How to Boost Immunity With Diet and Exercise
By Paul Rogers
Photo by ktylerconk
How many times have you seen an ad for some wonder ‘erb or other that’s supposed to boost the immune system. It’s echinacea today and some Chinese herb the next, as well as a vast array of products that the supplement industry claim “support the immune system” — whatever that means.
Diet and Immunity
I’m not suggesting that diet and nutrition don’t have an important role to play in maintaining a healthy immune system. Meeting the recommended intake of macronutrients, vitamins and minerals and fats, and consuming copious quantities of antioxidant nutrients as part of healthy eating is bound to promote good immune system function — as far as it goes. However, the evidence for consuming individual dietary components or special foods or supplements beyond the RDI (recommended dietary intake) is mostly speculative or at least inconclusive.
Exercise and Immunity
If you follow a healthy lifestyle approach with healthy eating and a program of physical activity, here are a few things to note about how the immune system responds to exercise:
- A regular, low to moderate intensity exercise habit is associated with a reduced incidence of infection compared with those who do very little exercise or physical activity.
- Heavy, and or prolonged exercise training can impair the immune system, possibly leading to susceptibility to infection, particularly in a period of up to 24 hours after a heavy training session or event.
- Exercising at high intensity for prolonged periods without food — 90 minutes and beyond for example — may make you especially vulnerable to infection as a result of immune system depression.
- Consuming carbohydrate at the rate of 30-60 grams an hour during intense and prolonged exercise can help to maintain immune system function. That’s 1-2 sports drinks and hour or equivalent. (One drink is probably adequate for most situations except for extreme conditions and intensity.)
- Meeting your daily requirements for micronutrients like zinc, iron, and B and C vitamins is essential. Although a multivitamin supplement may help, consuming mega quantities of vitamins and minerals may be counterproductive. See article on Vitamin C and training adaptation.
- A recent review confirmed the value of carbohydrate supplementation and a possible role for vitamin C (note caution above), but no other supplement showed up as useful for heavy exercisers.
It’s worth noting the value of carbohydrate to immunity in a balanced diet and exercise program. Low-carbohydrate intake with low blood glucose, plus the stresses of exercise, increases cortisol production to the point where the immune system is compromised. Low-carb, high-fat diets, especially saturated fat, are not appropriate if you have a robust exercise program. In addition, saturated fat has been shown to impair immune response. Low-carb is not where you want to be if you exercise a lot.
J Sports Sci. 2004 Jan;22(1):115-25. Exercise, nutrition and immune function. Gleeson M, Nieman DC, Pedersen BK.
JEur J Clin Nutr. 2007 Apr;61(4):443-60. Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis. Moreira A, Kekkonen RA, Delgado L, Fonseca J, Korpela R, Haahtela T.
Scand J Immunol. 2008 Jul;68(1):30 42. Differential effects of a saturated and a monounsaturated fatty acid on MHC class I antigen presentation. Shaikh SR, Mitchell D, Carroll E, Li M, Schneck J, Edidin M.
Food and Fitness Science Roundup
By Paul RogersFor this regular roundup, I try to find work that tells us something significant or new in the context of the field of study.
New Recommendations for Vitamin D Intake for Children from the American Academy of Pediatrics
A recommendation for a doubling of recommended dietary intake of an essential nutrient for any population sector is substantial news in nutrition science. The AAP list the reasons and the strategy here.
http://www.aap.org/pressroom/nce/nce08vitamind.htm
Coffee Drinking Does not Raise Mortality
Up to 6 cups a day and risks were still normal and even slightly lower than the consumers of much more moderate quantities. Adjustment of cardiovascular risk seems to be the difference — perhaps by lowering the risk of type 2 diabetes?
Ann Intern Med. 2008 Jun 17;148(12):904-14. The relationship of coffee consumption with mortality. Lopez-Garcia E, van Dam RM, Li TY, Rodriguez-Artalejo F, Hu FB.
