Per Drs. Rod Jackson, Joanna Broad, Jennie Connor, and Susan Wells of the University of Auckland, “Do not assume there is a window in which the health benefits of alcohol are greater than the harms…” [1].
It is common to hear conventionally-trained cardiologists and other healthcare providers recommend a reasonable intake of wine or state that a periodic consumption of alcohol can actually help prevent against the onset of cardiovascular disease. Unfortunately, the notion of alcohol being beneficial for the heart is misguided and dangerous, and in this short article I’ll explain why. Firstly, the majority of evidence that seemingly supports a low level of alcohol being in the diet comes from epidemiological or observational studies, and as Jayasekara et al. have stated, “The quality of the epidemiologic evidence relating to a protective effect of low-dose alcohol consumption has been challenged” [2]. Much of the impact of alcohol drinking on mortality and the progression of disease states has been misinterpreted or viewed narrow-mindedly, as a large meta-analysis published in 2014 has explained: “These findings suggest that reductions of alcohol consumption, even for light to moderate drinkers, may be beneficial for cardiovascular health. Our results therefore challenge the concept of a cardioprotective effect associated with light to moderate alcohol consumption reported in observational studies and suggest that this effect may have been due to residual confounding or selection bias” [3]. Uncontrolled confounding can account for at least some, if not all, of the reported cardioprotective associations in non-randomized studies, as concluded in a paper by Naimi et al., “These findings suggest that some or all of the apparent protective effect of moderate alcohol consumption on CVD may be due to residual or unmeasured confounding” [4]. The results of observational studies can also be distorted by underlying poor health in nondrinkers and the existence of greater underlying health in light and moderate drinkers versus heavy drinkers. Further corroboration has been offered by Shaper, Wannamethee, and Walker: “The data suggest that the observed alcohol-mortality relationships are produced by pre-existing disease and by the movement of men with such disease into non-drinking or occasional-drinking categories. The concept of a “protective” effect of drinking on mortality, ignoring the dynamic relationship between ill-health and drinking behaviour, is likely to be ill founded” [5]. We must also refrain from looking at variables in isolation, for the effect of alcohol on HDL (high-density lipoprotein) cholesterol and platelet aggregation can only be considered positive if we ignore all of alcohol’s negative effects on the cardiovascular system and the body at large [6]. In that vein, let’s now examine the physiological consequences of tippling. Moderate alcohol intake can increase plasma triglyceride concentration which can heighten cardiovascular disease risk in men and women independent of HDL cholesterol changes [7] [8]. Normally, plasma triglycerides are hydrolyzed by the enzyme lipoprotein lipase in capillary endothelial cells, but alcohol can inhibit this enzyme and keep plasma triglycerides elevated by hindering the typical maturation of VLDLs (very-low-density lipoproteins) to IDLs (intermediate-density lipoproteins) and then to LDLs (low-density lipoproteins) as triglycerides are removed by lipoprotein lipase [9]. Thus, the consumption of alcohol can boost the plasma’s concentration of triglyceride-rich lipoproteins which can be atherogenic (TGRLs can worsen arterial wall permeability and cause vascular injury) [10] [11]. Alcohol can also inhibit the secretion of VLDLs from the liver (promoting the development of fatty liver) by impairing hepatocyte microtubule formation or obstructing the synthesis of phosphatidylcholine [12]. Ideally, the secretion of VLDLs by the liver is adequate to thwart fatty liver disease but insufficient to cause an abnormal accumulation of triglycerides in the blood by way of overwhelming the circulatory system’s metabolizing of these lipid carriers. As a far better alternative to liquor, daily supplementation with niacin (vitamin B3) can greatly and safely drop plasma triglycerides and LDLs as well as raise HDLs [13]. In fact, niacin, as expressed by Carlson, “lowers the levels of all atherogenic lipoproteins – VLDL and LDL with subclasses as well as Lp(a) – and in addition it raises more than any other drug the levels of the protective HDL lipoproteins” [14]. Overarchingly, alcohol interferes with the normal metabolism of lipids in the body, and through multiple pathways this can encourage the development of cardiovascular disease [15]. Moving on to a comparison between grapes and wine, whole juice from purple grapes has been shown to decrease platelet aggregation, boost platelet-derived nitric oxide release, and lower superoxide (a strong free radical) production in vivo [16]. And red grape juice has been found to more effectively curb atherosclerosis and improve lipid and antioxidant parameters versus red wine or dealcoholized red wine [17]. Accordingly, we