In a longitudinal study, researchers conduct several observations of the same participants over a period of time, sometimes lasting many years. The benefit of a longitudinal study is that researchers are able to detect developments or changes in the characteristics of the target population at both the group and the individual level. The key here is that longitudinal studies extend beyond a single moment in time (see cross-sectional study).

Mechanism of alcohol in the cancer development

 Researchers have hypothesized multiple ways that alcohol may increase the risk of certain cancers:

• When alcohol is consumed, it is broken down into a toxic chemical substance called acetaldehyde. Acetaldehyde can damage DNA (the genetic material that makes up genes) inside our cells and can further avoid the repair of this damage in the DNA. This is important because it allows cancer to develop.
• Generation of free radicals (chemically reactive molecules that may contain oxygen), which can additionally damage DNA, proteins, and lipids (fats) in the body through a process called oxidation, when oxygen containing radicals are involved, which is exacerbated by the presence of alcohol and acetaldehyde, particularly at higher BAC levels (above approx. 0.5-0.8 ‰, Gessner et al 2019, Ströhle et al 2012).
• Alcohol can impair the body’s ability to break down and absorb a variety of nutrients that may be associated with cancer risk, including vitamin A; nutrients in the vitamin B complex, such as folate, niacin and vitamin B12,vitamin C, vitamin D, vitamin E, and carotenoids (provitamin A). In addition, excess alcohol consumption reduces energy intake (by decreasing appetite, causing nausea and vomiting), consumes energy and vitamins during its metabolisation by the liver, and increases the elimination of metabolites by the kidney.
• Alcohol acts as a dissolvent and makes it easier for cells in the mouth and throat to absorb other cancer-causing chemicals, in particular those of the tobacco smoke.
• Alcohol can increase the levels of certain hormones in the body, including oestrogen. It is known that high levels of oestrogen can promote the development of breast cancer.

https://www.cancer.gov/about-cancer/causes-prevention/risk/alcohol/alcohol-fact-sheet

is defined as moderate intake of alcoholic beverages, with wine preference (≥80% of alcohol consumed as wine) and drinking only with meals.

the basic idea of the Mendelian randomization is to use genetic variables as instrumental variables, i.e., genes associated with an exposure (in this study, alcohol consumption or alcohol metabolism) but not directly related to outcome (in this study, HDL-cholesterol and other lipid parameters).  Since the genetic pattern is determined before birth, it should not (at least, in theory) be confounded by later lifestyle exposures or outcome variables.  Thus, it allows the investigators to make causal inference.

Mendelian randomization provides an approach to addressing questions of causality without many of the typical biases that impact the validity of traditional epidemiologic approaches. While Mendelian randomization studies can provide important suggestive evidence for causal relations between risk factor (consumption of alcoholic beverages in this case) and disease outcome (blood lipid levels), they are not true experiments and are dependent on several assumptions. Evidence from randomized controlled trials, when possible, should continue to guide clinical decisions.

is a method of summarizing the results of the same research purpose and comprehensively evaluating its combined effect. It can be an objective, systematic, comprehensive, qualitative and quantitative statistical analysis. It has functions that improve estimates of effect, construct a general review method for omitting inadequate study conclusions, and reinforce the effectiveness of statistical results to yield more comprehensive and reliable study results that are more representative of the general population.

refers to energy expenditure from sports and walking during the week.

a cluster of abnormalities including increased abdominal fat, poor ability to use the hormone insulin, high blood pressure and high blood levels of triglycerides.

The Moli-sani study (www.moli-sani.org) is a cohort study aiming at evaluating the risk factors (environmental, genetics, bio-molecular) linked to chronic-degenerative disease with particular regard to cancer, cardiovascular, cerebrovascular and neurodegenerative disease.

Source: http://www.neurodegenerationresearch.eu/cohort/the-moli-sani-study/

More information about the Moli Sani study on our databse: https://www.wineinformationcouncil.eu/index.php?option=com_jak2filter&view=itemlist&Itemid=499&issearch=1&isc=1&searchword=Moli%20sani 

is a signaling molecule produced by the body that helps the body cells to communicate. It signals the body to release more blood to the organs when needed. One of the common ways to increase the concentration of NO in the body is through exercise. While working out, body muscles need more oxygen, which is supplied with blood. The heart pumps with high pressure to supply sufficient blood to the muscles; the lining of the arteries releases NO into the blood in order to relax and widen the vessel wall and thus, more blood can pass through. However, with age, blood vessels and NO-systems become inefficient due to free radicals, poor diet, etc., causing veins and arteries to deteriorate. It helps in supplying the sufficient amount of blood flow to the tissues and therefore, allows smooth muscles to relax.

Is a common, often “silent” liver disease. It resembles alcoholic liver disease, but occurs in people who drink little or no alcohol. The major feature in NASH is fat in the liver, along with inflammation and damage. Most individuals with NASH feel well and are not aware that they have a liver problem. Nevertheless, NASH can be severe and can lead to cirrhosis, in which the liver is permanently damaged and scarred and no longer able to work properly.

is defined as the presence of fat in the liver ( with > 5,5% of liver cells being fatty, hepatic steatosis) after the excluding secondary causes of fat accumulation in the liver (e.g. significant alcohol consumption, certain medications, and other medical conditions). NAFLD occurs when the liver has problems breaking down lipids, causing fat to build up in the liver tissue. NAFLD is now the most common chronic liver disease in high-income countries, and it is estimated to affect at least 25%–40% of the general population. It can progress from simple steatosis to non-alcoholic steatohepatitis (NASH) and hepatic fibrosis to liver cancer.

Like intervention studies, observational studies attempt to understand cause-and-effect relationships. However, unlike interventions, the researcher is not able to control how subjects are assigned to groups and/or which treatments each group receives. Researchers record variables’ values as they naturally occur (can be retrospective or prospective) during a certain follow up period (see Intervention studies).

Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a prescription from a healthcare professional, as opposed to prescription drugs, which may be sold only to consumers possessing a valid prescription.

is a group of cholesterol compounds that contain extra oxygen atoms were found to be highly toxic and highly effective in producing arteriosclerosis. The highly damaging oxycholesterols are found in foods in which cholesterol is subjected to heating and exposure to the oxygen of the air during food processing, cooking or preservation.

is an inflammatory disease of the pancreas associated with inappropriate release of digestive enzymes into the small intestine to aid the digestion of carbohydrates, proteins, and fat as well as the release of the hormones glucagon and insulin into the blood stream. These hormones are involved in the blood glucose metabolism.

Acute pancreatitis occurs suddenly and most often resolves within several days. Most cases of acute pancreatitis are linked to gallstones. Cigarette smoking and heavy alcohol use have been associated with risk of pancreatitis.

Chronic pancreatitis occurs most commonly after an episode of acute pancreatitis and is the result of ongoing inflammation of the pancreas. Damage to the pancreas from excessive alcohol use may not cause symptoms for many years, but then the person may suddenly develop severe pancreatitis symptoms, including severe pain and loss of pancreatic function, resulting in digestion and blood sugar abnormalities.