by John P. Thomas
Health Impact News
Food is much more than a fuel we put in our tank to keep us running. Food defines our relationship to other people and determines our health. I grew up in a Polish American ethnic culture. We had certain foods that defined our culture. We saw the food of other ethnic groups as being strange and not part of our family traditions. We sometimes enjoyed their food, but we thought that our food was the best.
When I consider the dozens of dietary programs that promise health, healing, and longevity, I see a great cultural divide that is much deeper than the ethnic food preferences I had when I was a child. The divide is not based on ethnic origin, but on allegiance to a specific dietary eating program.
When I was following the low fat high carbohydrate standard American diet (SAD) recommended by the US government, I was convinced that I was protecting my health for the future. I shook my head in disgust at those who were eating butter and 12 ounce rib eye steaks. At another time, when I was a vegetarian, I knew I had the answer to diet and health and looked at the meat eating world with a superior smirk. During other years, when I let the lusts of my tongue and my addiction to sugar control my food choices, I lived in denial about diet and health. I didn’t mind being 80 pounds overweight — after all, I reckoned, if food tastes good, then why shouldn’t I enjoy it? Why shouldn’t I give in to my constant cravings and indulge myself?
During the years of living by diets that were fundamentally quite different, I found myself believing in contradictory sets of facts about food. One set of opposing theories involved eating raw food verses eating cooked food. Sometimes I believed that fruits and vegetables should be eaten raw, and at other times I believed that these foods should be cooked. It just depended on which book I read last.
The question of whether food should be eaten raw or cooked is at the center of many diets. Often, people develop an entire dietary theory based on a handful of research studies or on nothing more than conjecture, association, or opinion. Many beliefs about eating raw or eating cooked food are often nothing more than myths and pseudoscience. The flawed science and myths found in one diet book seem to flow easily into other subsequent books as if no one had ever stopped to question the truth of what was written.
IS EATING COOKED FOOD GOOD OR BAD?
It would be easy to pick a few books and a handful of research studies to categorically prove that all food should be eaten raw. It also would be just as easy to find a similar number of authors and research studies that prove that all food should be cooked before it is eaten. Let’s look at some of the science behind eating raw or eating cooked.
Powerful Phytochemicals in Vegetables
I have reviewed the abstracts of a couple hundred scientific research studies on topics related to the health benefits of eating raw or cooked vegetables. The actual scientific abstracts for some of the studies I will discuss are provided below, and some are in the Resources section located at the end of this article. A large amount of the current research examines the effects of food on cancer. The raw vegetables verses cooked vegetables debate is often explored in terms of content of antioxidant compounds, but there are many other phytochemical compounds in vegetables, which are important for health. Some studies focus less on the exact phytochemical content in vegetables, and instead seek to determine whether there is a general relationship between total vegetable/fruit consumption and the rate of new cancer cases, or a decreased death rate for people with cancer who eat vegetables.
Most bioactive food constituents are derived from plants; those so derived are collectively called phytochemicals. The large majority of these phytochemicals are redox active molecules and therefore defined as antioxidants. Antioxidants can eliminate free radicals and other reactive oxygen and nitrogen species, and these reactive species contribute to most chronic diseases.1
Antioxidants from food can provide direct positive health effects in the human body. They can help with cell maintenance and DNA repair, and are considered important for longevity.2
EATING RAW OR EATING COOKED
Those who believe that all vegetables should be eaten raw, and those who believe all vegetables should be cooked will be disappointed in the results of the clinical research when it comes to total phytochemical compounds in vegetables. The research simply does not present consistent proof for either point of view. Results from three reviews of the literature for the past twenty years are summarized below. When the reviewers use the term “inversely related,” they mean, for example, as vegetable consumption increases, cancer rates decrease, or alternatively, as vegetable consumption decreases, cancer rates increase.
