Garden delays newsletter
Calorie restriction and longevity, resveratrol, and grape seed extract
Structured exercise for diabetes
Niacin and statin study stopped
Fish oil lowers stent clotting
Brisk walking helps prostate cancer
This newsletter for May was delayed for a few reasons. One was moving back to New Hampshire earlier this year than usual. Then we had lots of work putting in the garden. We came up early partly to get a head start on the garden. We have now planted, in addition to many flowers, beds of arugula, giant red mustard greens, Swiss chard, cilantro, tomatoes, eggplants, basil, zucchini and yellow squash, ancho peppers and cayennes. This year I have also added sugar snap peas and yellow wax beans.
We have scallions and a variety of lettuces, plus spinach, mizuna, and tat soi (another Brassica family, or cruciferous, vegetable), so our salads will be quite eclectic. We love eating a lot of greens, and these are tremendously valuable sources of nutrition. Many of these can also be stir-fried, and when they are as abundant as the red mustard and arugula, the only way to use them all up is to add them to cooked dishes (they lose their spicy oomph when cooked, but they are still nutritious).
Such quantities are valuable for vegetarian diets. One cardiologist I know told me that even though there are many vegetarians in India, they are “dropping like flies” from heart disease. This glib comment ignores the details of the data; in cities and other areas where they have abundant sugar, fat, and processed foods, obesity and heart disease are problems, but in rural areas this is not the case. The data showed that the difference boiled down (pun intended) to the abundance or lack of leafy greens and fruits in the diet (the lack being associated with more heart disease).
If you have any space at all, try to grow some vegetables. If you have absolutely no garden space, you can even do it in pots or window boxes right on the deck or porch or at the end of the driveway. If you have any lawn (a great consumer of water and often of chemicals), it is easy to convert some to garden. As a side benefit, gardening is also a very good way to exercise, even though it is not usually an adequate substitute for aerobics or resistance training.
In every species studied, restricting caloric intake below what would normally be consumed leads to greater longevity. However, this usually requires a 25 percent reduction in calories below ad lib consumption. Very few people are dedicated enough to pursue this for a long time, and they are often uncomfortable when they do (although not always). Why calorie restriction (CR) works is not clear, although there have been many theories. One is that reducing metabolic activity lowers exposure to toxic byproducts. Another is that a reduction in core body temperature contributes to longevity. (Soare A, et al., Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans. Aging (Albany NY). 2011 Apr;3(4):374-9.)
If you want to pursue it, you can find many websites with guidelines so that you do not do it incorrectly. You still need to eat lots of vegetables and fruits. One effect of CR is to turn on a chemical pathway called the “sirtuin” pathway. Sirtuins are enzymes that apparently regulate aging in a wide variety of species. In order to achieve the benefits of calorie restriction, researchers have been trying to find supplements (or, of course, drugs) that might mimic these effects, such as turning on the sirtuin pathway.
One such supplement is resveratrol, a polyphenol found in purple grapes (and red wine in higher levels), some berries (blueberries and cranberries), and peanuts (a cup of boiled peanuts has about the same amount as a 5-oz. glass of red wine). These foods can provide a few milligrams of resveratrol in typical servings.
Supplements of resveratrol are usually derived from Japanese knotweed (Polygonum cuspidatum) and often contain from 30 mg to 200 mg per capsule. A typical dose is about 35 mg twice per day.
Sirtuins influence cell survival as well as inflammation, energy metabolism, and cancer. (Li X, Kazgan N, Mammalian sirtuins and energy metabolism. Int J Biol Sci. 2011;7(5):575-87. Epub 2011 May 9.) While you may be interested in calorie restriction to enhance longevity, you might get some of the same benefits from resveratrol. However, it is still a good idea to eat fewer calories than in the typical industrialized diet (which can no longer really be called the “Western” diet as it has travelled around the world).
Resveratrol also has benefits when combined with grape seed extract. In a cellular study, researchers examined colon cancer cells for their rate of apoptosis (programmed cell death). They used lower than usual doses to see if they could get similar results to higher doses when the supplements were combined. The combination both suppressed proliferation of the cancer cells and induced apoptosis. (Radhakrishnan S, et al., Resveratrol potentiates grape seed extract induced human colon cancer cell apoptosis. Front Biosci (Elite Ed). 2011 Jun 1;3:1509-1523).
