene in someone following a typical Western diet likely reflects mostly carrot consumption compared to the wide variety of green and yellow vegetables that would be consumed as part of a nutritarian diet, from which further benefits would be expected to accrue from the variety of phytochemicals contained within those vegetables.

Examples of foods with a high α-carotene to calorie ratio[11]:Cabbage - Flickr - La Grande Farmers' Market

  • Bok choy
  • Cabbage
  • Red peppers
  • Carrots
  • Swiss chard
  • Green peppers
  • Asparagus
  • Collards
  • Broccoli
  • Winter squash
  • Peas

 

 

 

 

 

Now imagine if such a study was done on people eating the dietary quality I recommend, which would result in levels even much higher than those in the study, and imagine if a diet of this quality was done for more than 10 years and with other synergistic foods, such as mushrooms, onions, berries and seeds. Just imagine...

 

References:

1. State-Specific Trends in Fruit and Vegetable Consumption Among Adults --- United States, 2000--2009. U.S. Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report September 10, 2010 November 24, 2010]; Available from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5935a1.htm.
2. Krinsky, N.I. and E.J. Johnson, Carotenoid actions and their relation to health and disease. Mol Aspects Med, 2005. 26(6): p. 459-516.
3. Lauretani, F., et al., Low total plasma carotenoids are independent predictors of mortality among older persons: the InCHIANTI study. Eur J Nutr, 2008. 47(6): p. 335-40.
4. Akbaraly, T.N., A. Favier, and C. Berr, Total plasma carotenoids and mortality in the elderly: results of the Epidemiology of Vascular Ageing (EVA) study. Br J Nutr, 2009. 101(1): p. 86-92.
5. Ito, Y., et al., A population-based follow-up study on mortality from cancer or cardiovascular disease and serum carotenoids, retinol and tocopherols in Japanese inhabitants. Asian Pac J Cancer Prev, 2006. 7(4): p. 533-46.
6. Ray, A.L., et al., Low serum selenium and total carotenoids predict mortality among older women living in the community: the women's health and aging studies. J Nutr, 2006. 136(1): p. 172-6.
7. Bjelakovic, G., et al., Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev, 2008(2): p. CD007176.
8. Bjelakovic, G., et al., Systematic review: primary and secondary prevention of gastrointestinal cancers with antioxidant supplements. Aliment Pharmacol Ther, 2008. 28(6): p. 689-703.
9. Druesne-Pecollo, N., et al., Beta-carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials. Int J Cancer, 2010. 127(1): p. 172-84.
10. Li, C., et al., Serum {alpha}-Carotene Concentrations and Risk of Death Among US Adults: The Third National Health and Nutrition Examination Survey Follow-up Study. Arch Intern Med, 2010.
11. NutritionData.com: Nutrient Search Tool. 2009]; Available from: http://www.nutritiondata.com/tools/nutrient-search.

 

Low-carb, high-protein diet increases risk of death from all causes

The low-carb fad has had its peak, and although it is declining in popularity, the myth persists that eating lots of meat and little or no ‘carbs’ is a great way to lose weight.

Meat

Plenty of studies have established that low-carb diets are moderately effective for weight loss over periods of 6 months to 2 years[1-3], though much of the weight lost initially is typically regained. This may be a better option than the processed food-soda diet many other Americans consume, so of course they are moderately effective – the number of calories consumed decreases as refined carbohydrates are eliminated from the diet. Low-carbohydrate diets cause people to lose some weight but at what cost? The short durations of these studies meant that they could not determine whether the diets are sustainable for long-term health. The current state of the medical literature would suggest that they are not – there is abundant data associating high meat consumption with adverse outcomes: weight gain, cardiovascular disease, cancer, diabetes, and all-cause mortality, just to name a few.[4-10] I have been warning for years that the long-term outcome of meat-based diets would not be favorable.

A long-term observational study of low-carbohydrate diets has finally been published this Tuesday in the Annals of Internal Medicine, and the results are intriguing. This study by researchers from the Harvard School of Public Health is the nail in the coffin of the low-carb, high-protein myth. The article details data from a prospective study in which 130,000 total participants provided information about their eating habits and were followed for a minimum of twenty years – this is true long-term data. At baseline, none of the participants had heart disease, cancer, or diabetes. The researchers classified the participants’ diets according to degree of adherence to the following dietary patterns: overall low-carbohydrate, animal-based low-carbohydrate, and high-vegetable low carbohydrate. They then compared death rates between the highest and lowest adherence groups for each pattern.

