Aspirin acts as a blood thinner which is believed to account for much of its benefit of protecting against heart attacks and strokes. But that same action, along with a tendency to deplete the stomach's protective lining, can lead to a danger of gastrointestinal bleeding and possibly bleeding in the brain.
   Despite hundreds of clinical trials the appropriate dose of aspirin to prevent myocardial infarction and stroke is uncertain. In the US the doses most frequently recommended are 80 mg, 160 mg, or 325 mg per day. Because aspirin can cause major bleeding the appropriate dose is the lowest dose that is effective in preventing both MI and stroke because these two diseases frequently co-exist. Aspirin use for preventing heart attacks is underutilized. Its regular use, but not other nonsteroidal anti-inflammatory drugs (NSAIDs), is associated with a reduced incidence of cancer and cancer-related deaths, particularly among former smokers and those who never smoked. NSAIDs include commonly used analgesic drugs, such as ibuprofen and naproxen, that are usually available over-the-counter.

Comparison to dietary supplements that thin the blood
How much fish oil capsules, ginkgo biloba, EGCG, etc. would it take to equal the dosage (or rather, blood thinning effects of) a baby aspirin?
   I am not aware of such comparison studies so it is difficult to say. Furthermore the dietary supplements have influences on the body that are very different than aspirin even though they have blood thinning potential as a commonality. It is not known at this time whether taking fish oil capsules or eating more fish reduces or eliminates the need to take aspirin. It is likely that the dose of aspirin could be reduced in those who take fish oils supplements.

Guidelines from the U.S. Preventive Services Task Force
Aspirin recommended for: Some men 45 and older with risk factors for heart disease, assuming no history of ulcers or other bleeding dangers. Some women 55 and older with risk factors for stroke, and no history of bleeding danger.

Aspirin not recommended for: Men younger than 45, and women younger than 55. Anyone 80 and older.
  
Aspirin for heart attack prevention
My personal opinion is that aspirin, in a dosage of 81 mg 2 or 3 times a week, should provide enough benefits and at the same time minimize the risk for stomach ulcer or bleeding. There is no need to take higher dosages for cardiovascular health.

Should you stop your daily aspirin use?
Many doctors recommend their healthy patients to take a daily dose of aspirin in order to prevent heart attacks. Do the anti-coagulant benefits trump the potential risks, or vice versa? The results of the Aspirin for Asymptomatic Atherosclerosis (AAA) study found that the risks of bleeding from taking aspirin were such that its routine use in healthy people was not advised, although the researchers did agree its benefits in patients with a history of vascular problems such as heart attack or stroke. Professor Peter Weissberg, medical director of the British Heart Foundation which helped fund the research, says, "The findings of this study agree with our current advice that people who do not have symptomatic or diagnosed artery or heart disease should not take aspirin, because the risks of bleeding may outweigh the benefits." The study was led by Professor Gerry Fowkes from the Wolfson Unit for Prevention of Peripheral Vascular Diseases in Edinburgh, Scotland, and presented at the European Society of Cardiology Congress in Barcelona in August 2009. The study involved 3,350 men and women aged 50 to 75 years who tests revealed may have a condition where the arteries in their legs were narrowed -- but who had no symptoms of heart disease or history of heart attack. They were given either a daily 100 mg dose of aspirin or a placebo and monitored over eight years. While there was no difference in the number of heart attacks, strokes and other cardiovascular events, major bleeding occurred in two percent of the aspirin group compared to just 1.2 percent of the placebo group.
    Comments: If you have no vascular problems, it is not necessary to take aspirin. If you wish to take it, limit your dosage to a baby aspirin two or three times a week rather than daily. A baby aspirin has 81 mg. Also consider fish oil softgels or other herbal supplements since they can help with thinning the blood.

Aspirin side effects
Though medical journal articles endlessly promote the use of aspirin to ward off blood clots, heart attack and stroke, the U.S. Food and Drug Administration says daily aspirin therapy isn't for everyone. Is it possible that long-term daily use of aspirin in healthy people is unnecessary? While aspirin can help those at risk of heart attack or stroke by preventing the formation of dangerous clots, unwanted side effects could also include stomach bleeding, bleeding in the brain, and kidney failure. Easy bruising is also bothersome for many people taking aspirin.
   Dr. Sahelian says: One option is to take a baby aspirin two or three times a week and hence minimize the potential side effects from aspirin use.