This review of medical literature from 1994 to 2003 summarizes the relationship between raw and cooked vegetables and cancer risk and examines whether they may affect cancer risk differently. Twenty-eight studies examined the relationship between raw and cooked vegetables and risk for various cancers. Twenty-one studies assessed raw, but not cooked, vegetables and cancer risk. The majority of these assessed risk of oral, pharyngeal, laryngeal, esophageal, lung, gastric, and colorectal cancers. Most showed that vegetables, raw or cooked, were inversely related to these cancers.
However, more consistent results were found for oral, pharyngeal, laryngeal, esophageal, and gastric cancers. Nine of the 11 studies of raw and cooked vegetables showed statistically significant inverse relationships of these cancers with raw vegetables, but only 4 with cooked vegetables. The few studies of breast, lung, and colorectal cancers also suggested an inverse relationship with both raw and cooked vegetables, but these results were less consistent. In the two studies of prostate cancer, there was no association with either raw or cooked vegetables. One of two bladder cancer studies found an inverse relationship with cooked, but not raw, vegetables.
Possible mechanisms by which cooking affects the relationship between vegetables and cancer risk include changes in availability of some nutrients, destruction of digestive enzymes, and alteration of the structure and digestibility of food. Both raw and cooked vegetable consumption are inversely related to epithelial cancers, particularly those of the upper gastrointestinal tract, and possibly breast cancer; however, these relationships may be stronger for raw vegetables than cooked vegetables.3
In other words, the research shows that people who ate larger amounts of vegetable seems to have lower rates of cancer. Some of the research found that the relationship was stronger for people who ate raw vegetables and some found it stronger for cooked vegetables. In still other studies, it didn’t matter whether the vegetables were eaten cooked or raw.
In 2010, researchers conducted another review of scientific studies comparing antioxidant levels in raw vegetables verses various forms of cooked vegetables. They also found varying results. Some studies, which examined the consequences of heat treatment on the total phenolic content of vegetables, highlighted the value of raw vegetables, while other studies found greater value in cooking vegetables.4
A study published in April of 2014, reviewed 100 previous studies related to phytochemical content of vegetables. Phytochemical content refers to a broader range of compounds than antioxidants, but includes antioxidants. This review did not support the practice of eating only raw or only cooked vegetables. They noted two important observations. Cooking does damage phytochemical content, but cooking also softens the plant matrix (tough cell structure of plants), which helps to release more phytochemical compounds. Thus, depending on the vegetable being cooked, the cooking method, and the phytonutrient compound being studied, cooking can provide greater nutrient availability.5
BENEFITS OF EATING SPECIFIC FOODS RAW OR COOKED
Let’s see what research studies tell us about eating a few foods raw or cooked. There are many studies on other foods that could have been shared. I selected these foods, because they either have received recent attention in the media or they are popular foods.
Quite an extensive amount of research has been done on the health benefits of tomatoes. I found 253 published research papers on the topic of tomatoes, lycopene and cancer. There are many more studies on other aspects of raw/cooked tomatoes and health. “Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models.”6
In a 2012 study, researchers measured the lycopene levels in blood after people ate raw crushed tomatoes, raw crushed tomatoes with olive oil, and cooked crushed tomatoes with olive oil. They found, “Raw crushed tomato consumption did not significantly influence plasma lycopene concentration. Consumption of raw crushed tomato with olive oil and cooked tomatoes with olive oil, significantly increased blood lycopene levels.”7 In this case, olive oil was necessary to help lycopene be used within the human body.
In an earlier study, researchers compared the effects of eating raw and cooked cherry tomatoes. They did not find a significant rise in lycopene or beta-carotene in the blood for either group, probably, because they apparently did not add oil to the tomatoes, but they did find that domestically cooked tomatoes significantly increase naringenin and chlorogenic acid levels. Both naringenin and chlorogenic acid are widely studied for their potential healthy properties. The researchers believe that cooking contributed to the bioavailability of these polyphenols, which play an important biological role in human physiology.8
The bottom line for tomatoes is that there are benefits for eating them raw and cooked. However, it is best to eat them with healthy fat such as virgin olive oil to obtain the benefits of lycopene. Cooking tomatoes increases the availability of phytochemicals, so go ahead and enjoy them both raw and cooked, to get the greatest nutritional benefit.
