The benefits of wine, when consumed in limited quantities, are highlighted in the public media and scientific press releases. The benefit of wine mainly is being a potent antioxidant. The restricted amount for drinking is stressed majorly due to the bane of heavy metals present in wine. As they also promote oxidative stress (E.g.: oxidative stress in case of lipids), the intake amount is prescribed to be not greater than 250 mL/day.
Heart-related illnesses i.e., cardiovascular diseases are very prevalent in the current generation. When included in everyday lifestyle wine shall render wider benefits like combating banes of saturated fat-rich food habits. If the consumption levels exceed the predefined amounts ill effects shall outweigh the profits.
What are the heavy metals?
Strictly speaking, heavy metals were defined as those with a higher density than 5 g/mL4. But the collective term now includes arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), vanadium (V) and zinc (Zn).
Focus heavy metals
Some interest also exists in aluminum, cobalt, strontium, and other rarer metals.
|Fe||haem moieties of hemoglobin and cytochromes|
|Cu||amine oxidases, caeruloplasmin, dopamine hydrolase, and collagen synthesis|
|Cr (lesser amounts)||glucose homeostasis|
|Zn||protein synthesis, stabilization of DNA and RNA|
|K, Ca, Mg||high intracellular content|
Other heavy metals ions are not believed to be essential to health, even in trace amounts.
Why are heavy metals toxic?
The toxicity of heavy metals could be by the displacement of physiologically appropriate metals.
Cadmium can replace Copper and Iron. This is predominantly observed in cytoplasmic and membrane proteins. Particularly in divalent form, the free heavy metal ions can encourage the production of superoxide and hydroxyl radicals. This can lead to oxidative damage of lipids, nucleic acids, and proteins.
Cadmium does not directly produce superoxide. But the promotion of apoptosis by Cd is through the generation of hydrogen peroxide. This effect could be antagonized by the antioxidant, glutathione.
At lower concentration levels it promotes lipid peroxidation and nucleic acid damage in a glioma cell culture model.
Divalent ions can bind to proteins and disrupt their function. They could also have adverse effects on DNA, particularly at CpG nucleotide sequences where methylation of cytosine requires the nucleotides to be intact.
A provisional tolerable weekly intake (PTWI) has been used to serve as a guide for exposure to individual heavy metals.
Another method has been proposed to evaluate lifelong exposure to heavy metals: the target health quotient (THQ). This formulation has the ideal value of less than unity.
THQ = f.te .m.c /1000 R.w.tn
f is the frequency of exposure in days/year,
te is the time of exposure in years,
m is the mass of beverage consumed in g/day,
c is the concentration of the metal in the beverage in μg/g,
R is the oral reference intake dose in mg/kg/day,
w is the body mass and
tn is the time averaging for noncarcinogens in days.
For the consumption of wine, the time is generally taken from 18 years of age to the average life expectancy and the average masses for males and females are applied in the calculation. The sum of THQ values of different metals could be taken as a crude global exposure.
Diving in for details
The impact of the heavy metals on oxidative stress towards lipids, proteins, and nucleic acids is significant. This would be comparatively easy to assess in vitro and ex vivo. It also could provide mechanistic insight into potential harm.
In vivo studies for harmful effects would be difficult and, at least in the short term, may not reveal the increasing damage. Large extended-term population studies with dependable and comprehensive information about dietary and beverage intakes, possibly involving genetic and metabonomic sub-studies as well, are required to be able to evaluate the impact of heavy metals on health.
Although the heavy metals play a role in the organoleptic characteristics and aging of wine, research is required to fully understand their requirements in the wine-making process and the impact that methods to remove the individual or collective heavy metals have on the storage and appreciation of wine.
The wine can, therefore, be regarded as a foundation of heavy metals looked-for for nutritional reasons. But it may also expose the consumer to undesirable doses or kinds of heavy metals. Even if not toxicity in the short to medium term, the heavy metals may pose a cumulative risk especially when the individual has high exposure to these metals from other sources.
The medical occupation and the community should be aware of the potentially lethal effects of heavy metal intake. There are currently, however, no clear recommendations for heavy metal content in and intake from wine but there are some recommendations for nutritional intake.
The balance of epidemiologic studies suggests a favorable effect of wine on cardiovascular risk despite the variable and possibly disadvantageous intake of heavy metals.
A healthy routine with moderate ingesting of wine may thus last without unwarranted concern if wines are screened for disagreeably high heavy metal concentrations and dietary intake is within tolerable limits.
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Hi! This is Lekha
Pursuing B.Tech (FTM) from NIFTEM
Proactive knowledge seeker always curious to know current buzz in food industry. I love writing. So here i am!