Also see: Does Coffee Kill or Cure?
Red Wine Seems to Cut Risk of Lung Cancer
What? Not another reason to drink red wine! The authors do counsel against excessive consumption.
Cancer Epidemiol Biomarkers Prev. 2008 Oct;17(10):2692-9. Alcoholic Beverage Intake and Risk of Lung Cancer: The California Men’s Health Study. Chao C, Slezak JM, Caan BJ, Quinn VP.
Vitamin C Interferes with Training Adaptation and Performance
I noticed the possibility of this a few years ago while researching the utility of antioxidants like vitamin C to benefit athletic performance. Vitamin C seemed to inhibit phosphofructokinase, which is an important enzyme in glycolysis (breakdown and use of glucose for energy). Considering that many athletes and fitness buffs seem to take vitamin C supplements, it may be worth noting. Moderate dietary intake is likely not a problem. We need more information on this one before the panic sets in.
Am J Clin Nutr. 2008 Jan;87(1):142-9. Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. Gomez-Cabrera MC, Domenech E, Romagnoli M, Arduini A, Borras C, Pallardo FV, Sastre J, Viña J.
Caffeine Plus Carbohydrate Increases Glycogen Storage
As far as I am aware, this is the first time this has been shown. About 500 mg caffeine is a lot of coffee though.
J Appl Physiol. 2008 Jul;105(1):7-13. High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine. Pedersen DJ, Lessard SJ, Coffey VG, Churchley EG, Wootton AM, Ng T, Watt MJ, Hawley JA.
New Glycemic Index and Load Tables
If you’re into the GI, you’ll need this. More on the GI in another article. I’m not a big fan.
Click through to here from the abstract and you can download the free tables.
Diabetes Care. 2008 Oct 3. International tables of glycemic index and glycemic load values: 2008. Atkinson FS, Foster-Powell K, Brand-Miller JC.
Check out the Food for Life, Fit for Life Training Program. Free download available.
The Truth About Organic Food
By Paul Rogers
Photo by bittenword
I’ve been a keen gardener most of my life, following a strong family tradition. We’ve grown everything from flowers and ornamentals to fruit trees and vegetables — with varying measures of success. Organic growing in a home garden, and wherever feasible commercially, just seems like sensible environmental management to me . . . and it’s especially applicable to home gardening. I’ve also written about organic growing and been a member of a growers group for decades.
Organics may not be the only solution
Even so, I’m not an absolutist, and I am a pragmatist . . . I accept that there may be other farming and cultivation systems that could indeed be regarded as “sustainable and healthy” even though they may not pass organic certification. But that’s not my argument here. I’m going to look critically at the notion of why you should buy organic food and whether the advantages stack up — give or take a few generalisations.
Here are the usual reasons for supporting organic food production:
- It’s healthier because few, and low-toxic pesticides are used and residues on crops are not a problem
- It’s healthier because organic food is higher in dietary nutrients
- It’s more sustainable because soil is managed better without chemical fertilizers
- It’s safer and sustainable because beneficial organisms like bees and predatory organisms and wildlife are not poisoned by pesticides
- It’s safer because humans are not poisoned by pesticides as they use them.
Pesticide residues
Even allowing for cheating, it is clear from testing that organic food has fewer residues of detectable pesticides than non-organic food. The issue is whether the presence of residues in non-organic food is a health hazard. Clearly, in some cases it is. The cases of aldicarb pesticide poisoning from melons in California is a classic case. This was only detected because of the severe symptoms. Many other cases are likely in which the victim has less acute symptoms and the cause remains unidentified. And, the effect of long-term exposure to small quantities of residues is unknown, but could be significant.
Testing for safe food. With the world food supply increasingly traded across borders, ensuring “clean” food by monitoring it for contaminants has become increasingly difficult. Recent issues in food safety in relation to food products imported from China make this all too clear.