The authors’ conclusions: A low-carbohydrate diet rich in animal foods was associated with a 23% increased risk of death from all causes (14% increased risk of death from cardiovascular disease). In contrast, a low-carbohydrate diet rich in vegetables was associated with a 20% decreased risk of death from all causes (23% decreased risk of death from cardiovascular disease).[11]

The low-carb proponents had one thing right: the avoidance of refined carbohydrates – white flour, white rice, white pasta, added sugars, etc. are disease-promoting foods. However, the protein sources emphasized in most low-carb diets are micronutrient-poor animal products rather than micronutrient-packed plant products. The current study suggests that plant sources of protein (for example vegetables, nuts, beans, and seeds) promote longevity, whereas high protein animal foods have the opposite effect. This data supports the essential nutritional concept I illustrate with my health equation: Health = Nutrients / Calories. Micronutrient density determines the quality of one’s diet, and since animal products are deficient in micronutrients, they should be minimized. The authors agree that their results likely reflect the lack of protective fiber, minerals, vitamins, and phytochemicals in animal products. [12]

Many proponents of meat-based diets argue that the refined carbohydrate rather than the meat content of the American diet is to blame for our skyrocketing rates of chronic disease. However, too many studies contradict this opinion – and this study clearly demonstrates that choosing plant foods instead of animal foods, even within the context of minimal refined carbohydrate, promotes longevity.

There really should not be any controversy anymore about the health effects of low-carb, high-protein diets. This study (among others) confirms that the current amount of animal-source foods within the American diet should be reduced, not increased, and that meat-centered diets promote premature death; and that diets based predominantly on whole plant foods are lifespan-enhancing.

The “nutritarian” diet I recommend is unique because it focuses on consuming more of the highest micronutrient containing vegetation, as it reduces animal products to a condiment or minimal role held to less than 10 percent of total calories. Vegetables rule!

References:

1. Foster, G.D., et al., Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial. Ann Intern Med, 2010. 153(3): p. 147-57.
2. Brinkworth, G.D., et al., Long-term effects of a very-low-carbohydrate weight loss diet compared with an isocaloric low-fat diet after 12 mo. Am J Clin Nutr, 2009. 90(1): p. 23-32.
3. Sacks, F.M., et al., Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med, 2009. 360(9): p. 859-73.
4. Sinha, R., et al., Meat intake and mortality: a prospective study of over half a million people. Arch Intern Med, 2009. 169(6): p. 562-71.
5. Vergnaud, A.C., et al., Meat consumption and prospective weight change in participants of the EPIC-PANACEA study. Am J Clin Nutr, 2010. 92(2): p. 398-407.
6. Zheng, W. and S.-A. Lee, Well-Done Meat Intake, Heterocyclic Amine Exposure, and Cancer Risk. Nutrition and Cancer, 2009. 61(4): p. 437-446.
7. Key, T.J., et al., Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr, 1999. 70(3 Suppl): p. 516S-524S.
8. Ashaye, A., J. Gaziano, and L. Djousse, Red meat consumption and risk of heart failure in male physicians. Nutr Metab Cardiovasc Dis, 2010.
9. Snowdon, D.A., R.L. Phillips, and G.E. Fraser, Meat consumption and fatal ischemic heart disease. Prev Med, 1984. 13(5): p. 490-500.
10. Aune, D., G. Ursin, and M.B. Veierod, Meat consumption and the risk of type 2 diabetes: a systematic review and meta-analysis of cohort studies. Diabetologia, 2009. 52(11): p. 2277-87.
11. Fung TT, v.D.R., Hankinson SE,Stampfer M, Willett WC, Hu FB, Low-Carbohydrate Diets and All-Cause and Cause-Specific Mortality: Two Cohort Studies. Ann Intern Med, 2010. 153(5): p. 289-298.
12. Fiore, K. Low-Carb Diet is Better When Rich in Veggies. 2010 September 7, 2010]; Available from: http://www.medpagetoday.com/PrimaryCare/DietNutrition/22035.

 

The longer your waistline...

Although body mass index (BMI) is a popular indicator of normal, overweight, or obese, it is certainly an imperfect indicator. BMI takes into account only height and weight, but not muscle mass or weight distribution.