Aspirin or Plavix?
Adding the blood-thinning drug Plavix to a daily dose of aspirin does not lower the risk of death, heart attack or stroke in high-risk patients. In a study of more than 15,000 patients, combining Plavix, sold by Sanofi-Aventis SA and Bristol-Myers Squibb Co., with aspirin may do more harm than good for patients at risk of developing heart disease, but it can help those who have already suffered a heart attack or stroke. The results confirm that aspirin is "the gold standard" for treating heart risk. Plavix is the current standard treatment among so-called anti-platelet drugs, which are used to prevent blood clots that can cause a heart attack, unstable angina, or stroke. Aspirin, also a blood thinner, acts on a different platelet receptor than Plavix, which has more potent effects. The trial results confirm that aspirin has the best benefit-to-risk and the best benefit-to-cost ratios of other blood thinning drugs.

Aspirin equally good in men and women
Some studies have suggested that aspirin is less effective for preventing heart attack in women than in men, although women do benefit from a similar reduction in risk of stroke due to a blocked artery. However, other studies show both a man and a woman benefit from low dose aspirin use. Overall, though, it appears that women with a low or average risk of having a heart attack are not likely to get much of benefit from aspirin use for heart attack prevention. Perhaps fish oils are just as good for blood thinning.

Bladder cancer
Dr. Jason R. Gee at the University of Wisconsin-Madison, has determined that the use of aspirin reduces recurrence of superficial non muscle invasive bladder cancer. British Journal of Urology International 2009.

Aspirin for colon cancer
The risks of aspirin, including stomach bleeding, outweigh its potential benefits in preventing colon cancer in people who have just an average risk of cancer, unless the dose of aspirin is very small and the drug is not taken every day. People with no reason to believe they have a high likelihood of colorectal cancer, including those with a family history of the disease, should not take high dose aspirin or other non-steroidal anti-inflammatory drugs to try to prevent it. But people who take aspirin to prevent other conditions such as heart disease should continue to discuss with their doctors whether it is worthwhile. Taking more than 300 mg per day of aspirin, ibuprofen or other similar drugs, known as NSAIDs, can cause hemorrhagic stroke, intestinal bleeding or kidney failure. Low doses of aspirin, less than 100 mg a day, can reduce the risk for heart disease.

Aspirin for heart attack prevention
Although it's well known that taking aspirin regularly can lower a person's risk of heart disease, few Americans, it seems, use the common pain reliever for heart health. Use of aspirin for the prevention of a first or second heart attack or stroke is very low, even among adults at increased risk for such events. Large numbers of people at relatively high risk for heart attack and stroke just aren't getting a recommendation from their doctor to take aspirin, or if they are getting it they aren't hearing it. 

Aspirin and sleep
A small amount may not have much of an influence, but a high dose could interfere with sleep patterns.

Electroencephalogr Clin Neurophysiology. 1980.
Two groups of 8 females were given either 3 times 600 mg aspirin or placebo daily for 4 days. With aspirin, slow wave sleep was significantly decreased and stage 2 sleep significantly increased. Aspirin also significantly disrupted intra-subject night-to-night continuity of several sleep stages during drug and recovery nights.

Questions

Q. A recent angiogram has revealed that I have blockage in a smaller artery traversing the left side of my heart. The cardiologist did not want to try stenting, as he feels it would likely re-block and it may do harm to larger arteries in trying to reach the smaller restricted artery. I am taking two blood pressure meds and Vytorin. The cardiologist has also prescribed a daily aspirin tablet. In his book on reversing heart disease, Dean Ornish cites clinical trials that indicated that aspirin reduced the number of heart attacks, BUT it also had negative other effects - - e.g., an increase in hemorrhagic strokes and ulcer problems. Do you have a general opinion on the advisability of an aspirin regimen? Thank you.
   A. There is a wide range of opinions among doctors regarding the use of aspirin and the appropriate dosage of aspirin. My personal opinion is to use a baby aspirin a few days a week and to also take fish oil capsules or krill oil capsules along with a higher consumption of a variety of vegetables.