Organic food has more nutrients
This is the one the professional agriculture, health and nutrition communities have resisted so strongly for so many years. In essence, it is a complex issue. To measure this accurately, you really need to set up controlled growing conditions for a reasonable comparison, and even though quite a few early studies showed advantages for organics in some nutrients like vitamin C, iron, omega-3s and a few other minerals, the design was often somewhat amateurish — until the European Union Newcastle University study came along. Read the results here: “Organic produce better for you”.
Variability abounds. The authors caution that variations in qualities exist across the organic and non-organic spectrum. What this might mean for you, as a purchaser, is that a badly grown organic apple could very well be inferior to a well-grown non-organic apple. One might expect that across a continuum of organic produce, the nutrient value may be higher, but don’t expect that any one purchase will give you that guarantee.
Phytonutrients finally. Over the years of this organic nutrient debate, the one thing that has mostly been absent is an evaluation of the non-vitamin and mineral nutrients. These are the antioxidants, the polyphenolics, carotenes, sulphur compounds, the omega-3s and many more that are known to be health-giving principles in foods. Finally, this also seems to have been answered. In the Newcastle University study:
They found levels of antioxidants in milk from organic cattle were between 50% and 80% higher than normal milk.
This is not surprising, overall, because Alyson Mitchell, associate professor and food chemist at the University of California, Davis, found exactly the same thing in her work analysing tomatoes. Soluble fertilisers, especially nitrogen, and strong pesticides may inhibit the plant production of phenolic compounds. See Mitchell again for a discussion.
One would have to say that early professional bias against the idea of organics having higher overall nutrient values, in a dietary sense, seems to have been ill-founded and perhaps influenced by various vested interests. However, this should not suggest that eating organic foods, even with a premium supply of antioxidants, results in superior health outcomes: that is yet to be proven.
Organic growing is more sustainable
As a general rule this is probably true, and is likely to be more so for smallholdings rather than large commercial enterprises. The definition and evaluation of “sustainability” is variable, but one issue is the recycling of inputs to the system versus importing inputs like organic fertilizers from elsewhere. Sustainability is about being able to make systems last without degrading the system.
Nevertheless, several recent studies — University of Michigan, the USDA and the FAO and others, have found that organics actually outperform conventional agriculture in measures of soil sustainability and biological sustainability — and may even approach the production efficiency of non-organic farms in some cases.
Safer for wildlife and diversity
New Scientist reports: “Organic farming boosts diversity”.
Organic farming increases biodiversity at every level of the food chain – all the way from lowly bacteria to mammals. This is the conclusion of the largest review ever done of studies from around the world comparing organic and conventional agriculture.
Enough said about that one.
Occupational health and safety
This is the sleeper issue in organic production. It receives less attention than other aspects. The human health legacy of toxic pesticides in developing nations has been monumental. And even in the developed nations, the misuse and overuse of pesticides has resulted in substantial impacts on human health. The US Agricultural Health Study has reported on some such results.
Here is what esteemed toxicologists Levine and Doull said about pesticide poisoning worldwide in 1992:
Global estimates of acute pesticide morbidity and mortality. Levine RS, Doull J. Rev Environ Contam Toxicol. 1992;129:29-50.
Mathematical models have projected increasing numbers of pesticide poisoning throughout the world, rising from 500,000 cases/yr in 1972 to 25,000,000 cases/yr in a 1990 estimate.
Summing up
Organic food is more expensive; you have to decide if it’s worth it. In addition, the science of organics is a bit fuzzy at times. Some modern pesticides actually have lower toxicity than approved organic pesticides. The more popular and affordable organic food becomes, the more we will see mainstream food manufacturers taking advantage of it. No folks, the organic pop tart is not a health food. Overall, though, organics is a neat package of environmental health and safety practice. I support it strongly.