In a 2006 study, researchers compared the nutritional differences between raw broccoli, boiled broccoli, and steamed broccoli. The cooking of broccoli produced increased levels of polyphenols, glucosinolates, beta-carotene, lutein, alpha- and gamma-tocopherols, and antioxidant activity when compared to raw broccoli. Vitamin C did decrease in boiled broccoli.9 However, in a 2010 study of broccoli consumption among people with Bladder cancer, they found that raw broccoli had greater value than cooked broccoli.10
The bottom line with broccoli is that eating it raw has benefits and eating it cooked has benefits. We need not go to one extreme or the other. Enjoy it both ways to promote your health.
Consumption of raw garlic has been shown to have anticancer properties and offers help for the prevention of cardiovascular disease, however, when garlic is cooked, it loses some of its ability to prevent disease.11 In a study of lung cancer it was found that the consumption of raw garlic two or more times per week was associated with lower rates of lung cancer.12
The bottom line for garlic is that its greatest health benefits come from eating it raw, but it can still be enjoyed cooked. Just be aware that it will contain lower levels of antioxidant compounds. There is no reason not to enjoy roasted garlic, garlic soup, or add garlic to your stir-fry at the last minute before serving. Garlic is still healthy after cooking, but you will need to eat more of it to gain the health benefit than if you ate it raw. Shorter cooking times will preserve higher levels of phytonutrients.
Mushrooms have become very popular in recent years, and are eaten both raw and cooked. An article about eating various types of mushrooms including the most common grocery store variety indicates concern about digestibility and toxicity.
The mycochitin composition of mushroom cell walls, as opposed to cellulose walls of plant cells, is difficult for humans to digest. … The cooking process helps break down fungal cell walls, rendering mushroom flesh not only more readily digestible, but also releasing significant nutritional value contained within the cells. … The list of edible mushrooms considered safe for raw consumption is quite short. Even species commonly eaten raw, especially the ubiquitous button mushroom, Agaricus bisporus, have their drawbacks. Buttons and many other edible mushrooms contain various hydrazines, a group of chemical compounds generally considered carcinogenic. For the most part, these compounds are heat sensitive, readily volatilized and expunged from the fungal flesh by proper cooking.13
The bottom line with mushrooms is that cooking removes the mild carcinogenic substances they contain and allows the anticancer polysaccharides to be released from the hard to digest cell structure of the fungus. For this reason, you may wish to skip the raw mushrooms on the salad bar and choose to eat them cooked.
Virgin Coconut Oil
Antioxidants are naturally present in virgin coconut oil produced by the wet-milling method. The antioxidant levels in this type of coconut oil actually increase when some heat is used during processing. Many virgin coconut oils are produced with no heat, or “cold pressed.” While this is an advantage in the olive oil industry, it is a disadvantage in producing coconut oil.
However, not all coconut oils will contain equal amounts of antioxidants. Refined coconut oils would have little or none, and virgin coconut oils that are produced by the wet- milling method where heat is used will have the highest antioxidant levels.
The unique antioxidants found in wet-milled virgin coconut oil have been successfully used in animal studies to treat induced arthritis. Researchers in India extracted the antioxidants from wet-milled virgin coconut oil and injected them into rats with advanced arthritis, and found that these unique antioxidants reduced inflammation associated with arthritis more effectively than current pharmaceutical drugs. These findings were previously reported by Health Impact News earlier in 2014.14
The bottom line with coconut oil is that heating does not damage the oil. When it is used for cooking, it can be heated up to 350 degrees F. Additionally, you can increase your consumption of important antioxidant compounds by eating wet-milled virgin coconut oil that was heated when it was processed.15
ENZYMES IN FOOD
A discussion of raw food and cooked food would not be complete without a consideration of enzymes. The enzymes that are present in raw foods are destroyed when the food is cooked or heated above 116-118 degrees F. This applies to fruits, vegetables, dairy products, nuts, oils, and meats. The important question here is whether the destruction of enzymes represents a serious concern for people who seek to maintain good health and live a long life. Enzymes will be discussed in a separate article .