Glycohemoglobin or hemoglobin A(1c), (HbA(1c) is a blood test that reflects the average serum glucose level for a 60-day period, It is routinely used to evaluate diabetics for their sugar control. Exercise is one of the best ways for diabetics to control their blood sugar. It now appears that structured exercise programs are better at controlling blood sugar than self-directed exercise routines. It is not that the exercise is not as beneficial when you do it yourself, it is that the consistency is lacking for most people without the supervision.
In an evaluation of studies over 30 years, researchers retrieved 47 randomized, controlled trials with a total of 8538 patients. Half of the participants were given exercise advice and the other half were in the supervised programs. Normal HbA(1c) is from 4 to 6 percent. Compared to those subjects given only advice, those in the structured programs had an overall decline of 0.67 percent, while the controls had no change in levels.
Not all exercise was equal. Aerobic exercise let to a decline of 0.73 percent in HbA(1c) and resistance training (muscle building) led to a drop of 0.51 percent. Those subjects who exercised for more than 150 minutes per week had a drop of 0.89 percent. Those who received exercise advice with dietary advice at the same time had a drop of HbA(1c) of 0.58 percent, quite a significant number. (Umpierre D, et al., Physical activity advice only or structured exercise training and association with HbA1c levels in type 2 diabetes: a systematic review and meta-analysis. JAMA. 2011 May 4;305(17):1790-9.)
Exercise and nutrition play a great role in controlling diabetes (while at the same time helping to prevent circulatory problems, among the most serious complications of diabetes). A number of dietary supplements also help, including chromium (up to 1000 mcg per day), alpha lipoic acid 1000 to 1200 mg daily), vitamin D, and vanadium, among others.
A study of niacin (nicotinic acid, or vitamin B3) was recently stopped by the NIH eight months earlier than planned. The rationale was that niacin appeared not to have any beneficial effect in this group of patients. While niacin raises HDL and lowers triglycerides, it was not clear that this reduction of risk factors would translate into reduced heart attacks and mortality.
The ineffectiveness of niacin received all of the press attention, but that was not the only feature of the study. All of the participants received at least one statin drug, and many received another drug as well, and what was found was no further improvement by adding niacin to their drug regimen. Their average age was 64 and all of them had prior heart disease. (National Heart, Lung, and Blood Institute of the NIH. Press release, NIH stops clinical trial on combination cholesterol treatment. May 28, 2011.) It is not at all clear from this study that niacin, which lowers risk factors, would not help those who are not taking drugs. Usually, niacin is a safer and cheaper substitute for those drugs, rather than just an additional treatment.
One problem that I have not seen mentioned is that it is hard to do a double-blind trial with niacin. Even timed-release niacin often causes a flush of the skin for about 20 minutes, a harmless reaction that can be uncomfortable at times. This would make the subjects taking niacin aware of what they were taking. Those who did not get such a flush would very likely know they were not taking niacin. One of the principal investigators in this study noted that the result is “unexpected and a striking contrast to the results of previous trials and observational studies.”
Balloon angioplasty and stent placement are now commonly performed cardiac interventions. After the procedures to open diseased blood vessels, patients are given drugs to reduce platelet activity and thus prevent blood clotting in the artery that might result from the atherosclerotic disease or from the stent itself.
In a new study, 30 subjects and 24 controls were given the usual medications with or without additional fish oil concentrates containing 1000 mg of omega-3 fatty acids. At the start and at 30 days, they were evaluated for their risk of clotting. Those treated with the fish oil in addition to the usual drugs had significantly reduced clotting activity and less oxidative stress. (Gajos G, et al., Reduced thrombin formation and altered fibrin clot properties induced by polyunsaturated omega-3 fatty acids on top of dual antiplatelet therapy in patients undergoing percutaneous coronary Intervention (OMEGA-PCI Clot). Arterioscler Thromb Vasc Biol. 2011 May 26. [Epub ahead of print])
Some evidence suggests that exercise helps prostate cancer, but earlier research might have misinterpreted the results. In a new study, researchers set out to do a prospective study of men who had already had a diagnosis of prostate cancer. (If it is not a prospective study, reduced cancer among exercisers might mean that those diagnosed with cancer stopped exercising after the diagnosis.)
These researchers evaluated 1455 men diagnosed with localized prostate cancer. During the study of 2750 person-years, they observed 117 events including recurrences, bone metastases and prostate cancer deaths. Men who walked briskly for three hours per week or more had a 57 percent lower risk of progression. Slower walking or fewer hours were not associated with any such benefits. (Richman EL, et al., Physical activity after diagnosis and risk of prostate cancer progression: data from the Cancer of the Prostate Strategic Urologic Research Endeavor. Cancer Res. 2011 May 24. [Epub ahead of print])
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