Top 10 Antioxidants of All Time
By Paul Rogers
Pic by ninjapoodles
Okay, I know that title is over the top, but it’s tongue-in-cheek as well. We hear so much about the value of antioxidants that I get a little unimpressed sometimes. But wait, this is the real deal. Everyone likes a list and the Nutrient Data Lab of the United States Department of Agriculture has released an updated ORAC list of the antioxidant power of plant foods.
Antioxidants rule, okay?
ORAC stands for ‘Oxygen Radical Absorbance Capacity’. Oxygen radicals or free radicals are reactive chemical particles created when an electron gets dislodged from a molecule leaving an unpaired electron. This makes the particle highly reactive. Oxygen radicals result from natural processes like digestion and metabolism but also from exposure to radiation and pollutants.
Antioxidants such as vitamin C, E and the mineral selenium are able to quench these free radicals and stop them from reacting with important molecules in the body like DNA and causing cancer and many other diseases. As well as antioxidant vitamins and minerals, a host of antioxidants exist as phytonutrients in plants. Polyphenols in red grapes and wine and cacao beans (chocolate) are well-publicised examples.
The ORAC database lists the scores for individual fruits, nuts, cereals, beans, herbs and vegetables. Here are my favourites. The higher the score, the greater the antioxidant capacity. The measures are in micromoles per 100 grams.
1. Herbs and spices. As a group these are powerful antioxidants. Values for tumeric, 159,000 and oregano 200,000 are good examples. Not all herbs and spices are as high as this, but when you see some other food scores you will understand how powerful these plants are in antioxidant value. On the other hand, we only consume them in comparatively small quantities compared to a whole apple for example.
2. Apples, raw. Both granny smith and red delicious are at the top of the apples scores at around 4000 units. You need to leave the skin on for best effect.
3. Red wine has excellent capacity, as we often read, at 5000 units compared to white wine at 400 per 100 grams. Raw grapes and grape juice are in the range of 800 to 1000, so you can see that processing the skins of red grapes in wine production seems to improve the antioxidant capacity substantially.
4. Artichokes (globe) cooked. Up around the 9000 units per 100 grams, so quite a powerful punch in this vegetable. I eat the canned varieties, lightly fried in olive oil, on vegetarian pizzas and in curries. Who would have thought it?
5. Chocolate, unsweetened, baking. Get your chocky fix and also around 50,000 units/100 grams. That’s a powerful dose, and if you keep the sugar and saturated fat low, quite a healthy dose as well. Cocoa powder is around 80,000/100 grams. A teaspoon of that is only a few grams.
6. Berries. Blueberries and blackberries are in the range 5000 to 6000, cranberries 9000, elderberries 14,000 and strawberries under 4000. I don’t know why blueberries seem to get all the publicity around the place. Apples and plums are close.
7. Plums, raw. 6000 to 7000 for various varieties and prunes even higher. Dried fruits generally rank higher than fresh fruits, so I’ve not included them here. (Dried fruits may be high in antioxidants but are also high in sugars, mainly fructose.)
8. Red cabbage, raw and cooked. In this case, the cooked red cabbage is 3000 and the raw cabbage closer to 2000. Again, processing the red tissue seems to release more antioxidants — like grapes. White cabbage is the same — cooked higher than uncooked — yet both are under 1000 units.
9. Nuts, raw. Most nuts are excellent. Almonds over 4000, pecans 17,000 and hazelnuts 9000, pistachios 7000 and walnuts 13,000.
10. Cereals and bran. Wholegrain consumption consistently shows up as protective for type 2 diabetes and heart disease. Not surprising when some of these numbers are computed: rice bran 15,000; sorghum brans up to 240,000. Heavy wholegrain breads and cereals generally rate in the 2000 units range.
Antioxidant strategies
To summarise, there’s a powerful punch available in many herbs and spices, fruits and nuts and whole grains, and to a lesser extent, in many of our favourite vegetables. Carrots and tomatoes are surprisingly unimpressive, but that doesn’t mean this is the last word. It’s possible factors other than what is measured in this database are at work. And it seems to me that low-carbers who like to avoid most fruits are missing out on a lot of antioxidant variety and power.