Is it best to eat vegetables raw or cooked? Research from the scientific studies that I reviewed concerning the health benefits of raw and cooked vegetables does not support limiting one’s diet to one or the other. Some studies found health benefits for eating vegetables raw while others found important benefits from eating them cooked. Thus, we can get the best of both options by eating a combination of raw and cooked vegetables during the course of the week. Cooking methods and cooking times will affect the nutrient availability of vegetables.16
Some foods such as mushrooms are better eaten cooked than raw, while garlic is best eaten raw. Coconut Oil can be heated without concern when used for cooking, and wet-milled virgin coconut oil that was heated when it was processed will contain increased levels of antioxidant compounds.
Based on what has been discussed, heat can be safely and beneficially used for cooking most foods, and in some cases, the use of heat and traditional cooking temperatures will produce improved nutritional value.
The following suggestions will help you when you prepare cooked vegetables.
- Boiled vegetables will release some nutrients into the cooking water. Thus, if you boil your vegetables, then consider saving the cooking water and adding some of it to your soup recipes. Don’t waste the nutrient content by dumping the water down the drain. A good soup always needs some type of healthy fat such as olive oil, coconut oil, butter, cream, or fat from meat. The fat enhances flavor and makes some antioxidant compounds more available. So, don’t skimp on the fat.
- Steaming vegetables preserves the most nutrients. Serve steamed vegetables with butter, olive oil, or coconut oil to enhance the flavor and to facilitate availability of antioxidants.
- Stir-frying can cause nutrients to be lost into the oil. Don’t drain the oil before serving the vegetables. The oil contains great flavor and vegetable nutrition. Use coconut oil or olive oil for your frying and keep your stir-fry temperature below 350 degrees F.
- Cooking times for vegetables should be long enough to soften the vegetables so that they can be chewed into fine particles. This also frees antioxidant and other compounds from the fibrous cell structure of vegetables, which make the nutrients more available for digestion.17 Your mother’s teaching was correct, chew your food well to get the maximum nutritional benefit.
If your digestive system is able to handle raw vegetables, then by all means enjoy them! Just remember that when you eat some of your vegetables raw and some cooked, you will get the maximum benefits from the vegetables you eat.
1. “The total antioxidant content of more than 3100 foods, beverages, spices, herbs and supplements used worldwide,” Nutrition Journal, 1/22/2010. http://www.nutritionj.com/content/9/1/3
3. “Raw versus cooked vegetables and cancer risk,” Cancer Epidemiol Biomarkers Prev., 9/13/2004, PMID: 15342442.
4. “Effects of Thermal Treatment on the Phenolic Content and Antioxidant Activity of Some Vegetables,” Asian Journal of Clinical Nutrition, 2: 93-100, 7/1/2010. http://scialert.net/fulltext/?doi=ajcn.2010.93.100&org=11
ABSTRACT: Vegetables are valuable sources of nutrients and they are also being recognized for their antioxidant properties. To assess the benefits and value of phenolic compounds in extracts, it is imperative to evaluate the effects of different processing methods applied to foods on the ultimate quantities/activities of the phenolics. In this study, the effects of thermal treatment on some vegetables are reviewed.
In most studies on the effects of heat treatment on the total phenolic content, the results are contradicting. Some researchers reported an increase in the phenolic content whilst others observed a decrease. In some researches an attempt was made to simulate the actual cooking conditions and as a result in some papers the cooking conditions were not explicitly specified. The data generated using the actual cooking conditions is beneficial when included in food composition databases as it will enable the users to evaluate the actual amounts of bioactive compounds consumed.