Scientists are now finding that waist circumference may be the best indicator of disease risk related to excess weight – waist circumference has been associated with diabetes, heart disease, inflammation, elevated cholesterol, sleep apnea, and hypertension. Waist circumference has gained interest because it is an indicator of visceral fat, believed to be more deleterious to health than subcutaneous fat. The exact mechanisms by which visceral fat confers greater risk than subcutaneous fat are still unclear, but it is known that these two types of fat have different gene expression profiles, visceral fat more frequently expressing certain substances that may contribute to chronic diseases.1,2

A new study that followed over 100,000 individuals for nine years has found that waist circumference correlates with risk of death, supporting the previous links between visceral fat and disease. When comparing waist size only, they found that very large waist circumferences – 120 cm (47 inches) for men and 102 cm (40 inches) for women – were associated with a doubling of the risk of death from all causes.

obese couple

The most striking finding in this study was that increased waist circumference is an important predictor of mortality regardless of BMI. Even in those with “normal” range BMI, increased the risk of death. A 4-inch increase in waist circumference was associated with a 16% increase in mortality risk in men and 25% increase in mortality risk in women. 

This means that excess fat around the waist is a significant risk – even in “normal weight” individuals.3 This data suggests that the size of one’s waist is even more important than the number on the scale.

Of course there is no way for us to control our bodies’ distribution of fat – whether our excess fat goes to our hips or around our organs – but we can control how much excess fat we have. Any and all excess fat is dangerous - it increases insulin levels and promotes inflammation, not to mention placing unnecessary demand on the heart. Focusing on nutrient density - emphasizing foods that minimize calories and maximize disease-protective nutrients – is an effective way to keep excess fat – both visceral and subcutaneous – to a minimum.

 

References:

1. Matsuzawa Y. Establishment of a concept of visceral fat syndrome and discovery of adiponectin. Proc Jpn Acad Ser B Phys Biol Sci. 2010;86(2):131-41.

2. Bergman RN, Kim SP, Catalano KJ, et al. Why visceral fat is bad: mechanisms of the metabolic syndrome. Obesity (Silver Spring). 2006 Feb;14 Suppl 1:16S-19S.

3. Jacobs EJ, Newton CC, Wang Y, et al. Waist circumference and all-cause mortality in a large US cohort. Arch Intern Med. 2010 Aug 9;170(15):1293-301.

Cardiovascular Fitness Means Healthier Heart

Go outside and run! Because a new study in the Journal of the American Medical Association shows people with high levels of physical fitness, i.e. cardiorespiratory fitness (CRF), have lower risk of all-cause mortality and heart disease. Experts analyzed data from more than 100,000 individuals, including 84,323 people with coronary heart disease, and findings revealed people with low CRF had a 70% higher risk of all-cause death and a 56% higher risk of heart disease or cardiovascular event than those with high CRF; HealthDay News explains.

You need to exercise! Exercise keeps you fit, builds strong bones and muscles, and more! It goes double for heart health. In March, a study showed exercising after a heart attack helps improve blood flow by 10%, but Canadians didn’t get the message. They don’t exercise enough.

In related news, a previous report found diabetic men who stay active live longer. Now, if you’re too lazy to run, cycle, swim, whatever. Check out Oscar Pistorius, he does it with no legs!

Image credit: Ed Yourdon

Red Meat Pinned to Blindness in Old Age

Sorry cows, a new study in the American Journal of Epidemiology links higher risk of age-related macular degeneration, i.e. blindness, with heavy consumption of red meat. Australian researchers recruited 6,734 people, ages 58 to 69, living in Melbourne, surveying them about how much meat they ate, and then taking macular photographs of their retinas to evaluate eye health. Findings revealed participants eating red meat 10 times a week were 47% more likely to develop age-related macular degeneration than those eating less red meat; Medical News Today reports.

Red meat is vile. In November a report found harmful bacteria, called Subtilase cytotoxin gravitates to red meat and dairy products. Then just last week, consuming large amounts of red and processed meat was associated with higher risk of cancer and cardiovascular mortality and beyond that, eating red meat has been linked to metabolic syndrome, a known predictor of heart disease.

In related news, previous research shows antioxidants from foods, such as spinach, kale and collard greens promote eye health and reduce the risk of age-related macular degeneration.

Image credit: moonpie dig it