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May 2013

Vitamin C and drug-resistant TB
Mediterranean diet and dementia
Vitamin D helps Crohn’s patients
Omega-3 fats and macular degeneration
Berries improve glycemic response
[Practical guidelines are now included at the end of each article]

Vitamin C and drug-resistant TB

Tuberculosis prevention and treatment have improved dramatically over the decades, partly due to better hygiene, better nutrition, and drug treatments. However, multi-drug resistant TB (MDR-TB) is an increasing problem. The bacterium has been treated successfully with isoniazid and rifampicin. However, when treatment is interrupted before complete eradication of the bacteria, the remaining organisms can develop resistance. MDR-TB is tuberculosis that is resistant to at least those two drugs that are the first choices in treatment.

Good hygiene, proper nutrition, and appropriate treatment are very important, because MDR-TB is easily transmitted by airborne transfer of the bacteria through coughing. TB bacteria are quite common, but most exposed people do not get the disease because the resistance of the host is more important than the availability of the organism. In the early days of my career in nutritional medicine, I visited with Nevin Scrimshaw, a world famous nutritionist at MIT, and he told me that “the TB bacillus by itself does not cause TB, because if it did, everyone would have it.” He then told me of the importance of the host resistance.

New information suggests that vitamin C is effective in killing the MDR-TB. In high enough concentrations it triggers the production of free radicals that kill the TB, but so far the specific research is only in the laboratory environment in test tubes. However, achieving those levels of vitamin C in the blood stream is possible using intravenous administration of the vitamin. This is how vitamin C is used to treat cancer. Vitamin C sterilizes cultures of both drug-sensitive and drug-resistant TB. It works through a variety of effects on biological processes. (Vilchèze C, et al., Mycobacterium tuberculosis is extraordinarily sensitive to killing by a vitamin C-induced Fenton reaction. Nat Commun. 2013;4:1881. doi: 10.1038/ncomms2898.) In high enough doses, vitamin C induces a reaction that releases free radicals, for example, peroxides, that kill the TB bacterium.

Practical guidelines:

Keep your fitness and nutritional practices up to the highest levels to make sure your resistance is strong, and try to control your stress levels. Take your supplements, including vitamin C, as many of them are very helpful in improving immune function. However, if you have an infectious disease, consider getting higher doses through intravenous administration. In the unlikely event that you are exposed to or infected with MDR-TB, getting IV vitamin C is a wise course of action.

Mediterranean diet and dementia

A number of studies have revealed the value of a Mediterranean-type diet (MeD) to reduce a range of health problems, although it is not a panacea, and the rates of certain diseases are still higher in the Mediterrnean countries than in regions with lower fat diets. However, new research shows the value of the Mediterranean diet in reducing the risk of developing cognitive dysfunction and dementia.

Researchers evaluated 17,478 individuals and identified cognitive impairment using a Six-item-Screener in 1248 individuals. Those subjects with a higher adherence to MeD had a statistically significant 13 percent lower likelihood of cognitive impairment. In non-diabetic participants, they found a 19 percent reduction, while in diabetics they found no benefit. (Tsivgoulis G, Adherence to a Mediterranean diet and risk of incident cognitive impairment. Neurology. 2013 Apr 30;80(18):1684-1692.)

Practical guidelines:

Such cognitive impairment is often a prelude to dementia, so it is wise to actively engage in preventive measures. The MeD includes lots of fruits and vegetables, seeds and nuts, whole grains and legumes, and small amounts of fish and chicken, and little processed meat or dairy. A diet of whole, natural, minimally processed foods that are mainly vegetarian fulfills this guideline. In addition, curried foods or supplements of curcumin may provide additional benefits, as this component of turmeric has been associated with lower rates of Alzheimer’s disease.

Vitamin D helps Crohn’s patients

Crohn’s disease is an inflammatory bowel disorder, mostly occurring near the end of the small intestine and start of the colon, but potentially affecting almost any area of the bowel. Symptoms include bloody stools, diarrhea and constipation, abdominal pain, and cramps. Recent studies suggest a relationship of low vitamin D levels to the incidence and severity of Crohn’s disease. In a pilot study of 18 patients, administration of vitamin D supplements for 24 weeks led to a significant reduction in the Crohn’s Disease Activity Index (CDAI) as well as the quality-of-life scores.

The patients were started on 1000 IU of vitamin D3 supplements and it was increased gradually until their serum levels rose over 40 ng/ml, or up to a maximum of 5000 IU. Of the 18 patients in the study, 14 of them required the maximum dose to adequately raise blood levels. The mean CDAI went from 230 down to 118. The vitamin D supplement program lasted for 24 weeks. (Yang L, et al., Therapeutic effect of vitamin D supplementation in a pilot study of Crohn's patients. Clin Transl Gastroenterol. 2013 Apr 18;4:e33. doi: 10.1038/ctg.2013.1.)

Patients with Crohn’s disease often experience muscle weakness, fatigue, and diminished quality of life. These could be due to the chronic inflammation, poor intestinal function, or nutrient inadequacies, or possibly other causes. In an evaluation of 27 Crohn’s patients in remission, half were given 2000 IUs of vitamin D or a placebo for three months. Those who took the vitamin D had a better quality of life, greater muscle strength, and less physical and emotional fatigue. (This was in a news report from HealthDay News prior to a presentation at a digestive disease conference by Tara Raftery, a research dietitian.)