CONCLUSION: The results of the present investigations showed that all the thermal treatment methods affected the total content of phenolics and antioxidant properties of the vegetables; however, other treatments such as microwave treatment exhibited more deleterious effects than the other methods. Thus appropriate methods might be sought for the processing of such vegetables to retain their antioxidant components at maximum level. Most losses are due to the leaching of antioxidant compounds from the vegetables into the cooking water during the prolonged exposure to water and heat. Therefore, it is vital to use less water and cooking time and also to consume the water used for boiling so as to obtain the optimum benefits of bioactive compounds present in vegetables.
5. “The effect of cooking on the phytochemical content of vegetables,” J Sci Food Agric., April 2014, PMID: 24227349.
Abstract: Cooking induces many chemical and physical modifications in foods; among these the phytochemical content can change. Many authors have studied variations in vegetable nutrients after cooking, and great variability in the data has been reported. In this review more than 100 articles from indexed scientific journals were considered in order to assess the effect of cooking on different phytochemical classes. Changes in phytochemicals upon cooking may result from two opposite phenomena: (1) thermal degradation, which reduces their concentration, and (2) a matrix softening effect, which increases the extractability of phytochemicals, resulting in a higher concentration with respect to the raw material. The final effect of cooking on phytochemical concentration depends on the processing parameters, the structure of food matrix, and the chemical nature of the specific compound. Looking at the different cooking procedures it can be concluded that steaming will ensure better preservation/extraction yield of phenols and glucosinolates than do other cooking methods: steamed tissues are not in direct contact with the cooking material (water or oil) so leaching of soluble compounds into water is minimised and, at the same time, thermal degradation is limited. Carotenoids showed a different behaviour; a positive effect on extraction and the solubilisation of carotenes were reported after severe processing.
6. “Multiple molecular and cellular mechanisms of action of lycopene in cancer inhibition,” Evid Based Complement Alternat Med. 7/21/2013, PMID: 23970935.
Abstract: Epidemiological studies suggest that including fruits, vegetables, and whole grains in regular dietary intake might prevent and reverse cellular carcinogenesis, reducing the incidence of primary tumours. Bioactive components present in food can simultaneously modulate more than one carcinogenic process, including cancer metabolism, hormonal balance, transcriptional activity, cell-cycle control, apoptosis, inflammation, angiogenesis and metastasis. Some studies have shown an inverse correlation between a diet rich in fruits, vegetables, and carotenoids and a low incidence of different types of cancer. Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models. In vitro studies have shown that lycopene treatment can selectively arrest cell growth and induce apoptosis in cancer cells without affecting normal cells. In vivo studies have revealed that lycopene treatment inhibits tumour growth in the liver, lung, prostate, breast, and colon. Clinical studies have shown that lycopene protects against prostate cancer. One of the main challenges in cancer prevention is the integration of new molecular findings into clinical practice. Thus, the identification of molecular biomarkers associated with lycopene levels is essential for improving our understanding of the mechanisms underlying its antineoplastic activity.
7. “Influence of cooking procedure on the bioavailability of lycopene in tomatoes,” Nutr Hosp., Sep-Oct 2012, PMID: 23478703.
BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the influence of raw and processed tomato consumption on plasma lycopene concentration in healthy volunteers. A cross-over dietary intervention study was employed.
PATIENTS AND METHODS: Fifteen healthy subjects were included in the study. Plasma lycopene concentration was assayed by HPLC.
RESULTS: Raw crushed tomato consumption did not significantly influence plasma lycopene concentration. Consumption of raw crushed tomato with olive oil and cooked tomatoes with olive oil, significantly increased blood lycopene levels.
8.“Effect of domestic cooking on human bioavailability of naringenin, chlorogenic acid, lycopene and beta-carotene in cherry tomatoes,” Eur J Nutr., 4/5/2004, PMID: 15309458
BACKGROUND: Epidemiological data showed that tomato and tomato product (sauce, paste) consumption is associated with a protective effect against the development of some chronic-degenerative diseases. Tomato antioxidant bioactive molecules such as carotenoids and polyphenols could be responsible, at least in part, for the healthy effect observed. The bioavailability of these compounds is an essential requirement to sustain their in vivo role. While it is well known that many factors can influence the bioaccessibility of carotenoids from the food matrix, there is little information about the factors affecting phenolic compounds’ bioaccessibility.
