The Health Effects of Nitrate, a Comprehensive (aka Very Very Long) Review of the Literature

The following is a portion of my thesis, focusing on the literature regarding the health effects of dietary nitrate:

Nitrate Consumption: A Historical Perspective

The use of salt to preserve meat has been in use as far back as 900 BC, when written records indicated Greeks produced salt for use in the curing of meat.14 Around 200 BC, Roman records make note of a reddening effect of salt on meat, which is now believed to be due to nitrate, a common contaminant in salt. Similarly, written records from near this time period in China and India indicate that saltpeter (potassium nitrate) was being used to cure meat.1 A more thorough understanding of this phenomenon appears in scientific literature in the late 20th century, when various researchers from Germany determined that not only does adding nitrate impart a redness to the meat it is added to, but this effect depends on the nitrate ion being converted into nitrite.15 Likely more valuable than the reddening effect of nitrate is its antibacterial effect when used as an additive in meat products. Although capable of inhibiting a number of pathogenic bacteria prone to infecting meat, nitrate, again following conversion to nitrite, most notably inhibits Clostridium botulinum.16 Continue reading

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Salt and Cardiovascular Disease

Introduction

The issue of salt is one of the most contentious topics in nutrition today. Major government agencies have recommended salt restriction for years, yet strong push back by scientists and researchers, especially recently, has led many to question the validity of such a stance. The main factor causing salt to be portrayed as “bad” is due to the link between salt intake and higher blood pressure. Research conducted by Lewis K. Dahl, inspired in part by Dr. Walter Kempner’s “Rice diet”, is credited with the scientific acceptance of the theory that eating salt causes one’s blood pressure to rise. Since high blood pressure is a risk factor for cardiovascular disease, it has been thought that restricting salt would help prevent the occurrence of things like strokes and heart attacks. Of course nutrition is rarely so simple. Continue reading

Sunlight and Heart Disease; Why Infrared Light Matters More than Vitamin D

The practice of “heliotherapy” or the use of light (generally sunlight) to produce health benefits dates back as far as Hippocrates, who is said to have recommended sunlight exposure for medical purposes. Since this time it has been established that wavelengths of light contained in sunshine can have notable effects on human health. Ultraviolet light stimulates the production of vitamin D in the skin. Visible light (especially blue light), when it reaches the eyes, suppresses the synthesis of the hormone melatonin. Finally, infrared light also appears to have notable biological effects which will be discussed later. Continue reading

What can “The Mediterranean Diet” Tell Us About Preventing Heart Disease?

Heart Disease and The Mediterranean Diet(s)

Our nutrition voyage begins in the city of Lyon. It was here in France’s second largest city that a team of researchers, led cardiologist Michel de Lorgeril, recruited 605 people to participate in what would be a groundbreaking clinical experiment. The individuals in this study had their differences; they weren’t all the same age (although most were middle aged), they weren’t the same gender (although most were men), they had differences relating to education level, racial background, cholesterol levels, blood pressure, height, weight, and so and on. However, there was one similarity which all these people shared, one life experience which became the the reason for their inclusion in de Lorgeril’s study: they had all experienced a myocardial infarction, commonly known as a heart attack. Continue reading

Growth Hormone and Aging Continued: IGF-1 Levels and Longevity

As suggested in the last post growth hormone and its downstream partner IGF-1 have a somewhat controversial standing with regard to aging and longevity. Although observations of animals seem to suggest GH/IGF-1 shortens lifespan, such observations are not as clear with humans. Additionally, while GH/IGF-1 does seem to promote cancer it also to seems to prevent cardiovascular disease, depending on the context. Continue reading

Diet and blood pressure

Given the evidence that high blood pressure can negatively effect heart disease risk, lowering blood pressure with diet is perhaps a reasonable goal. The following are my recommendations for lowering blood pressure with food.

1. Garlic seems to lower blood pressure (1). In fact, garlic seems to be one of the most effective anti-hypertensive foods studied on humans.