Practical guidelines:

Vitamin D has numerous benefits as I have previously written, so most adults would benefit from some supplementation of 1000 to 2000 IU per day, but it is always a good idea to know your serum level of 25-OH vitamin D3. A good range is 40-60 ng/ml, although some researchers suggest up to 100 ng/ml. You can get some from sun exposure, but in most latitudes this is not a reliable source. Food sources include salmon (especially wild salmon). I have seen some “experts” caution against supplements, but mention “fortified” foods as a source. This means they are supplements, but simply added to foods (often foods with negative health effects) as opposed to taking them in pill form. Frequently these fortified sources contain synthetic vitamin D (D2), which is not as good as natural (D3).

Omega-3 fats and macular degeneration

Omega-3 fatty acids include alpha-linolenic acid (ALA, but not to be confused with alpha lipoic acid) and its derivatives, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA is essential in the diet. Humans manufacture the EPA and DHA from ALA through several enzymatic reactions. Sometimes the production is limited by age, diabetes, illness, or allergies, and possibly toxic exposures.

Food sources of ALA include flax seeds and flax seed oil, which have abundant ALA, and walnuts, as well as canola and perilla oils, and soybeans or soybean oil. The food sources of EPA and DHA include fish (especially wild salmon and sardines) and some seaweeds, as well as algae, which is where the fish get it. Infants get EPA and DHA from human breast milk.

People whose production of EPA and DHA is low may benefit from direct food sources or supplements. A new study shows that plasma levels of omega-3 fatty acids are associated with the risk of developing age-related macular degeneration (ARMD). The researchers evaluated 963 residents of Bordeaux, France who were 73 years old or more. After an initial exam they were followed for an average of 31 months and checked for the development of ARMD. (Merle BM, et al., High concentrations of plasma n3 fatty acids are associated with decreased risk for late age-related macular degeneration. J Nutr. 2013 Apr;143(4):505-11. doi: 10.3945/jn.112.171033. Epub 2013 Feb 13.)

They found that a high blood level of any omega-3 fatty acids was associated with a 35 to 38 percent reduction in the risk for late stage ARMD. It made little difference whether it was the 18-carbon fat (ALA) or the 20- or 22- carbon fat (EPA and DHA), so you can choose vegetarian or fish sources of your omega-3 fats.

Practical guidelines:

Flaxseed oil is a nutritious source of omega-3 fatty acids. You can use it in salad dressings or as a topping for a baked potato or other foods. Once it is extracted from the seeds, the oil is very susceptible to oxidation, so keep it in the refrigerator and do not use it for cooking. I get a few bottles and keep them in the freezer except for the one that I have opened, which I try to use up within a few weeks. Typically, one or two tablespoons of oil per day is enough, but remember that it is also rich in calories, as is any oil.

If you prefer, you can eat fish (wild salmon and sardines are the best sources) or take fish oil supplements. Typically the dose is 1000 to 2000 mg of fish oil extract, containing up to a total of 1000 mg of the omega-3 oils.

Berries improve glycemic response

Berries are known to be healthy sources of antioxidants and numerous protective phytochemicals, among them pigments called anthocyanins, a flavonoid called quercetin, and a phenol called ellagic acid, as well as vitamin C. They help maintain memory and cognitive function, prevent cancer, and protect vision (partly because of the lutein they contain). Berries are also rich in fiber that helps promote good intestinal function.

New research shows that berries can improve sugar metabolism. The starch in white bread leads to a high blood glucose and insulin response after eating. Rye bread also raises the glucose level, but does not produce the same level of insulin response as white bread. Study subjects, including 13 to 20 women, participated in three randomized, controlled, 2-hour meal studies.

They were fed wheat bread or rye bread with equal amounts of starch in each meal, and were also given either 150 grams of whole-berry puree or no berries to provide reference points. They were then tested with various berry mixtures or individual berries such as strawberries, bilberries, cranberries, and black currants, as well as raspberries, lingonberries and chokeberries. (Törrönen R, et al., Berries reduce postprandial insulin responses to wheat and rye breads in healthy women. J Nutr. 2013 Apr;143(4):430-6.)

Strawberries and the berry mixture reduced the glucose response to the breads, while virtually all of the berry mixtures or individual berries reduced the insulin response to both breads. The authors concluded that consuming berries with white bread or rye bread reduces the body’s need for insulin to maintain normal glucose metabolism after eating. Apparently, even whole grains produce some glycemic response and insulin production, if less than refined grains, and berries attenuate that response.

Practical guidelines:

Berries sometimes seem like miraculous fruits for all of their health benefits. I suggest consuming a wide variety of berries regularly. I often eat strawberries, blueberries, blackberries, and raspberries, either fresh or frozen and put in smoothies. However, conventionally grown berries are among the most likely foods to be contaminated with pesticides, so I always buy organic berries or pick my own at a local farm that is Certified Naturally Grown (a private standard equivalent to organic in quality), or pick my own blackberries at my New Hampshire home.

Of course, avoiding all refined flours (breads, pastas, pastries, etc.) is likely to be most helpful, and I am sure most of my readers already do that. Whole grain varieties of these foods are routinely available. One can’t know from this study, but berries may well improve glucose and starch tolerance from other food sources. For diabetics, berries may improve sugar control and prevent some of the complications of the condition.

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From September to June, I see patients in New Smyrna Beach, Florida.
Call 386-409-7747, or send an email to to make arrangements.

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Information herein is not medical advice or direction. All material in this newsletter is provided for information only. Its contents should not be used to provide medical advice on individual problems. Consult a health care professional for medical or health advice.