AIM OF THE STUDY: This investigation was carried out to evaluate the effect of domestic cooking on the bioavailability in humans of antioxidant molecules after the administration of a test meal containing cherry tomatoes.
METHODS: A cross-over design was conducted. Subjects (3 females and 2 males) consumed experimental meals containing fresh and cooked cherry tomatoes. Blood collection was performed at different time intervals (0, 2, 4, 6, 8 and 24 h).
RESULTS: Carotenoid and phenol plasma concentrations were measured. Plasma levels of lycopene and beta-carotene were not significantly different with respect to the baseline after ingestion of both the test meals, while plasma concentrations of naringenin and chlorogenic acid increased significantly with respect to the baseline (P<0.05) after administration of cooked cherry tomatoes, but not after administration of fresh cherry tomatoes.
CONCLUSIONS: The present study indicated that domestically cooked tomatoes significantly increase naringenin and chlorogenic acid plasma levels. Considering that both naringenin and chlorogenic acid are widely studied for their potential healthy properties, evidence of their bioavailability and of the factors influencing their bioaccessibility is an important tool to sustain the possibility that these polyphenols play a biological role in human physiology.
9. “Changes in the content of health-promoting compounds and antioxidant activity of broccoli after domestic processing,” Food Addit Contam., 11/23,2006, PMID: 17071511.
Abstract: The effect of water- and steam-cooking on the content of vitamin C, polyphenols, carotenoids, tocopherols and glucosinolates, as well as on the antioxidant activity of broccoli, are reported. Flavonoids, phenolic acids, vitamins C and E, beta-carotene, lutein, and glucosinolates in domestically processed broccoli were quantified using high-performance liquid chromatography (HPLC) methods; total polyphenols were determined with Folin-Ciocalteu reagent. The antioxidant capacities of broccoli extracts were evaluated using the Trolox equivalent antioxidant capacity (TEAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The results indicated that steam-cooking of broccoli results in an increase in polyphenols, as well as the main glucosinolates and their total content as compared with fresh broccoli, whereas cooking in water has the opposite effect. Steam-cooking of broccoli has no influence on vitamin C, whereas cooking in water significantly lowers its content. Both, water- and steam-cooking of broccoli results in an increase in beta-carotene, lutein, and alpha- and gamma-tocopherols as compared with fresh broccoli. Similar effects of steaming and water-cooking of broccoli on their antioxidant activity were observed.
10. “Intake of cruciferous vegetables modifies bladder cancer survival,” Cancer Epidemiol Biomarkers Prev., July 2010, PMID: 20551305.
BACKGROUND: Intake of cruciferous vegetables, a rich source of dietary isothiocyanates, has been inversely associated with risk of bladder cancer. Due to the potent antiproliferative effects of dietary isothiocyanates on bladder cancer in in vitro and in vivo models, cruciferous vegetable intake may also play a role in survival among patients with bladder cancer.
METHODS: Using information obtained from the Roswell Park Cancer Institute Tumor Registry, patient medical records, and routinely collected questionnaire data, we examined potential associations between intake of cruciferous vegetables and survival among bladder cancer patients. As cooking can substantially reduce or destroy isothiocyanates, consumption of raw versus cooked cruciferous vegetables was examined separately. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard models.
RESULTS: A total of 239 bladder cancer patients were included in the study. After an average of 8 years of follow-up, 179 deaths occurred, with 101 deaths attributable to bladder cancer. After adjustment for other prognostic factors, a strong and significant inverse association was observed between bladder cancer mortality and broccoli intake, in particular raw broccoli intake (> or =1 versus <1 serving per month; HR for overall death, 0.57; 95% CI, 0.39-0.83; HR for disease-specific death, 0.43; 95% CI, 0.25-0.74). There were no significant associations for total vegetables, total fruits, or other individual cruciferous vegetables.