can attribute the genuine benefit to heart health from wine to the polyphenols found in grapes, and not to ethanol (ethanol can be directly toxic to the cardiovascular system and can raise blood pressure) [18]. Furthermore, resveratrol consumption through grapes but not through wine has been associated with a reduced breast cancer risk, while a heightened breast cancer risk has been associated with consuming red wine [19] [20]. Even a light intake of alcohol (less than or equal to one drink per day) can notably escalate oral cancer risk [21]. Furthermore, persistent wine intake can lead to dental erosion, and there is concern over the amount of toxic metals (like lead, cadmium, and arsenic) that can be found in various wines [22] [23]. Now there is no doubt that resveratrol itself can be greatly cardioprotective and beneficial to the body. Though it’s important to remember that resveratrol certainly is not the only acting polyphenol in wine and grapes [24]. Resveratrol can excellently exert anti-inflammatory, antioxidant, and vasodilation effects, in addition to being able to suppress tumor growth and protect neurons in the brain against damage [25] [26] [27]. More specifically, resveratrol helps to regulate redox homeostasis in humans and can block the oxidation of LDLs (drinking wine or other alcoholic beverages can up LDL oxidation), as well as induce apoptosis in cancer cells and better both insulin sensitivity and blood pressure [28] [29] [30] [31] [32]. After the ingestion of an alcoholic beverage, most of the ethanol will be oxidized in the liver by the enzyme alcohol dehydrogenase, yielding the highly toxic metabolite acetaldehyde [33]. Ideally, yielded acetaldehyde will be quickly converted into acetate by another liver enzyme, acetaldehyde dehydrogenase, with the help of glutathione. Acetate should then be converted into acetyl coenzyme A and ultimately into water and carbon dioxide. With a deficient supply of glutathione however, acetaldehyde can accumulate in the body and wreak havoc as it is a major generator of free radicals and a known carcinogen [34]. Also note that acetaldehyde occurs naturally in alcoholic beverages in addition to arising from ethanol metabolism [35]. We know that acetaldehyde directly impairs the contractile function of the heart, disrupts cardiac excitation-contraction coupling, and fosters lipid peroxidation and oxidative damage in the heart [36]. And ethanol metabolites termed ‘fatty acid ethyl esters’ can encourage injury to the liver, heart, and pancreas [37]. Acetaldehyde can also induce mitochondrial dysfunction and stress endoplasmic reticula, as well as negatively modify and form adducts with various proteins that stimulates the crafting of antibodies against acetaldehyde epitopes (which can lead to autoimmune responses) [38] [39] [40]. Acetaldehyde may contribute to organ damage (including the brain) by way of inflammatory cytokines and the same forming of protein adducts just mentioned too [41]. As a side note, acetaldehyde-induced dysfunction of the heart can be somewhat ameliorated by thiamine (vitamin B1) and folate (vitamin B9) [42]. Wrapping up my argument with a few more consequences of tippling, alcoholic beverages can suppress impeding wave motility in the small intestine (cutting the amount of time ingested food has to be properly digested), injure the gut mucosa and intestinal microbiota (potentially causing small intestinal bacterial overgrowth), magnify the translocation of bacterial toxins (like lipopolysaccharide) from the gut to the blood (which can contribute to liver and heart disease progression), and increase the permeability of the intestinal wall (creating a leaky gut) [43] [44] [45] [46] [47]. Importantly, ethanol (a carcinogen itself) can also facilitate the activation of procarcinogens (turning them into carcinogens) and the conversion of xenobiotics to toxic metabolites, enhancing the harmfulness of dietary and environmental toxins [48] [49]. Lastly, ethanol exposure can lead to atrophy of all skeletal muscle fiber types, lowered muscle capillarity, and altered metabolism in muscle tissue too [50]. In conclusion, I am not stating that alcohol, especially red wine, is the worst thing we could possibly put into our bodies. If you’d like to indulge in a drink here and there, by all means do your thing. Just please don’t assume that by knocking a few back you’re doing something to improve the health of your heart as some who should know better have suggested. Alternatively, simply eating some grapes and berries (plus some niacin-rich foods like chicken, turkey, sunflower seeds, green peas, and avocados) will beautifully supply your body with plenty to support your cardiovascular system and more without any of the ill effects of ethanol and its metabolites. Appropriately supplementing with isolated niacin and resveratrol would be another option for safely profiting the heart. Chalk another one up for food as medicine. 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AuthorDenton Coleman is an Exercise Physiologist and Medical Researcher. Archives
October 2023
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