Q. Is it true that EGCG, the extract from green tea, can inhibit platelets similar to aspirin?
   A. We have seen one such study comparing aspirin and EGCG.

Platelet aggregation inhibitors in hot water extract of green tea.
Chem Pharm Bull (Tokyo). 1990 Mar;38(3):790-3. Ito-en Central Research Institute, Shizuoka, Japan.
The effect of hot water extract of green tea on the collagen-induced aggregation of washed rabbit platelets was examined. The extract lowered submaximal aggregation and prolonged the lag time in a dose-dependent manner. After fractionation of the extract, it was revealed that the tea catechins (tannins) are active principles for inhibition and that ester-type catechins are more effective than free-type catechins. One of the ester type catechins, epigallocatechin gallate ( EGCG ), suppressed the collagen-induced platelet aggregation completely at the concentration of 0.2 mg/ml (= 0.45 mM). Comparing IC50 values of EGCG and aspirin it was found that the potency of EGCG is comparable to that of aspirin. Thrombin- and platelet activating factor (PAF)-induced aggregation was also inhibited by EGCG. The elevation of cyclic adenosine 3',5'-monophosphate (cAMP) level was not observed in EGCG treated platelets.

Q. I would be grateful for your thoughts on taking Ginkgo biloba and aspirin. The combination is stated to be inadvisable because of enhanced bleeding risk. Should a person starting ginkgo stop aspirin entirely ? How great is this stated risk ? Would taking ginkgo say 120mgm a day, substitute entirely for taking 100 mg enteric coated aspirin daily? There must be some stated comparison between the two. If there is not please let me know.
   A. We are not aware of any studies that have compared the blood thinning properties of ginkgo biloba versus aspirin. Whether to use ginkgo along with aspirin may depend on the dosage used and a person's inherent clotting baseline which is different from person to person.

Q. In terms of being a blood-thinning agent, what is the equivalency of 1 fish oil capsule (1000 mg) compared to a baby aspirin (81 mg)? In other words, how many 1,000 mg. fish oil capsules would it take to equal a baby aspirin?
   A. This is a good question and I don't have a good answer. I have not seen studies comparing the blood thinning properties of fish oils compared to aspirin.

Does silibinin extract interfere with the blood thinning effect of aspririn?
     Probably not but I am not sure.

I read your report about the daily aspirin and its influence on heart patients. A group has requested for me to locate a KOSHER aspirin since most do not have that certification. I located an aspirin that is KOSHER, however they come in dosage of 100mg only. I am interested in importing that product, however I AM CONCERNED ABOUT THE DOSAGE. Would the 100mg be less benefit since it carries more bleeding risks. Can it be worked out to be taken less times per week and in fact it would be even of more beneficial.
    A baby aspirin is 91 mg while a regular aspirin is 325 mg. There is no major difference between 81 mg and 100 mg and the stronger one can be taken less frequently.

I am 46. I taka 81 mh aspirin every day, also Prilosac for my acid. My question is, does Prilosac block aspirin benefits.
    Prilosec (omeprazole) is used to treat symptoms of GERD and other conditions caused by excess stomach acid. Some studies indicate the use of this medication reduces the absorption of aspirin although the clinical significance is not fully understood.

Everywhere we read that people over 50 should take a low dose aspirin each day for heart attacks in men and stroke prevention in women. Some doctors recommend to take 2 baby aspirin daily. SO - I know it can cause bleeding in GI tract - and there is enteric coated to prevent this bleeding BUT I like to use natural or alternative things when I can. Since the aspirin I believe is used to prevent the clots that cause strokes &heart attacks or at least thin them, would the following be good or what can you suggest? Garlic Nattokinase Coq10 grape seed Xtract guggull carnitine, just dont know who to ask - my MD is clueless.
    There are no easy answers since each person has a different blood clotting or thinning predisposition and each person has a different diet. As a general rule I prefer to limit baby aspirin use to once or twice a week and have a higher intake of several herbs and nutrients that thin the blood.