CONCLUSIONS: Considering the strong preclinical evidence, intake of broccoli may improve bladder cancer survival.
IMPACT: Further prospective investigation is warranted to confirm the potential role of cruciferous vegetables in bladder cancer prognosis.
11. “Effect of cooking on garlic (Allium sativum L.) antiplatelet activity and thiosulfinates content,” J Agric Food Chem. February 21, 2007, PMID: 17256959.
Abstract: The raw form of garlic and some of its preparations are widely recognized as antiplatelet agents that may contribute to the prevention of cardiovascular disease. Herein, we examined the in-vitro antiaggregatory activity (IVAA) of human blood platelets induced by extracts of garlic samples that were previously heated (in the form of crushed versus uncrushed cloves) using different cooking methods and intensities. The concentrations of allicin and pyruvate, two predictors of antiplatelet strength, were also monitored. Oven-heating at 200 degrees C or immersing in boiling water for 3 min or less did not affect the ability of garlic to inhibit platelet aggregation (as compared to raw garlic), whereas heating for 6 min completely suppressed IVAA in uncrushed, but not in previously crushed, samples. The latter samples had reduced, yet significant, antiplatelet activity. Prolonged incubation (more than 10 min) at these temperatures completely suppressed IVAA. Microwaved garlic had no effect on platelet aggregation. However, increasing the concentration of garlic juice in the aggregation reaction had a positive IVAA dose response in crushed, but not in uncrushed, microwaved samples. The addition of raw garlic juice to microwaved uncrushed garlic restored a full complement of antiplatelet activity that was completely lost without the garlic addition. Garlic-induced IVAA was always associated with allicin and pyruvate levels. Our results suggest that (1) allicin and thiosulfinates are responsible for the IVAA response, (2) crushing garlic before moderate cooking can reduce the loss of activity, and (3) the partial loss of antithrombotic effect in crushed-cooked garlic may be compensated by increasing the amount consumed.
12. “Raw garlic consumption as a protective factor for lung cancer, a population-based case-control study in a Chinese population,” Cancer Prev Res (Phila)., July 2013, PMID: 23658367.
Abstract: Protective effect of garlic on the development of cancer has been reported in the in vitro and in vivo experimental studies; however, few human epidemiologic studies have evaluated the relationship. A population-based case-control study has been conducted in a Chinese population from 2003 to 2010, with the aim to explore the association between raw garlic consumption and lung cancer. Epidemiologic data were collected by face-to-face interviews using a standard questionnaire among 1,424 lung cancer cases and 4,543 healthy controls. Unconditional logistic regression was used to estimate adjusted ORs and their 95% confidence intervals (CI), and to evaluate ratio of ORs (ROR) for multiplicative interactions between raw garlic consumption and other risk factors. After adjusting for potential confounding factors, raw garlic consumption of 2 times or more per week is inversely associated with lung cancer (OR = 0.56; 95% CI, 0.44-0.72) with a monotonic dose-response relationship (Ptrend < 0.001). Furthermore, strong interactions at either additive and/or multiplicative scales were observed between raw garlic consumption and tobacco smoking [synergy index (SI) = 0.70; 95% CI, 0.57-0.85; and ROR = 0.78; 95% CI, 0.67-0.90], as well as high-temperature cooking oil fume (ROR = 0.77; 95% CI, 0.59-1.00). In conclusion, protective association between intake of raw garlic and lung cancer has been observed with a dose-response pattern, suggesting that garlic may potentially serve as a chemopreventive agent for lung cancer. Effective components in garlic in lung cancer chemoprevention warrant further in-depth investigation.