2. Hibiscus tea seems to powerfully reduce blood pressure (2,3) although it hasn’t been as thoroughly studied as the other items on this list.

3. Two minerals which appear to lower blood pressure somewhat are potassium (5) and magnesium (6). These minerals can be found in most fruits and vegetables. Calcium produces a fairly small reduction in blood pressure (7). Perhaps because it provides both calcium, potassium, and some magnesium dairy products appear to lower blood pressure to a decent degree (8). Fermented dairy, such as yogurt, may produce even greater reductions in blood pressure (9-11).

4. Although sodium is probably the first thing a lot of people think of when talking about diet and lowering blood pressure I think some caution is needed. I have a post upcoming on sodium, but essentially sodium may be worth lowering if a person has a large intake  but at a certain point sodium restriction may cause health problems. Some studies have suggested low sodium intakes may worsen insulin sensitivity and even shorten lifespan. I recommend roughly 1 to 1 & 1/2 teaspoon/ of salt per day, or about 2000 to 3000 mg of sodium for most people.

References:

1. http://www.ncbi.nlm.nih.gov/pubmed/18554422
2. http://jn.nutrition.org/content/140/2/298.short
3. http://www.sciencedirect.com/science/article/pii/S0378874198001573
4. http://www.sciencedirect.com/science/article/pii/S0944711309002293
5. http://www.nature.com/jhh/journal/v17/n7/full/1001575a.html
6. http://ajh.oxfordjournals.org/content/15/8/691.short
7. http://jama.jamanetwork.com/article.aspx?articleid=399639
8. http://realhealthanswers.com/docs/Journal-Articles/MiscFruit/NE%20Journal%20of%20Medicine%20-%20Dietary%20Patterns%20on%20Blood%20Pressure.pdf
9. http://ajcn.nutrition.org/content/64/5/767.short
10. http://ajcn.nutrition.org/content/77/2/326.full.pdf+html
11. http://www.sciencedirect.com/science/article/pii/S089570610400754X

Sugar and Diabetes

Introduction

It seems as if many theories about nutrition take hold in popular culture as a function of our human tendency towards word association.

The old belief, held by many even today, that eating fat will lead a person to become fat is probably partly rooted in the words we use. However this belief is somewhat misguided (calories are the main dietary determinant of weight loss, not fat), so why did it catch on? Well, would so many people have clung fervently to the idea that a low-fat diet should be the go to for weight loss had we called the fat on our bodies “adipose tissue” as it is so often referred to in the medical field? What if we called the fat in our diet “lipids”, or some other interchangeable term? In an alternate universe following a different lexicon would there have been as many people following a low-lipid diet for the purpose of adipose tissue reduction?

Phrased like that I kind of doubt it.

A similar example can probably be noted in the widespread idea that sugar causes diabetes. Diabetes is a disease characterized by high blood sugar. Even though the sugar in this scenario is in fact glucose, the use of the word “sugar” has almost certainly established in the minds of people a connection between this “sugar” in the blood and your basic dietary sugar, made up of glucose and fructose.

Were our colloquialisms more accurate we would say diabetics have high blood glucose and call “sugar” either sucrose or a mixture of glucose and fructose, whichever was more appropriate in the situation. This may have alleviated some of the unscientific condemnation of “sugar” as a cause of diabetes and the inevitable recommendation that diabetics avoid sugar at all costs.

Clearly I am beginning this post with some critical pronouncements. However, this issue is, in my opinion, one of the most complex, misunderstood, and important topics in nutrition today. The vilification of fructose is an increasingly popular dogma which I strongly oppose not just because I disagree with it, but because of the ramifications of this belief. Some health “professionals” have gone so far as to make the obstructive claim that fruit is contraindicated in people with diabetes and a risky food in general given the fructose it contains.

Bullshit.

In this post I will be evaluating the belief that “sugar causes diabetes” primarily by critically evaluating the claim that fructose adversely affects insulin sensitivity.

Continue reading