Here’s what you could do to maximise your antioxidant consumption.
- Grow your own fruit and veges organically if possible. Recent analysis by Alyson Mitchell has shown that organically grown plants generally have higher antioxidant capacities than those conventionally grown. (An article on this is on the way.)
- Make regular use of powerful herbs and spices like ginger, tumeric, galangal, oregano, thyme and many others. Grow them when you are able.
- Eat plenty of non-starchy fruit and vegetables. That means adding lots of green leafy vegetables and non-starchy fruits and root vegetables to your bananas and potato consumption.
Eat daily of raw nuts and cooked whole grains. - If you drink alcohol, a glass or two of red wine each day, preferably with meals, is a reasonable approach.
Why You Need to Eat Your Greens
By Paul Rogers
Spinach pic by Moria
Green leafy vegetables like spinach, lettuce, Chinese vegetables, kale and many others are part of the evolutionary heritage of primates — and humans are no exception. Eating carefully selected green leafy plants for millions of years must have made human biochemistry beautifully adapted to these foods. Too bad many of us don’t eat enough.
They contain valuable vitamins and minerals and antioxidants including iron, lutein for the eyes and other carotenoids, magnesium for heart and muscle, folate for the heart and pregnancy, vitamin K for bones — and one nutrient that regularly gets overlooked: the plant form of omega 3 called alpha linolenic acid or ALA, which is not to be confused with the other polyunsaturated fat called linoleic acid. ALA is a shorter chain length omega 3 that the body can covert to the longer chain EPA and DHA or fish oil omega 3s. ALA is also found in walnuts and canola oil.
The other omega 3
ALA also seems to protect us from heart disease like it’s longer-chain relations EPA and DHA. In fact, that’s how animals get EPA and DHA — from eating green grass and leaves and converting ALA. And that’s why free-range beef or chickens feeding on natural grass and litter are healthier to eat than lot or coop feed animals.
What to eat, and how to prepare
I make a real effort to eat leafy greens regularly. I’ve settled on ones that I like and I grow them organically as well as buy from the supermarket. I eat mainly spinach, cos lettuce, Italian parsley (not the curly leaf one) and rainbow silverbeet, called chard in some regions. I live in a sub-tropical climatic zone, so the spinach tends to be seasonal, requiring colder weather. The cos and silverbeet will grow in all except the hottest times of year, with the silverbeet being pretty much perennial if you allow it to be. The parsley dies off and self-seeds brilliantly for next year.
Last seasons cos self-seeded and grew like a wheat-field. Fantastic. Pick the dark greens leaves when you need them and they just keep coming after a touch of blood and bone fertiliser. Unfortunately, the rabbits also found them. Such is life.
Spinach can be eaten in salads or cooked lightly with a little olive oil, garlic, pepper and lemon juice. Like some southern Europeans, I like a large bowl, steaming hot. The silverbeet is a little stronger and works better in omelettes and stir-fries for me. Parsley is more useful with the tough stems cut off, but then you can use in stir fries, salads, omelettes, bowl noodles and soups or just nibble.
Fresh, dark cos with lemon juice, pepper to taste and a small amount of olive or soy oil (more ALA in soy), with a little low-fat feta if you like, makes a great companion for main courses.
How greens help
Find some greens that you can eat on a regular basis and make them a regular part of your diet. If you exercise a lot you need a potent brew of natural antioxidants to ward off the oxidation products of exercise. If you’re trying to lose weight with a low-calorie diet, nutrient-rich foods are important to ensure you get your recommended daily allowance of vitamins and minerasls for good health. I prefer not to juice — you’ll probably lower the GI anyway — and supplements are pretty much a waste of time. So go greens!
Subscribe RSS