13. “On Eating Raw Mushrooms,” David Campbell, Retreaved 4/11/2014, Originally published in “Mycena News,” November 2008. http://www.mykoweb.com/articles/EatingRawMushrooms.html
14. “Antioxidants Present in Virgin Coconut Oil Inhibit Inflammation Associated with Arthritis,” Brian Shilhavy, Health Impact News, healthimpactnews.com, Retreived 4/17/2014. http://healthimpactnews.com/2014/study-antioxidants-present-in-virgin-coconut-oil-inhibits-inflammation-associated-with-arthritis/
15. “What Type of Coconut Oil is Best? How to Choose a Coconut Oil,” Brian Shilhavy, Health Impact News, healthimpactnews.com, Retreived 4/17/2014. http://healthimpactnews.com/2014/what-type-of-coconut-oil-is-best-how-to-choose-a-coconut-oil/
16. “Effects of different cooking methods on nutritional and physicochemical characteristics of selected vegetables,” J Agric Food Chem., 1/9/2008, PMID: 18069785.
Abstract: The objective of the present study was to evaluate the effect of three common cooking practices (i.e., boiling, steaming, and frying) on phytochemical contents (i.e., polyphenols, carotenoids, glucosinolates, and ascorbic acid), total antioxidant capacities (TAC), as measured by three different analytical assays [Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP), ferric reducing antioxidant power (FRAP)] and physicochemical parameters of three vegetables (carrots, courgettes, and broccoli). Water-cooking treatments better preserved the antioxidant compounds, particularly carotenoids, in all vegetables analyzed and ascorbic acid in carrots and courgettes. Steamed vegetables maintained a better texture quality than boiled ones, whereas boiled vegetables showed limited discoloration. Fried vegetables showed the lowest degree of softening, even though antioxidant compounds were less retained. An overall increase of TEAC, FRAP, and TRAP values was observed in all cooked vegetables, probably because of matrix softening and increased extractability of compounds, which could be partially converted into more antioxidant chemical species. Our findings defy the notion that processed vegetables offer lower nutritional quality and also suggest that for each vegetable a cooking method would be preferred to preserve the nutritional and physicochemical qualities.
17. “Particle size reduction leading to cell wall rupture is more important for the β-carotene bioaccessibility of raw compared to thermally processed carrots,” J Agric Food Chem., 12/22/2010,PMID: 21121612
Abstract: The amount of nutrients that can be released from food products (i.e., nutrient in vitro bioaccessibility) is often studied as it is a starting point for investigating nutrient bioavailability, an indicator for the nutritional value of food products. However, the importance of mastication as a particle size reduction technique is poorly understood and is often neglected during in vitro procedures determining bioaccessibility. Therefore, the aim of the present work was to study the effect of mechanical breakdown on the β-carotene bioaccessibility of carrot samples, having different textural/structural characteristics (as a result of thermal processing). In the first part of this study, the all-E-β-carotene bioaccessibility of carrot particles of different sizes (ranging from cell fragments up to large cell clusters), generated from raw as well as from gently and intensely cooked carrot samples, was determined. In the second part of the study, the effect of human mastication on the particle size reduction of raw as well as of gently and intensely cooked carrot samples was investigated in order to allow identification and validation of a technique that could mimic mastication during in vitro procedures. Results showed a strong dependency of the all-E-β-carotene bioaccessibility on the particle size for raw and gently cooked carrots. After intense cooking, on the other hand, a considerable amount of all-E-β-carotene could be released from cell fragments (smaller than a cell) as well as from small and large cell clusters. Hence, the importance of mechanical breakdown, and thus also of (in vitro) mastication, is dependent on the carrot sample that is considered (i.e., the extent to which the carrot sample has been thermally processed prior to the particle size reduction). Structural changes occurring during mechanical and thermal processing are hereby key factors determining the all-E-β-carotene bioaccessibility. The average particle size distribution curves of raw and cooked carrots, which were chewed by 15 persons, could be mimicked by mixing 50 g of carrots using a Grindomix (Retsch) at 2500 rpm during 5 s. Based on this scientific knowledge, the identified in vitro mastication technique was successfully integrated in the in vitro digestion procedure determining the all-E-β-carotene bioaccessibility of carrot samples.